#!/bin/sh
# -*- mode: Python -*-

# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

""":"
# bash code here; finds a suitable python interpreter and execs this file.
# prefer unqualified "python" if suitable:
python -c 'import sys; sys.exit(not (0x020500b0 < sys.hexversion < 0x03000000))' 2>/dev/null \
    && exec python "$0" "$@"
for pyver in 2.6 2.7 2.5; do
    which python$pyver > /dev/null 2>&1 && exec python$pyver "$0" "$@"
done
echo "No appropriate python interpreter found." >&2
exit 1
":"""

from __future__ import with_statement

import cmd
import codecs
import ConfigParser
import csv
import getpass
import locale
import multiprocessing
import optparse
import os
import platform
import sys
import time
import traceback
import warnings
from contextlib import contextmanager
from functools import partial
from glob import glob
from StringIO import StringIO
from uuid import UUID

description = "CQL Shell for Apache Cassandra"
version = "5.0.1"

readline = None
try:
    # check if tty first, cause readline doesn't check, and only cares
    # about $TERM. we don't want the funky escape code stuff to be
    # output if not a tty.
    if sys.stdin.isatty():
        import readline
except ImportError:
    pass

CQL_LIB_PREFIX = 'cassandra-driver-internal-only-'

CASSANDRA_PATH = os.path.join(os.path.dirname(os.path.realpath(__file__)), '..')

# use bundled libs for python-cql and thrift, if available. if there
# is a ../lib dir, use bundled libs there preferentially.
ZIPLIB_DIRS = [os.path.join(CASSANDRA_PATH, 'lib')]
myplatform = platform.system()
if myplatform == 'Linux':
    ZIPLIB_DIRS.append('/usr/share/cassandra/lib')

if os.environ.get('CQLSH_NO_BUNDLED', ''):
    ZIPLIB_DIRS = ()


def find_zip(libprefix):
    for ziplibdir in ZIPLIB_DIRS:
        zips = glob(os.path.join(ziplibdir, libprefix + '*.zip'))
        if zips:
            return max(zips)   # probably the highest version, if multiple

cql_zip = find_zip(CQL_LIB_PREFIX)
if cql_zip:
    ver = os.path.splitext(os.path.basename(cql_zip))[0][len(CQL_LIB_PREFIX):]
    sys.path.insert(0, os.path.join(cql_zip, 'cassandra-driver-' + ver))

third_parties = ('futures-', 'six-')

for lib in third_parties:
    lib_zip = find_zip(lib)
    if lib_zip:
        sys.path.insert(0, lib_zip)

warnings.filterwarnings("ignore", r".*blist.*")
try:
    import cassandra
except ImportError, e:
    sys.exit("\nPython Cassandra driver not installed, or not on PYTHONPATH.\n"
             'You might try "pip install cassandra-driver".\n\n'
             'Python: %s\n'
             'Module load path: %r\n\n'
             'Error: %s\n' % (sys.executable, sys.path, e))

from cassandra.auth import PlainTextAuthProvider
from cassandra.cluster import Cluster, PagedResult
from cassandra.metadata import (ColumnMetadata, KeyspaceMetadata,
                                TableMetadata, protect_name, protect_names,
                                protect_value)
from cassandra.policies import WhiteListRoundRobinPolicy
from cassandra.protocol import QueryMessage, ResultMessage
from cassandra.query import SimpleStatement, ordered_dict_factory

# cqlsh should run correctly when run out of a Cassandra source tree,
# out of an unpacked Cassandra tarball, and after a proper package install.
cqlshlibdir = os.path.join(CASSANDRA_PATH, 'pylib')
if os.path.isdir(cqlshlibdir):
    sys.path.insert(0, cqlshlibdir)

from cqlshlib import cql3handling, cqlhandling, pylexotron, sslhandling
from cqlshlib.displaying import (ANSI_RESET, BLUE, COLUMN_NAME_COLORS, CYAN,
                                 RED, FormattedValue, colorme)
from cqlshlib.formatting import (DEFAULT_DATE_FORMAT, DEFAULT_NANOTIME_FORMAT,
                                 DEFAULT_TIMESTAMP_FORMAT, DateTimeFormat,
                                 format_by_type, format_value_utype,
                                 formatter_for)
from cqlshlib.tracing import print_trace, print_trace_session
from cqlshlib.util import get_file_encoding_bomsize, trim_if_present

DEFAULT_HOST = '127.0.0.1'
DEFAULT_PORT = 9042
DEFAULT_CQLVER = '3.3.1'
DEFAULT_PROTOCOL_VERSION = 4
DEFAULT_CONNECT_TIMEOUT_SECONDS = 5

DEFAULT_FLOAT_PRECISION = 5
DEFAULT_MAX_TRACE_WAIT = 10

if readline is not None and readline.__doc__ is not None and 'libedit' in readline.__doc__:
    DEFAULT_COMPLETEKEY = '\t'
else:
    DEFAULT_COMPLETEKEY = 'tab'

cqldocs = None
cqlruleset = None

epilog = """Connects to %(DEFAULT_HOST)s:%(DEFAULT_PORT)d by default. These
defaults can be changed by setting $CQLSH_HOST and/or $CQLSH_PORT. When a
host (and optional port number) are given on the command line, they take
precedence over any defaults.""" % globals()

parser = optparse.OptionParser(description=description, epilog=epilog,
                               usage="Usage: %prog [options] [host [port]]",
                               version='cqlsh ' + version)
parser.add_option("-C", "--color", action='store_true', dest='color',
                  help='Always use color output')
parser.add_option("--no-color", action='store_false', dest='color',
                  help='Never use color output')
parser.add_option('--ssl', action='store_true', help='Use SSL', default=False)
parser.add_option("-u", "--username", help="Authenticate as user.")
parser.add_option("-p", "--password", help="Authenticate using password.")
parser.add_option('-k', '--keyspace', help='Authenticate to the given keyspace.')
parser.add_option("-f", "--file", help="Execute commands from FILE, then exit")
parser.add_option('--debug', action='store_true',
                  help='Show additional debugging information')
parser.add_option("--encoding", help="Specify a non-default encoding for output.  If you are " +
                  "experiencing problems with unicode characters, using utf8 may fix the problem." +
                  " (Default from system preferences: %s)" % (locale.getpreferredencoding(),))
parser.add_option("--cqlshrc", help="Specify an alternative cqlshrc file location.")
parser.add_option('--cqlversion', default=DEFAULT_CQLVER,
                  help='Specify a particular CQL version (default: %default).'
                       ' Examples: "3.0.3", "3.1.0"')
parser.add_option("-e", "--execute", help='Execute the statement and quit.')
parser.add_option("--connect-timeout", default=DEFAULT_CONNECT_TIMEOUT_SECONDS, dest='connect_timeout',
                  help='Specify the connection timeout in seconds (default: %default seconds).')

optvalues = optparse.Values()
(options, arguments) = parser.parse_args(sys.argv[1:], values=optvalues)

# BEGIN history/config definition
HISTORY_DIR = os.path.expanduser(os.path.join('~', '.cassandra'))

if hasattr(options, 'cqlshrc'):
    CONFIG_FILE = options.cqlshrc
    if not os.path.exists(CONFIG_FILE):
        print '\nWarning: Specified cqlshrc location `%s` does not exist.  Using `%s` instead.\n' % (CONFIG_FILE, HISTORY_DIR)
        CONFIG_FILE = os.path.join(HISTORY_DIR, 'cqlshrc')
else:
    CONFIG_FILE = os.path.join(HISTORY_DIR, 'cqlshrc')

HISTORY = os.path.join(HISTORY_DIR, 'cqlsh_history')
if not os.path.exists(HISTORY_DIR):
    try:
        os.mkdir(HISTORY_DIR)
    except OSError:
        print '\nWarning: Cannot create directory at `%s`. Command history will not be saved.\n' % HISTORY_DIR

OLD_CONFIG_FILE = os.path.expanduser(os.path.join('~', '.cqlshrc'))
if os.path.exists(OLD_CONFIG_FILE):
    if os.path.exists(CONFIG_FILE):
        print '\nWarning: cqlshrc config files were found at both the old location (%s) and \
                the new location (%s), the old config file will not be migrated to the new \
                location, and the new location will be used for now.  You should manually \
                consolidate the config files at the new location and remove the old file.' \
                % (OLD_CONFIG_FILE, CONFIG_FILE)
    else:
        os.rename(OLD_CONFIG_FILE, CONFIG_FILE)
OLD_HISTORY = os.path.expanduser(os.path.join('~', '.cqlsh_history'))
if os.path.exists(OLD_HISTORY):
    os.rename(OLD_HISTORY, HISTORY)
# END history/config definition

CQL_ERRORS = (
    cassandra.AlreadyExists, cassandra.AuthenticationFailed, cassandra.InvalidRequest,
    cassandra.Timeout, cassandra.Unauthorized, cassandra.OperationTimedOut,
    cassandra.cluster.NoHostAvailable,
    cassandra.connection.ConnectionBusy, cassandra.connection.ProtocolError, cassandra.connection.ConnectionException,
    cassandra.protocol.ErrorMessage, cassandra.protocol.InternalError, cassandra.query.TraceUnavailable
)

debug_completion = bool(os.environ.get('CQLSH_DEBUG_COMPLETION', '') == 'YES')

# we want the cql parser to understand our cqlsh-specific commands too
my_commands_ending_with_newline = (
    'help',
    '?',
    'consistency',
    'serial',
    'describe',
    'desc',
    'show',
    'source',
    'capture',
    'login',
    'debug',
    'tracing',
    'expand',
    'paging',
    'exit',
    'quit',
    'clear',
    'cls'
)


cqlsh_syntax_completers = []


def cqlsh_syntax_completer(rulename, termname):
    def registrator(f):
        cqlsh_syntax_completers.append((rulename, termname, f))
        return f
    return registrator


cqlsh_extra_syntax_rules = r'''
<cqlshCommand> ::= <CQL_Statement>
                 | <specialCommand> ( ";" | "\n" )
                 ;

<specialCommand> ::= <describeCommand>
                   | <consistencyCommand>
                   | <serialConsistencyCommand>
                   | <showCommand>
                   | <sourceCommand>
                   | <captureCommand>
                   | <copyCommand>
                   | <loginCommand>
                   | <debugCommand>
                   | <helpCommand>
                   | <tracingCommand>
                   | <expandCommand>
                   | <exitCommand>
                   | <pagingCommand>
                   | <clearCommand>
                   ;

<describeCommand> ::= ( "DESCRIBE" | "DESC" )
                                  ( "FUNCTIONS" ksname=<keyspaceName>?
                                  | "FUNCTION" udf=<anyFunctionName>
                                  | "AGGREGATES" ksname=<keyspaceName>?
                                  | "AGGREGATE" uda=<userAggregateName>
                                  | "KEYSPACES"
                                  | "KEYSPACE" ksname=<keyspaceName>?
                                  | ( "COLUMNFAMILY" | "TABLE" ) cf=<columnFamilyName>
                                  | "INDEX" idx=<indexName>
                                  | "MATERIALIZED" "VIEW" mv=<materializedViewName>
                                  | ( "COLUMNFAMILIES" | "TABLES" )
                                  | "FULL"? "SCHEMA"
                                  | "CLUSTER"
                                  | "TYPES"
                                  | "TYPE" ut=<userTypeName>
                                  | (ksname=<keyspaceName> | cf=<columnFamilyName> | idx=<indexName> | mv=<materializedViewName>))
                    ;

<consistencyCommand> ::= "CONSISTENCY" ( level=<consistencyLevel> )?
                       ;

<consistencyLevel> ::= "ANY"
                     | "ONE"
                     | "TWO"
                     | "THREE"
                     | "QUORUM"
                     | "ALL"
                     | "LOCAL_QUORUM"
                     | "EACH_QUORUM"
                     | "SERIAL"
                     | "LOCAL_SERIAL"
                     | "LOCAL_ONE"
                     ;

<serialConsistencyCommand> ::= "SERIAL" "CONSISTENCY" ( level=<serialConsistencyLevel> )?
                             ;

<serialConsistencyLevel> ::= "SERIAL"
                           | "LOCAL_SERIAL"
                           ;

<showCommand> ::= "SHOW" what=( "VERSION" | "HOST" | "SESSION" sessionid=<uuid> )
                ;

<sourceCommand> ::= "SOURCE" fname=<stringLiteral>
                  ;

<captureCommand> ::= "CAPTURE" ( fname=( <stringLiteral> | "OFF" ) )?
                   ;

<copyCommand> ::= "COPY" cf=<columnFamilyName>
                         ( "(" [colnames]=<colname> ( "," [colnames]=<colname> )* ")" )?
                         ( dir="FROM" ( fname=<stringLiteral> | "STDIN" )
                         | dir="TO"   ( fname=<stringLiteral> | "STDOUT" ) )
                         ( "WITH" <copyOption> ( "AND" <copyOption> )* )?
                ;

<copyOption> ::= [optnames]=<identifier> "=" [optvals]=<copyOptionVal>
               ;

<copyOptionVal> ::= <identifier>
                  | <stringLiteral>
                  ;

# avoiding just "DEBUG" so that this rule doesn't get treated as a terminal
<debugCommand> ::= "DEBUG" "THINGS"?
                 ;

<helpCommand> ::= ( "HELP" | "?" ) [topic]=( /[a-z_]*/ )*
                ;

<tracingCommand> ::= "TRACING" ( switch=( "ON" | "OFF" ) )?
                   ;

<expandCommand> ::= "EXPAND" ( switch=( "ON" | "OFF" ) )?
                   ;

<pagingCommand> ::= "PAGING" ( switch=( "ON" | "OFF" | /[0-9]+/) )?
                  ;

<loginCommand> ::= "LOGIN" username=<username> (password=<stringLiteral>)?
                 ;

<exitCommand> ::= "exit" | "quit"
                ;

<clearCommand> ::= "CLEAR" | "CLS"
                 ;

<qmark> ::= "?" ;
'''


@cqlsh_syntax_completer('helpCommand', 'topic')
def complete_help(ctxt, cqlsh):
    return sorted([t.upper() for t in cqldocs.get_help_topics() + cqlsh.get_help_topics()])


def complete_source_quoted_filename(ctxt, cqlsh):
    partial_path = ctxt.get_binding('partial', '')
    head, tail = os.path.split(partial_path)
    exhead = os.path.expanduser(head)
    try:
        contents = os.listdir(exhead or '.')
    except OSError:
        return ()
    matches = filter(lambda f: f.startswith(tail), contents)
    annotated = []
    for f in matches:
        match = os.path.join(head, f)
        if os.path.isdir(os.path.join(exhead, f)):
            match += '/'
        annotated.append(match)
    return annotated


cqlsh_syntax_completer('sourceCommand', 'fname')(complete_source_quoted_filename)
cqlsh_syntax_completer('captureCommand', 'fname')(complete_source_quoted_filename)


@cqlsh_syntax_completer('copyCommand', 'fname')
def copy_fname_completer(ctxt, cqlsh):
    lasttype = ctxt.get_binding('*LASTTYPE*')
    if lasttype == 'unclosedString':
        return complete_source_quoted_filename(ctxt, cqlsh)
    partial_path = ctxt.get_binding('partial')
    if partial_path == '':
        return ["'"]
    return ()


@cqlsh_syntax_completer('copyCommand', 'colnames')
def complete_copy_column_names(ctxt, cqlsh):
    existcols = map(cqlsh.cql_unprotect_name, ctxt.get_binding('colnames', ()))
    ks = cqlsh.cql_unprotect_name(ctxt.get_binding('ksname', None))
    cf = cqlsh.cql_unprotect_name(ctxt.get_binding('cfname'))
    colnames = cqlsh.get_column_names(ks, cf)
    if len(existcols) == 0:
        return [colnames[0]]
    return set(colnames[1:]) - set(existcols)


COPY_OPTIONS = ('DELIMITER', 'QUOTE', 'ESCAPE', 'HEADER', 'ENCODING', 'TIMEFORMAT', 'NULL')


@cqlsh_syntax_completer('copyOption', 'optnames')
def complete_copy_options(ctxt, cqlsh):
    optnames = map(str.upper, ctxt.get_binding('optnames', ()))
    direction = ctxt.get_binding('dir').upper()
    opts = set(COPY_OPTIONS) - set(optnames)
    if direction == 'FROM':
        opts -= ('ENCODING',)
        opts -= ('TIMEFORMAT',)
    return opts


@cqlsh_syntax_completer('copyOption', 'optvals')
def complete_copy_opt_values(ctxt, cqlsh):
    optnames = ctxt.get_binding('optnames', ())
    lastopt = optnames[-1].lower()
    if lastopt == 'header':
        return ['true', 'false']
    return [cqlhandling.Hint('<single_character_string>')]


class NoKeyspaceError(Exception):
    pass


class KeyspaceNotFound(Exception):
    pass


class ColumnFamilyNotFound(Exception):
    pass


class IndexNotFound(Exception):
    pass


class MaterializedViewNotFound(Exception):
    pass


class ObjectNotFound(Exception):
    pass


class VersionNotSupported(Exception):
    pass


class UserTypeNotFound(Exception):
    pass


class FunctionNotFound(Exception):
    pass


class AggregateNotFound(Exception):
    pass


class DecodeError(Exception):
    verb = 'decode'

    def __init__(self, thebytes, err, colname=None):
        self.thebytes = thebytes
        self.err = err
        self.colname = colname

    def __str__(self):
        return str(self.thebytes)

    def message(self):
        what = 'value %r' % (self.thebytes,)
        if self.colname is not None:
            what = 'value %r (for column %r)' % (self.thebytes, self.colname)
        return 'Failed to %s %s : %s' \
               % (self.verb, what, self.err)

    def __repr__(self):
        return '<%s %s>' % (self.__class__.__name__, self.message())


class FormatError(DecodeError):
    verb = 'format'


def full_cql_version(ver):
    while ver.count('.') < 2:
        ver += '.0'
    ver_parts = ver.split('-', 1) + ['']
    vertuple = tuple(map(int, ver_parts[0].split('.')) + [ver_parts[1]])
    return ver, vertuple


def format_value(val, output_encoding, addcolor=False, date_time_format=None,
                 float_precision=None, colormap=None, nullval=None):
    if isinstance(val, DecodeError):
        if addcolor:
            return colorme(repr(val.thebytes), colormap, 'error')
        else:
            return FormattedValue(repr(val.thebytes))
    return format_by_type(type(val), val, output_encoding, colormap=colormap,
                          addcolor=addcolor, nullval=nullval, date_time_format=date_time_format,
                          float_precision=float_precision)


def show_warning_without_quoting_line(message, category, filename, lineno, file=None, line=None):
    if file is None:
        file = sys.stderr
    try:
        file.write(warnings.formatwarning(message, category, filename, lineno, line=''))
    except IOError:
        pass
warnings.showwarning = show_warning_without_quoting_line
warnings.filterwarnings('always', category=cql3handling.UnexpectedTableStructure)


def describe_interval(seconds):
    desc = []
    for length, unit in ((86400, 'day'), (3600, 'hour'), (60, 'minute')):
        num = int(seconds) / length
        if num > 0:
            desc.append('%d %s' % (num, unit))
            if num > 1:
                desc[-1] += 's'
        seconds %= length
    words = '%.03f seconds' % seconds
    if len(desc) > 1:
        words = ', '.join(desc) + ', and ' + words
    elif len(desc) == 1:
        words = desc[0] + ' and ' + words
    return words


def auto_format_udts():
    # when we see a new user defined type, set up the shell formatting for it
    udt_apply_params = cassandra.cqltypes.UserType.apply_parameters

    def new_apply_params(cls, *args, **kwargs):
        udt_class = udt_apply_params(*args, **kwargs)
        formatter_for(udt_class.typename)(format_value_utype)
        return udt_class

    cassandra.cqltypes.UserType.udt_apply_parameters = classmethod(new_apply_params)

    make_udt_class = cassandra.cqltypes.UserType.make_udt_class

    def new_make_udt_class(cls, *args, **kwargs):
        udt_class = make_udt_class(*args, **kwargs)
        formatter_for(udt_class.tuple_type.__name__)(format_value_utype)
        return udt_class

    cassandra.cqltypes.UserType.make_udt_class = classmethod(new_make_udt_class)


class FrozenType(cassandra.cqltypes._ParameterizedType):
    """
    Needed until the bundled python driver adds FrozenType.
    """
    typename = "frozen"
    num_subtypes = 1

    @classmethod
    def deserialize_safe(cls, byts, protocol_version):
        subtype, = cls.subtypes
        return subtype.from_binary(byts)

    @classmethod
    def serialize_safe(cls, val, protocol_version):
        subtype, = cls.subtypes
        return subtype.to_binary(val, protocol_version)


class Shell(cmd.Cmd):
    custom_prompt = os.getenv('CQLSH_PROMPT', '')
    if custom_prompt is not '':
        custom_prompt += "\n"
    default_prompt = custom_prompt + "cqlsh> "
    continue_prompt = "   ... "
    keyspace_prompt = custom_prompt + "cqlsh:%s> "
    keyspace_continue_prompt = "%s    ... "
    show_line_nums = False
    debug = False
    stop = False
    last_hist = None
    shunted_query_out = None
    use_paging = True
    csv_dialect_defaults = dict(delimiter=',', doublequote=False,
                                escapechar='\\', quotechar='"')
    default_page_size = 100

    def __init__(self, hostname, port, color=False,
                 username=None, password=None, encoding=None, stdin=None, tty=True,
                 completekey=DEFAULT_COMPLETEKEY, use_conn=None,
                 cqlver=DEFAULT_CQLVER, keyspace=None,
                 tracing_enabled=False, expand_enabled=False,
                 display_nanotime_format=DEFAULT_NANOTIME_FORMAT,
                 display_timestamp_format=DEFAULT_TIMESTAMP_FORMAT,
                 display_date_format=DEFAULT_DATE_FORMAT,
                 display_float_precision=DEFAULT_FLOAT_PRECISION,
                 max_trace_wait=DEFAULT_MAX_TRACE_WAIT,
                 ssl=False,
                 single_statement=None,
                 client_timeout=10,
                 protocol_version=DEFAULT_PROTOCOL_VERSION,
                 connect_timeout=DEFAULT_CONNECT_TIMEOUT_SECONDS):
        cmd.Cmd.__init__(self, completekey=completekey)
        self.hostname = hostname
        self.port = port
        self.auth_provider = None
        if username:
            if not password:
                password = getpass.getpass()
            self.auth_provider = PlainTextAuthProvider(username=username, password=password)
        self.username = username
        self.keyspace = keyspace
        self.ssl = ssl
        self.tracing_enabled = tracing_enabled
        self.page_size = self.default_page_size
        self.expand_enabled = expand_enabled
        if use_conn:
            self.conn = use_conn
        else:
            self.conn = Cluster(contact_points=(self.hostname,), port=self.port, cql_version=cqlver,
                                protocol_version=protocol_version,
                                auth_provider=self.auth_provider,
                                ssl_options=sslhandling.ssl_settings(hostname, CONFIG_FILE) if ssl else None,
                                load_balancing_policy=WhiteListRoundRobinPolicy([self.hostname]),
                                connect_timeout=connect_timeout)
        self.owns_connection = not use_conn
        self.set_expanded_cql_version(cqlver)

        if keyspace:
            self.session = self.conn.connect(keyspace)
        else:
            self.session = self.conn.connect()

        self.color = color

        self.display_nanotime_format = display_nanotime_format
        self.display_timestamp_format = display_timestamp_format
        self.display_date_format = display_date_format

        self.display_float_precision = display_float_precision

        # If there is no schema metadata present (due to a schema mismatch), force schema refresh
        if not self.conn.metadata.keyspaces:
            self.refresh_schema_metadata_best_effort()

        self.session.default_timeout = client_timeout
        self.session.row_factory = ordered_dict_factory
        self.get_connection_versions()

        self.current_keyspace = keyspace

        self.display_timestamp_format = display_timestamp_format
        self.display_nanotime_format = display_nanotime_format
        self.display_date_format = display_date_format

        self.max_trace_wait = max_trace_wait
        self.session.max_trace_wait = max_trace_wait
        if encoding is None:
            encoding = locale.getpreferredencoding()
        self.encoding = encoding
        self.output_codec = codecs.lookup(encoding)

        self.statement = StringIO()
        self.lineno = 1
        self.in_comment = False

        self.prompt = ''
        if stdin is None:
            stdin = sys.stdin
        self.tty = tty
        if tty:
            self.reset_prompt()
            self.report_connection()
            print 'Use HELP for help.'
        else:
            self.show_line_nums = True
        self.stdin = stdin
        self.query_out = sys.stdout
        self.consistency_level = cassandra.ConsistencyLevel.ONE
        self.serial_consistency_level = cassandra.ConsistencyLevel.SERIAL
        # the python driver returns BLOBs as string, but we expect them as bytearrays
        cassandra.cqltypes.BytesType.deserialize = staticmethod(lambda byts, protocol_version: bytearray(byts))
        cassandra.cqltypes.CassandraType.support_empty_values = True

        auto_format_udts()

        self.empty_lines = 0
        self.statement_error = False
        self.single_statement = single_statement

    def refresh_schema_metadata_best_effort(self):
        try:
            self.conn.refresh_schema_metadata(5)  # will throw exception if there is a schema mismatch
        except Exception:
            self.printerr("Warning: schema version mismatch detected, which might be caused by DOWN nodes; if "
                          "this is not the case, check the schema versions of your nodes in system.local and "
                          "system.peers.")
            self.conn.refresh_schema_metadata(0)

    def set_expanded_cql_version(self, ver):
        ver, vertuple = full_cql_version(ver)
        self.cql_version = ver
        self.cql_ver_tuple = vertuple

    def cqlver_atleast(self, major, minor=0, patch=0):
        return self.cql_ver_tuple[:3] >= (major, minor, patch)

    def myformat_value(self, val, **kwargs):
        if isinstance(val, DecodeError):
            self.decoding_errors.append(val)
        try:
            dtformats = DateTimeFormat(timestamp_format=self.display_timestamp_format,
                                       date_format=self.display_date_format, nanotime_format=self.display_nanotime_format)
            return format_value(val, self.output_codec.name,
                                addcolor=self.color, date_time_format=dtformats,
                                float_precision=self.display_float_precision, **kwargs)
        except Exception, e:
            err = FormatError(val, e)
            self.decoding_errors.append(err)
            return format_value(err, self.output_codec.name, addcolor=self.color)

    def myformat_colname(self, name, table_meta=None):
        column_colors = COLUMN_NAME_COLORS.copy()
        # check column role and color appropriately
        if table_meta:
            if name in [col.name for col in table_meta.partition_key]:
                column_colors.default_factory = lambda: RED
            elif name in [col.name for col in table_meta.clustering_key]:
                column_colors.default_factory = lambda: CYAN
        return self.myformat_value(name, colormap=column_colors)

    def report_connection(self):
        self.show_host()
        self.show_version()

    def show_host(self):
        print "Connected to %s at %s:%d." % \
            (self.applycolor(self.get_cluster_name(), BLUE),
              self.hostname,
              self.port)

    def show_version(self):
        vers = self.connection_versions.copy()
        vers['shver'] = version
        # system.Versions['cql'] apparently does not reflect changes with
        # set_cql_version.
        vers['cql'] = self.cql_version
        print "[cqlsh %(shver)s | Cassandra %(build)s | CQL spec %(cql)s | Native protocol v%(protocol)s]" % vers

    def show_session(self, sessionid):
        print_trace_session(self, self.session, sessionid)

    def get_connection_versions(self):
        result, = self.session.execute("select * from system.local where key = 'local'")
        vers = {
            'build': result['release_version'],
            'protocol': result['native_protocol_version'],
            'cql': result['cql_version'],
        }
        self.connection_versions = vers

    def get_keyspace_names(self):
        return map(str, self.conn.metadata.keyspaces.keys())

    def get_columnfamily_names(self, ksname=None):
        if ksname is None:
            ksname = self.current_keyspace

        return map(str, self.get_keyspace_meta(ksname).tables.keys())

    def get_materialized_view_names(self, ksname=None):
        if ksname is None:
            ksname = self.current_keyspace

        return map(str, self.get_keyspace_meta(ksname).views.keys())

    def get_index_names(self, ksname=None):
        if ksname is None:
            ksname = self.current_keyspace

        return map(str, self.get_keyspace_meta(ksname).indexes.keys())

    def get_column_names(self, ksname, cfname):
        if ksname is None:
            ksname = self.current_keyspace
        layout = self.get_table_meta(ksname, cfname)
        return [str(col) for col in layout.columns]

    def get_usertype_names(self, ksname=None):
        if ksname is None:
            ksname = self.current_keyspace

        return self.get_keyspace_meta(ksname).user_types.keys()

    def get_usertype_layout(self, ksname, typename):
        if ksname is None:
            ksname = self.current_keyspace

        ks_meta = self.get_keyspace_meta(ksname)

        try:
            user_type = ks_meta.user_types[typename]
        except KeyError:
            raise UserTypeNotFound("User type %r not found" % typename)

        return [(field_name, field_type.cql_parameterized_type())
                for field_name, field_type in zip(user_type.field_names, user_type.field_types)]

    def get_userfunction_names(self, ksname=None):
        if ksname is None:
            ksname = self.current_keyspace

        return map(lambda f: f.name, self.get_keyspace_meta(ksname).functions.values())

    def get_useraggregate_names(self, ksname=None):
        if ksname is None:
            ksname = self.current_keyspace

        return map(lambda f: f.name, self.get_keyspace_meta(ksname).aggregates.values())

    def get_cluster_name(self):
        return self.conn.metadata.cluster_name

    def get_partitioner(self):
        return self.conn.metadata.partitioner

    def get_keyspace_meta(self, ksname):
        if ksname not in self.conn.metadata.keyspaces:
            raise KeyspaceNotFound('Keyspace %r not found.' % ksname)
        return self.conn.metadata.keyspaces[ksname]

    def get_keyspaces(self):
        return self.conn.metadata.keyspaces.values()

    def get_ring(self):
        if self.current_keyspace is None or self.current_keyspace == 'system':
            raise NoKeyspaceError("Ring view requires a current non-system keyspace")
        self.conn.metadata.token_map.rebuild_keyspace(self.current_keyspace, build_if_absent=True)
        return self.conn.metadata.token_map.tokens_to_hosts_by_ks[self.current_keyspace]

    def get_table_meta(self, ksname, tablename):
        if ksname is None:
            ksname = self.current_keyspace
        ksmeta = self.get_keyspace_meta(ksname)

        if tablename not in ksmeta.tables:
            if ksname == 'system_auth' and tablename in ['roles', 'role_permissions']:
                self.get_fake_auth_table_meta(ksname, tablename)
            else:
                raise ColumnFamilyNotFound("Column family %r not found" % tablename)
        else:
            return ksmeta.tables[tablename]

    def get_fake_auth_table_meta(self, ksname, tablename):
        # may be using external auth implementation so internal tables
        # aren't actually defined in schema. In this case, we'll fake
        # them up
        if tablename == 'roles':
            ks_meta = KeyspaceMetadata(ksname, True, None, None)
            table_meta = TableMetadata(ks_meta, 'roles')
            table_meta.columns['role'] = ColumnMetadata(table_meta, 'role', cassandra.cqltypes.UTF8Type)
            table_meta.columns['is_superuser'] = ColumnMetadata(table_meta, 'is_superuser', cassandra.cqltypes.BooleanType)
            table_meta.columns['can_login'] = ColumnMetadata(table_meta, 'can_login', cassandra.cqltypes.BooleanType)
        elif tablename == 'role_permissions':
            ks_meta = KeyspaceMetadata(ksname, True, None, None)
            table_meta = TableMetadata(ks_meta, 'role_permissions')
            table_meta.columns['role'] = ColumnMetadata(table_meta, 'role', cassandra.cqltypes.UTF8Type)
            table_meta.columns['resource'] = ColumnMetadata(table_meta, 'resource', cassandra.cqltypes.UTF8Type)
            table_meta.columns['permission'] = ColumnMetadata(table_meta, 'permission', cassandra.cqltypes.UTF8Type)
        else:
            raise ColumnFamilyNotFound("Column family %r not found" % tablename)

    def get_index_meta(self, ksname, idxname):
        if ksname is None:
            ksname = self.current_keyspace
        ksmeta = self.get_keyspace_meta(ksname)

        if idxname not in ksmeta.indexes:
            raise IndexNotFound("Index %r not found" % idxname)

        return ksmeta.indexes[idxname]

    def get_view_meta(self, ksname, viewname):
        if ksname is None:
            ksname = self.current_keyspace
        ksmeta = self.get_keyspace_meta(ksname)

        if viewname not in ksmeta.views:
            raise MaterializedViewNotFound("Materialized view %r not found" % viewname)
        return ksmeta.views[viewname]

    def get_object_meta(self, ks, name):
        if name is None:
            if ks and ks in self.conn.metadata.keyspaces:
                return self.conn.metadata.keyspaces[ks]
            elif self.current_keyspace is None:
                raise ObjectNotFound("%r not found in keyspaces" % (ks))
            else:
                name = ks
                ks = self.current_keyspace

        if ks is None:
            ks = self.current_keyspace

        ksmeta = self.get_keyspace_meta(ks)

        if name in ksmeta.tables:
            return ksmeta.tables[name]
        elif name in ksmeta.indexes:
            return ksmeta.indexes[name]
        elif name in ksmeta.views:
            return ksmeta.views[name]

        raise ObjectNotFound("%r not found in keyspace %r" % (name, ks))

    def get_usertypes_meta(self):
        data = self.session.execute("select * from system.schema_usertypes")
        if not data:
            return cql3handling.UserTypesMeta({})

        return cql3handling.UserTypesMeta.from_layout(data)

    def get_trigger_names(self, ksname=None):
        if ksname is None:
            ksname = self.current_keyspace

        return [trigger.name
                for table in self.get_keyspace_meta(ksname).tables.values()
                for trigger in table.triggers.values()]

    def reset_statement(self):
        self.reset_prompt()
        self.statement.truncate(0)
        self.empty_lines = 0

    def reset_prompt(self):
        if self.current_keyspace is None:
            self.set_prompt(self.default_prompt, True)
        else:
            self.set_prompt(self.keyspace_prompt % self.current_keyspace, True)

    def set_continue_prompt(self):
        if self.empty_lines >= 3:
            self.set_prompt("Statements are terminated with a ';'.  You can press CTRL-C to cancel an incomplete statement.")
            self.empty_lines = 0
            return
        if self.current_keyspace is None:
            self.set_prompt(self.continue_prompt)
        else:
            spaces = ' ' * len(str(self.current_keyspace))
            self.set_prompt(self.keyspace_continue_prompt % spaces)
        self.empty_lines = self.empty_lines + 1 if not self.lastcmd else 0

    @contextmanager
    def prepare_loop(self):
        readline = None
        if self.tty and self.completekey:
            try:
                import readline
            except ImportError:
                if myplatform == 'Windows':
                    print "WARNING: pyreadline dependency missing.  Install to enable tab completion."
                pass
            else:
                old_completer = readline.get_completer()
                readline.set_completer(self.complete)
                if readline.__doc__ is not None and 'libedit' in readline.__doc__:
                    readline.parse_and_bind("bind -e")
                    readline.parse_and_bind("bind '" + self.completekey + "' rl_complete")
                    readline.parse_and_bind("bind ^R em-inc-search-prev")
                else:
                    readline.parse_and_bind(self.completekey + ": complete")
        try:
            yield
        finally:
            if readline is not None:
                readline.set_completer(old_completer)

    def get_input_line(self, prompt=''):
        if self.tty:
            self.lastcmd = raw_input(prompt)
            line = self.lastcmd + '\n'
        else:
            self.lastcmd = self.stdin.readline()
            line = self.lastcmd
            if not len(line):
                raise EOFError
        self.lineno += 1
        return line

    def use_stdin_reader(self, until='', prompt=''):
        until += '\n'
        while True:
            try:
                newline = self.get_input_line(prompt=prompt)
            except EOFError:
                return
            if newline == until:
                return
            yield newline

    def cmdloop(self):
        """
        Adapted from cmd.Cmd's version, because there is literally no way with
        cmd.Cmd.cmdloop() to tell the difference between "EOF" showing up in
        input and an actual EOF.
        """
        with self.prepare_loop():
            while not self.stop:
                try:
                    if self.single_statement:
                        line = self.single_statement
                        self.stop = True
                    else:
                        line = self.get_input_line(self.prompt)
                    self.statement.write(line)
                    if self.onecmd(self.statement.getvalue()):
                        self.reset_statement()
                except EOFError:
                    self.handle_eof()
                except CQL_ERRORS, cqlerr:
                    self.printerr(str(cqlerr))
                except KeyboardInterrupt:
                    self.reset_statement()
                    print

    def onecmd(self, statementtext):
        """
        Returns true if the statement is complete and was handled (meaning it
        can be reset).
        """

        try:
            statements, in_batch = cqlruleset.cql_split_statements(statementtext)
        except pylexotron.LexingError, e:
            if self.show_line_nums:
                self.printerr('Invalid syntax at char %d' % (e.charnum,))
            else:
                self.printerr('Invalid syntax at line %d, char %d'
                              % (e.linenum, e.charnum))
            statementline = statementtext.split('\n')[e.linenum - 1]
            self.printerr('  %s' % statementline)
            self.printerr(' %s^' % (' ' * e.charnum))
            return True

        while statements and not statements[-1]:
            statements = statements[:-1]
        if not statements:
            return True
        if in_batch or statements[-1][-1][0] != 'endtoken':
            self.set_continue_prompt()
            return
        for st in statements:
            try:
                self.handle_statement(st, statementtext)
            except Exception, e:
                if self.debug:
                    traceback.print_exc()
                else:
                    self.printerr(e)
        return True

    def handle_eof(self):
        if self.tty:
            print
        statement = self.statement.getvalue()
        if statement.strip():
            if not self.onecmd(statement):
                self.printerr('Incomplete statement at end of file')
        self.do_exit()

    def handle_statement(self, tokens, srcstr):
        # Concat multi-line statements and insert into history
        if readline is not None:
            nl_count = srcstr.count("\n")

            new_hist = srcstr.replace("\n", " ").rstrip()

            if nl_count > 1 and self.last_hist != new_hist:
                readline.add_history(new_hist)

            self.last_hist = new_hist
        cmdword = tokens[0][1]
        if cmdword == '?':
            cmdword = 'help'
        custom_handler = getattr(self, 'do_' + cmdword.lower(), None)
        if custom_handler:
            parsed = cqlruleset.cql_whole_parse_tokens(tokens, srcstr=srcstr,
                                                       startsymbol='cqlshCommand')
            if parsed and not parsed.remainder:
                # successful complete parse
                return custom_handler(parsed)
            else:
                return self.handle_parse_error(cmdword, tokens, parsed, srcstr)
        return self.perform_statement(cqlruleset.cql_extract_orig(tokens, srcstr))

    def handle_parse_error(self, cmdword, tokens, parsed, srcstr):
        if cmdword.lower() in ('select', 'insert', 'update', 'delete', 'truncate',
                               'create', 'drop', 'alter', 'grant', 'revoke',
                               'batch', 'list'):
            # hey, maybe they know about some new syntax we don't. type
            # assumptions won't work, but maybe the query will.
            return self.perform_statement(cqlruleset.cql_extract_orig(tokens, srcstr))
        if parsed:
            self.printerr('Improper %s command (problem at %r).' % (cmdword, parsed.remainder[0]))
        else:
            self.printerr('Improper %s command.' % cmdword)

    def do_use(self, parsed):
        ksname = parsed.get_binding('ksname')
        result, future = self.perform_simple_statement(SimpleStatement(parsed.extract_orig()))
        if result:
            if ksname[0] == '"' and ksname[-1] == '"':
                self.current_keyspace = self.cql_unprotect_name(ksname)
            else:
                self.current_keyspace = ksname.lower()

    def do_select(self, parsed):
        tracing_was_enabled = self.tracing_enabled
        ksname = parsed.get_binding('ksname')
        stop_tracing = ksname == 'system_traces' or (ksname is None and self.current_keyspace == 'system_traces')
        self.tracing_enabled = self.tracing_enabled and not stop_tracing
        statement = parsed.extract_orig()
        self.perform_statement(statement)
        self.tracing_enabled = tracing_was_enabled

    def perform_statement(self, statement):
        stmt = SimpleStatement(statement, consistency_level=self.consistency_level, serial_consistency_level=self.serial_consistency_level, fetch_size=self.page_size if self.use_paging else None)
        result, future = self.perform_simple_statement(stmt)

        if future:
            if future.warnings:
                self.print_warnings(future.warnings)

            if self.tracing_enabled:
                try:
                    trace = future.get_query_trace(self.max_trace_wait)
                    if trace:
                        print_trace(self, trace)
                    elif stmt.trace_id:
                        self.writeresult("This statement trace may be incomplete", color=RED)
                        self.show_session(stmt.trace_id)
                    else:
                        msg = "Statement trace did not complete within %d seconds" % (self.session.max_trace_wait)
                        self.writeresult(msg, color=RED)
                except Exception, err:
                    self.printerr("Unable to fetch query trace: %s" % (str(err),))

        return result

    def parse_for_select_meta(self, query_string):
        try:
            parsed = cqlruleset.cql_parse(query_string)[1]
        except IndexError:
            return None
        ks = self.cql_unprotect_name(parsed.get_binding('ksname', None))
        name = self.cql_unprotect_name(parsed.get_binding('cfname', None))
        try:
            return self.get_table_meta(ks, name)
        except ColumnFamilyNotFound:
            try:
                return self.get_view_meta(ks, name)
            except MaterializedViewNotFound:
                raise ObjectNotFound("%r not found in keyspace %r" % (name, ks))

    def parse_for_update_meta(self, query_string):
        try:
            parsed = cqlruleset.cql_parse(query_string)[1]
        except IndexError:
            return None
        ks = self.cql_unprotect_name(parsed.get_binding('ksname', None))
        cf = self.cql_unprotect_name(parsed.get_binding('cfname'))
        return self.get_table_meta(ks, cf)

    def perform_simple_statement(self, statement):
        if not statement:
            return False, None
        rows = None
        while True:
            try:
                future = self.session.execute_async(statement, trace=self.tracing_enabled)
                rows = future.result(self.session.default_timeout)
                break
            except cassandra.OperationTimedOut, err:
                self.refresh_schema_metadata_best_effort()
                self.printerr(str(err.__class__.__name__) + ": " + str(err))
                return False, None
            except CQL_ERRORS, err:
                self.printerr(str(err.__class__.__name__) + ": " + str(err))
                return False, None
            except Exception, err:
                import traceback
                self.printerr(traceback.format_exc())
                return False, None

        if statement.query_string[:6].lower() == 'select':
            self.print_result(rows, self.parse_for_select_meta(statement.query_string))
        elif statement.query_string.lower().startswith("list users") or statement.query_string.lower().startswith("list roles"):
            self.print_result(rows, self.get_table_meta('system_auth', 'roles'))
        elif statement.query_string.lower().startswith("list"):
            self.print_result(rows, self.get_table_meta('system_auth', 'role_permissions'))
        elif rows:
            # CAS INSERT/UPDATE
            self.writeresult("")
            self.print_static_result(rows, self.parse_for_update_meta(statement.query_string))
        self.flush_output()
        return True, future

    def print_result(self, rows, table_meta):
        self.decoding_errors = []

        self.writeresult("")
        if isinstance(rows, PagedResult) and self.tty:
            num_rows = 0
            while True:
                page = list(rows.current_response)
                if not page:
                    break
                num_rows += len(page)
                self.print_static_result(page, table_meta)
                if not rows.response_future.has_more_pages:
                    break
                raw_input("---MORE---")

                rows.response_future.start_fetching_next_page()
                result = rows.response_future.result()
                if rows.response_future.has_more_pages:
                    rows.current_response = result.current_response
                else:
                    rows.current_response = iter(result)
        else:
            rows = list(rows or [])
            num_rows = len(rows)
            self.print_static_result(rows, table_meta)
        self.writeresult("(%d rows)" % num_rows)

        if self.decoding_errors:
            for err in self.decoding_errors[:2]:
                self.writeresult(err.message(), color=RED)
            if len(self.decoding_errors) > 2:
                self.writeresult('%d more decoding errors suppressed.'
                                 % (len(self.decoding_errors) - 2), color=RED)

    def print_static_result(self, rows, table_meta):
        if not rows:
            if not table_meta:
                return
            # print header only
            colnames = table_meta.columns.keys()  # full header
            formatted_names = [self.myformat_colname(name, table_meta) for name in colnames]
            self.print_formatted_result(formatted_names, None)
            return

        colnames = rows[0].keys()
        formatted_names = [self.myformat_colname(name, table_meta) for name in colnames]
        formatted_values = [map(self.myformat_value, row.values()) for row in rows]

        if self.expand_enabled:
            self.print_formatted_result_vertically(formatted_names, formatted_values)
        else:
            self.print_formatted_result(formatted_names, formatted_values)

    def print_formatted_result(self, formatted_names, formatted_values):
        # determine column widths
        widths = [n.displaywidth for n in formatted_names]
        if formatted_values is not None:
            for fmtrow in formatted_values:
                for num, col in enumerate(fmtrow):
                    widths[num] = max(widths[num], col.displaywidth)

        # print header
        header = ' | '.join(hdr.ljust(w, color=self.color) for (hdr, w) in zip(formatted_names, widths))
        self.writeresult(' ' + header.rstrip())
        self.writeresult('-%s-' % '-+-'.join('-' * w for w in widths))

        # stop if there are no rows
        if formatted_values is None:
            self.writeresult("")
            return

        # print row data
        for row in formatted_values:
            line = ' | '.join(col.rjust(w, color=self.color) for (col, w) in zip(row, widths))
            self.writeresult(' ' + line)

        self.writeresult("")

    def print_formatted_result_vertically(self, formatted_names, formatted_values):
        max_col_width = max([n.displaywidth for n in formatted_names])
        max_val_width = max([n.displaywidth for row in formatted_values for n in row])

        # for each row returned, list all the column-value pairs
        for row_id, row in enumerate(formatted_values):
            self.writeresult("@ Row %d" % (row_id + 1))
            self.writeresult('-%s-' % '-+-'.join(['-' * max_col_width, '-' * max_val_width]))
            for field_id, field in enumerate(row):
                column = formatted_names[field_id].ljust(max_col_width, color=self.color)
                value = field.ljust(field.displaywidth, color=self.color)
                self.writeresult(' ' + " | ".join([column, value]))
            self.writeresult('')

    def print_warnings(self, warnings):
        if warnings is None or len(warnings) == 0:
            return

        self.writeresult('')
        self.writeresult('Warnings :')
        for warning in warnings:
            self.writeresult(warning)
            self.writeresult('')

    def emptyline(self):
        pass

    def parseline(self, line):
        # this shouldn't be needed
        raise NotImplementedError

    def complete(self, text, state):
        if readline is None:
            return
        if state == 0:
            try:
                self.completion_matches = self.find_completions(text)
            except Exception:
                if debug_completion:
                    import traceback
                    traceback.print_exc()
                else:
                    raise
        try:
            return self.completion_matches[state]
        except IndexError:
            return None

    def find_completions(self, text):
        curline = readline.get_line_buffer()
        prevlines = self.statement.getvalue()
        wholestmt = prevlines + curline
        begidx = readline.get_begidx() + len(prevlines)
        stuff_to_complete = wholestmt[:begidx]
        return cqlruleset.cql_complete(stuff_to_complete, text, cassandra_conn=self,
                                       debug=debug_completion, startsymbol='cqlshCommand')

    def set_prompt(self, prompt, prepend_user=False):
        if prepend_user and self.username:
            self.prompt = "%s@%s" % (self.username, prompt)
            return
        self.prompt = prompt

    def cql_unprotect_name(self, namestr):
        if namestr is None:
            return
        return cqlruleset.dequote_name(namestr)

    def cql_unprotect_value(self, valstr):
        if valstr is not None:
            return cqlruleset.dequote_value(valstr)

    def print_recreate_keyspace(self, ksdef, out):
        out.write(ksdef.export_as_string())
        out.write("\n")

    def print_recreate_columnfamily(self, ksname, cfname, out):
        """
        Output CQL commands which should be pasteable back into a CQL session
        to recreate the given table.

        Writes output to the given out stream.
        """
        out.write(self.get_table_meta(ksname, cfname).export_as_string())
        out.write("\n")

    def print_recreate_index(self, ksname, idxname, out):
        """
        Output CQL commands which should be pasteable back into a CQL session
        to recreate the given index.

        Writes output to the given out stream.
        """
        out.write(self.get_index_meta(ksname, idxname).export_as_string())
        out.write("\n")

    def print_recreate_materialized_view(self, ksname, viewname, out):
        """
        Output CQL commands which should be pasteable back into a CQL session
        to recreate the given materialized view.

        Writes output to the given out stream.
        """
        out.write(self.get_view_meta(ksname, viewname).export_as_string())
        out.write("\n")

    def print_recreate_object(self, ks, name, out):
        """
        Output CQL commands which should be pasteable back into a CQL session
        to recreate the given object (ks, table or index).

        Writes output to the given out stream.
        """
        out.write(self.get_object_meta(ks, name).export_as_string())
        out.write("\n")

    def describe_keyspaces(self):
        print
        cmd.Cmd.columnize(self, protect_names(self.get_keyspace_names()))
        print

    def describe_keyspace(self, ksname):
        print
        self.print_recreate_keyspace(self.get_keyspace_meta(ksname), sys.stdout)
        print

    def describe_columnfamily(self, ksname, cfname):
        if ksname is None:
            ksname = self.current_keyspace
        if ksname is None:
            raise NoKeyspaceError("No keyspace specified and no current keyspace")
        print
        self.print_recreate_columnfamily(ksname, cfname, sys.stdout)
        print

    def describe_index(self, ksname, idxname):
        print
        self.print_recreate_index(ksname, idxname, sys.stdout)
        print

    def describe_materialized_view(self, ksname, viewname):
        if ksname is None:
            ksname = self.current_keyspace
        if ksname is None:
            raise NoKeyspaceError("No keyspace specified and no current keyspace")
        print
        self.print_recreate_materialized_view(ksname, viewname, sys.stdout)
        print

    def describe_object(self, ks, name):
        print
        self.print_recreate_object(ks, name, sys.stdout)
        print

    def describe_columnfamilies(self, ksname):
        print
        if ksname is None:
            for k in self.get_keyspaces():
                name = protect_name(k.name)
                print 'Keyspace %s' % (name,)
                print '---------%s' % ('-' * len(name))
                cmd.Cmd.columnize(self, protect_names(self.get_columnfamily_names(k.name)))
                print
        else:
            cmd.Cmd.columnize(self, protect_names(self.get_columnfamily_names(ksname)))
            print

    def describe_functions(self, ksname=None):
        print
        if ksname is None:
            for ksmeta in self.get_keyspaces():
                name = protect_name(ksmeta.name)
                print 'Keyspace %s' % (name,)
                print '---------%s' % ('-' * len(name))
                cmd.Cmd.columnize(self, protect_names(ksmeta.functions.keys()))
                print
        else:
            ksmeta = self.get_keyspace_meta(ksname)
            cmd.Cmd.columnize(self, protect_names(ksmeta.functions.keys()))
            print

    def describe_function(self, ksname, functionname):
        if ksname is None:
            ksname = self.current_keyspace
        if ksname is None:
            raise NoKeyspaceError("No keyspace specified and no current keyspace")
        print
        ksmeta = self.get_keyspace_meta(ksname)
        functions = filter(lambda f: f.name == functionname, ksmeta.functions.values())
        if len(functions) == 0:
            raise FunctionNotFound("User defined function %r not found" % functionname)
        print "\n\n".join(func.as_cql_query(formatted=True) for func in functions)
        print

    def describe_aggregates(self, ksname=None):
        print
        if ksname is None:
            for ksmeta in self.get_keyspaces():
                name = protect_name(ksmeta.name)
                print 'Keyspace %s' % (name,)
                print '---------%s' % ('-' * len(name))
                cmd.Cmd.columnize(self, protect_names(ksmeta.aggregates.keys()))
                print
        else:
            ksmeta = self.get_keyspace_meta(ksname)
            cmd.Cmd.columnize(self, protect_names(ksmeta.aggregates.keys()))
            print

    def describe_aggregate(self, ksname, aggregatename):
        if ksname is None:
            ksname = self.current_keyspace
        if ksname is None:
            raise NoKeyspaceError("No keyspace specified and no current keyspace")
        print
        ksmeta = self.get_keyspace_meta(ksname)
        aggregates = filter(lambda f: f.name == aggregatename, ksmeta.aggregates.values())
        if len(aggregates) == 0:
            raise FunctionNotFound("User defined aggregate %r not found" % aggregatename)
        print "\n\n".join(aggr.as_cql_query(formatted=True) for aggr in aggregates)
        print

    def describe_usertypes(self, ksname):
        print
        if ksname is None:
            for ksmeta in self.get_keyspaces():
                name = protect_name(ksmeta.name)
                print 'Keyspace %s' % (name,)
                print '---------%s' % ('-' * len(name))
                cmd.Cmd.columnize(self, protect_names(ksmeta.user_types.keys()))
                print
        else:
            ksmeta = self.get_keyspace_meta(ksname)
            cmd.Cmd.columnize(self, protect_names(ksmeta.user_types.keys()))
            print

    def describe_usertype(self, ksname, typename):
        if ksname is None:
            ksname = self.current_keyspace
        if ksname is None:
            raise NoKeyspaceError("No keyspace specified and no current keyspace")
        print
        ksmeta = self.get_keyspace_meta(ksname)
        try:
            usertype = ksmeta.user_types[typename]
        except KeyError:
            raise UserTypeNotFound("User type %r not found" % typename)
        print usertype.as_cql_query(formatted=True)
        print

    def describe_cluster(self):
        print '\nCluster: %s' % self.get_cluster_name()
        p = trim_if_present(self.get_partitioner(), 'org.apache.cassandra.dht.')
        print 'Partitioner: %s\n' % p
        # TODO: snitch?
        # snitch = trim_if_present(self.get_snitch(), 'org.apache.cassandra.locator.')
        # print 'Snitch: %s\n' % snitch
        if self.current_keyspace is not None and self.current_keyspace != 'system':
            print "Range ownership:"
            ring = self.get_ring()
            for entry in ring.items():
                print ' %39s  [%s]' % (str(entry[0].value), ', '.join([host.address for host in entry[1]]))
            print

    def describe_schema(self, include_system=False):
        print
        for k in self.get_keyspaces():
            if include_system or k.name not in cql3handling.SYSTEM_KEYSPACES:
                self.print_recreate_keyspace(k, sys.stdout)
                print

    def do_describe(self, parsed):
        """
        DESCRIBE [cqlsh only]

        (DESC may be used as a shorthand.)

          Outputs information about the connected Cassandra cluster, or about
          the data stored on it. Use in one of the following ways:

        DESCRIBE KEYSPACES

          Output the names of all keyspaces.

        DESCRIBE KEYSPACE [<keyspacename>]

          Output CQL commands that could be used to recreate the given
          keyspace, and the tables in it. In some cases, as the CQL interface
          matures, there will be some metadata about a keyspace that is not
          representable with CQL. That metadata will not be shown.

          The '<keyspacename>' argument may be omitted when using a non-system
          keyspace; in that case, the current keyspace will be described.

        DESCRIBE TABLES

          Output the names of all tables in the current keyspace, or in all
          keyspaces if there is no current keyspace.

        DESCRIBE TABLE <tablename>

          Output CQL commands that could be used to recreate the given table.
          In some cases, as above, there may be table metadata which is not
          representable and which will not be shown.

        DESCRIBE INDEX <indexname>

          Output CQL commands that could be used to recreate the given index.
          In some cases, there may be index metadata which is not representable
          and which will not be shown.

        DESCRIBE MATERIALIZED VIEW <viewname>

          Output CQL commands that could be used to recreate the given materialized view.
          In some cases, there may be materialized view metadata which is not representable
          and which will not be shown.

        DESCRIBE CLUSTER

          Output information about the connected Cassandra cluster, such as the
          cluster name, and the partitioner and snitch in use. When you are
          connected to a non-system keyspace, also shows endpoint-range
          ownership information for the Cassandra ring.

        DESCRIBE [FULL] SCHEMA

          Output CQL commands that could be used to recreate the entire (non-system) schema.
          Works as though "DESCRIBE KEYSPACE k" was invoked for each non-system keyspace
          k. Use DESCRIBE FULL SCHEMA to include the system keyspaces.

        DESCRIBE FUNCTIONS <keyspace>

          Output the names of all user defined functions in the given keyspace.

        DESCRIBE FUNCTION [<keyspace>.]<function>

          Describe the given user defined function.

        DESCRIBE AGGREGATES <keyspace>

          Output the names of all user defined aggregates in the given keyspace.

        DESCRIBE AGGREGATE [<keyspace>.]<aggregate>

          Describe the given user defined aggregate.

        DESCRIBE <objname>

          Output CQL commands that could be used to recreate the entire object schema,
          where object can be either a keyspace or a table or an index or a materialized
          view (in this order).
  """
        what = parsed.matched[1][1].lower()
        if what == 'functions':
            ksname = self.cql_unprotect_name(parsed.get_binding('ksname', None))
            self.describe_functions(ksname)
        elif what == 'function':
            ksname = self.cql_unprotect_name(parsed.get_binding('ksname', None))
            functionname = self.cql_unprotect_name(parsed.get_binding('udfname'))
            self.describe_function(ksname, functionname)
        elif what == 'aggregates':
            ksname = self.cql_unprotect_name(parsed.get_binding('ksname', None))
            self.describe_aggregates(ksname)
        elif what == 'aggregate':
            ksname = self.cql_unprotect_name(parsed.get_binding('ksname', None))
            aggregatename = self.cql_unprotect_name(parsed.get_binding('udaname'))
            self.describe_aggregate(ksname, aggregatename)
        elif what == 'keyspaces':
            self.describe_keyspaces()
        elif what == 'keyspace':
            ksname = self.cql_unprotect_name(parsed.get_binding('ksname', ''))
            if not ksname:
                ksname = self.current_keyspace
                if ksname is None:
                    self.printerr('Not in any keyspace.')
                    return
            self.describe_keyspace(ksname)
        elif what in ('columnfamily', 'table'):
            ks = self.cql_unprotect_name(parsed.get_binding('ksname', None))
            cf = self.cql_unprotect_name(parsed.get_binding('cfname'))
            self.describe_columnfamily(ks, cf)
        elif what == 'index':
            ks = self.cql_unprotect_name(parsed.get_binding('ksname', None))
            idx = self.cql_unprotect_name(parsed.get_binding('idxname', None))
            self.describe_index(ks, idx)
        elif what == 'materialized' and parsed.matched[2][1].lower() == 'view':
            ks = self.cql_unprotect_name(parsed.get_binding('ksname', None))
            mv = self.cql_unprotect_name(parsed.get_binding('mvname'))
            self.describe_materialized_view(ks, mv)
        elif what in ('columnfamilies', 'tables'):
            self.describe_columnfamilies(self.current_keyspace)
        elif what == 'types':
            self.describe_usertypes(self.current_keyspace)
        elif what == 'type':
            ks = self.cql_unprotect_name(parsed.get_binding('ksname', None))
            ut = self.cql_unprotect_name(parsed.get_binding('utname'))
            self.describe_usertype(ks, ut)
        elif what == 'cluster':
            self.describe_cluster()
        elif what == 'schema':
            self.describe_schema(False)
        elif what == 'full' and parsed.matched[2][1].lower() == 'schema':
            self.describe_schema(True)
        elif what:
            ks = self.cql_unprotect_name(parsed.get_binding('ksname', None))
            name = self.cql_unprotect_name(parsed.get_binding('cfname'))
            if not name:
                name = self.cql_unprotect_name(parsed.get_binding('idxname', None))
            if not name:
                name = self.cql_unprotect_name(parsed.get_binding('mvname', None))
            self.describe_object(ks, name)
    do_desc = do_describe

    def do_copy(self, parsed):
        r"""
        COPY [cqlsh only]

          COPY x FROM: Imports CSV data into a Cassandra table
          COPY x TO: Exports data from a Cassandra table in CSV format.

        COPY <table_name> [ ( column [, ...] ) ]
             FROM ( '<filename>' | STDIN )
             [ WITH <option>='value' [AND ...] ];

        COPY <table_name> [ ( column [, ...] ) ]
             TO ( '<filename>' | STDOUT )
             [ WITH <option>='value' [AND ...] ];

        Available options and defaults:

          DELIMITER=','           - character that appears between records
          QUOTE='"'               - quoting character to be used to quote fields
          ESCAPE='\'              - character to appear before the QUOTE char when quoted
          HEADER=false            - whether to ignore the first line
          NULL=''                 - string that represents a null value
          ENCODING='utf8'         - encoding for CSV output (COPY TO only)
          TIME_FORMAT=            - timestamp strftime format (COPY TO only)
            '%Y-%m-%d %H:%M:%S%z'   defaults to time_format value in cqlshrc

        When entering CSV data on STDIN, you can use the sequence "\."
        on a line by itself to end the data input.
        """
        ks = self.cql_unprotect_name(parsed.get_binding('ksname', None))
        if ks is None:
            ks = self.current_keyspace
            if ks is None:
                raise NoKeyspaceError("Not in any keyspace.")
        cf = self.cql_unprotect_name(parsed.get_binding('cfname'))
        columns = parsed.get_binding('colnames', None)
        if columns is not None:
            columns = map(self.cql_unprotect_name, columns)
        else:
            # default to all known columns
            columns = self.get_column_names(ks, cf)
        fname = parsed.get_binding('fname', None)
        if fname is not None:
            fname = os.path.expanduser(self.cql_unprotect_value(fname))
        copyoptnames = map(str.lower, parsed.get_binding('optnames', ()))
        copyoptvals = map(self.cql_unprotect_value, parsed.get_binding('optvals', ()))
        cleancopyoptvals = [optval.decode('string-escape') for optval in copyoptvals]
        opts = dict(zip(copyoptnames, cleancopyoptvals))

        timestart = time.time()

        direction = parsed.get_binding('dir').upper()
        if direction == 'FROM':
            rows = self.perform_csv_import(ks, cf, columns, fname, opts)
            verb = 'imported'
        elif direction == 'TO':
            rows = self.perform_csv_export(ks, cf, columns, fname, opts)
            verb = 'exported'
        else:
            raise SyntaxError("Unknown direction %s" % direction)

        timeend = time.time()
        print "\n%d rows %s in %s." % (rows, verb, describe_interval(timeend - timestart))

    def perform_csv_import(self, ks, cf, columns, fname, opts):
        dialect_options = self.csv_dialect_defaults.copy()
        if 'quote' in opts:
            dialect_options['quotechar'] = opts.pop('quote')
        if 'escape' in opts:
            dialect_options['escapechar'] = opts.pop('escape')
        if 'delimiter' in opts:
            dialect_options['delimiter'] = opts.pop('delimiter')
        nullval = opts.pop('null', '')
        header = bool(opts.pop('header', '').lower() == 'true')
        if dialect_options['quotechar'] == dialect_options['escapechar']:
            dialect_options['doublequote'] = True
            del dialect_options['escapechar']
        if opts:
            self.printerr('Unrecognized COPY FROM options: %s'
                          % ', '.join(opts.keys()))
            return 0

        if fname is None:
            do_close = False
            print "[Use \. on a line by itself to end input]"
            linesource = self.use_stdin_reader(prompt='[copy] ', until=r'\.')
        else:
            do_close = True
            try:
                linesource = open(fname, 'rb')
            except IOError, e:
                self.printerr("Can't open %r for reading: %s" % (fname, e))
                return 0

        current_record = None

        try:
            if header:
                linesource.next()
            reader = csv.reader(linesource, **dialect_options)

            from multiprocessing import Pipe, cpu_count

            # Pick a resonable number of child processes. We need to leave at
            # least one core for the parent process.  This doesn't necessarily
            # need to be capped at 4, but it's currently enough to keep
            # a single local Cassandra node busy, and I see lower throughput
            # with more processes.
            try:
                num_processes = max(1, min(4, cpu_count() - 1))
            except NotImplementedError:
                num_processes = 1

            processes, pipes = [], [],
            for i in range(num_processes):
                parent_conn, child_conn = Pipe()
                pipes.append(parent_conn)
                processes.append(ImportProcess(self, child_conn, ks, cf, columns, nullval))

            for process in processes:
                process.start()

            meter = RateMeter(10000)
            for current_record, row in enumerate(reader, start=1):
                # write to the child process
                pipes[current_record % num_processes].send((current_record, row))

                # update the progress and current rate periodically
                meter.increment()

                # check for any errors reported by the children
                if (current_record % 100) == 0:
                    if self._check_child_pipes(current_record, pipes):
                        # no errors seen, continue with outer loop
                        continue
                    else:
                        # errors seen, break out of outer loop
                        break
        except Exception, exc:
            if current_record is None:
                # we failed before we started
                self.printerr("\nError starting import process:\n")
                self.printerr(str(exc))
                if self.debug:
                    traceback.print_exc()
            else:
                self.printerr("\n" + str(exc))
                self.printerr("\nAborting import at record #%d. "
                              "Previously inserted records and some records after "
                              "this number may be present."
                              % (current_record,))
                if self.debug:
                    traceback.print_exc()
        finally:
            # send a message that indicates we're done
            for pipe in pipes:
                pipe.send((None, None))

            for process in processes:
                process.join()

            self._check_child_pipes(current_record, pipes)

            for pipe in pipes:
                pipe.close()

            if do_close:
                linesource.close()
            elif self.tty:
                print

        return current_record

    def _check_child_pipes(self, current_record, pipes):
        # check the pipes for errors from child processes
        for pipe in pipes:
            if pipe.poll():
                try:
                    (record_num, error) = pipe.recv()
                    self.printerr("\n" + str(error))
                    self.printerr(
                        "Aborting import at record #%d. "
                        "Previously inserted records are still present, "
                        "and some records after that may be present as well."
                        % (record_num,))
                    return False
                except EOFError:
                    # pipe is closed, nothing to read
                    self.printerr("\nChild process died without notification, "
                                  "aborting import at record #%d. Previously "
                                  "inserted records are probably still present, "
                                  "and some records after that may be present "
                                  "as well." % (current_record,))
                    return False
        return True

    def perform_csv_export(self, ks, cf, columns, fname, opts):
        dialect_options = self.csv_dialect_defaults.copy()

        if 'quote' in opts:
            dialect_options['quotechar'] = opts.pop('quote')
        if 'escape' in opts:
            dialect_options['escapechar'] = opts.pop('escape')
        if 'delimiter' in opts:
            dialect_options['delimiter'] = opts.pop('delimiter')
        encoding = opts.pop('encoding', 'utf8')
        nullval = opts.pop('null', '')
        header = bool(opts.pop('header', '').lower() == 'true')
        timestamp_format = opts.pop('time_format', self.display_timestamp_format)
        if dialect_options['quotechar'] == dialect_options['escapechar']:
            dialect_options['doublequote'] = True
            del dialect_options['escapechar']

        if opts:
            self.printerr('Unrecognized COPY TO options: %s'
                          % ', '.join(opts.keys()))
            return 0

        if fname is None:
            do_close = False
            csvdest = sys.stdout
        else:
            do_close = True
            try:
                csvdest = open(fname, 'wb')
            except IOError, e:
                self.printerr("Can't open %r for writing: %s" % (fname, e))
                return 0

        meter = RateMeter(10000)
        try:
            dtformats = DateTimeFormat(timestamp_format, self.display_date_format, self.display_nanotime_format)
            dump = self.prep_export_dump(ks, cf, columns)
            writer = csv.writer(csvdest, **dialect_options)
            if header:
                writer.writerow(columns)
            for row in dump:
                fmt = lambda v: \
                    format_value(v, output_encoding=encoding, nullval=nullval,
                                 date_time_format=dtformats,
                                 float_precision=self.display_float_precision).strval
                writer.writerow(map(fmt, row.values()))
                meter.increment()
        finally:
            if do_close:
                csvdest.close()
        return meter.current_record

    def prep_export_dump(self, ks, cf, columns):
        if columns is None:
            columns = self.get_column_names(ks, cf)
        columnlist = ', '.join(protect_names(columns))
        query = 'SELECT %s FROM %s.%s' % (columnlist, protect_name(ks), protect_name(cf))
        return self.session.execute(query)

    def do_show(self, parsed):
        """
        SHOW [cqlsh only]

          Displays information about the current cqlsh session. Can be called in
          the following ways:

        SHOW VERSION

          Shows the version and build of the connected Cassandra instance, as
          well as the versions of the CQL spec and the Thrift protocol that
          the connected Cassandra instance understands.

        SHOW HOST

          Shows where cqlsh is currently connected.

        SHOW SESSION <sessionid>

          Pretty-prints the requested tracing session.
        """
        showwhat = parsed.get_binding('what').lower()
        if showwhat == 'version':
            self.get_connection_versions()
            self.show_version()
        elif showwhat == 'host':
            self.show_host()
        elif showwhat.startswith('session'):
            session_id = parsed.get_binding('sessionid').lower()
            self.show_session(UUID(session_id))
        else:
            self.printerr('Wait, how do I show %r?' % (showwhat,))

    def do_source(self, parsed):
        """
        SOURCE [cqlsh only]

        Executes a file containing CQL statements. Gives the output for each
        statement in turn, if any, or any errors that occur along the way.

        Errors do NOT abort execution of the CQL source file.

        Usage:

          SOURCE '<file>';

        That is, the path to the file to be executed must be given inside a
        string literal. The path is interpreted relative to the current working
        directory. The tilde shorthand notation ('~/mydir') is supported for
        referring to $HOME.

        See also the --file option to cqlsh.
        """
        fname = parsed.get_binding('fname')
        fname = os.path.expanduser(self.cql_unprotect_value(fname))
        try:
            encoding, bom_size = get_file_encoding_bomsize(fname)
            f = codecs.open(fname, 'r', encoding)
            f.seek(bom_size)
        except IOError, e:
            self.printerr('Could not open %r: %s' % (fname, e))
            return
        subshell = Shell(self.hostname, self.port,
                         color=self.color, encoding=self.encoding, stdin=f,
                         tty=False, use_conn=self.conn, cqlver=self.cql_version,
                         display_timestamp_format=self.display_timestamp_format,
                         display_date_format=self.display_date_format,
                         display_nanotime_format=self.display_nanotime_format,
                         display_float_precision=self.display_float_precision,
                         max_trace_wait=self.max_trace_wait)
        subshell.cmdloop()
        f.close()

    def do_capture(self, parsed):
        """
        CAPTURE [cqlsh only]

        Begins capturing command output and appending it to a specified file.
        Output will not be shown at the console while it is captured.

        Usage:

          CAPTURE '<file>';
          CAPTURE OFF;
          CAPTURE;

        That is, the path to the file to be appended to must be given inside a
        string literal. The path is interpreted relative to the current working
        directory. The tilde shorthand notation ('~/mydir') is supported for
        referring to $HOME.

        Only query result output is captured. Errors and output from cqlsh-only
        commands will still be shown in the cqlsh session.

        To stop capturing output and show it in the cqlsh session again, use
        CAPTURE OFF.

        To inspect the current capture configuration, use CAPTURE with no
        arguments.
        """
        fname = parsed.get_binding('fname')
        if fname is None:
            if self.shunted_query_out is not None:
                print "Currently capturing query output to %r." % (self.query_out.name,)
            else:
                print "Currently not capturing query output."
            return

        if fname.upper() == 'OFF':
            if self.shunted_query_out is None:
                self.printerr('Not currently capturing output.')
                return
            self.query_out.close()
            self.query_out = self.shunted_query_out
            self.color = self.shunted_color
            self.shunted_query_out = None
            del self.shunted_color
            return

        if self.shunted_query_out is not None:
            self.printerr('Already capturing output to %s. Use CAPTURE OFF'
                          ' to disable.' % (self.query_out.name,))
            return

        fname = os.path.expanduser(self.cql_unprotect_value(fname))
        try:
            f = open(fname, 'a')
        except IOError, e:
            self.printerr('Could not open %r for append: %s' % (fname, e))
            return
        self.shunted_query_out = self.query_out
        self.shunted_color = self.color
        self.query_out = f
        self.color = False
        print 'Now capturing query output to %r.' % (fname,)

    def do_tracing(self, parsed):
        """
        TRACING [cqlsh]

          Enables or disables request tracing.

        TRACING ON

          Enables tracing for all further requests.

        TRACING OFF

          Disables tracing.

        TRACING

          TRACING with no arguments shows the current tracing status.
        """
        self.tracing_enabled = SwitchCommand("TRACING", "Tracing").execute(self.tracing_enabled, parsed, self.printerr)

    def do_expand(self, parsed):
        """
        EXPAND [cqlsh]

          Enables or disables expanded (vertical) output.

        EXPAND ON

          Enables expanded (vertical) output.

        EXPAND OFF

          Disables expanded (vertical) output.

        EXPAND

          EXPAND with no arguments shows the current value of expand setting.
        """
        self.expand_enabled = SwitchCommand("EXPAND", "Expanded output").execute(self.expand_enabled, parsed, self.printerr)

    def do_consistency(self, parsed):
        """
        CONSISTENCY [cqlsh only]

           Overrides default consistency level (default level is ONE).

        CONSISTENCY <level>

           Sets consistency level for future requests.

           Valid consistency levels:

           ANY, ONE, TWO, THREE, QUORUM, ALL, LOCAL_ONE, LOCAL_QUORUM, EACH_QUORUM, SERIAL and LOCAL_SERIAL.

           SERIAL and LOCAL_SERIAL may be used only for SELECTs; will be rejected with updates.

        CONSISTENCY

           CONSISTENCY with no arguments shows the current consistency level.
        """
        level = parsed.get_binding('level')
        if level is None:
            print 'Current consistency level is %s.' % (cassandra.ConsistencyLevel.value_to_name[self.consistency_level])
            return

        self.consistency_level = cassandra.ConsistencyLevel.name_to_value[level.upper()]
        print 'Consistency level set to %s.' % (level.upper(),)

    def do_serial(self, parsed):
        """
        SERIAL CONSISTENCY [cqlsh only]

           Overrides serial consistency level (default level is SERIAL).

        SERIAL CONSISTENCY <level>

           Sets consistency level for future conditional updates.

           Valid consistency levels:

           SERIAL, LOCAL_SERIAL.

        SERIAL CONSISTENCY

           SERIAL CONSISTENCY with no arguments shows the current consistency level.
        """
        level = parsed.get_binding('level')
        if level is None:
            print 'Current serial consistency level is %s.' % (cassandra.ConsistencyLevel.value_to_name[self.serial_consistency_level])
            return

        self.serial_consistency_level = cassandra.ConsistencyLevel.name_to_value[level.upper()]
        print 'Serial consistency level set to %s.' % (level.upper(),)

    def do_login(self, parsed):
        """
        LOGIN [cqlsh only]

           Changes login information without requiring restart.

        LOGIN <username> (<password>)

           Login using the specified username. If password is specified, it will be used
           otherwise, you will be prompted to enter.
        """
        username = parsed.get_binding('username')
        password = parsed.get_binding('password')
        if password is None:
            password = getpass.getpass()
        else:
            password = password[1:-1]

        auth_provider = PlainTextAuthProvider(username=username, password=password)

        conn = Cluster(contact_points=(self.hostname,), port=self.port, cql_version=self.conn.cql_version,
                       protocol_version=self.conn.protocol_version,
                       auth_provider=auth_provider,
                       ssl_options=self.conn.ssl_options,
                       load_balancing_policy=WhiteListRoundRobinPolicy([self.hostname]),
                       connect_timeout=self.conn.connect_timeout)

        if self.current_keyspace:
            session = conn.connect(self.current_keyspace)
        else:
            session = conn.connect()

        # Update after we've connected in case we fail to authenticate
        self.conn = conn
        self.auth_provider = auth_provider
        self.username = username
        self.session = session

    def do_exit(self, parsed=None):
        """
        EXIT/QUIT [cqlsh only]

        Exits cqlsh.
        """
        self.stop = True
        if self.owns_connection:
            self.conn.shutdown()
    do_quit = do_exit

    def do_clear(self, parsed):
        """
        CLEAR/CLS [cqlsh only]

        Clears the console.
        """
        import subprocess
        subprocess.call(['clear', 'cls'][myplatform == 'Windows'], shell=True)
    do_cls = do_clear

    def do_debug(self, parsed):
        import pdb
        pdb.set_trace()

    def get_help_topics(self):
        topics = [t[3:] for t in dir(self) if t.startswith('do_') and getattr(self, t, None).__doc__]
        for hide_from_help in ('quit',):
            topics.remove(hide_from_help)
        return topics

    def columnize(self, slist, *a, **kw):
        return cmd.Cmd.columnize(self, sorted([u.upper() for u in slist]), *a, **kw)

    def do_help(self, parsed):
        """
        HELP [cqlsh only]

        Gives information about cqlsh commands. To see available topics,
        enter "HELP" without any arguments. To see help on a topic,
        use "HELP <topic>".
        """
        topics = parsed.get_binding('topic', ())
        if not topics:
            shell_topics = [t.upper() for t in self.get_help_topics()]
            self.print_topics("\nDocumented shell commands:", shell_topics, 15, 80)
            cql_topics = [t.upper() for t in cqldocs.get_help_topics()]
            self.print_topics("CQL help topics:", cql_topics, 15, 80)
            return
        for t in topics:
            if t.lower() in self.get_help_topics():
                doc = getattr(self, 'do_' + t.lower()).__doc__
                self.stdout.write(doc + "\n")
            elif t.lower() in cqldocs.get_help_topics():
                cqldocs.print_help_topic(t)
            else:
                self.printerr("*** No help on %s" % (t,))

    def do_paging(self, parsed):
        """
        PAGING [cqlsh]

          Enables or disables query paging.

        PAGING ON

          Enables query paging for all further queries.

        PAGING OFF

          Disables paging.

        PAGING

          PAGING with no arguments shows the current query paging status.
        """
        (self.use_paging, requested_page_size) = SwitchCommandWithValue(
            "PAGING", "Query paging", value_type=int).execute(self.use_paging, parsed, self.printerr)
        if self.use_paging and requested_page_size is not None:
            self.page_size = requested_page_size
        if self.use_paging:
            print("Page size: {}".format(self.page_size))
        else:
            self.page_size = self.default_page_size

    def applycolor(self, text, color=None):
        if not color or not self.color:
            return text
        return color + text + ANSI_RESET

    def writeresult(self, text, color=None, newline=True, out=None):
        if out is None:
            out = self.query_out
        out.write(self.applycolor(str(text), color) + ('\n' if newline else ''))

    def flush_output(self):
        self.query_out.flush()

    def printerr(self, text, color=RED, newline=True, shownum=None):
        self.statement_error = True
        if shownum is None:
            shownum = self.show_line_nums
        if shownum:
            text = '%s:%d:%s' % (self.stdin.name, self.lineno, text)
        self.writeresult(text, color, newline=newline, out=sys.stderr)


class ImportProcess(multiprocessing.Process):

    def __init__(self, parent, pipe, ks, cf, columns, nullval):
        multiprocessing.Process.__init__(self)
        self.pipe = pipe
        self.nullval = nullval
        self.ks = ks
        self.cf = cf

        # validate we can fetch metdata but don't store it since win32 needs to pickle
        parent.get_table_meta(ks, cf)

        self.columns = columns
        self.consistency_level = parent.consistency_level
        self.connect_timeout = parent.conn.connect_timeout
        self.hostname = parent.hostname
        self.port = parent.port
        self.ssl = parent.ssl
        self.auth_provider = parent.auth_provider
        self.cql_version = parent.conn.cql_version
        self.debug = parent.debug

    def run(self):
        new_cluster = Cluster(
            contact_points=(self.hostname,),
            port=self.port,
            cql_version=self.cql_version,
            protocol_version=DEFAULT_PROTOCOL_VERSION,
            auth_provider=self.auth_provider,
            ssl_options=sslhandling.ssl_settings(self.hostname, CONFIG_FILE) if self.ssl else None,
            load_balancing_policy=WhiteListRoundRobinPolicy([self.hostname]),
            compression=None,
            connect_timeout=self.connect_timeout)
        session = new_cluster.connect(self.ks)
        conn = session._pools.values()[0]._connection

        table_meta = new_cluster.metadata.keyspaces[self.ks].tables[self.cf]

        pk_cols = [col.name for col in table_meta.primary_key]
        cqltypes = [table_meta.columns[name].typestring for name in self.columns]
        pk_indexes = [self.columns.index(col.name) for col in table_meta.primary_key]
        query = 'INSERT INTO %s.%s (%s) VALUES (%%s)' % (
            protect_name(table_meta.keyspace.name),
            protect_name(table_meta.name),
            ', '.join(protect_names(self.columns)))

        # we need to handle some types specially
        should_escape = [t in ('ascii', 'text', 'timestamp', 'date', 'time', 'inet') for t in cqltypes]

        insert_timestamp = int(time.time() * 1e6)

        def callback(record_num, response):
            # This is the callback we register for all inserts.  Because this
            # is run on the event-loop thread, we need to hold a lock when
            # adjusting in_flight.
            with conn.lock:
                conn.in_flight -= 1

            if not isinstance(response, ResultMessage):
                # It's an error. Notify the parent process and let it send
                # a stop signal to all child processes (including this one).
                self.pipe.send((record_num, str(response)))
                if isinstance(response, Exception) and self.debug:
                    traceback.print_exc(response)

        current_record = 0
        insert_num = 0
        try:
            while True:
                # To avoid totally maxing out the connection,
                # defer to the reactor thread when we're close
                # to capacity
                if conn.in_flight > (conn.max_request_id * 0.9):
                    conn._readable = True
                    time.sleep(0.05)
                    continue

                try:
                    (current_record, row) = self.pipe.recv()
                except EOFError:
                    # the pipe was closed and there's nothing to receive
                    sys.stdout.write('Failed to read from pipe:\n\n')
                    sys.stdout.flush()
                    conn._writable = True
                    conn._readable = True
                    break

                # see if the parent process has signaled that we are done
                if (current_record, row) == (None, None):
                    conn._writable = True
                    conn._readable = True
                    self.pipe.close()
                    break

                # format the values in the row
                for i, value in enumerate(row):
                    if value != self.nullval:
                        if should_escape[i]:
                            row[i] = protect_value(value)
                    elif i in pk_indexes:
                        # By default, nullval is an empty string. See CASSANDRA-7792 for details.
                        message = "Cannot insert null value for primary key column '%s'." % (pk_cols[i],)
                        if self.nullval == '':
                            message += " If you want to insert empty strings, consider using " \
                                       "the WITH NULL=<marker> option for COPY."
                        self.pipe.send((current_record, message))
                        return
                    else:
                        row[i] = 'null'

                full_query = query % (','.join(row),)
                query_message = QueryMessage(
                    full_query, self.consistency_level, serial_consistency_level=None,
                    fetch_size=None, paging_state=None, timestamp=insert_timestamp)

                request_id = conn.get_request_id()
                conn.send_msg(query_message, request_id=request_id, cb=partial(callback, current_record))

                with conn.lock:
                    conn.in_flight += 1

                # every 50 records, clear the pending writes queue and read
                # any responses we have
                if insert_num % 50 == 0:
                    conn._writable = True
                    conn._readable = True

                insert_num += 1
        except Exception, exc:
            self.pipe.send((current_record, str(exc)))
        finally:
            # wait for any pending requests to finish
            while conn.in_flight > 0:
                conn._readable = True
                time.sleep(0.1)

            new_cluster.shutdown()

    def stop(self):
        self.terminate()


class RateMeter(object):

    def __init__(self, log_rate):
        self.log_rate = log_rate
        self.last_checkpoint_time = time.time()
        self.current_rate = 0.0
        self.current_record = 0

    def increment(self):
        self.current_record += 1

        if (self.current_record % self.log_rate) == 0:
            new_checkpoint_time = time.time()
            new_rate = self.log_rate / (new_checkpoint_time - self.last_checkpoint_time)
            self.last_checkpoint_time = new_checkpoint_time

            # smooth the rate a bit
            if self.current_rate == 0.0:
                self.current_rate = new_rate
            else:
                self.current_rate = (self.current_rate + new_rate) / 2.0

            output = 'Processed %s rows; Write: %.2f rows/s\r' % \
                     (self.current_record, self.current_rate)
            sys.stdout.write(output)
            sys.stdout.flush()


class SwitchCommand(object):
    command = None
    description = None

    def __init__(self, command, desc):
        self.command = command
        self.description = desc

    def execute(self, state, parsed, printerr):
        switch = parsed.get_binding('switch')
        if switch is None:
            if state:
                print "%s is currently enabled. Use %s OFF to disable" \
                      % (self.description, self.command)
            else:
                print "%s is currently disabled. Use %s ON to enable." \
                      % (self.description, self.command)
            return state

        if switch.upper() == 'ON':
            if state:
                printerr('%s is already enabled. Use %s OFF to disable.'
                         % (self.description, self.command))
                return state
            print 'Now %s is enabled' % (self.description,)
            return True

        if switch.upper() == 'OFF':
            if not state:
                printerr('%s is not enabled.' % (self.description,))
                return state
            print 'Disabled %s.' % (self.description,)
            return False


class SwitchCommandWithValue(SwitchCommand):
    """The same as SwitchCommand except it also accepts a value in place of ON.

    This returns a tuple of the form: (SWITCH_VALUE, PASSED_VALUE)
    eg: PAGING 50 returns (True, 50)
        PAGING OFF returns (False, None)
        PAGING ON returns (True, None)

    The value_type must match for the PASSED_VALUE, otherwise it will return None.
    """
    def __init__(self, command, desc, value_type=int):
        SwitchCommand.__init__(self, command, desc)
        self.value_type = value_type

    def execute(self, state, parsed, printerr):
        binary_switch_value = SwitchCommand.execute(self, state, parsed, printerr)
        switch = parsed.get_binding('switch')
        try:
            value = self.value_type(switch)
            binary_switch_value = True
        except (ValueError, TypeError):
            value = None
        return (binary_switch_value, value)


def option_with_default(cparser_getter, section, option, default=None):
    try:
        return cparser_getter(section, option)
    except ConfigParser.Error:
        return default


def raw_option_with_default(configs, section, option, default=None):
    """
    Same (almost) as option_with_default() but won't do any string interpolation.
    Useful for config values that include '%' symbol, e.g. time format string.
    """
    try:
        return configs.get(section, option, raw=True)
    except ConfigParser.Error:
        return default


def should_use_color():
    if not sys.stdout.isatty():
        return False
    if os.environ.get('TERM', '') in ('dumb', ''):
        return False
    try:
        import subprocess
        p = subprocess.Popen(['tput', 'colors'], stdout=subprocess.PIPE)
        stdout, _ = p.communicate()
        if int(stdout.strip()) < 8:
            return False
    except (OSError, ImportError, ValueError):
        # oh well, we tried. at least we know there's a $TERM and it's
        # not "dumb".
        pass
    return True


def read_options(cmdlineargs, environment):
    configs = ConfigParser.SafeConfigParser()
    configs.read(CONFIG_FILE)

    rawconfigs = ConfigParser.RawConfigParser()
    rawconfigs.read(CONFIG_FILE)

    optvalues = optparse.Values()
    optvalues.username = option_with_default(configs.get, 'authentication', 'username')
    optvalues.password = option_with_default(rawconfigs.get, 'authentication', 'password')
    optvalues.keyspace = option_with_default(configs.get, 'authentication', 'keyspace')
    optvalues.completekey = option_with_default(configs.get, 'ui', 'completekey',
                                                DEFAULT_COMPLETEKEY)
    optvalues.color = option_with_default(configs.getboolean, 'ui', 'color')
    optvalues.time_format = raw_option_with_default(configs, 'ui', 'time_format',
                                                    DEFAULT_TIMESTAMP_FORMAT)
    optvalues.nanotime_format = raw_option_with_default(configs, 'ui', 'nanotime_format',
                                                        DEFAULT_NANOTIME_FORMAT)
    optvalues.date_format = raw_option_with_default(configs, 'ui', 'date_format',
                                                    DEFAULT_DATE_FORMAT)
    optvalues.float_precision = option_with_default(configs.getint, 'ui', 'float_precision',
                                                    DEFAULT_FLOAT_PRECISION)
    optvalues.field_size_limit = option_with_default(configs.getint, 'csv', 'field_size_limit', csv.field_size_limit())
    optvalues.max_trace_wait = option_with_default(configs.getfloat, 'tracing', 'max_trace_wait',
                                                   DEFAULT_MAX_TRACE_WAIT)

    optvalues.debug = False
    optvalues.file = None
    optvalues.ssl = False
    optvalues.encoding = None

    optvalues.tty = sys.stdin.isatty()
    optvalues.cqlversion = option_with_default(configs.get, 'cql', 'version', DEFAULT_CQLVER)
    optvalues.connect_timeout = option_with_default(configs.getint, 'connection', 'timeout', DEFAULT_CONNECT_TIMEOUT_SECONDS)
    optvalues.execute = None

    (options, arguments) = parser.parse_args(cmdlineargs, values=optvalues)

    hostname = option_with_default(configs.get, 'connection', 'hostname', DEFAULT_HOST)
    port = option_with_default(configs.get, 'connection', 'port', DEFAULT_PORT)

    try:
        options.connect_timeout = int(options.connect_timeout)
    except ValueError:
        parser.error('"%s" is not a valid timeout.' % (options.connect_timeout,))
        options.connect_timeout = DEFAULT_CONNECT_TIMEOUT_SECONDS

    options.client_timeout = option_with_default(configs.get, 'connection', 'client_timeout', '10')
    if options.client_timeout.lower() == 'none':
        options.client_timeout = None
    else:
        options.client_timeout = int(options.client_timeout)

    hostname = environment.get('CQLSH_HOST', hostname)
    port = environment.get('CQLSH_PORT', port)

    if len(arguments) > 0:
        hostname = arguments[0]
    if len(arguments) > 1:
        port = arguments[1]

    if options.file or options.execute:
        options.tty = False

    if options.execute and not options.execute.endswith(';'):
        options.execute += ';'

    if optvalues.color in (True, False):
        options.color = optvalues.color
    else:
        if options.file is not None:
            options.color = False
        else:
            options.color = should_use_color()

    options.cqlversion, cqlvertup = full_cql_version(options.cqlversion)
    if cqlvertup[0] < 3:
        parser.error('%r is not a supported CQL version.' % options.cqlversion)
    else:
        options.cqlmodule = cql3handling

    try:
        port = int(port)
    except ValueError:
        parser.error('%r is not a valid port number.' % port)
    return options, hostname, port


def setup_cqlruleset(cqlmodule):
    global cqlruleset
    cqlruleset = cqlmodule.CqlRuleSet
    cqlruleset.append_rules(cqlsh_extra_syntax_rules)
    for rulename, termname, func in cqlsh_syntax_completers:
        cqlruleset.completer_for(rulename, termname)(func)
    cqlruleset.commands_end_with_newline.update(my_commands_ending_with_newline)


def setup_cqldocs(cqlmodule):
    global cqldocs
    cqldocs = cqlmodule.cqldocs


def init_history():
    if readline is not None:
        try:
            readline.read_history_file(HISTORY)
        except IOError:
            pass
        delims = readline.get_completer_delims()
        delims.replace("'", "")
        delims += '.'
        readline.set_completer_delims(delims)


def save_history():
    if readline is not None:
        try:
            readline.write_history_file(HISTORY)
        except IOError:
            pass


def main(options, hostname, port):
    setup_cqlruleset(options.cqlmodule)
    setup_cqldocs(options.cqlmodule)
    init_history()
    csv.field_size_limit(options.field_size_limit)

    if options.file is None:
        stdin = None
    else:
        try:
            encoding, bom_size = get_file_encoding_bomsize(options.file)
            stdin = codecs.open(options.file, 'r', encoding)
            stdin.seek(bom_size)
        except IOError, e:
            sys.exit("Can't open %r: %s" % (options.file, e))

    if options.debug:
        sys.stderr.write("Using CQL driver: %s\n" % (cassandra,))
        sys.stderr.write("Using connect timeout: %s seconds\n" % (options.connect_timeout,))

    try:
        shell = Shell(hostname,
                      port,
                      color=options.color,
                      username=options.username,
                      password=options.password,
                      stdin=stdin,
                      tty=options.tty,
                      completekey=options.completekey,
                      cqlver=options.cqlversion,
                      keyspace=options.keyspace,
                      display_timestamp_format=options.time_format,
                      display_nanotime_format=options.nanotime_format,
                      display_date_format=options.date_format,
                      display_float_precision=options.float_precision,
                      max_trace_wait=options.max_trace_wait,
                      ssl=options.ssl,
                      single_statement=options.execute,
                      client_timeout=options.client_timeout,
                      connect_timeout=options.connect_timeout,
                      encoding=options.encoding)
    except KeyboardInterrupt:
        sys.exit('Connection aborted.')
    except CQL_ERRORS, e:
        sys.exit('Connection error: %s' % (e,))
    except VersionNotSupported, e:
        sys.exit('Unsupported CQL version: %s' % (e,))
    if options.debug:
        shell.debug = True

    shell.cmdloop()
    save_history()
    batch_mode = options.file or options.execute
    if batch_mode and shell.statement_error:
        sys.exit(2)


if __name__ == '__main__':
    main(*read_options(sys.argv[1:], os.environ))

# vim: set ft=python et ts=4 sw=4 :