rocksdb/thrift/lib/cpp/protocol/TCompactProtocol.h
Dhruba Borthakur bfaa1bd26c Cleanup thrift header files.
Move thrift api  from thrift/leveldb.thrift to thrift/if/leveldb.thrift

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2012-07-10 10:19:49 -07:00

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C++

/*
* 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.
*/
#ifndef THRIFT_PROTOCOL_TCOMPACTPROTOCOL_H_
#define THRIFT_PROTOCOL_TCOMPACTPROTOCOL_H_ 1
#include "thrift/lib/cpp/protocol/TVirtualProtocol.h"
#include <stack>
#include <boost/shared_ptr.hpp>
namespace apache { namespace thrift { namespace protocol {
/**
* C++ Implementation of the Compact Protocol as described in THRIFT-110
*/
template <class Transport_>
class TCompactProtocolT
: public TVirtualProtocol< TCompactProtocolT<Transport_> > {
public:
static const int8_t VERSION_N = 2;
static const int8_t VERSION_LOW = 1;
static const int8_t VERSION_DOUBLE_BE = 2;
static const int8_t PROTOCOL_ID = static_cast<int8_t>(0x82);
static const int8_t VERSION_MASK = 0x1f; // 0001 1111
protected:
// Normally we can define static const data members of integral
// type here. However there appears to be a gcc issue when the
// high bit is set (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49896)
// unless we cast to a value that fits in an int8_t (0x82 and 0xE0 are
// uint8_t)
static const int8_t TYPE_MASK = static_cast<int8_t>(0xE0);
static const int32_t TYPE_SHIFT_AMOUNT = 5;
Transport_* trans_;
/**
* (Writing) If we encounter a boolean field begin, save the TField here
* so it can have the value incorporated.
*/
struct {
const char* name;
TType fieldType;
int16_t fieldId;
} booleanField_;
/**
* (Reading) If we read a field header, and it's a boolean field, save
* the boolean value here so that readBool can use it.
*/
struct {
bool hasBoolValue;
bool boolValue;
} boolValue_;
/**
* Used to keep track of the last field for the current and previous structs,
* so we can do the delta stuff.
*/
std::stack<int16_t> lastField_;
int16_t lastFieldId_;
int8_t version_;
public:
explicit TCompactProtocolT(boost::shared_ptr<Transport_> trans) :
TVirtualProtocol< TCompactProtocolT<Transport_> >(trans),
trans_(trans.get()),
lastFieldId_(0),
version_(VERSION_N),
string_limit_(0),
string_buf_(NULL),
string_buf_size_(0),
container_limit_(0) {
booleanField_.name = NULL;
boolValue_.hasBoolValue = false;
}
TCompactProtocolT(boost::shared_ptr<Transport_> trans,
int32_t string_limit,
int32_t container_limit) :
TVirtualProtocol< TCompactProtocolT<Transport_> >(trans),
trans_(trans.get()),
lastFieldId_(0),
version_(VERSION_N),
string_limit_(string_limit),
string_buf_(NULL),
string_buf_size_(0),
container_limit_(container_limit) {
booleanField_.name = NULL;
boolValue_.hasBoolValue = false;
}
virtual ~TCompactProtocolT() {
if (string_buf_) {
free(string_buf_);
}
}
/** Set this if you need backwards compatibility with an old version */
void setVersion(const int8_t version) {
version_ = version;
}
/**
* Writing functions
*/
virtual uint32_t writeMessageBegin(const std::string& name,
const TMessageType messageType,
const int32_t seqid);
uint32_t writeStructBegin(const char* name);
uint32_t writeStructEnd();
uint32_t writeFieldBegin(const char* name,
const TType fieldType,
const int16_t fieldId);
uint32_t writeFieldStop();
uint32_t writeListBegin(const TType elemType,
const uint32_t size);
uint32_t writeSetBegin(const TType elemType,
const uint32_t size);
virtual uint32_t writeMapBegin(const TType keyType,
const TType valType,
const uint32_t size);
uint32_t writeBool(const bool value);
uint32_t writeByte(const int8_t byte);
uint32_t writeI16(const int16_t i16);
uint32_t writeI32(const int32_t i32);
uint32_t writeI64(const int64_t i64);
uint32_t writeDouble(const double dub);
uint32_t writeString(const char* str);
template <class String_>
uint32_t writeString(const String_& str);
template <class String_>
uint32_t writeBinary(const String_& str);
/**
* These methods are called by structs, but don't actually have any wired
* output or purpose
*/
virtual uint32_t writeMessageEnd() { return 0; }
uint32_t writeMapEnd() { return 0; }
uint32_t writeListEnd() { return 0; }
uint32_t writeSetEnd() { return 0; }
uint32_t writeFieldEnd() { return 0; }
protected:
int32_t writeFieldBeginInternal(const char* name,
const TType fieldType,
const int16_t fieldId,
int8_t typeOverride);
uint32_t writeCollectionBegin(int8_t elemType, int32_t size);
uint32_t writeVarint32(uint32_t n);
uint32_t writeVarint64(uint64_t n);
uint64_t i64ToZigzag(const int64_t l);
uint32_t i32ToZigzag(const int32_t n);
inline int8_t getCompactType(int8_t ttype);
public:
uint32_t readMessageBegin(std::string& name,
TMessageType& messageType,
int32_t& seqid);
uint32_t readStructBegin(std::string& name);
uint32_t readStructEnd();
uint32_t readFieldBegin(std::string& name,
TType& fieldType,
int16_t& fieldId);
uint32_t readMapBegin(TType& keyType,
TType& valType,
uint32_t& size);
uint32_t readListBegin(TType& elemType,
uint32_t& size);
uint32_t readSetBegin(TType& elemType,
uint32_t& size);
uint32_t readBool(bool& value);
// Provide the default readBool() implementation for std::vector<bool>
using TVirtualProtocol< TCompactProtocolT<Transport_> >::readBool;
uint32_t readByte(int8_t& byte);
uint32_t readI16(int16_t& i16);
uint32_t readI32(int32_t& i32);
uint32_t readI64(int64_t& i64);
uint32_t readDouble(double& dub);
template <class String_>
uint32_t readString(String_& str);
template <class String_>
uint32_t readBinary(String_& str);
/*
*These methods are here for the struct to call, but don't have any wire
* encoding.
*/
uint32_t readMessageEnd() { return 0; }
uint32_t readFieldEnd() { return 0; }
uint32_t readMapEnd() { return 0; }
uint32_t readListEnd() { return 0; }
uint32_t readSetEnd() { return 0; }
protected:
uint32_t readVarint32(int32_t& i32);
uint32_t readVarint64(int64_t& i64);
int32_t zigzagToI32(uint32_t n);
int64_t zigzagToI64(uint64_t n);
TType getTType(int8_t type);
// Buffer for reading strings, save for the lifetime of the protocol to
// avoid memory churn allocating memory on every string read
int32_t string_limit_;
uint8_t* string_buf_;
int32_t string_buf_size_;
int32_t container_limit_;
};
typedef TCompactProtocolT<TTransport> TCompactProtocol;
/**
* Constructs compact protocol handlers
*/
template <class Transport_>
class TCompactProtocolFactoryT : public TProtocolFactory {
public:
TCompactProtocolFactoryT() :
string_limit_(0),
container_limit_(0) {}
TCompactProtocolFactoryT(int32_t string_limit, int32_t container_limit) :
string_limit_(string_limit),
container_limit_(container_limit) {}
virtual ~TCompactProtocolFactoryT() {}
void setStringSizeLimit(int32_t string_limit) {
string_limit_ = string_limit;
}
void setContainerSizeLimit(int32_t container_limit) {
container_limit_ = container_limit;
}
boost::shared_ptr<TProtocol> getProtocol(boost::shared_ptr<TTransport> trans) {
boost::shared_ptr<Transport_> specific_trans =
boost::dynamic_pointer_cast<Transport_>(trans);
TProtocol* prot;
if (specific_trans) {
prot = new TCompactProtocolT<Transport_>(specific_trans, string_limit_,
container_limit_);
} else {
prot = new TCompactProtocol(trans, string_limit_, container_limit_);
}
return boost::shared_ptr<TProtocol>(prot);
}
private:
int32_t string_limit_;
int32_t container_limit_;
};
typedef TCompactProtocolFactoryT<TTransport> TCompactProtocolFactory;
}}} // apache::thrift::protocol
#include "TCompactProtocol.tcc"
#endif