brotli/enc/streams.h
2016-06-03 11:19:23 +02:00

123 lines
3.1 KiB
C++

/* Copyright 2009 Google Inc. All Rights Reserved.
Distributed under MIT license.
See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
*/
/* Input and output classes for streaming brotli compression. */
#ifndef BROTLI_ENC_STREAMS_H_
#define BROTLI_ENC_STREAMS_H_
#include <stdio.h>
#include <string>
#include "../common/types.h"
#include "./port.h"
namespace brotli {
/* Input interface for the compression routines. */
class BrotliIn {
public:
virtual ~BrotliIn(void) {}
/* Return a pointer to the next block of input of at most n bytes.
Return the actual length in *nread.
At end of data, return NULL. Don't return NULL if there is more data
to read, even if called with n == 0.
Read will only be called if some of its bytes are needed. */
virtual const void* Read(size_t n, size_t* nread) = 0;
};
/* Output interface for the compression routines. */
class BrotliOut {
public:
virtual ~BrotliOut(void) {}
/* Write n bytes of data from buf.
Return true if all written, false otherwise. */
virtual bool Write(const void *buf, size_t n) = 0;
};
/* Adapter class to make BrotliIn objects from raw memory. */
class BrotliMemIn : public BrotliIn {
public:
BrotliMemIn(const void* buf, size_t len);
void Reset(const void* buf, size_t len);
/* returns the amount of data consumed */
size_t position(void) const { return pos_; }
const void* Read(size_t n, size_t* OUTPUT);
private:
const void* buf_; /* start of input buffer */
size_t len_; /* length of input */
size_t pos_; /* current read position within input */
};
/* Adapter class to make BrotliOut objects from raw memory. */
class BrotliMemOut : public BrotliOut {
public:
BrotliMemOut(void* buf, size_t len);
void Reset(void* buf, size_t len);
/* returns the amount of data written */
size_t position(void) const { return pos_; }
bool Write(const void* buf, size_t n);
private:
void* buf_; /* start of output buffer */
size_t len_; /* length of output */
size_t pos_; /* current write position within output */
};
/* Adapter class to make BrotliOut objects from a string. */
class BrotliStringOut : public BrotliOut {
public:
/* Create a writer that appends its data to buf.
buf->size() will grow to at most max_size
buf is expected to be empty when constructing BrotliStringOut. */
BrotliStringOut(std::string* buf, size_t max_size);
void Reset(std::string* buf, size_t max_len);
bool Write(const void* buf, size_t n);
private:
std::string* buf_; /* start of output buffer */
size_t max_size_; /* max length of output */
};
/* Adapter class to make BrotliIn object from a file. */
class BrotliFileIn : public BrotliIn {
public:
BrotliFileIn(FILE* f, size_t max_read_size);
~BrotliFileIn(void);
const void* Read(size_t n, size_t* bytes_read);
private:
FILE* f_;
char* buf_;
size_t buf_size_;
};
/* Adapter class to make BrotliOut object from a file. */
class BrotliFileOut : public BrotliOut {
public:
explicit BrotliFileOut(FILE* f);
bool Write(const void* buf, size_t n);
private:
FILE* f_;
};
} /* namespace brotli */
#endif /* BROTLI_ENC_STREAMS_H_ */