334 lines
8.9 KiB
C++
334 lines
8.9 KiB
C++
/*!
|
|
* Copyright (c) 2015 by Contributors
|
|
* \file io.h
|
|
* \brief defines serializable interface of dmlc
|
|
*/
|
|
#ifndef DMLC_IO_H_
|
|
#define DMLC_IO_H_
|
|
#include <cstdio>
|
|
#include <string>
|
|
#include <vector>
|
|
#include <istream>
|
|
#include <ostream>
|
|
#include <streambuf>
|
|
#include <cassert>
|
|
|
|
/*! \brief namespace for dmlc */
|
|
namespace dmlc {
|
|
/*!
|
|
* \brief interface of stream I/O for serialization
|
|
*/
|
|
class Stream {
|
|
public:
|
|
/*!
|
|
* \brief reads data from a stream
|
|
* \param ptr pointer to a memory buffer
|
|
* \param size block size
|
|
* \return the size of data read
|
|
*/
|
|
virtual size_t Read(void *ptr, size_t size) = 0;
|
|
/*!
|
|
* \brief writes data to a stream
|
|
* \param ptr pointer to a memory buffer
|
|
* \param size block size
|
|
*/
|
|
virtual void Write(const void *ptr, size_t size) = 0;
|
|
/*! \brief virtual destructor */
|
|
virtual ~Stream(void) {}
|
|
/*!
|
|
* \brief generic factory function
|
|
* create an stream, the stream will close the underlying files
|
|
* upon deletion
|
|
* \param uri the uri of the input currently we support
|
|
* hdfs://, s3://, and file:// by default file:// will be used
|
|
* \param flag can be "w", "r", "a"
|
|
*/
|
|
static Stream *Create(const char *uri, const char* const flag);
|
|
// helper functions to write/read different data structures
|
|
/*!
|
|
* \brief writes a vector
|
|
* \param vec vector to be written/serialized
|
|
*/
|
|
template<typename T>
|
|
inline void Write(const std::vector<T> &vec);
|
|
/*!
|
|
* \brief loads a vector
|
|
* \param out_vec vector to be loaded/deserialized
|
|
* \return whether the load was successful
|
|
*/
|
|
template<typename T>
|
|
inline bool Read(std::vector<T> *out_vec);
|
|
/*!
|
|
* \brief writes a string
|
|
* \param str the string to be written/serialized
|
|
*/
|
|
inline void Write(const std::string &str);
|
|
/*!
|
|
* \brief loads a string
|
|
* \param out_str string to be loaded/deserialized
|
|
* \return whether the load/deserialization was successful
|
|
*/
|
|
inline bool Read(std::string *out_str);
|
|
};
|
|
|
|
/*! \brief interface of i/o stream that support seek */
|
|
class SeekStream: public Stream {
|
|
public:
|
|
// virtual destructor
|
|
virtual ~SeekStream(void) {}
|
|
/*! \brief seek to certain position of the file */
|
|
virtual void Seek(size_t pos) = 0;
|
|
/*! \brief tell the position of the stream */
|
|
virtual size_t Tell(void) = 0;
|
|
/*! \return whether we are at end of file */
|
|
virtual bool AtEnd(void) const = 0;
|
|
};
|
|
|
|
/*! \brief interface for serializable objects */
|
|
class Serializable {
|
|
public:
|
|
/*!
|
|
* \brief load the model from a stream
|
|
* \param fi stream where to load the model from
|
|
*/
|
|
virtual void Load(Stream *fi) = 0;
|
|
/*!
|
|
* \brief saves the model to a stream
|
|
* \param fo stream where to save the model to
|
|
*/
|
|
virtual void Save(Stream *fo) const = 0;
|
|
};
|
|
|
|
/*!
|
|
* \brief input split header, used to create input split on input dataset
|
|
* this class can be used to obtain filesystem invariant splits from input files
|
|
*/
|
|
class InputSplit {
|
|
public:
|
|
/*!
|
|
* \brief read next record, store into out_data
|
|
* the data in outcomming record depends on the input data format
|
|
* if input is text data, each line is returned as a record (\n not included)
|
|
* if input is recordio, each record is returned
|
|
* \param out_data the string that stores the line data, \n is not included
|
|
* \return true of next line was found, false if we read all the lines
|
|
*/
|
|
virtual bool ReadRecord(std::string *out_data) = 0;
|
|
/*! \brief destructor*/
|
|
virtual ~InputSplit(void) {}
|
|
/*!
|
|
* \brief factory function:
|
|
* create input split given a uri
|
|
* \param uri the uri of the input, can contain hdfs prefix
|
|
* \param part_index the part id of current input
|
|
* \param num_parts total number of splits
|
|
*/
|
|
static InputSplit* Create(const char *uri,
|
|
unsigned part_index,
|
|
unsigned num_parts);
|
|
};
|
|
|
|
/*!
|
|
* \brief a std::ostream class that can can wrap Stream objects,
|
|
* can use ostream with that output to underlying Stream
|
|
*
|
|
* Usage example:
|
|
* \code
|
|
*
|
|
* Stream *fs = Stream::Create("hdfs:///test.txt", "w");
|
|
* dmlc::ostream os(fs);
|
|
* os << "hello world" << std::endl;
|
|
* delete fs;
|
|
* \endcode
|
|
*/
|
|
class ostream : public std::basic_ostream<char> {
|
|
public:
|
|
/*!
|
|
* \brief construct std::ostream type
|
|
* \param stream the Stream output to be used
|
|
* \param buffer_size internal streambuf size
|
|
*/
|
|
explicit ostream(Stream *stream,
|
|
size_t buffer_size = 1 << 10)
|
|
: basic_ostream<char>(NULL), buf_(buffer_size) {
|
|
this->set_stream(stream);
|
|
}
|
|
// explictly synchronize the buffer
|
|
virtual ~ostream() {
|
|
buf_.pubsync();
|
|
}
|
|
/*!
|
|
* \brief set internal stream to be stream, reset states
|
|
* \param stream new stream as output
|
|
*/
|
|
inline void set_stream(Stream *stream) {
|
|
buf_.set_stream(stream);
|
|
this->rdbuf(&buf_);
|
|
}
|
|
|
|
private:
|
|
// internal streambuf
|
|
class OutBuf : public std::streambuf {
|
|
public:
|
|
explicit OutBuf(size_t buffer_size)
|
|
: stream_(NULL), buffer_(buffer_size) {
|
|
assert(buffer_.size() > 0);
|
|
}
|
|
// set stream to the buffer
|
|
inline void set_stream(Stream *stream);
|
|
|
|
private:
|
|
/*! \brief internal stream by StreamBuf */
|
|
Stream *stream_;
|
|
/*! \brief internal buffer */
|
|
std::vector<char> buffer_;
|
|
// override sync
|
|
inline int_type sync(void);
|
|
// override overflow
|
|
inline int_type overflow(int c);
|
|
};
|
|
/*! \brief buffer of the stream */
|
|
OutBuf buf_;
|
|
};
|
|
|
|
/*!
|
|
* \brief a std::istream class that can can wrap Stream objects,
|
|
* can use istream with that output to underlying Stream
|
|
*
|
|
* Usage example:
|
|
* \code
|
|
*
|
|
* Stream *fs = Stream::Create("hdfs:///test.txt", "r");
|
|
* dmlc::istream is(fs);
|
|
* is >> mydata;
|
|
* delete fs;
|
|
* \endcode
|
|
*/
|
|
class istream : public std::basic_istream<char> {
|
|
public:
|
|
/*!
|
|
* \brief construct std::ostream type
|
|
* \param stream the Stream output to be used
|
|
* \param buffer_size internal buffer size
|
|
*/
|
|
explicit istream(Stream *stream,
|
|
size_t buffer_size = 1 << 10)
|
|
: basic_istream<char>(NULL), buf_(buffer_size) {
|
|
this->set_stream(stream);
|
|
}
|
|
virtual ~istream() {}
|
|
/*!
|
|
* \brief set internal stream to be stream, reset states
|
|
* \param stream new stream as output
|
|
*/
|
|
inline void set_stream(Stream *stream) {
|
|
buf_.set_stream(stream);
|
|
this->rdbuf(&buf_);
|
|
}
|
|
|
|
private:
|
|
// internal streambuf
|
|
class InBuf : public std::streambuf {
|
|
public:
|
|
explicit InBuf(size_t buffer_size)
|
|
: stream_(NULL), buffer_(buffer_size) {
|
|
assert(buffer_.size() > 0);
|
|
}
|
|
// set stream to the buffer
|
|
inline void set_stream(Stream *stream);
|
|
|
|
private:
|
|
/*! \brief internal stream by StreamBuf */
|
|
Stream *stream_;
|
|
/*! \brief internal buffer */
|
|
std::vector<char> buffer_;
|
|
// override underflow
|
|
inline int_type underflow();
|
|
};
|
|
/*! \brief input buffer */
|
|
InBuf buf_;
|
|
};
|
|
|
|
// implementations of inline functions
|
|
template<typename T>
|
|
inline void Stream::Write(const std::vector<T> &vec) {
|
|
size_t sz = vec.size();
|
|
this->Write(&sz, sizeof(sz));
|
|
if (sz != 0) {
|
|
this->Write(&vec[0], sizeof(T) * sz);
|
|
}
|
|
}
|
|
template<typename T>
|
|
inline bool Stream::Read(std::vector<T> *out_vec) {
|
|
size_t sz;
|
|
if (this->Read(&sz, sizeof(sz)) == 0) return false;
|
|
out_vec->resize(sz);
|
|
if (sz != 0) {
|
|
if (this->Read(&(*out_vec)[0], sizeof(T) * sz) == 0) return false;
|
|
}
|
|
return true;
|
|
}
|
|
inline void Stream::Write(const std::string &str) {
|
|
size_t sz = str.length();
|
|
this->Write(&sz, sizeof(sz));
|
|
if (sz != 0) {
|
|
this->Write(&str[0], sizeof(char) * sz);
|
|
}
|
|
}
|
|
inline bool Stream::Read(std::string *out_str) {
|
|
size_t sz;
|
|
if (this->Read(&sz, sizeof(sz)) == 0) return false;
|
|
out_str->resize(sz);
|
|
if (sz != 0) {
|
|
if (this->Read(&(*out_str)[0], sizeof(char) * sz) == 0) {
|
|
return false;
|
|
}
|
|
}
|
|
return true;
|
|
}
|
|
|
|
// implementations for ostream
|
|
inline void ostream::OutBuf::set_stream(Stream *stream) {
|
|
if (stream_ != NULL) this->pubsync();
|
|
this->stream_ = stream;
|
|
this->setp(&buffer_[0], &buffer_[0] + buffer_.size() - 1);
|
|
}
|
|
inline int ostream::OutBuf::sync(void) {
|
|
if (stream_ == NULL) return -1;
|
|
std::ptrdiff_t n = pptr() - pbase();
|
|
stream_->Write(pbase(), n);
|
|
this->pbump(-n);
|
|
return 0;
|
|
}
|
|
inline int ostream::OutBuf::overflow(int c) {
|
|
*(this->pptr()) = c;
|
|
std::ptrdiff_t n = pptr() - pbase();
|
|
this->pbump(-n);
|
|
if (c == EOF) {
|
|
stream_->Write(pbase(), n);
|
|
} else {
|
|
stream_->Write(pbase(), n + 1);
|
|
}
|
|
return c;
|
|
}
|
|
|
|
// implementations for istream
|
|
inline void istream::InBuf::set_stream(Stream *stream) {
|
|
stream_ = stream;
|
|
this->setg(&buffer_[0], &buffer_[0], &buffer_[0]);
|
|
}
|
|
inline int istream::InBuf::underflow() {
|
|
char *bhead = &buffer_[0];
|
|
if (this->gptr() == this->egptr()) {
|
|
size_t sz = stream_->Read(bhead, buffer_.size());
|
|
this->setg(bhead, bhead, bhead + sz);
|
|
}
|
|
if (this->gptr() == this->egptr()) {
|
|
return traits_type::eof();
|
|
} else {
|
|
return traits_type::to_int_type(*gptr());
|
|
}
|
|
}
|
|
} // namespace dmlc
|
|
#endif // DMLC_IO_H_
|