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/*
*
* 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.
*
*/
package org.apache.qpid.transport.codec;
import org.apache.qpid.transport.RangeSet;
import org.apache.qpid.transport.Struct;
import java.util.List;
import java.util.Map;
import java.util.UUID;
/**
* Decoder interface.
* Each concrete implementor must specify how to decode given values.
*
* @author Rafael H. Schloming
*/
public interface Decoder
{
/**
* Tells whether there are any remaining byte(s) to be read.
*
* @return true if there are remaining bytes, false otherwise.
*/
boolean hasRemaining();
/**
* The uint8 type is an 8-bit unsigned integral value.
*
* @return an 8-bit unsigned integral value.
*/
short readUint8();
/**
*The uint16 type is a 16-bit unsigned integral value encoded in network byte order.
*
* @return a 16-bit unsigned integral value encoded in network byte order.
*/
int readUint16();
/**
*The uint32 type is a 32-bit unsigned integral value encoded in network byte order.
*
* @return a 32-bit unsigned integral value encoded in network byte order.
*/
long readUint32();
/**
* The uint64 type is a 64-bit unsigned integral value encoded in network byte order.
*
* @return a 64-bit unsigned integral value encoded in network byte order.
*/
long readUint64();
/**
* The datetime type encodes a date and time using the 64 bit POSIX time_t format.
*
* @return a date and time using the 64 bit POSIX time_t format.
*/
long readDatetime();
/**
* The uuid type encodes a universally unique id as defined by RFC-4122.
* The format and operations for this type can be found in section 4.1.2 of RFC-4122.
*
* @return a universally unique id as defined by RFC-4122.
*/
UUID readUuid();
/**
// *The sequence-no type encodes, in network byte order, a serial number as defined in RFC-1982.
*
* @return a serial number as defined in RFC-1982.
*/
int readSequenceNo();
RangeSet readSequenceSet(); // XXX
RangeSet readByteRanges(); // XXX
/**
* The str8 type encodes up to 255 octets worth of UTF-8 unicode.
* The number of octets of unicode is first encoded as an 8-bit unsigned integral value.
* This is followed by the actual UTF-8 unicode.
* Note that the encoded size refers to the number of octets of unicode, not necessarily the number of characters since
* the UTF-8 unicode may include multi-byte character sequences.
*
* @return a string.
*/
String readStr8();
/**
* The str16 type encodes up to 65535 octets worth of UTF-8 unicode.
* The number of octets is first encoded as a 16-bit unsigned integral value in network byte order.
* This is followed by the actual UTF-8 unicode.
* Note that the encoded size refers to the number of octets of unicode, not necessarily the number of unicode
* characters since the UTF-8 unicode may include multi-byte character sequences.
*
* @return a string.
*/
String readStr16();
/**
* The vbin8 type encodes up to 255 octets of opaque binary data.
*
* @return a byte array.
*/
byte[] readVbin8();
/**
* The vbin16 type encodes up to 65535 octets of opaque binary data.
*
* @return the corresponding byte array.
*/
byte[] readVbin16();
/**
* The vbin32 type encodes up to 4294967295 octets of opaque binary data.
*
* @return the corresponding byte array.
*/
byte[] readVbin32();
/**
* The struct32 type describes any coded struct with a 32-bit (4 octet) size.
* The type is restricted to be only coded structs with a 32-bit size, consequently the first six octets of any encoded
* value for this type MUST always contain the size, class-code, and struct-code in that order.
* The size is encoded as a 32-bit unsigned integral value in network byte order that is equal to the size of the
* encoded field-data, packing-flags, class-code, and struct-code. The class-code is a single octet that may be set to any
* valid class code.
* The struct-code is a single octet that may be set to any valid struct code within the given class-code.
* The first six octets are then followed by the packing flags and encoded field data.
* The presence and quantity of packingflags, as well as the specific fields are determined by the struct definition
* identified with the encoded class-code and struct-code.
*
* @return the decoded struct.
*/
Struct readStruct32();
/**
* A map is a set of distinct keys where each key has an associated (type,value) pair.
* The triple of the key, type, and value, form an entry within a map. Each entry within a given map MUST have a
* distinct key.
* A map is encoded as a size in octets, a count of the number of entries, followed by the encoded entries themselves.
* An encoded map may contain up to (4294967295 - 4) octets worth of encoded entries.
* The size is encoded as a 32-bit unsigned integral value in network byte order equal to the number of octets worth of
* encoded entries plus 4. (The extra 4 octets is added for the entry count.)
* The size is then followed by the number of entries encoded as a 32-bit unsigned integral value in network byte order.
* Finally the entries are encoded sequentially.
* An entry is encoded as the key, followed by the type, and then the value. The key is always a string encoded as a str8.
* The type is a single octet that may contain any valid AMQP type code.
* The value is encoded according to the rules defined by the type code for that entry.
*
* @return the decoded map.
*/
Map<String,Object> readMap();
/**
* A list is an ordered sequence of (type, value) pairs. The (type, value) pair forms an item within the list.
* The list may contain items of many distinct types. A list is encoded as a size in octets, followed by a count of the
* number of items, followed by the items themselves encoded in their defined order.
* An encoded list may contain up to (4294967295 - 4) octets worth of encoded items.
* The size is encoded as a 32-bit unsigned integral value in network byte order equal to the number of octets worth
* of encoded items plus 4. (The extra4 octets is added for the item count.)
* The size is then followed by the number of items encoded as a 32-bit unsigned integral value in network byte order.
* Finally the items are encoded sequentially in their defined order.
* An item is encoded as the type followed by the value. The type is a single octet that may contain any valid AMQP type
* code.
* The value is encoded according to the rules defined by the type code for that item.
*
* @return the decoded list.
*/
List<Object> readList();
/**
* An array is an ordered sequence of values of the same type.
* The array is encoded in as a size in octets, followed by a type code, then a count of the number values in the array,
* and finally the values encoded in their defined order.
* An encoded array may contain up to (4294967295 - 5) octets worth of encoded values.
* The size is encoded as a 32-bit unsigned integral value in network byte order equal to the number of octets worth of
* encoded values plus 5. (The extra 5 octets consist of 4 octets for the count of the number of values, and one octet to
* hold the type code for the items inthe array.)
* The size is then followed by a single octet that may contain any valid AMQP type code.
* The type code is then followed by the number of values encoded as a 32-bit unsigned integral value in network byte
* order.
* Finally the values are encoded sequentially in their defined order according to the rules defined by the type code for
* the array.
*
* @return the decoded array.
*/
List<Object> readArray();
/**
*
* @param type the type of the struct.
* @return the decoded struct.
*/
Struct readStruct(int type);
/**
* The float type encodes a single precision 32-bit floating point number.
* The format and operations are defined by the IEEE 754 standard for 32-bit single precision floating point numbers.
*
* @return the decoded float.
*/
float readFloat();
/**
* The double type encodes a double precision 64-bit floating point number.
* The format and operations are defined by the IEEE 754 standard for 64-bit double precision floating point numbers.
*
* @return the decoded double
*/
double readDouble();
/**
* The int8 type is a signed integral value encoded using an 8-bit two's complement representation.
*
* @return the decoded integer.
*/
byte readInt8();
/**
* The int16 type is a signed integral value encoded using a 16-bit two's complement representation in network byte order.
*
* @return the decoded integer.
*/
short readInt16();
/**
* The int32 type is a signed integral value encoded using a 32-bit two's complement representation in network byte order.
*
* @return the decoded integer.
*/
int readInt32();
/**
* The int64 type is a signed integral value encoded using a 64-bit two's complement representation in network byte order.
*
* @return the decoded integer (as long).
*/
long readInt64();
/**
* The bin128 type consists of 16 consecutive octets of opaque binary data.
*
* @return the decoded byte array.
*/
byte [] readBin128();
/**
* Reads the remaining bytes on the underlying buffer.
*
* @return the remaining bytes on the underlying buffer.
*/
byte[] readRemainingBytes();
/**
* Reads the given number of bytes.
*
* @param howManyBytes how many bytes need to be read?
* @return a byte array containing the requested data.
*/
byte[] readBytes (int howManyBytes);
}