/**
* 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 HADOOP_SERIAL_UTILS_HH
#define HADOOP_SERIAL_UTILS_HH
#include <string>
namespace HadoopUtils {
/**
* A simple exception class that records a message for the user.
*/
class Error {
private:
std::string error;
public:
/**
* Create an error object with the given message.
*/
Error(const std::string& msg);
/**
* Construct an error object with the given message that was created on
* the given file, line, and functino.
*/
Error(const std::string& msg,
const std::string& file, int line, const std::string& function);
/**
* Get the error message.
*/
const std::string& getMessage() const;
};
/**
* Check to make sure that the condition is true, and throw an exception
* if it is not. The exception will contain the message and a description
* of the source location.
*/
#define HADOOP_ASSERT(CONDITION, MESSAGE) \
{ \
if (!(CONDITION)) { \
throw HadoopUtils::Error((MESSAGE), __FILE__, __LINE__, \
__PRETTY_FUNCTION__); \
} \
}
/**
* An interface for an input stream.
*/
class InStream {
public:
/**
* Reads len bytes from the stream into the buffer.
* @param buf the buffer to read into
* @param buflen the length of the buffer
* @throws Error if there are problems reading
*/
virtual void read(void *buf, size_t len) = 0;
virtual ~InStream() {}
};
/**
* An interface for an output stream.
*/
class OutStream {
public:
/**
* Write the given buffer to the stream.
* @param buf the data to write
* @param len the number of bytes to write
* @throws Error if there are problems writing
*/
virtual void write(const void *buf, size_t len) = 0;
/**
* Flush the data to the underlying store.
*/
virtual void flush() = 0;
virtual ~OutStream() {}
};
/**
* A class to read a file as a stream.
*/
class FileInStream : public InStream {
public:
FileInStream();
bool open(const std::string& name);
bool open(FILE* file);
void read(void *buf, size_t buflen);
bool skip(size_t nbytes);
bool close();
virtual ~FileInStream();
private:
/**
* The file to write to.
*/
FILE *mFile;
/**
* Does is this class responsible for closing the FILE*?
*/
bool isOwned;
};
/**
* A class to write a stream to a file.
*/
class FileOutStream: public OutStream {
public:
/**
* Create a stream that isn't bound to anything.
*/
FileOutStream();
/**
* Create the given file, potentially overwriting an existing file.
*/
bool open(const std::string& name, bool overwrite);
bool open(FILE* file);
void write(const void* buf, size_t len);
bool advance(size_t nbytes);
void flush();
bool close();
virtual ~FileOutStream();
private:
FILE *mFile;
bool isOwned;
};
/**
* A stream that reads from a string.
*/
class StringInStream: public InStream {
public:
StringInStream(const std::string& str);
virtual void read(void *buf, size_t buflen);
private:
const std::string& buffer;
std::string::const_iterator itr;
};
void serializeInt(int32_t t, OutStream& stream);
int32_t deserializeInt(InStream& stream);
void serializeLong(int64_t t, OutStream& stream);
int64_t deserializeLong(InStream& stream);
void serializeFloat(float t, OutStream& stream);
float deserializeFloat(InStream& stream);
void serializeString(const std::string& t, OutStream& stream);
void deserializeString(std::string& t, InStream& stream);
}
#endif
