Windows-Server-2003/base/ntos/inc/xpress.h

167 lines
4.6 KiB
C

#ifndef _XPRESS_H_
#define _XPRESS_H_
#ifdef _MSC_VER
#pragma once
#endif
/* -------------------------------------------------------------------- */
/* */
/* Copyright (c) 1991-1999 by Andrew Kadatch */
/* */
/* -------------------------------------------------------------------- */
#ifdef __cplusplus
extern "C" {
#endif
/* ---------------------- Common declarations ------------------------- */
/* ------------------- */
// max. size of input block
#define XPRESS_MAX_BLOCK_LOG 16
#define XPRESS_MAX_BLOCK (1 << XPRESS_MAX_BLOCK_LOG)
// preferred data alignment to avoid misaligned accesses
#define XPRESS_ALIGNMENT 8
// declare default calling convention used in xpress
#if !defined (UNIX) && !defined (XPRESS_CALL)
#define XPRESS_CALL __stdcall
#endif
// user-supplied callback function that allocates memory
// if there is no memory available it shall return NULL
typedef
void *
XPRESS_CALL
XpressAllocFn
(
void *context, // user-defined context (as passed to XpressEncodeCreate)
int size // size of memory block to allocate
);
// user-supplied callback function that releases memory
typedef
void
XPRESS_CALL
XpressFreeFn
(
void *context, // user-defined context (as passed to XpressEncodeClose)
void *address // pointer to the block to be freed
);
/* ----------------------------- Encoder ------------------------------ */
/* ------- */
// declare unique anonymous types for type safety
typedef struct {int XpressEncodeDummy;} *XpressEncodeStream;
// allocate and initialize encoder's data structures
// returns NULL if callback returned NULL (not enough memory)
XpressEncodeStream
XPRESS_CALL
XpressEncodeCreate
(
int MaxOrigSize, // max size of original data block
void *context, // user-defined context info (will be passed to AllocFn)
XpressAllocFn *AllocFn, // memory allocation callback
int CompressionLevel // use 0 for speed, 9 for quality
);
// callback function called by XpressEncode to indicate compression progress
typedef
void
XPRESS_CALL
XpressProgressFn
(
void *context, // user-defined context
int compressed // size of processed original data
);
// returns size of compressed data
// if compression failed then compressed buffer is left as is, and
// original data should be saved instead
int
XPRESS_CALL
XpressEncode
(
XpressEncodeStream stream, // encoder's workspace
void *CompAdr, int CompSize, // compressed data region
const void *OrigAdr, int OrigSize, // input data block
XpressProgressFn *ProgressFn, // NULL or progress callback
void *ProgressContext, // user-defined context that will be passed to ProgressFn
int ProgressSize // call ProgressFn each time ProgressSize bytes processed
);
// invalidate input stream and release workspace memory
void
XPRESS_CALL
XpressEncodeClose
(
XpressEncodeStream stream, // encoder's workspace
void *context, XpressFreeFn *FreeFn // memory releasing callback
);
/* ----------------------------- Decoder ------------------------------ */
/* ------- */
// declare unique anonymous types for type safety
typedef struct {int XpressDecodeDummy;} *XpressDecodeStream;
// allocate memory for decoder. Returns NULL if not enough memory.
XpressDecodeStream
XPRESS_CALL
XpressDecodeCreate
(
void *context, // user-defined context info (will be passed to AllocFn)
XpressAllocFn *AllocFn // memory allocation callback
);
// decode compressed block. Returns # of decoded bytes or -1 otherwise
int
XPRESS_CALL
XpressDecode
(
XpressDecodeStream stream, // decoder's workspace
void *OrigAdr, int OrigSize, // original data region
int DecodeSize, // # of bytes to decode ( <= OrigSize)
const void *CompAdr, int CompSize // compressed data block
);
void
XPRESS_CALL
XpressDecodeClose
(
XpressDecodeStream stream, // encoder's workspace
void *context, // user-defined context info (will be passed to FreeFn)
XpressFreeFn *FreeFn // callback that releases the memory
);
/* ------------------------------ CRC32 ------------------------------- */
/* ----- */
int
XPRESS_CALL
XpressCrc32
(
const void *data, // beginning of data block
int bytes, // number of bytes
int crc // initial value
);
#ifdef __cplusplus
};
#endif
#endif /* _XPRESS_H_ */