| /* |
| * 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. |
| */ |
| |
| /* $Rev$ $Date$ */ |
| |
| #ifndef tuscany_leveldb_hpp |
| #define tuscany_leveldb_hpp |
| |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <sys/stat.h> |
| #include <leveldb/db.h> |
| |
| #include "string.hpp" |
| #include "list.hpp" |
| #include "value.hpp" |
| #include "monad.hpp" |
| #include "../../modules/scheme/eval.hpp" |
| |
| namespace tuscany { |
| namespace leveldb { |
| |
| /** |
| * A reallocatable buffer. |
| */ |
| class buffer { |
| public: |
| operator void*() const throw() { |
| return buf; |
| } |
| |
| operator unsigned char*() const throw() { |
| return (unsigned char*)buf; |
| } |
| |
| operator char*() const throw() { |
| return (char*)buf; |
| } |
| |
| private: |
| buffer(const unsigned int size, void* buf) : size(size), buf(buf) { |
| } |
| |
| unsigned int size; |
| void* buf; |
| |
| friend const buffer mkbuffer(const unsigned int sz); |
| friend const buffer mkbuffer(const buffer& b, const unsigned int newsz); |
| friend const bool free(const buffer& b); |
| }; |
| |
| /** |
| * Make a new buffer. |
| */ |
| const buffer mkbuffer(const unsigned int sz) { |
| return buffer(sz, malloc(sz)); |
| } |
| |
| /** |
| * Make a new buffer by reallocating an existing one. |
| */ |
| const buffer mkbuffer(const buffer& b, const unsigned int sz) { |
| if (sz <= b.size) |
| return b; |
| return buffer(sz, realloc(b.buf, sz)); |
| } |
| |
| /** |
| * Free a buffer. |
| */ |
| const bool free(const buffer&b) { |
| ::free(b.buf); |
| return true; |
| } |
| |
| /** |
| * Convert a database name to an absolute path. |
| */ |
| const string absdbname(const string& name) { |
| if (length(name) == 0 || c_str(name)[0] == '/') |
| return name; |
| char cwd[512]; |
| if (getcwd(cwd, sizeof(cwd)) == NULL) |
| return name; |
| return string(cwd) + "/" + name; |
| } |
| |
| /** |
| * Represents a LevelDB connection. |
| */ |
| class LevelDB { |
| public: |
| LevelDB() : owner(false), fd(-1) { |
| debug("leveldb::leveldb"); |
| st.st_ino = 0; |
| } |
| |
| LevelDB(const string& name) : owner(true), name(absdbname(name)), fd(-1) { |
| debug(name, "leveldb::leveldb::name"); |
| st.st_ino = 0; |
| } |
| |
| LevelDB(const LevelDB& c) : owner(false), name(c.name), fd(c.fd) { |
| debug("leveldb::leveldb::copy"); |
| st.st_ino = c.st.st_ino; |
| } |
| |
| const LevelDB& operator=(const LevelDB& c) { |
| debug("leveldb::leveldb::operator="); |
| if(this == &c) |
| return *this; |
| owner = false; |
| name = c.name; |
| fd = c.fd; |
| st.st_ino = c.st.st_ino; |
| return *this; |
| } |
| |
| ~LevelDB() { |
| debug("leveldb::~leveldb"); |
| if (!owner) |
| return; |
| if (fd == -1) |
| return; |
| close(fd); |
| } |
| |
| private: |
| bool owner; |
| string name; |
| leveldb::DB* db; |
| struct stat st; |
| |
| friend const string dbname(const LevelDB& db); |
| friend const failable<int> dbopen(LevelDB& db); |
| friend const failable<bool> dbclose(LevelDB& db); |
| }; |
| |
| /** |
| * Return the name of the database. |
| */ |
| const string dbname(const LevelDB& db) { |
| return db.name; |
| } |
| |
| /** |
| * Open a database. |
| */ |
| const failable<int> dbopen(LevelDB& db) { |
| |
| // Get database file serial number |
| struct stat st; |
| const int s = stat(c_str(db.name), &st); |
| if (s == -1) |
| return mkfailure<int>(string("Couldn't leveldb read database stat: ") + db.name); |
| |
| leveldb::DB* ldb; |
| leveldb::Options options; |
| options.create_if_missing = true; |
| leveldb::Status status = leveldb::DB::Open(options, s, &ldb); |
| db.db = ldb; |
| } |
| |
| /** |
| * Close a database. |
| */ |
| const failable<bool> dbclose(LevelDB& db) { |
| delete db.db; |
| db.db = NULL; |
| return true; |
| } |
| |
| |
| const failable<bool> post(const value& key, const value& val, LevelDB& db) { |
| debug(key, "leveldb::post::key"); |
| debug(val, "leveldb::post::value"); |
| debug(dbname(db), "leveldb::post::dbname"); |
| |
| const string ks(scheme::writeValue(key)); |
| const string vs(scheme::writeValue(val)); |
| |
| put(ks, vs, db); |
| |
| debug(r, "leveldb::post::result"); |
| return r; |
| } |
| |
| |
| const failable<bool> put(const value& key, const value& val, LevelDB& db) { |
| debug(key, "leveldb::put::key"); |
| debug(val, "leveldb::put::value"); |
| debug(dbname(db), "leveldb::put::dbname"); |
| |
| const string ks(scheme::writeValue(key)); |
| const string vs(scheme::writeValue(val)); |
| |
| debug(r, "leveldb::put::result"); |
| return r; |
| } |
| |
| /** |
| * Get an item from the database. |
| */ |
| const failable<value> get(const value& key, LevelDB& db) { |
| debug(key, "leveldb::get::key"); |
| debug(dbname(db), "leveldb::get::dbname"); |
| |
| const string ks(scheme::writeValue(key)); |
| |
| std::string data; |
| db.db->Get(leveldb::ReadOptions(), key, &data); |
| const value val(scheme::readValue(string(data))); |
| |
| debug(val, "leveldb::get::result"); |
| return val; |
| } |
| |
| /** |
| * Delete an item from the database |
| */ |
| struct delUpdate { |
| const string ks; |
| delUpdate(const string& ks) : ks(ks) { |
| } |
| const failable<bool> operator()(buffer& buf, const unsigned int klen, unused const unsigned int vlen) const { |
| if (ks == string((char*)buf, klen)) |
| return false; |
| return true; |
| } |
| }; |
| |
| struct delFinish { |
| delFinish() { |
| } |
| const failable<bool> operator()(unused struct db_make& dbm) const { |
| return true; |
| } |
| }; |
| |
| const failable<bool> del(const value& key, LevelDB& db) { |
| debug(key, "leveldb::delete::key"); |
| debug(dbname(db), "leveldb::delete::dbname"); |
| |
| const string ks(scheme::writeValue(key)); |
| |
| leveldb::Status s = db.db->Delete(leveldb::WriteOptions(), key); |
| |
| debug(r, "leveldb::delete::result"); |
| return s.ok(); |
| } |
| |
| } |
| } |
| |
| #endif /* tuscany_leveldb_hpp */ |