diff options
Diffstat (limited to 'include/linux/zlib.h')
-rw-r--r-- | include/linux/zlib.h | 209 |
1 files changed, 129 insertions, 80 deletions
diff --git a/include/linux/zlib.h b/include/linux/zlib.h index 4fa32f0d4df8..9e3192a7dc6f 100644 --- a/include/linux/zlib.h +++ b/include/linux/zlib.h | |||
@@ -1,7 +1,6 @@ | |||
1 | /* zlib.h -- interface of the 'zlib' general purpose compression library | 1 | /* zlib.h -- interface of the 'zlib' general purpose compression library |
2 | version 1.1.3, July 9th, 1998 | ||
3 | 2 | ||
4 | Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler | 3 | Copyright (C) 1995-2005 Jean-loup Gailly and Mark Adler |
5 | 4 | ||
6 | This software is provided 'as-is', without any express or implied | 5 | This software is provided 'as-is', without any express or implied |
7 | warranty. In no event will the authors be held liable for any damages | 6 | warranty. In no event will the authors be held liable for any damages |
@@ -24,7 +23,7 @@ | |||
24 | 23 | ||
25 | 24 | ||
26 | The data format used by the zlib library is described by RFCs (Request for | 25 | The data format used by the zlib library is described by RFCs (Request for |
27 | Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt | 26 | Comments) 1950 to 1952 in the files http://www.ietf.org/rfc/rfc1950.txt |
28 | (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). | 27 | (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). |
29 | */ | 28 | */ |
30 | 29 | ||
@@ -33,7 +32,22 @@ | |||
33 | 32 | ||
34 | #include <linux/zconf.h> | 33 | #include <linux/zconf.h> |
35 | 34 | ||
36 | #define ZLIB_VERSION "1.1.3" | 35 | /* zlib deflate based on ZLIB_VERSION "1.1.3" */ |
36 | /* zlib inflate based on ZLIB_VERSION "1.2.3" */ | ||
37 | |||
38 | /* | ||
39 | This is a modified version of zlib for use inside the Linux kernel. | ||
40 | The main changes are to perform all memory allocation in advance. | ||
41 | |||
42 | Inflation Changes: | ||
43 | * Z_PACKET_FLUSH is added and used by ppp_deflate. Before returning | ||
44 | this checks there is no more input data available and the next data | ||
45 | is a STORED block. It also resets the mode to be read for the next | ||
46 | data, all as per PPP requirements. | ||
47 | * Addition of zlib_inflateIncomp which copies incompressible data into | ||
48 | the history window and adjusts the accoutning without calling | ||
49 | zlib_inflate itself to inflate the data. | ||
50 | */ | ||
37 | 51 | ||
38 | /* | 52 | /* |
39 | The 'zlib' compression library provides in-memory compression and | 53 | The 'zlib' compression library provides in-memory compression and |
@@ -48,9 +62,18 @@ | |||
48 | application must provide more input and/or consume the output | 62 | application must provide more input and/or consume the output |
49 | (providing more output space) before each call. | 63 | (providing more output space) before each call. |
50 | 64 | ||
65 | The compressed data format used by default by the in-memory functions is | ||
66 | the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped | ||
67 | around a deflate stream, which is itself documented in RFC 1951. | ||
68 | |||
51 | The library also supports reading and writing files in gzip (.gz) format | 69 | The library also supports reading and writing files in gzip (.gz) format |
52 | with an interface similar to that of stdio. | 70 | with an interface similar to that of stdio. |
53 | 71 | ||
72 | The zlib format was designed to be compact and fast for use in memory | ||
73 | and on communications channels. The gzip format was designed for single- | ||
74 | file compression on file systems, has a larger header than zlib to maintain | ||
75 | directory information, and uses a different, slower check method than zlib. | ||
76 | |||
54 | The library does not install any signal handler. The decoder checks | 77 | The library does not install any signal handler. The decoder checks |
55 | the consistency of the compressed data, so the library should never | 78 | the consistency of the compressed data, so the library should never |
56 | crash even in case of corrupted input. | 79 | crash even in case of corrupted input. |
@@ -119,7 +142,8 @@ typedef z_stream *z_streamp; | |||
119 | #define Z_SYNC_FLUSH 3 | 142 | #define Z_SYNC_FLUSH 3 |
120 | #define Z_FULL_FLUSH 4 | 143 | #define Z_FULL_FLUSH 4 |
121 | #define Z_FINISH 5 | 144 | #define Z_FINISH 5 |
122 | /* Allowed flush values; see deflate() below for details */ | 145 | #define Z_BLOCK 6 /* Only for inflate at present */ |
146 | /* Allowed flush values; see deflate() and inflate() below for details */ | ||
123 | 147 | ||
124 | #define Z_OK 0 | 148 | #define Z_OK 0 |
125 | #define Z_STREAM_END 1 | 149 | #define Z_STREAM_END 1 |
@@ -155,13 +179,6 @@ typedef z_stream *z_streamp; | |||
155 | 179 | ||
156 | /* basic functions */ | 180 | /* basic functions */ |
157 | 181 | ||
158 | extern const char * zlib_zlibVersion (void); | ||
159 | /* The application can compare zlibVersion and ZLIB_VERSION for consistency. | ||
160 | If the first character differs, the library code actually used is | ||
161 | not compatible with the zlib.h header file used by the application. | ||
162 | This check is automatically made by deflateInit and inflateInit. | ||
163 | */ | ||
164 | |||
165 | extern int zlib_deflate_workspacesize (void); | 182 | extern int zlib_deflate_workspacesize (void); |
166 | /* | 183 | /* |
167 | Returns the number of bytes that needs to be allocated for a per- | 184 | Returns the number of bytes that needs to be allocated for a per- |
@@ -315,9 +332,9 @@ extern int zlib_inflateInit (z_streamp strm); | |||
315 | extern int zlib_inflate (z_streamp strm, int flush); | 332 | extern int zlib_inflate (z_streamp strm, int flush); |
316 | /* | 333 | /* |
317 | inflate decompresses as much data as possible, and stops when the input | 334 | inflate decompresses as much data as possible, and stops when the input |
318 | buffer becomes empty or the output buffer becomes full. It may some | 335 | buffer becomes empty or the output buffer becomes full. It may introduce |
319 | introduce some output latency (reading input without producing any output) | 336 | some output latency (reading input without producing any output) except when |
320 | except when forced to flush. | 337 | forced to flush. |
321 | 338 | ||
322 | The detailed semantics are as follows. inflate performs one or both of the | 339 | The detailed semantics are as follows. inflate performs one or both of the |
323 | following actions: | 340 | following actions: |
@@ -341,11 +358,26 @@ extern int zlib_inflate (z_streamp strm, int flush); | |||
341 | must be called again after making room in the output buffer because there | 358 | must be called again after making room in the output buffer because there |
342 | might be more output pending. | 359 | might be more output pending. |
343 | 360 | ||
344 | If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much | 361 | The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, |
345 | output as possible to the output buffer. The flushing behavior of inflate is | 362 | Z_FINISH, or Z_BLOCK. Z_SYNC_FLUSH requests that inflate() flush as much |
346 | not specified for values of the flush parameter other than Z_SYNC_FLUSH | 363 | output as possible to the output buffer. Z_BLOCK requests that inflate() stop |
347 | and Z_FINISH, but the current implementation actually flushes as much output | 364 | if and when it gets to the next deflate block boundary. When decoding the |
348 | as possible anyway. | 365 | zlib or gzip format, this will cause inflate() to return immediately after |
366 | the header and before the first block. When doing a raw inflate, inflate() | ||
367 | will go ahead and process the first block, and will return when it gets to | ||
368 | the end of that block, or when it runs out of data. | ||
369 | |||
370 | The Z_BLOCK option assists in appending to or combining deflate streams. | ||
371 | Also to assist in this, on return inflate() will set strm->data_type to the | ||
372 | number of unused bits in the last byte taken from strm->next_in, plus 64 | ||
373 | if inflate() is currently decoding the last block in the deflate stream, | ||
374 | plus 128 if inflate() returned immediately after decoding an end-of-block | ||
375 | code or decoding the complete header up to just before the first byte of the | ||
376 | deflate stream. The end-of-block will not be indicated until all of the | ||
377 | uncompressed data from that block has been written to strm->next_out. The | ||
378 | number of unused bits may in general be greater than seven, except when | ||
379 | bit 7 of data_type is set, in which case the number of unused bits will be | ||
380 | less than eight. | ||
349 | 381 | ||
350 | inflate() should normally be called until it returns Z_STREAM_END or an | 382 | inflate() should normally be called until it returns Z_STREAM_END or an |
351 | error. However if all decompression is to be performed in a single step | 383 | error. However if all decompression is to be performed in a single step |
@@ -355,29 +387,44 @@ extern int zlib_inflate (z_streamp strm, int flush); | |||
355 | uncompressed data. (The size of the uncompressed data may have been saved | 387 | uncompressed data. (The size of the uncompressed data may have been saved |
356 | by the compressor for this purpose.) The next operation on this stream must | 388 | by the compressor for this purpose.) The next operation on this stream must |
357 | be inflateEnd to deallocate the decompression state. The use of Z_FINISH | 389 | be inflateEnd to deallocate the decompression state. The use of Z_FINISH |
358 | is never required, but can be used to inform inflate that a faster routine | 390 | is never required, but can be used to inform inflate that a faster approach |
359 | may be used for the single inflate() call. | 391 | may be used for the single inflate() call. |
360 | 392 | ||
361 | If a preset dictionary is needed at this point (see inflateSetDictionary | 393 | In this implementation, inflate() always flushes as much output as |
362 | below), inflate sets strm-adler to the adler32 checksum of the | 394 | possible to the output buffer, and always uses the faster approach on the |
363 | dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise | 395 | first call. So the only effect of the flush parameter in this implementation |
364 | it sets strm->adler to the adler32 checksum of all output produced | 396 | is on the return value of inflate(), as noted below, or when it returns early |
365 | so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or | 397 | because Z_BLOCK is used. |
366 | an error code as described below. At the end of the stream, inflate() | 398 | |
367 | checks that its computed adler32 checksum is equal to that saved by the | 399 | If a preset dictionary is needed after this call (see inflateSetDictionary |
368 | compressor and returns Z_STREAM_END only if the checksum is correct. | 400 | below), inflate sets strm->adler to the adler32 checksum of the dictionary |
401 | chosen by the compressor and returns Z_NEED_DICT; otherwise it sets | ||
402 | strm->adler to the adler32 checksum of all output produced so far (that is, | ||
403 | total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described | ||
404 | below. At the end of the stream, inflate() checks that its computed adler32 | ||
405 | checksum is equal to that saved by the compressor and returns Z_STREAM_END | ||
406 | only if the checksum is correct. | ||
407 | |||
408 | inflate() will decompress and check either zlib-wrapped or gzip-wrapped | ||
409 | deflate data. The header type is detected automatically. Any information | ||
410 | contained in the gzip header is not retained, so applications that need that | ||
411 | information should instead use raw inflate, see inflateInit2() below, or | ||
412 | inflateBack() and perform their own processing of the gzip header and | ||
413 | trailer. | ||
369 | 414 | ||
370 | inflate() returns Z_OK if some progress has been made (more input processed | 415 | inflate() returns Z_OK if some progress has been made (more input processed |
371 | or more output produced), Z_STREAM_END if the end of the compressed data has | 416 | or more output produced), Z_STREAM_END if the end of the compressed data has |
372 | been reached and all uncompressed output has been produced, Z_NEED_DICT if a | 417 | been reached and all uncompressed output has been produced, Z_NEED_DICT if a |
373 | preset dictionary is needed at this point, Z_DATA_ERROR if the input data was | 418 | preset dictionary is needed at this point, Z_DATA_ERROR if the input data was |
374 | corrupted (input stream not conforming to the zlib format or incorrect | 419 | corrupted (input stream not conforming to the zlib format or incorrect check |
375 | adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent | 420 | value), Z_STREAM_ERROR if the stream structure was inconsistent (for example |
376 | (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not | 421 | if next_in or next_out was NULL), Z_MEM_ERROR if there was not enough memory, |
377 | enough memory, Z_BUF_ERROR if no progress is possible or if there was not | 422 | Z_BUF_ERROR if no progress is possible or if there was not enough room in the |
378 | enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR | 423 | output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and |
379 | case, the application may then call inflateSync to look for a good | 424 | inflate() can be called again with more input and more output space to |
380 | compression block. | 425 | continue decompressing. If Z_DATA_ERROR is returned, the application may then |
426 | call inflateSync() to look for a good compression block if a partial recovery | ||
427 | of the data is desired. | ||
381 | */ | 428 | */ |
382 | 429 | ||
383 | 430 | ||
@@ -547,16 +594,36 @@ extern int inflateInit2 (z_streamp strm, int windowBits); | |||
547 | The windowBits parameter is the base two logarithm of the maximum window | 594 | The windowBits parameter is the base two logarithm of the maximum window |
548 | size (the size of the history buffer). It should be in the range 8..15 for | 595 | size (the size of the history buffer). It should be in the range 8..15 for |
549 | this version of the library. The default value is 15 if inflateInit is used | 596 | this version of the library. The default value is 15 if inflateInit is used |
550 | instead. If a compressed stream with a larger window size is given as | 597 | instead. windowBits must be greater than or equal to the windowBits value |
551 | input, inflate() will return with the error code Z_DATA_ERROR instead of | 598 | provided to deflateInit2() while compressing, or it must be equal to 15 if |
552 | trying to allocate a larger window. | 599 | deflateInit2() was not used. If a compressed stream with a larger window |
553 | 600 | size is given as input, inflate() will return with the error code | |
554 | inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | 601 | Z_DATA_ERROR instead of trying to allocate a larger window. |
555 | memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative | 602 | |
556 | memLevel). msg is set to null if there is no error message. inflateInit2 | 603 | windowBits can also be -8..-15 for raw inflate. In this case, -windowBits |
557 | does not perform any decompression apart from reading the zlib header if | 604 | determines the window size. inflate() will then process raw deflate data, |
558 | present: this will be done by inflate(). (So next_in and avail_in may be | 605 | not looking for a zlib or gzip header, not generating a check value, and not |
559 | modified, but next_out and avail_out are unchanged.) | 606 | looking for any check values for comparison at the end of the stream. This |
607 | is for use with other formats that use the deflate compressed data format | ||
608 | such as zip. Those formats provide their own check values. If a custom | ||
609 | format is developed using the raw deflate format for compressed data, it is | ||
610 | recommended that a check value such as an adler32 or a crc32 be applied to | ||
611 | the uncompressed data as is done in the zlib, gzip, and zip formats. For | ||
612 | most applications, the zlib format should be used as is. Note that comments | ||
613 | above on the use in deflateInit2() applies to the magnitude of windowBits. | ||
614 | |||
615 | windowBits can also be greater than 15 for optional gzip decoding. Add | ||
616 | 32 to windowBits to enable zlib and gzip decoding with automatic header | ||
617 | detection, or add 16 to decode only the gzip format (the zlib format will | ||
618 | return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is | ||
619 | a crc32 instead of an adler32. | ||
620 | |||
621 | inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough | ||
622 | memory, Z_STREAM_ERROR if a parameter is invalid (such as a null strm). msg | ||
623 | is set to null if there is no error message. inflateInit2 does not perform | ||
624 | any decompression apart from reading the zlib header if present: this will | ||
625 | be done by inflate(). (So next_in and avail_in may be modified, but next_out | ||
626 | and avail_out are unchanged.) | ||
560 | */ | 627 | */ |
561 | 628 | ||
562 | extern int zlib_inflateSetDictionary (z_streamp strm, | 629 | extern int zlib_inflateSetDictionary (z_streamp strm, |
@@ -564,16 +631,19 @@ extern int zlib_inflateSetDictionary (z_streamp strm, | |||
564 | uInt dictLength); | 631 | uInt dictLength); |
565 | /* | 632 | /* |
566 | Initializes the decompression dictionary from the given uncompressed byte | 633 | Initializes the decompression dictionary from the given uncompressed byte |
567 | sequence. This function must be called immediately after a call of inflate | 634 | sequence. This function must be called immediately after a call of inflate, |
568 | if this call returned Z_NEED_DICT. The dictionary chosen by the compressor | 635 | if that call returned Z_NEED_DICT. The dictionary chosen by the compressor |
569 | can be determined from the Adler32 value returned by this call of | 636 | can be determined from the adler32 value returned by that call of inflate. |
570 | inflate. The compressor and decompressor must use exactly the same | 637 | The compressor and decompressor must use exactly the same dictionary (see |
571 | dictionary (see deflateSetDictionary). | 638 | deflateSetDictionary). For raw inflate, this function can be called |
639 | immediately after inflateInit2() or inflateReset() and before any call of | ||
640 | inflate() to set the dictionary. The application must insure that the | ||
641 | dictionary that was used for compression is provided. | ||
572 | 642 | ||
573 | inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a | 643 | inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a |
574 | parameter is invalid (such as NULL dictionary) or the stream state is | 644 | parameter is invalid (such as NULL dictionary) or the stream state is |
575 | inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the | 645 | inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the |
576 | expected one (incorrect Adler32 value). inflateSetDictionary does not | 646 | expected one (incorrect adler32 value). inflateSetDictionary does not |
577 | perform any decompression: this will be done by subsequent calls of | 647 | perform any decompression: this will be done by subsequent calls of |
578 | inflate(). | 648 | inflate(). |
579 | */ | 649 | */ |
@@ -614,40 +684,19 @@ extern int zlib_inflateIncomp (z_stream *strm); | |||
614 | containing the data at next_in (except that the data is not output). | 684 | containing the data at next_in (except that the data is not output). |
615 | */ | 685 | */ |
616 | 686 | ||
617 | /* various hacks, don't look :) */ | ||
618 | |||
619 | /* deflateInit and inflateInit are macros to allow checking the zlib version | ||
620 | * and the compiler's view of z_stream: | ||
621 | */ | ||
622 | extern int zlib_deflateInit_ (z_streamp strm, int level, | ||
623 | const char *version, int stream_size); | ||
624 | extern int zlib_inflateInit_ (z_streamp strm, | ||
625 | const char *version, int stream_size); | ||
626 | extern int zlib_deflateInit2_ (z_streamp strm, int level, int method, | ||
627 | int windowBits, int memLevel, | ||
628 | int strategy, const char *version, | ||
629 | int stream_size); | ||
630 | extern int zlib_inflateInit2_ (z_streamp strm, int windowBits, | ||
631 | const char *version, int stream_size); | ||
632 | #define zlib_deflateInit(strm, level) \ | 687 | #define zlib_deflateInit(strm, level) \ |
633 | zlib_deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) | 688 | zlib_deflateInit2((strm), (level), Z_DEFLATED, MAX_WBITS, \ |
689 | DEF_MEM_LEVEL, Z_DEFAULT_STRATEGY) | ||
634 | #define zlib_inflateInit(strm) \ | 690 | #define zlib_inflateInit(strm) \ |
635 | zlib_inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) | 691 | zlib_inflateInit2((strm), DEF_WBITS) |
636 | #define zlib_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ | ||
637 | zlib_deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ | ||
638 | (strategy), ZLIB_VERSION, sizeof(z_stream)) | ||
639 | #define zlib_inflateInit2(strm, windowBits) \ | ||
640 | zlib_inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) | ||
641 | 692 | ||
693 | extern int zlib_deflateInit2(z_streamp strm, int level, int method, | ||
694 | int windowBits, int memLevel, | ||
695 | int strategy); | ||
696 | extern int zlib_inflateInit2(z_streamp strm, int windowBits); | ||
642 | 697 | ||
643 | #if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL) | 698 | #if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL) |
644 | struct internal_state {int dummy;}; /* hack for buggy compilers */ | 699 | struct internal_state {int dummy;}; /* hack for buggy compilers */ |
645 | #endif | 700 | #endif |
646 | 701 | ||
647 | extern const char * zlib_zError (int err); | ||
648 | #if 0 | ||
649 | extern int zlib_inflateSyncPoint (z_streamp z); | ||
650 | #endif | ||
651 | extern const uLong * zlib_get_crc_table (void); | ||
652 | |||
653 | #endif /* _ZLIB_H */ | 702 | #endif /* _ZLIB_H */ |