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raze/polymer/eduke32/source/xdelta3/xdelta3.h
terminx 265ff9dbfd Add xdelta3, required for some broken multiplayer updates I plan on committing later 
git-svn-id: https://svn.eduke32.com/eduke32@2661 1a8010ca-5511-0410-912e-c29ae57300e0
2012-05-17 21:27:19 +00:00

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/* xdelta 3 - delta compression tools and library
* Copyright (C) 2001, 2003, 2004, 2005, 2006, 2007,
* 2008, 2009, 2010. Joshua P. MacDonald
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* To know more about Xdelta, start by reading xdelta3.c. If you are
* ready to use the API, continue reading here. There are two
* interfaces -- xd3_encode_input and xd3_decode_input -- plus a dozen
* or so related calls. This interface is styled after Zlib. */
#ifndef _XDELTA3_H_
#define _XDELTA3_H_
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
/****************************************************************/
/* Default configured value of stream->winsize. If the program
* supplies xd3_encode_input() with data smaller than winsize the
* stream will automatically buffer the input, otherwise the input
* buffer is used directly.
*/
#ifndef XD3_DEFAULT_WINSIZE
#define XD3_DEFAULT_WINSIZE (1U << 23)
#endif
/* Default total size of the source window used in xdelta3-main.h */
#ifndef XD3_DEFAULT_SRCWINSZ
#define XD3_DEFAULT_SRCWINSZ (1U << 26)
#endif
/* When Xdelta requests a memory allocation for certain buffers, it
* rounds up to units of at least this size. The code assumes (and
* asserts) that this is a power-of-two. */
#ifndef XD3_ALLOCSIZE
#define XD3_ALLOCSIZE (1U<<14)
#endif
/* The XD3_HARDMAXWINSIZE parameter is a safety mechanism to protect
* decoders against malicious files. The decoder will never decode a
* window larger than this. If the file specifies VCD_TARGET the
* decoder may require two buffers of this size.
*
* 8-16MB is reasonable, probably don't need to go larger. */
#ifndef XD3_HARDMAXWINSIZE
#define XD3_HARDMAXWINSIZE (1U<<24)
#endif
/* The IOPT_SIZE value sets the size of a buffer used to batch
* overlapping copy instructions before they are optimized by picking
* the best non-overlapping ranges. The larger this buffer, the
* longer a forced xd3_srcwin_setup() decision is held off. Setting
* this value to 0 causes an unlimited buffer to be used. */
#ifndef XD3_DEFAULT_IOPT_SIZE
#define XD3_DEFAULT_IOPT_SIZE (1U<<15)
#endif
/* The maximum distance backward to search for small matches */
#ifndef XD3_DEFAULT_SPREVSZ
#define XD3_DEFAULT_SPREVSZ (1U<<18)
#endif
/* The default compression level
*/
#ifndef XD3_DEFAULT_LEVEL
#define XD3_DEFAULT_LEVEL 1
#endif
#ifndef XD3_DEFAULT_SECONDARY_LEVEL
#define XD3_DEFAULT_SECONDARY_LEVEL 1
#endif
#ifndef XD3_USE_LARGEFILE64
#define XD3_USE_LARGEFILE64 1
#endif
/* Sizes and addresses within VCDIFF windows are represented as usize_t
*
* For source-file offsets and total file sizes, total input and
* output counts, the xoff_t type is used. The decoder and encoder
* generally check for overflow of the xoff_t size (this is tested at
* the 32bit boundary [xdelta3-test.h]).
*/
#ifndef _WIN32
#include <stdint.h>
typedef unsigned int usize_t;
#else
#define WIN32_LEAN_AND_MEAN
#if XD3_USE_LARGEFILE64
/* 64 bit file offsets: uses GetFileSizeEx and SetFilePointerEx.
* requires Win2000 or newer version of WinNT */
#define WINVER 0x0500
#define _WIN32_WINNT 0x0500
#else
/* 32 bit (DWORD) file offsets: uses GetFileSize and
* SetFilePointer. compatible with win9x-me and WinNT4 */
#define WINVER 0x0400
#define _WIN32_WINNT 0x0400
#endif
#include <windows.h>
typedef unsigned int usize_t;
#ifdef _MSC_VER
#define inline
typedef signed int ssize_t;
typedef unsigned char uint8_t;
typedef unsigned short uint16_t;
typedef unsigned long uint32_t;
typedef ULONGLONG uint64_t;
#else
/* mingw32, lcc and watcom provide a proper header */
#include <stdint.h>
#endif
#endif
/* TODO: note that SIZEOF_USIZE_T is never set to 8, although it should be for
* a 64bit platform. OTOH, may be that using 32bits is appropriate even on a
* 64bit platform because we allocate large arrays of these values. */
#if XD3_USE_LARGEFILE64
#define __USE_FILE_OFFSET64 1 /* GLIBC: for 64bit fileops, ... ? */
#ifndef _LARGEFILE_SOURCE
#define _LARGEFILE_SOURCE
#endif
#ifndef _FILE_OFFSET_BITS
#define _FILE_OFFSET_BITS 64
#endif
typedef uint64_t xoff_t;
#define SIZEOF_XOFF_T 8
#define SIZEOF_USIZE_T 4
#ifndef WIN32
#define Q "ll"
#else
#define Q "I64"
#endif
#else
typedef uint32_t xoff_t;
#define SIZEOF_XOFF_T 4
#define SIZEOF_USIZE_T 4
#define Q
#endif
#define USE_UINT32 (SIZEOF_USIZE_T == 4 || \
SIZEOF_XOFF_T == 4 || REGRESSION_TEST)
#define USE_UINT64 (SIZEOF_USIZE_T == 8 || \
SIZEOF_XOFF_T == 8 || REGRESSION_TEST)
/* TODO: probably should do something better here. */
#ifndef UNALIGNED_OK
#if defined(__i386__) || defined(__i486__) || defined(__i586__) || \
defined(__i686__) || defined(_X86_) || defined(__x86_64__)
#define UNALIGNED_OK 1
#else
#define UNALIGNED_OK 0
#endif
#endif
/**********************************************************************/
/* Whether to build the encoder, otherwise only build the decoder. */
#ifndef XD3_ENCODER
#define XD3_ENCODER 1
#endif
/* The code returned when main() fails, also defined in system
includes. */
#ifndef EXIT_FAILURE
#define EXIT_FAILURE 1
#endif
/* REGRESSION TEST enables the "xdelta3 test" command, which runs a
series of self-tests. */
#ifndef REGRESSION_TEST
#define REGRESSION_TEST 0
#endif
/* XD3_DEBUG=1 enables assertions and various statistics. Levels > 1
* enable some additional output only useful during development and
* debugging. */
#ifndef XD3_DEBUG
#define XD3_DEBUG 0
#endif
#ifndef PYTHON_MODULE
#define PYTHON_MODULE 0
#endif
#ifndef SWIG_MODULE
#define SWIG_MODULE 0
#endif
/* There are three string matching functions supplied: one fast, one
* slow (default), and one soft-configurable. To disable any of
* these, use the following definitions. */
#ifndef XD3_BUILD_SLOW
#define XD3_BUILD_SLOW 1
#endif
#ifndef XD3_BUILD_FAST
#define XD3_BUILD_FAST 1
#endif
#ifndef XD3_BUILD_FASTER
#define XD3_BUILD_FASTER 1
#endif
#ifndef XD3_BUILD_FASTEST
#define XD3_BUILD_FASTEST 1
#endif
#ifndef XD3_BUILD_SOFT
#define XD3_BUILD_SOFT 1
#endif
#ifndef XD3_BUILD_DEFAULT
#define XD3_BUILD_DEFAULT 1
#endif
#if XD3_DEBUG
#include <stdio.h>
#endif
/* XPRINT. Debug output and VCDIFF_TOOLS functions report to stderr.
* I have used an irregular style to abbreviate [fprintf(stderr, "] as
* [DP(RINT "]. */
#define DP fprintf
#define RINT stderr,
typedef struct _xd3_stream xd3_stream;
typedef struct _xd3_source xd3_source;
typedef struct _xd3_hash_cfg xd3_hash_cfg;
typedef struct _xd3_smatcher xd3_smatcher;
typedef struct _xd3_rinst xd3_rinst;
typedef struct _xd3_dinst xd3_dinst;
typedef struct _xd3_hinst xd3_hinst;
typedef struct _xd3_winst xd3_winst;
typedef struct _xd3_rpage xd3_rpage;
typedef struct _xd3_addr_cache xd3_addr_cache;
typedef struct _xd3_output xd3_output;
typedef struct _xd3_desect xd3_desect;
typedef struct _xd3_iopt_buflist xd3_iopt_buflist;
typedef struct _xd3_rlist xd3_rlist;
typedef struct _xd3_sec_type xd3_sec_type;
typedef struct _xd3_sec_cfg xd3_sec_cfg;
typedef struct _xd3_sec_stream xd3_sec_stream;
typedef struct _xd3_config xd3_config;
typedef struct _xd3_code_table_desc xd3_code_table_desc;
typedef struct _xd3_code_table_sizes xd3_code_table_sizes;
typedef struct _xd3_slist xd3_slist;
typedef struct _xd3_whole_state xd3_whole_state;
typedef struct _xd3_wininfo xd3_wininfo;
/* The stream configuration has three callbacks functions, all of
* which may be supplied with NULL values. If config->getblk is
* provided as NULL, the stream returns XD3_GETSRCBLK. */
typedef void* (xd3_alloc_func) (void *opaque,
usize_t items,
usize_t size);
typedef void (xd3_free_func) (void *opaque,
void *address);
typedef int (xd3_getblk_func) (xd3_stream *stream,
xd3_source *source,
xoff_t blkno);
/* These are internal functions to delay construction of encoding
* tables and support alternate code tables. See the comments & code
* enabled by GENERIC_ENCODE_TABLES. */
typedef const xd3_dinst* (xd3_code_table_func) (void);
typedef int (xd3_comp_table_func) (xd3_stream *stream,
const uint8_t **data,
usize_t *size);
#if XD3_DEBUG
#define XD3_ASSERT(x) \
do { if (! (x)) { DP(RINT "%s:%d: XD3 assertion failed: %s\n", __FILE__, __LINE__, #x); \
abort (); } } while (0)
#else
#define XD3_ASSERT(x) (void)0
#endif /* XD3_DEBUG */
#ifdef __GNUC__
#ifndef max
#define max(x,y) ({ \
const typeof(x) _x = (x); \
const typeof(y) _y = (y); \
(void) (&_x == &_y); \
_x > _y ? _x : _y; })
#endif /* __GNUC__ */
#ifndef min
#define min(x,y) ({ \
const typeof(x) _x = (x); \
const typeof(y) _y = (y); \
(void) (&_x == &_y); \
_x < _y ? _x : _y; })
#endif
#else /* __GNUC__ */
#ifndef max
#define max(x,y) ((x) < (y) ? (y) : (x))
#endif
#ifndef min
#define min(x,y) ((x) < (y) ? (x) : (y))
#endif
#endif /* __GNUC__ */
/****************************************************************
PUBLIC ENUMS
******************************************************************/
/* These are the five ordinary status codes returned by the
* xd3_encode_input() and xd3_decode_input() state machines. */
typedef enum {
/* An application must be prepared to handle these five return
* values from either xd3_encode_input or xd3_decode_input, except
* in the case of no-source compression, in which case XD3_GETSRCBLK
* is never returned. More detailed comments for these are given in
* xd3_encode_input and xd3_decode_input comments, below. */
XD3_INPUT = -17703, /* need input */
XD3_OUTPUT = -17704, /* have output */
XD3_GETSRCBLK = -17705, /* need a block of source input (with no
* xd3_getblk function), a chance to do
* non-blocking read. */
XD3_GOTHEADER = -17706, /* (decode-only) after the initial VCDIFF &
first window header */
XD3_WINSTART = -17707, /* notification: returned before a window is
* processed, giving a chance to
* XD3_SKIP_WINDOW or not XD3_SKIP_EMIT that
* window. */
XD3_WINFINISH = -17708, /* notification: returned after
encode/decode & output for a window */
XD3_TOOFARBACK = -17709, /* (encoder only) may be returned by
getblk() if the block is too old */
XD3_INTERNAL = -17710, /* internal error */
XD3_INVALID = -17711, /* invalid config */
XD3_INVALID_INPUT = -17712, /* invalid input/decoder error */
XD3_NOSECOND = -17713, /* when secondary compression finds no
improvement. */
XD3_UNIMPLEMENTED = -17714, /* currently VCD_TARGET */
} xd3_rvalues;
/* special values in config->flags */
typedef enum
{
XD3_JUST_HDR = (1 << 1), /* used by VCDIFF tools, see
xdelta3-main.h. */
XD3_SKIP_WINDOW = (1 << 2), /* used by VCDIFF tools, see
xdelta3-main.h. */
XD3_SKIP_EMIT = (1 << 3), /* used by VCDIFF tools, see
xdelta3-main.h. */
XD3_FLUSH = (1 << 4), /* flush the stream buffer to
prepare for
xd3_stream_close(). */
XD3_SEC_DJW = (1 << 5), /* use DJW static huffman */
XD3_SEC_FGK = (1 << 6), /* use FGK adaptive huffman */
XD3_SEC_TYPE = (XD3_SEC_DJW | XD3_SEC_FGK),
XD3_SEC_NODATA = (1 << 7), /* disable secondary compression of
the data section. */
XD3_SEC_NOINST = (1 << 8), /* disable secondary compression of
the inst section. */
XD3_SEC_NOADDR = (1 << 9), /* disable secondary compression of
the addr section. */
XD3_SEC_NOALL = (XD3_SEC_NODATA | XD3_SEC_NOINST | XD3_SEC_NOADDR),
XD3_ADLER32 = (1 << 10), /* enable checksum computation in
the encoder. */
XD3_ADLER32_NOVER = (1 << 11), /* disable checksum verification in
the decoder. */
XD3_ALT_CODE_TABLE = (1 << 12), /* for testing th
e alternate code table encoding. */
XD3_NOCOMPRESS = (1 << 13), /* disable ordinary data
* compression feature, only search
* the source, not the target. */
XD3_BEGREEDY = (1 << 14), /* disable the "1.5-pass
* algorithm", instead use greedy
* matching. Greedy is off by
* default. */
XD3_ADLER32_RECODE = (1 << 15), /* used by "recode". */
/* 4 bits to set the compression level the same as the command-line
* setting -1 through -9 (-0 corresponds to the XD3_NOCOMPRESS flag,
* and is independent of compression level). This is for
* convenience, especially with xd3_encode_memory(). */
XD3_COMPLEVEL_SHIFT = 20, /* 20 - 24 */
XD3_COMPLEVEL_MASK = (0xF << XD3_COMPLEVEL_SHIFT),
XD3_COMPLEVEL_1 = (1 << XD3_COMPLEVEL_SHIFT),
XD3_COMPLEVEL_2 = (2 << XD3_COMPLEVEL_SHIFT),
XD3_COMPLEVEL_3 = (3 << XD3_COMPLEVEL_SHIFT),
XD3_COMPLEVEL_6 = (6 << XD3_COMPLEVEL_SHIFT),
XD3_COMPLEVEL_9 = (9 << XD3_COMPLEVEL_SHIFT),
} xd3_flags;
/* The values of this enumeration are set in xd3_config using the
* smatch_cfg variable. It can be set to default, slow, fast, etc.,
* and soft. */
typedef enum
{
XD3_SMATCH_DEFAULT = 0, /* Flags may contain XD3_COMPLEVEL bits,
else default. */
XD3_SMATCH_SLOW = 1,
XD3_SMATCH_FAST = 2,
XD3_SMATCH_FASTER = 3,
XD3_SMATCH_FASTEST = 4,
XD3_SMATCH_SOFT = 5,
} xd3_smatch_cfg;
/*********************************************************************
PRIVATE ENUMS
**********************************************************************/
/* stream->match_state is part of the xd3_encode_input state machine
* for source matching:
*
* 1. the XD3_GETSRCBLK block-read mechanism means reentrant matching
* 2. this state spans encoder windows: a match and end-of-window
* will continue in the next 3. the initial target byte and source
* byte are a presumed match, to avoid some computation in case the
* inputs are identical.
*/
typedef enum {
MATCH_TARGET = 0, /* in this state, attempt to match the start of
* the target with the previously set source
* address (initially 0). */
MATCH_BACKWARD = 1, /* currently expanding a match backward in the
source/target. */
MATCH_FORWARD = 2, /* currently expanding a match forward in the
source/target. */
MATCH_SEARCHING = 3, /* currently searching for a match. */
} xd3_match_state;
/* The xd3_encode_input state machine steps through these states in
* the following order. The matcher is reentrant and returns
* XD3_INPUT whenever it requires more data. After receiving
* XD3_INPUT, if the application reads EOF it should call
* xd3_stream_close().
*/
typedef enum {
ENC_INIT = 0, /* xd3_encode_input has never been called. */
ENC_INPUT = 1, /* waiting for xd3_avail_input () to be called. */
ENC_SEARCH = 2, /* currently searching for matches. */
ENC_INSTR = 3, /* currently formatting output. */
ENC_FLUSH = 4, /* currently emitting output. */
ENC_POSTOUT = 5, /* after an output section. */
ENC_POSTWIN = 6, /* after all output sections. */
ENC_ABORTED = 7, /* abort. */
} xd3_encode_state;
/* The xd3_decode_input state machine steps through these states in
* the following order. The matcher is reentrant and returns
* XD3_INPUT whenever it requires more data. After receiving
* XD3_INPUT, if the application reads EOF it should call
* xd3_stream_close().
*
* 0-8: the VCDIFF header
* 9-18: the VCDIFF window header
* 19-21: the three primary sections: data, inst, addr
* 22: producing output: returns XD3_OUTPUT, possibly XD3_GETSRCBLK,
* 23: return XD3_WINFINISH, set state=9 to decode more input
*/
typedef enum {
DEC_VCHEAD = 0, /* VCDIFF header */
DEC_HDRIND = 1, /* header indicator */
DEC_SECONDID = 2, /* secondary compressor ID */
DEC_TABLEN = 3, /* code table length */
DEC_NEAR = 4, /* code table near */
DEC_SAME = 5, /* code table same */
DEC_TABDAT = 6, /* code table data */
DEC_APPLEN = 7, /* application data length */
DEC_APPDAT = 8, /* application data */
DEC_WININD = 9, /* window indicator */
DEC_CPYLEN = 10, /* copy window length */
DEC_CPYOFF = 11, /* copy window offset */
DEC_ENCLEN = 12, /* length of delta encoding */
DEC_TGTLEN = 13, /* length of target window */
DEC_DELIND = 14, /* delta indicator */
DEC_DATALEN = 15, /* length of ADD+RUN data */
DEC_INSTLEN = 16, /* length of instruction data */
DEC_ADDRLEN = 17, /* length of address data */
DEC_CKSUM = 18, /* window checksum */
DEC_DATA = 19, /* data section */
DEC_INST = 20, /* instruction section */
DEC_ADDR = 21, /* address section */
DEC_EMIT = 22, /* producing data */
DEC_FINISH = 23, /* window finished */
DEC_ABORTED = 24, /* xd3_abort_stream */
} xd3_decode_state;
/************************************************************
internal types
************************************************************/
/* instruction lists used in the IOPT buffer */
struct _xd3_rlist
{
xd3_rlist *next;
xd3_rlist *prev;
};
/* the raw encoding of an instruction used in the IOPT buffer */
struct _xd3_rinst
{
uint8_t type;
uint8_t xtra;
uint8_t code1;
uint8_t code2;
usize_t pos;
usize_t size;
xoff_t addr;
xd3_rlist link;
};
/* the code-table form of an single- or double-instruction */
struct _xd3_dinst
{
uint8_t type1;
uint8_t size1;
uint8_t type2;
uint8_t size2;
};
/* the decoded form of a single (half) instruction. */
struct _xd3_hinst
{
uint8_t type;
uint32_t size; /* TODO: why decode breaks if this is usize_t? */
uint32_t addr; /* TODO: why decode breaks if this is usize_t? */
};
/* the form of a whole-file instruction */
struct _xd3_winst
{
uint8_t type; /* RUN, ADD, COPY */
uint8_t mode; /* 0, VCD_SOURCE, VCD_TARGET */
usize_t size;
xoff_t addr;
xoff_t position; /* absolute position of this inst */
};
/* used by the encoder to buffer output in sections. list of blocks. */
struct _xd3_output
{
uint8_t *base;
usize_t next;
usize_t avail;
xd3_output *next_page;
};
/* used by the decoder to buffer input in sections. */
struct _xd3_desect
{
const uint8_t *buf;
const uint8_t *buf_max;
uint32_t size; /* TODO: why decode breaks if this is usize_t? */
usize_t pos;
/* used in xdelta3-decode.h */
uint8_t *copied1;
usize_t alloc1;
/* used in xdelta3-second.h */
uint8_t *copied2;
usize_t alloc2;
};
/* the VCDIFF address cache, see the RFC */
struct _xd3_addr_cache
{
usize_t s_near;
usize_t s_same;
usize_t next_slot; /* the circular index for near */
usize_t *near_array; /* array of size s_near */
usize_t *same_array; /* array of size s_same*256 */
};
/* the IOPT buffer list is just a list of buffers, which may be allocated
* during encode when using an unlimited buffer. */
struct _xd3_iopt_buflist
{
xd3_rinst *buffer;
xd3_iopt_buflist *next;
};
/* This is the record of a pre-compiled configuration, a subset of
xd3_config. */
struct _xd3_smatcher
{
const char *name;
int (*string_match) (xd3_stream *stream);
usize_t large_look;
usize_t large_step;
usize_t small_look;
usize_t small_chain;
usize_t small_lchain;
usize_t max_lazy;
usize_t long_enough;
};
/* hash table size & power-of-two hash function. */
struct _xd3_hash_cfg
{
usize_t size;
usize_t shift;
usize_t mask;
};
/* the sprev list */
struct _xd3_slist
{
usize_t last_pos;
};
/* window info (for whole state) */
struct _xd3_wininfo {
xoff_t offset;
usize_t length;
uint32_t adler32;
};
/* whole state for, e.g., merge */
struct _xd3_whole_state {
usize_t addslen;
uint8_t *adds;
usize_t adds_alloc;
usize_t instlen;
xd3_winst *inst;
usize_t inst_alloc;
usize_t wininfolen;
xd3_wininfo *wininfo;
usize_t wininfo_alloc;
xoff_t length;
};
/********************************************************************
public types
*******************************************************************/
/* Settings for the secondary compressor. */
struct _xd3_sec_cfg
{
int data_type; /* Which section. (set automatically) */
usize_t ngroups; /* Number of DJW Huffman groups. */
usize_t sector_size; /* Sector size. */
int inefficient; /* If true, ignore efficiency check [avoid XD3_NOSECOND]. */
};
/* This is the user-visible stream configuration. */
struct _xd3_config
{
usize_t winsize; /* The encoder window size. */
usize_t sprevsz; /* How far back small string
matching goes */
usize_t iopt_size; /* entries in the
instruction-optimizing
buffer */
usize_t srcwin_maxsz; /* srcwin_size grows by a factor
of 2 when no matches are
found. encoder will not seek
back further than this. */
xd3_getblk_func *getblk; /* The three callbacks. */
xd3_alloc_func *alloc;
xd3_free_func *freef;
void *opaque; /* Not used. */
int flags; /* stream->flags are initialized
* from xd3_config & never
* modified by the library. Use
* xd3_set_flags to modify flags
* settings mid-stream. */
xd3_sec_cfg sec_data; /* Secondary compressor config: data */
xd3_sec_cfg sec_inst; /* Secondary compressor config: inst */
xd3_sec_cfg sec_addr; /* Secondary compressor config: addr */
xd3_smatch_cfg smatch_cfg; /* See enum: use fields below for
soft config */
xd3_smatcher smatcher_soft;
};
/* The primary source file object. You create one of these objects and
* initialize the first four fields. This library maintains the next
* 5 fields. The configured getblk implementation is responsible for
* setting the final 3 fields when called (and/or when XD3_GETSRCBLK
* is returned).
*/
struct _xd3_source
{
/* you set */
usize_t blksize; /* block size */
const char *name; /* its name, for debug/print
purposes */
void *ioh; /* opaque handle */
/* getblk sets */
xoff_t curblkno; /* current block number: client
sets after getblk request */
usize_t onblk; /* number of bytes on current
block: client sets, must be >= 0
and <= blksize */
const uint8_t *curblk; /* current block array: client
sets after getblk request */
/* xd3 sets */
usize_t srclen; /* length of this source window */
xoff_t srcbase; /* offset of this source window
in the source itself */
int shiftby; /* for power-of-two blocksizes */
int maskby; /* for power-of-two blocksizes */
xoff_t cpyoff_blocks; /* offset of dec_cpyoff in blocks */
usize_t cpyoff_blkoff; /* offset of copy window in
blocks, remainder */
xoff_t getblkno; /* request block number: xd3 sets
current getblk request */
/* See xd3_getblk() */
xoff_t max_blkno; /* Maximum block, if eof is known,
* otherwise, equals frontier_blkno
* (initially 0). */
xoff_t frontier_blkno; /* If eof is unknown, the next
* source position to be read.
* Otherwise, equal to
* max_blkno. */
usize_t onlastblk; /* Number of bytes on max_blkno */
int eof_known; /* Set to true when the first
* partial block is read. */
};
/* The primary xd3_stream object, used for encoding and decoding. You
* may access only two fields: avail_out, next_out. Use the methods
* above to operate on xd3_stream. */
struct _xd3_stream
{
/* input state */
const uint8_t *next_in; /* next input byte */
usize_t avail_in; /* number of bytes available at
next_in */
xoff_t total_in; /* how many bytes in */
/* output state */
uint8_t *next_out; /* next output byte */
usize_t avail_out; /* number of bytes available at
next_out */
usize_t space_out; /* total out space */
xoff_t current_window; /* number of windows encoded/decoded */
xoff_t total_out; /* how many bytes out */
/* to indicate an error, xd3 sets */
const char *msg; /* last error message, NULL if
no error */
/* source configuration */
xd3_source *src; /* source array */
/* encoder memory configuration */
usize_t winsize; /* suggested window size */
usize_t sprevsz; /* small string, previous window
size (power of 2) */
usize_t sprevmask; /* small string, previous window
size mask */
usize_t iopt_size;
usize_t iopt_unlimited;
usize_t srcwin_maxsz;
/* general configuration */
xd3_getblk_func *getblk; /* set nxtblk, nxtblkno to scanblkno */
xd3_alloc_func *alloc; /* malloc function */
xd3_free_func *free; /* free function */
void* opaque; /* private data object passed to
alloc, free, and getblk */
int flags; /* various options */
/* secondary compressor configuration */
xd3_sec_cfg sec_data; /* Secondary compressor config: data */
xd3_sec_cfg sec_inst; /* Secondary compressor config: inst */
xd3_sec_cfg sec_addr; /* Secondary compressor config: addr */
xd3_smatcher smatcher;
usize_t *large_table; /* table of large checksums */
xd3_hash_cfg large_hash; /* large hash config */
usize_t *small_table; /* table of small checksums */
xd3_slist *small_prev; /* table of previous offsets,
circular linked list */
int small_reset; /* true if small table should
be reset */
xd3_hash_cfg small_hash; /* small hash config */
xd3_addr_cache acache; /* the vcdiff address cache */
xd3_encode_state enc_state; /* state of the encoder */
usize_t taroff; /* base offset of the target input */
usize_t input_position; /* current input position */
usize_t min_match; /* current minimum match
length, avoids redundent
matches */
usize_t unencoded_offset; /* current input, first
* unencoded offset. this value
* is <= the first instruction's
* position in the iopt buffer,
* if there is at least one
* match in the buffer. */
// SRCWIN
// these variables plus srcwin_maxsz above (set by config)
int srcwin_decided; /* boolean: true if srclen and
srcbase have been
decided. */
int srcwin_decided_early; /* boolean: true if srclen
and srcbase were
decided early. */
xoff_t srcwin_cksum_pos; /* Source checksum position */
// MATCH
xd3_match_state match_state; /* encoder match state */
xoff_t match_srcpos; /* current match source
position relative to
srcbase */
xoff_t match_last_srcpos; /* previously attempted
* srcpos, to avoid loops. */
xoff_t match_minaddr; /* smallest matching address to
* set window params (reset each
* window xd3_encode_reset) */
xoff_t match_maxaddr; /* largest matching address to
* set window params (reset each
* window xd3_encode_reset) */
usize_t match_back; /* match extends back so far */
usize_t match_maxback; /* match extends back maximum */
usize_t match_fwd; /* match extends forward so far */
usize_t match_maxfwd; /* match extends forward maximum */
xoff_t maxsrcaddr; /* address of the last source
match (across windows) */
uint8_t *buf_in; /* for saving buffered input */
usize_t buf_avail; /* amount of saved input */
const uint8_t *buf_leftover; /* leftover content of next_in
(i.e., user's buffer) */
usize_t buf_leftavail; /* amount of leftover content */
xd3_output *enc_current; /* current output buffer */
xd3_output *enc_free; /* free output buffers */
xd3_output *enc_heads[4]; /* array of encoded outputs:
head of chain */
xd3_output *enc_tails[4]; /* array of encoded outputs:
tail of chain */
uint32_t recode_adler32; /* set the adler32 checksum
* during "recode". */
xd3_rlist iopt_used; /* instruction optimizing buffer */
xd3_rlist iopt_free;
xd3_rinst *iout; /* next single instruction */
xd3_iopt_buflist *iopt_alloc;
const uint8_t *enc_appheader; /* application header to encode */
usize_t enc_appheadsz; /* application header size */
/* decoder stuff */
xd3_decode_state dec_state; /* current DEC_XXX value */
usize_t dec_hdr_ind; /* VCDIFF header indicator */
usize_t dec_win_ind; /* VCDIFF window indicator */
usize_t dec_del_ind; /* VCDIFF delta indicator */
uint8_t dec_magic[4]; /* First four bytes */
usize_t dec_magicbytes; /* Magic position. */
usize_t dec_secondid; /* Optional secondary compressor ID. */
/* TODO: why decode breaks if this is usize_t? */
uint32_t dec_codetblsz; /* Optional code table: length. */
uint8_t *dec_codetbl; /* Optional code table: storage. */
usize_t dec_codetblbytes; /* Optional code table: position. */
/* TODO: why decode breaks if this is usize_t? */
uint32_t dec_appheadsz; /* Optional application header:
size. */
uint8_t *dec_appheader; /* Optional application header:
storage */
usize_t dec_appheadbytes; /* Optional application header:
position. */
usize_t dec_cksumbytes; /* Optional checksum: position. */
uint8_t dec_cksum[4]; /* Optional checksum: storage. */
uint32_t dec_adler32; /* Optional checksum: value. */
/* TODO: why decode breaks if this is usize_t? */
uint32_t dec_cpylen; /* length of copy window
(VCD_SOURCE or VCD_TARGET) */
xoff_t dec_cpyoff; /* offset of copy window
(VCD_SOURCE or VCD_TARGET) */
/* TODO: why decode breaks if this is usize_t? */
uint32_t dec_enclen; /* length of delta encoding */
/* TODO: why decode breaks if this is usize_t? */
uint32_t dec_tgtlen; /* length of target window */
#if USE_UINT64
uint64_t dec_64part; /* part of a decoded uint64_t */
#endif
#if USE_UINT32
uint32_t dec_32part; /* part of a decoded uint32_t */
#endif
xoff_t dec_winstart; /* offset of the start of
current target window */
xoff_t dec_window_count; /* == current_window + 1 in
DEC_FINISH */
usize_t dec_winbytes; /* bytes of the three sections
so far consumed */
usize_t dec_hdrsize; /* VCDIFF + app header size */
const uint8_t *dec_tgtaddrbase; /* Base of decoded target
addresses (addr >=
dec_cpylen). */
const uint8_t *dec_cpyaddrbase; /* Base of decoded copy
addresses (addr <
dec_cpylen). */
usize_t dec_position; /* current decoder position
counting the cpylen
offset */
usize_t dec_maxpos; /* maximum decoder position
counting the cpylen
offset */
xd3_hinst dec_current1; /* current instruction */
xd3_hinst dec_current2; /* current instruction */
uint8_t *dec_buffer; /* Decode buffer */
uint8_t *dec_lastwin; /* In case of VCD_TARGET, the
last target window. */
usize_t dec_lastlen; /* length of the last target
window */
xoff_t dec_laststart; /* offset of the start of last
target window */
usize_t dec_lastspace; /* allocated space of last
target window, for reuse */
xd3_desect inst_sect; /* staging area for decoding
window sections */
xd3_desect addr_sect;
xd3_desect data_sect;
xd3_code_table_func *code_table_func;
xd3_comp_table_func *comp_table_func;
const xd3_dinst *code_table;
const xd3_code_table_desc *code_table_desc;
xd3_dinst *code_table_alloc;
/* secondary compression */
const xd3_sec_type *sec_type;
xd3_sec_stream *sec_stream_d;
xd3_sec_stream *sec_stream_i;
xd3_sec_stream *sec_stream_a;
/* state for reconstructing whole files (e.g., for merge), this only
* supports loading USIZE_T_MAX instructions, adds, etc. */
xd3_whole_state whole_target;
/* statistics */
xoff_t n_scpy;
xoff_t n_tcpy;
xoff_t n_add;
xoff_t n_run;
xoff_t l_scpy;
xoff_t l_tcpy;
xoff_t l_add;
xoff_t l_run;
usize_t i_slots_used;
#if XD3_DEBUG
usize_t large_ckcnt;
/* memory usage */
usize_t alloc_cnt;
usize_t free_cnt;
#endif
};
/**************************************************************************
PUBLIC FUNCTIONS
**************************************************************************/
/* This function configures an xd3_stream using the provided in-memory
* input buffer, source buffer, output buffer, and flags. The output
* array must be large enough or else ENOSPC will be returned. This
* is the simplest in-memory encoding interface. */
int xd3_encode_memory (const uint8_t *input,
usize_t input_size,
const uint8_t *source,
usize_t source_size,
uint8_t *output_buffer,
usize_t *output_size,
usize_t avail_output,
int flags);
/* The reverse of xd3_encode_memory. */
int xd3_decode_memory (const uint8_t *input,
usize_t input_size,
const uint8_t *source,
usize_t source_size,
uint8_t *output_buf,
usize_t *output_size,
usize_t avail_output,
int flags);
/* This function encodes an in-memory input using a pre-configured
* xd3_stream. This allows the caller to set a variety of options
* which are not available in the xd3_encode/decode_memory()
* functions.
*
* The output array must be large enough to hold the output or else
* ENOSPC is returned. The source (if any) should be set using
* xd3_set_source_and_size() with a single-block xd3_source. This
* calls the underlying non-blocking interfaces,
* xd3_encode/decode_input(), handling the necessary input/output
* states. This method may be considered a reference for any
* application using xd3_encode_input() directly.
*
* xd3_stream stream;
* xd3_config config;
* xd3_source src;
*
* memset (& src, 0, sizeof (src));
* memset (& stream, 0, sizeof (stream));
* memset (& config, 0, sizeof (config));
*
* if (source != NULL)
* {
* src.size = source_size;
* src.blksize = source_size;
* src.curblkno = 0;
* src.onblk = source_size;
* src.curblk = source;
* xd3_set_source(&stream, &src);
* }
*
* config.flags = flags;
* config.srcwin_maxsz = source_size;
* config.winsize = input_size;
*
* ... set smatcher, appheader, encoding-table, compression-level, etc.
*
* xd3_config_stream(&stream, &config);
* xd3_encode_stream(&stream, ...);
* xd3_free_stream(&stream);
*/
int xd3_encode_stream (xd3_stream *stream,
const uint8_t *input,
usize_t input_size,
uint8_t *output,
usize_t *output_size,
usize_t avail_output);
/* The reverse of xd3_encode_stream. */
int xd3_decode_stream (xd3_stream *stream,
const uint8_t *input,
usize_t input_size,
uint8_t *output,
usize_t *output_size,
usize_t avail_size);
/* This is the non-blocking interface.
*
* Handling input and output states is the same for encoding or
* decoding using the xd3_avail_input() and xd3_consume_output()
* routines, inlined below.
*
* Return values:
*
* XD3_INPUT: the process requires more input: call
* xd3_avail_input() then repeat
*
* XD3_OUTPUT: the process has more output: read stream->next_out,
* stream->avail_out, then call xd3_consume_output(),
* then repeat
*
* XD3_GOTHEADER: (decoder-only) notification returned following the
* VCDIFF header and first window header. the decoder
* may use the header to configure itself.
*
* XD3_WINSTART: a general notification returned once for each
* window except the 0-th window, which is implied by
* XD3_GOTHEADER. It is recommended to use a
* switch-stmt such as:
*
* ...
* again:
* switch ((ret = xd3_decode_input (stream))) {
* case XD3_GOTHEADER: {
* assert(stream->current_window == 0);
* stuff;
* }
* // fallthrough
* case XD3_WINSTART: {
* something(stream->current_window);
* goto again;
* }
* ...
*
* XD3_WINFINISH: a general notification, following the complete
* input & output of a window. at this point,
* stream->total_in and stream->total_out are consistent
* for either encoding or decoding.
*
* XD3_GETSRCBLK: If the xd3_getblk() callback is NULL, this value
* is returned to initiate a non-blocking source read.
*/
int xd3_decode_input (xd3_stream *stream);
int xd3_encode_input (xd3_stream *stream);
/* The xd3_config structure is used to initialize a stream - all data
* is copied into stream so config may be a temporary variable. See
* the [documentation] or comments on the xd3_config structure. */
int xd3_config_stream (xd3_stream *stream,
xd3_config *config);
/* Since Xdelta3 doesn't open any files, xd3_close_stream is just an
* error check that the stream is in a proper state to be closed: this
* means the encoder is flushed and the decoder is at a window
* boundary. The application is responsible for freeing any of the
* resources it supplied. */
int xd3_close_stream (xd3_stream *stream);
/* This arranges for closes the stream to succeed. Does not free the
* stream.*/
void xd3_abort_stream (xd3_stream *stream);
/* xd3_free_stream frees all memory allocated for the stream. The
* application is responsible for freeing any of the resources it
* supplied. */
void xd3_free_stream (xd3_stream *stream);
/* This function informs the encoder or decoder that source matching
* (i.e., delta-compression) is possible. For encoding, this should
* be called before the first xd3_encode_input. A NULL source is
* ignored. For decoding, this should be called before the first
* window is decoded, but the appheader may be read first
* (XD3_GOTHEADER). After decoding the header, call xd3_set_source()
* if you have a source file. Note: if (stream->dec_win_ind & VCD_SOURCE)
* is true, it means the first window expects there to be a source file.
*/
int xd3_set_source (xd3_stream *stream,
xd3_source *source);
/* If the source size is known, call this instead of xd3_set_source().
* to avoid having stream->getblk called (and/or to avoid XD3_GETSRCBLK).
*
* Follow these steps:
xd3_source source;
memset(&source, 0, sizeof(source));
source.blksize = size;
source.onblk = size;
source.curblk = buf;
source.curblkno = 0;
int ret = xd3_set_source_and_size(&stream, &source, size);
...
*/
int xd3_set_source_and_size (xd3_stream *stream,
xd3_source *source,
xoff_t source_size);
/* This should be called before the first call to xd3_encode_input()
* to include application-specific data in the VCDIFF header. */
void xd3_set_appheader (xd3_stream *stream,
const uint8_t *data,
usize_t size);
/* xd3_get_appheader may be called in the decoder after XD3_GOTHEADER.
* For convenience, the decoder always adds a single byte padding to
* the end of the application header, which is set to zero in case the
* application header is a string. */
int xd3_get_appheader (xd3_stream *stream,
uint8_t **data,
usize_t *size);
/* To generate a VCDIFF encoded delta with xd3_encode_init() from
* another format, use:
*
* xd3_encode_init_partial() -- initialze encoder state (w/o hash tables)
* xd3_init_cache() -- reset VCDIFF address cache
* xd3_found_match() -- to report a copy instruction
*
* set stream->enc_state to ENC_INSTR and call xd3_encode_input as usual.
*/
int xd3_encode_init_partial (xd3_stream *stream);
void xd3_init_cache (xd3_addr_cache* acache);
int xd3_found_match (xd3_stream *stream,
usize_t pos, usize_t size,
xoff_t addr, int is_source);
/* Gives an error string for xdelta3-speficic errors, returns NULL for
system errors */
const char* xd3_strerror (int ret);
/* For convenience, zero & initialize the xd3_config structure with
specified flags. */
static inline
void xd3_init_config (xd3_config *config,
int flags)
{
memset (config, 0, sizeof (*config));
config->flags = flags;
}
/* This supplies some input to the stream.
*
* For encoding, if the input is larger than the configured window
* size (xd3_config.winsize), the entire input will be consumed and
* encoded anyway. If you wish to strictly limit the window size,
* limit the buffer passed to xd3_avail_input to the window size.
*
* For encoding, if the input is smaller than the configured window
* size (xd3_config.winsize), the library will create a window-sized
* buffer and accumulate input until a full-sized window can be
* encoded. XD3_INPUT will be returned. The input must remain valid
* until the next time xd3_encode_input() returns XD3_INPUT.
*
* For decoding, the input will be consumed entirely before XD3_INPUT
* is returned again.
*/
static inline
void xd3_avail_input (xd3_stream *stream,
const uint8_t *idata,
usize_t isize)
{
/* Even if isize is zero, the code expects a non-NULL idata. Why?
* It uses this value to determine whether xd3_avail_input has ever
* been called. If xd3_encode_input is called before
* xd3_avail_input it will return XD3_INPUT right away without
* allocating a stream->winsize buffer. This is to avoid an
* unwanted allocation. */
XD3_ASSERT (idata != NULL || isize == 0);
stream->next_in = idata;
stream->avail_in = isize;
}
/* This acknowledges receipt of output data, must be called after any
* XD3_OUTPUT return. */
static inline
void xd3_consume_output (xd3_stream *stream)
{
stream->avail_out = 0;
}
/* These are set for each XD3_WINFINISH return. */
static inline
int xd3_encoder_used_source (xd3_stream *stream) {
return stream->src != NULL && stream->src->srclen > 0;
}
static inline
xoff_t xd3_encoder_srcbase (xd3_stream *stream) {
return stream->src->srcbase;
}
static inline
usize_t xd3_encoder_srclen (xd3_stream *stream) {
return stream->src->srclen;
}
/* Checks for legal flag changes. */
static inline
void xd3_set_flags (xd3_stream *stream, int flags)
{
/* The bitwise difference should contain only XD3_FLUSH or
XD3_SKIP_WINDOW */
XD3_ASSERT(((flags ^ stream->flags) & ~(XD3_FLUSH | XD3_SKIP_WINDOW)) == 0);
stream->flags = flags;
}
/* Gives some extra information about the latest library error, if any
* is known. */
static inline
const char* xd3_errstring (xd3_stream *stream)
{
return stream->msg ? stream->msg : "";
}
/* 64-bit divisions are expensive, which is why we require a
* power-of-two source->blksize. To relax this restriction is
* relatively easy, see the history for xd3_blksize_div(). */
static inline
void xd3_blksize_div (const xoff_t offset,
const xd3_source *source,
xoff_t *blkno,
usize_t *blkoff) {
*blkno = (xoff_t) (offset >> source->shiftby);
*blkoff = (usize_t) (offset & source->maskby);
XD3_ASSERT (*blkoff < source->blksize);
}
static inline
void xd3_blksize_add (xoff_t *blkno,
usize_t *blkoff,
const xd3_source *source,
const usize_t add)
{
usize_t blkdiff;
/* Does not check for overflow, checked in xdelta3-decode.h. */
*blkoff += add;
blkdiff = *blkoff >> source->shiftby;
if (blkdiff)
{
*blkno += blkdiff;
*blkoff &= source->maskby;
}
XD3_ASSERT (*blkoff < source->blksize);
}
#endif /* _XDELTA3_H_ */
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