-/* inflate.c -- zlib interface to inflate modules
- * Copyright (C) 1995-1998 Mark Adler
- * For conditions of distribution and use, see copyright notice in zlib.h
+/* inflate.c -- zlib decompression
+ * Copyright (C) 1995-2003 Mark Adler
+ * For conditions of distribution and use, see copyright notice in zlib.h
+ */
+
+/*
+ * Change history:
+ *
+ * 1.2.beta0 24 Nov 2002
+ * - First version -- complete rewrite of inflate to simplify code, avoid
+ * creation of window when not needed, minimize use of window when it is
+ * needed, make inffast.c even faster, implement gzip decoding, and to
+ * improve code readability and style over the previous zlib inflate code
+ *
+ * 1.2.beta1 25 Nov 2002
+ * - Use pointers for available input and output checking in inffast.c
+ * - Remove input and output counters in inffast.c
+ * - Change inffast.c entry and loop from avail_in >= 7 to >= 6
+ * - Remove unnecessary second byte pull from length extra in inffast.c
+ * - Unroll direct copy to three copies per loop in inffast.c
+ *
+ * 1.2.beta2 4 Dec 2002
+ * - Change external routine names to reduce potential conflicts
+ * - Correct filename to inffixed.h for fixed tables in inflate.c
+ * - Make hbuf[] unsigned char to match parameter type in inflate.c
+ * - Change strm->next_out[-state->offset] to *(strm->next_out - state->offset)
+ * to avoid negation problem on Alphas (64 bit) in inflate.c
+ *
+ * 1.2.beta3 22 Dec 2002
+ * - Add comments on state->bits assertion in inffast.c
+ * - Add comments on op field in inftrees.h
+ * - Fix bug in reuse of allocated window after inflateReset()
+ * - Remove bit fields--back to byte structure for speed
+ * - Remove distance extra == 0 check in inflate_fast()--only helps for lengths
+ * - Change post-increments to pre-increments in inflate_fast(), PPC biased?
+ * - Add compile time option, POSTINC, to use post-increments instead (Intel?)
+ * - Make MATCH copy in inflate() much faster for when inflate_fast() not used
+ * - Use local copies of stream next and avail values, as well as local bit
+ * buffer and bit count in inflate()--for speed when inflate_fast() not used
+ *
+ * 1.2.beta4 1 Jan 2003
+ * - Split ptr - 257 statements in inflate_table() to avoid compiler warnings
+ * - Move a comment on output buffer sizes from inffast.c to inflate.c
+ * - Add comments in inffast.c to introduce the inflate_fast() routine
+ * - Rearrange window copies in inflate_fast() for speed and simplification
+ * - Unroll last copy for window match in inflate_fast()
+ * - Use local copies of window variables in inflate_fast() for speed
+ * - Pull out common write == 0 case for speed in inflate_fast()
+ * - Make op and len in inflate_fast() unsigned for consistency
+ * - Add FAR to lcode and dcode declarations in inflate_fast()
+ * - Simplified bad distance check in inflate_fast()
+ * - Added inflateBackInit(), inflateBack(), and inflateBackEnd() in new
+ * source file infback.c to provide a call-back interface to inflate for
+ * programs like gzip and unzip -- uses window as output buffer to avoid
+ * window copying
+ *
+ * 1.2.beta5 1 Jan 2003
+ * - Improved inflateBack() interface to allow the caller to provide initial
+ * input in strm.
+ * - Fixed stored blocks bug in inflateBack()
+ *
+ * 1.2.beta6 4 Jan 2003
+ * - Added comments in inffast.c on effectiveness of POSTINC
+ * - Typecasting all around to reduce compiler warnings
+ * - Changed loops from while (1) or do {} while (1) to for (;;), again to
+ * make compilers happy
+ * - Changed type of window in inflateBackInit() to unsigned char *
+ *
+ * 1.2.beta7 27 Jan 2003
+ * - Changed many types to unsigned or unsigned short to avoid warnings
+ * - Added inflateCopy() function
+ *
+ * 1.2.0 9 Mar 2003
+ * - Changed inflateBack() interface to provide separate opaque descriptors
+ * for the in() and out() functions
+ * - Changed inflateBack() argument and in_func typedef to swap the length
+ * and buffer address return values for the input function
+ * - Check next_in and next_out for Z_NULL on entry to inflate()
+ *
+ * The history for versions after 1.2.0 are in ChangeLog in zlib distribution.
*/
#include "zutil.h"
-#include "infblock.h"
-
-struct inflate_blocks_state {int dummy;}; /* for buggy compilers */
-
-typedef enum {
- METHOD, /* waiting for method byte */
- FLAG, /* waiting for flag byte */
- DICT4, /* four dictionary check bytes to go */
- DICT3, /* three dictionary check bytes to go */
- DICT2, /* two dictionary check bytes to go */
- DICT1, /* one dictionary check byte to go */
- DICT0, /* waiting for inflateSetDictionary */
- BLOCKS, /* decompressing blocks */
- CHECK4, /* four check bytes to go */
- CHECK3, /* three check bytes to go */
- CHECK2, /* two check bytes to go */
- CHECK1, /* one check byte to go */
- DONE, /* finished check, done */
- BAD} /* got an error--stay here */
-inflate_mode;
-
-/* inflate private state */
-struct internal_state {
-
- /* mode */
- inflate_mode mode; /* current inflate mode */
-
- /* mode dependent information */
- union {
- uInt method; /* if FLAGS, method byte */
- struct {
- uLong was; /* computed check value */
- uLong need; /* stream check value */
- } check; /* if CHECK, check values to compare */
- uInt marker; /* if BAD, inflateSync's marker bytes count */
- } sub; /* submode */
-
- /* mode independent information */
- int nowrap; /* flag for no wrapper */
- uInt wbits; /* log2(window size) (8..15, defaults to 15) */
- inflate_blocks_statef
- *blocks; /* current inflate_blocks state */
-
-};
-
-
-int ZEXPORT inflateReset(z)
-z_streamp z;
-{
- if (z == Z_NULL || z->state == Z_NULL)
- return Z_STREAM_ERROR;
- z->total_in = z->total_out = 0;
- z->msg = Z_NULL;
- z->state->mode = z->state->nowrap ? BLOCKS : METHOD;
- inflate_blocks_reset(z->state->blocks, z, Z_NULL);
- Tracev((stderr, "inflate: reset\n"));
- return Z_OK;
-}
+#include "inftrees.h"
+#include "inflate.h"
+#include "inffast.h"
+#ifdef MAKEFIXED
+# ifndef BUILDFIXED
+# define BUILDFIXED
+# endif
+#endif
+
+/* function prototypes */
+local void fixedtables OF((struct inflate_state FAR *state));
+local int updatewindow OF((z_streamp strm, unsigned out));
+#ifdef BUILDFIXED
+ void makefixed OF((void));
+#endif
+local unsigned syncsearch OF((unsigned FAR *have, unsigned char FAR *buf,
+ unsigned len));
-int ZEXPORT inflateEnd(z)
-z_streamp z;
+int ZEXPORT inflateReset(strm)
+z_streamp strm;
{
- if (z == Z_NULL || z->state == Z_NULL || z->zfree == Z_NULL)
- return Z_STREAM_ERROR;
- if (z->state->blocks != Z_NULL)
- inflate_blocks_free(z->state->blocks, z);
- ZFREE(z, z->state);
- z->state = Z_NULL;
- Tracev((stderr, "inflate: end\n"));
- return Z_OK;
-}
+ struct inflate_state FAR *state;
+ if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ strm->total_in = strm->total_out = state->total = 0;
+ strm->msg = Z_NULL;
+ strm->adler = 1; /* to support ill-conceived Java test suite */
+ state->mode = HEAD;
+ state->last = 0;
+ state->havedict = 0;
+ state->wsize = 0;
+ state->whave = 0;
+ state->hold = 0;
+ state->bits = 0;
+ state->lencode = state->distcode = state->next = state->codes;
+ Tracev((stderr, "inflate: reset\n"));
+ return Z_OK;
+}
-int ZEXPORT inflateInit2_(z, w, version, stream_size)
-z_streamp z;
-int w;
+int ZEXPORT inflateInit2_(strm, windowBits, version, stream_size)
+z_streamp strm;
+int windowBits;
const char *version;
int stream_size;
{
- if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
- stream_size != sizeof(z_stream))
- return Z_VERSION_ERROR;
-
- /* initialize state */
- if (z == Z_NULL)
- return Z_STREAM_ERROR;
- z->msg = Z_NULL;
- if (z->zalloc == Z_NULL)
- {
- z->zalloc = zcalloc;
- z->opaque = (voidpf)0;
- }
- if (z->zfree == Z_NULL) z->zfree = zcfree;
- if ((z->state = (struct internal_state FAR *)
- ZALLOC(z,1,sizeof(struct internal_state))) == Z_NULL)
- return Z_MEM_ERROR;
- z->state->blocks = Z_NULL;
-
- /* handle undocumented nowrap option (no zlib header or check) */
- z->state->nowrap = 0;
- if (w < 0)
- {
- w = - w;
- z->state->nowrap = 1;
- }
-
- /* set window size */
- if (w < 8 || w > 15)
- {
- inflateEnd(z);
- return Z_STREAM_ERROR;
- }
- z->state->wbits = (uInt)w;
-
- /* create inflate_blocks state */
- if ((z->state->blocks =
- inflate_blocks_new(z, z->state->nowrap ? Z_NULL : adler32, (uInt)1 << w))
- == Z_NULL)
- {
- inflateEnd(z);
- return Z_MEM_ERROR;
- }
- Tracev((stderr, "inflate: allocated\n"));
-
- /* reset state */
- inflateReset(z);
- return Z_OK;
-}
+ struct inflate_state FAR *state;
+ if (version == Z_NULL || version[0] != ZLIB_VERSION[0] ||
+ stream_size != (int)(sizeof(z_stream)))
+ return Z_VERSION_ERROR;
+ if (strm == Z_NULL) return Z_STREAM_ERROR;
+ strm->msg = Z_NULL; /* in case we return an error */
+ if (strm->zalloc == (alloc_func)0) {
+ strm->zalloc = zcalloc;
+ strm->opaque = (voidpf)0;
+ }
+ if (strm->zfree == (free_func)0) strm->zfree = zcfree;
+ state = (struct inflate_state FAR *)
+ ZALLOC(strm, 1, sizeof(struct inflate_state));
+ if (state == Z_NULL) return Z_MEM_ERROR;
+ Tracev((stderr, "inflate: allocated\n"));
+ strm->state = (voidpf)state;
+ if (windowBits < 0) {
+ state->wrap = 0;
+ windowBits = -windowBits;
+ }
+ else {
+ state->wrap = (windowBits >> 4) + 1;
+#ifdef GUNZIP
+ if (windowBits < 48) windowBits &= 15;
+#endif
+ }
+ if (windowBits < 8 || windowBits > 15) {
+ ZFREE(strm, state);
+ strm->state = Z_NULL;
+ return Z_STREAM_ERROR;
+ }
+ state->wbits = (unsigned)windowBits;
+ state->window = Z_NULL;
+ return inflateReset(strm);
+}
-int ZEXPORT inflateInit_(z, version, stream_size)
-z_streamp z;
+int ZEXPORT inflateInit_(strm, version, stream_size)
+z_streamp strm;
const char *version;
int stream_size;
{
- return inflateInit2_(z, DEF_WBITS, version, stream_size);
+ return inflateInit2_(strm, DEF_WBITS, version, stream_size);
+}
+
+/*
+ Return state with length and distance decoding tables and index sizes set to
+ fixed code decoding. Normally this returns fixed tables from inffixed.h.
+ If BUILDFIXED is defined, then instead this routine builds the tables the
+ first time it's called, and returns those tables the first time and
+ thereafter. This reduces the size of the code by about 2K bytes, in
+ exchange for a little execution time. However, BUILDFIXED should not be
+ used for threaded applications, since the rewriting of the tables and virgin
+ may not be thread-safe.
+ */
+local void fixedtables(state)
+struct inflate_state FAR *state;
+{
+#ifdef BUILDFIXED
+ static int virgin = 1;
+ static code *lenfix, *distfix;
+ static code fixed[544];
+
+ /* build fixed huffman tables if first call (may not be thread safe) */
+ if (virgin) {
+ unsigned sym, bits;
+ static code *next;
+
+ /* literal/length table */
+ sym = 0;
+ while (sym < 144) state->lens[sym++] = 8;
+ while (sym < 256) state->lens[sym++] = 9;
+ while (sym < 280) state->lens[sym++] = 7;
+ while (sym < 288) state->lens[sym++] = 8;
+ next = fixed;
+ lenfix = next;
+ bits = 9;
+ inflate_table(LENS, state->lens, 288, &(next), &(bits), state->work);
+
+ /* distance table */
+ sym = 0;
+ while (sym < 32) state->lens[sym++] = 5;
+ distfix = next;
+ bits = 5;
+ inflate_table(DISTS, state->lens, 32, &(next), &(bits), state->work);
+
+ /* do this just once */
+ virgin = 0;
+ }
+#else /* !BUILDFIXED */
+# include "inffixed.h"
+#endif /* BUILDFIXED */
+ state->lencode = lenfix;
+ state->lenbits = 9;
+ state->distcode = distfix;
+ state->distbits = 5;
}
+#ifdef MAKEFIXED
+#include <stdio.h>
-#define NEEDBYTE {if(z->avail_in==0)return r;r=f;}
-#define NEXTBYTE (z->avail_in--,z->total_in++,*z->next_in++)
+/*
+ Write out the inffixed.h that is #include'd above. Defining MAKEFIXED also
+ defines BUILDFIXED, so the tables are built on the fly. makefixed() writes
+ those tables to stdout, which would be piped to inffixed.h. A small program
+ can simply call makefixed to do this:
-int ZEXPORT inflate(z, f)
-z_streamp z;
-int f;
+ void makefixed(void);
+
+ int main(void)
+ {
+ makefixed();
+ return 0;
+ }
+
+ Then that can be linked with zlib built with MAKEFIXED defined and run:
+
+ a.out > inffixed.h
+ */
+void makefixed()
{
- int r;
- uInt b;
-
- if (z == Z_NULL || z->state == Z_NULL || z->next_in == Z_NULL)
- return Z_STREAM_ERROR;
- f = f == Z_FINISH ? Z_BUF_ERROR : Z_OK;
- r = Z_BUF_ERROR;
- while (1) switch (z->state->mode)
- {
- case METHOD:
- NEEDBYTE
- if (((z->state->sub.method = NEXTBYTE) & 0xf) != Z_DEFLATED)
- {
- z->state->mode = BAD;
- z->msg = (char*)"unknown compression method";
- z->state->sub.marker = 5; /* can't try inflateSync */
- break;
- }
- if ((z->state->sub.method >> 4) + 8 > z->state->wbits)
- {
- z->state->mode = BAD;
- z->msg = (char*)"invalid window size";
- z->state->sub.marker = 5; /* can't try inflateSync */
- break;
- }
- z->state->mode = FLAG;
- case FLAG:
- NEEDBYTE
- b = NEXTBYTE;
- if (((z->state->sub.method << 8) + b) % 31)
- {
- z->state->mode = BAD;
- z->msg = (char*)"incorrect header check";
- z->state->sub.marker = 5; /* can't try inflateSync */
- break;
- }
- Tracev((stderr, "inflate: zlib header ok\n"));
- if (!(b & PRESET_DICT))
- {
- z->state->mode = BLOCKS;
- break;
- }
- z->state->mode = DICT4;
- case DICT4:
- NEEDBYTE
- z->state->sub.check.need = (uLong)NEXTBYTE << 24;
- z->state->mode = DICT3;
- case DICT3:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE << 16;
- z->state->mode = DICT2;
- case DICT2:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE << 8;
- z->state->mode = DICT1;
- case DICT1:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE;
- z->adler = z->state->sub.check.need;
- z->state->mode = DICT0;
- return Z_NEED_DICT;
- case DICT0:
- z->state->mode = BAD;
- z->msg = (char*)"need dictionary";
- z->state->sub.marker = 0; /* can try inflateSync */
- return Z_STREAM_ERROR;
- case BLOCKS:
- r = inflate_blocks(z->state->blocks, z, r);
- if (r == Z_DATA_ERROR)
- {
- z->state->mode = BAD;
- z->state->sub.marker = 0; /* can try inflateSync */
- break;
- }
- if (r == Z_OK)
- r = f;
- if (r != Z_STREAM_END)
- return r;
- r = f;
- inflate_blocks_reset(z->state->blocks, z, &z->state->sub.check.was);
- if (z->state->nowrap)
- {
- z->state->mode = DONE;
- break;
- }
- z->state->mode = CHECK4;
- case CHECK4:
- NEEDBYTE
- z->state->sub.check.need = (uLong)NEXTBYTE << 24;
- z->state->mode = CHECK3;
- case CHECK3:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE << 16;
- z->state->mode = CHECK2;
- case CHECK2:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE << 8;
- z->state->mode = CHECK1;
- case CHECK1:
- NEEDBYTE
- z->state->sub.check.need += (uLong)NEXTBYTE;
-
- if (z->state->sub.check.was != z->state->sub.check.need)
- {
- z->state->mode = BAD;
- z->msg = (char*)"incorrect data check";
- z->state->sub.marker = 5; /* can't try inflateSync */
+ unsigned low, size;
+ struct inflate_state state;
+
+ fixedtables(&state);
+ puts(" /* inffixed.h -- table for decoding fixed codes");
+ puts(" * Generated automatically by makefixed().");
+ puts(" */");
+ puts("");
+ puts(" /* WARNING: this file should *not* be used by applications.");
+ puts(" It is part of the implementation of this library and is");
+ puts(" subject to change. Applications should only use zlib.h.");
+ puts(" */");
+ puts("");
+ size = 1U << 9;
+ printf(" static const code lenfix[%u] = {", size);
+ low = 0;
+ for (;;) {
+ if ((low % 7) == 0) printf("\n ");
+ printf("{%u,%u,%d}", state.lencode[low].op, state.lencode[low].bits,
+ state.lencode[low].val);
+ if (++low == size) break;
+ putchar(',');
+ }
+ puts("\n };");
+ size = 1U << 5;
+ printf("\n static const code distfix[%u] = {", size);
+ low = 0;
+ for (;;) {
+ if ((low % 6) == 0) printf("\n ");
+ printf("{%u,%u,%d}", state.distcode[low].op, state.distcode[low].bits,
+ state.distcode[low].val);
+ if (++low == size) break;
+ putchar(',');
+ }
+ puts("\n };");
+}
+#endif /* MAKEFIXED */
+
+/*
+ Update the window with the last wsize (normally 32K) bytes written before
+ returning. If window does not exist yet, create it. This is only called
+ when a window is already in use, or when output has been written during this
+ inflate call, but the end of the deflate stream has not been reached yet.
+ It is also called to create a window for dictionary data when a dictionary
+ is loaded.
+
+ Providing output buffers larger than 32K to inflate() should provide a speed
+ advantage, since only the last 32K of output is copied to the sliding window
+ upon return from inflate(), and since all distances after the first 32K of
+ output will fall in the output data, making match copies simpler and faster.
+ The advantage may be dependent on the size of the processor's data caches.
+ */
+local int updatewindow(strm, out)
+z_streamp strm;
+unsigned out;
+{
+ struct inflate_state FAR *state;
+ unsigned copy, dist;
+
+ state = (struct inflate_state FAR *)strm->state;
+
+ /* if it hasn't been done already, allocate space for the window */
+ if (state->window == Z_NULL) {
+ state->window = (unsigned char FAR *)
+ ZALLOC(strm, 1U << state->wbits,
+ sizeof(unsigned char));
+ if (state->window == Z_NULL) return 1;
+ }
+
+ /* if window not in use yet, initialize */
+ if (state->wsize == 0) {
+ state->wsize = 1U << state->wbits;
+ state->write = 0;
+ state->whave = 0;
+ }
+
+ /* copy state->wsize or less output bytes into the circular window */
+ copy = out - strm->avail_out;
+ if (copy >= state->wsize) {
+ zmemcpy(state->window, strm->next_out - state->wsize, state->wsize);
+ state->write = 0;
+ state->whave = state->wsize;
+ }
+ else {
+ dist = state->wsize - state->write;
+ if (dist > copy) dist = copy;
+ zmemcpy(state->window + state->write, strm->next_out - copy, dist);
+ copy -= dist;
+ if (copy) {
+ zmemcpy(state->window, strm->next_out - copy, copy);
+ state->write = copy;
+ state->whave = state->wsize;
+ }
+ else {
+ state->write += dist;
+ if (state->write == state->wsize) state->write = 0;
+ if (state->whave < state->wsize) state->whave += dist;
+ }
+ }
+ return 0;
+}
+
+/* Macros for inflate(): */
+
+/* check function to use adler32() for zlib or crc32() for gzip */
+#ifdef GUNZIP
+# define UPDATE(check, buf, len) \
+ (state->flags ? crc32(check, buf, len) : adler32(check, buf, len))
+#else
+# define UPDATE(check, buf, len) adler32(check, buf, len)
+#endif
+
+/* check macros for header crc */
+#ifdef GUNZIP
+# define CRC2(check, word) \
+ do { \
+ hbuf[0] = (unsigned char)(word); \
+ hbuf[1] = (unsigned char)((word) >> 8); \
+ check = crc32(check, hbuf, 2); \
+ } while (0)
+
+# define CRC4(check, word) \
+ do { \
+ hbuf[0] = (unsigned char)(word); \
+ hbuf[1] = (unsigned char)((word) >> 8); \
+ hbuf[2] = (unsigned char)((word) >> 16); \
+ hbuf[3] = (unsigned char)((word) >> 24); \
+ check = crc32(check, hbuf, 4); \
+ } while (0)
+#endif
+
+/* Load registers with state in inflate() for speed */
+#define LOAD() \
+ do { \
+ put = strm->next_out; \
+ left = strm->avail_out; \
+ next = strm->next_in; \
+ have = strm->avail_in; \
+ hold = state->hold; \
+ bits = state->bits; \
+ } while (0)
+
+/* Restore state from registers in inflate() */
+#define RESTORE() \
+ do { \
+ strm->next_out = put; \
+ strm->avail_out = left; \
+ strm->next_in = next; \
+ strm->avail_in = have; \
+ state->hold = hold; \
+ state->bits = bits; \
+ } while (0)
+
+/* Clear the input bit accumulator */
+#define INITBITS() \
+ do { \
+ hold = 0; \
+ bits = 0; \
+ } while (0)
+
+/* Get a byte of input into the bit accumulator, or return from inflate()
+ if there is no input available. */
+#define PULLBYTE() \
+ do { \
+ if (have == 0) goto inf_leave; \
+ have--; \
+ hold += (unsigned long)(*next++) << bits; \
+ bits += 8; \
+ } while (0)
+
+/* Assure that there are at least n bits in the bit accumulator. If there is
+ not enough available input to do that, then return from inflate(). */
+#define NEEDBITS(n) \
+ do { \
+ while (bits < (unsigned)(n)) \
+ PULLBYTE(); \
+ } while (0)
+
+/* Return the low n bits of the bit accumulator (n < 16) */
+#define BITS(n) \
+ ((unsigned)hold & ((1U << (n)) - 1))
+
+/* Remove n bits from the bit accumulator */
+#define DROPBITS(n) \
+ do { \
+ hold >>= (n); \
+ bits -= (unsigned)(n); \
+ } while (0)
+
+/* Remove zero to seven bits as needed to go to a byte boundary */
+#define BYTEBITS() \
+ do { \
+ hold >>= bits & 7; \
+ bits -= bits & 7; \
+ } while (0)
+
+/* Reverse the bytes in a 32-bit value */
+#define REVERSE(q) \
+ ((((q) >> 24) & 0xff) + (((q) >> 8) & 0xff00) + \
+ (((q) & 0xff00) << 8) + (((q) & 0xff) << 24))
+
+/*
+ inflate() uses a state machine to process as much input data and generate as
+ much output data as possible before returning. The state machine is
+ structured roughly as follows:
+
+ for (;;) switch (state) {
+ ...
+ case STATEn:
+ if (not enough input data or output space to make progress)
+ return;
+ ... make progress ...
+ state = STATEm;
break;
- }
- Tracev((stderr, "inflate: zlib check ok\n"));
- z->state->mode = DONE;
- case DONE:
- return Z_STREAM_END;
- case BAD:
- return Z_DATA_ERROR;
- default:
- return Z_STREAM_ERROR;
- }
-#ifdef NEED_DUMMY_RETURN
- return Z_STREAM_ERROR; /* Some dumb compilers complain without this */
+ ...
+ }
+
+ so when inflate() is called again, the same case is attempted again, and
+ if the appropriate resources are provided, the machine proceeds to the
+ next state. The NEEDBITS() macro is usually the way the state evaluates
+ whether it can proceed or should return. NEEDBITS() does the return if
+ the requested bits are not available. The typical use of the BITS macros
+ is:
+
+ NEEDBITS(n);
+ ... do something with BITS(n) ...
+ DROPBITS(n);
+
+ where NEEDBITS(n) either returns from inflate() if there isn't enough
+ input left to load n bits into the accumulator, or it continues. BITS(n)
+ gives the low n bits in the accumulator. When done, DROPBITS(n) drops
+ the low n bits off the accumulator. INITBITS() clears the accumulator
+ and sets the number of available bits to zero. BYTEBITS() discards just
+ enough bits to put the accumulator on a byte boundary. After BYTEBITS()
+ and a NEEDBITS(8), then BITS(8) would return the next byte in the stream.
+
+ NEEDBITS(n) uses PULLBYTE() to get an available byte of input, or to return
+ if there is no input available. The decoding of variable length codes uses
+ PULLBYTE() directly in order to pull just enough bytes to decode the next
+ code, and no more.
+
+ Some states loop until they get enough input, making sure that enough
+ state information is maintained to continue the loop where it left off
+ if NEEDBITS() returns in the loop. For example, want, need, and keep
+ would all have to actually be part of the saved state in case NEEDBITS()
+ returns:
+
+ case STATEw:
+ while (want < need) {
+ NEEDBITS(n);
+ keep[want++] = BITS(n);
+ DROPBITS(n);
+ }
+ state = STATEx;
+ case STATEx:
+
+ As shown above, if the next state is also the next case, then the break
+ is omitted.
+
+ A state may also return if there is not enough output space available to
+ complete that state. Those states are copying stored data, writing a
+ literal byte, and copying a matching string.
+
+ When returning, a "goto inf_leave" is used to update the total counters,
+ update the check value, and determine whether any progress has been made
+ during that inflate() call in order to return the proper return code.
+ Progress is defined as a change in either strm->avail_in or strm->avail_out.
+ When there is a window, goto inf_leave will update the window with the last
+ output written. If a goto inf_leave occurs in the middle of decompression
+ and there is no window currently, goto inf_leave will create one and copy
+ output to the window for the next call of inflate().
+
+ In this implementation, the flush parameter of inflate() only affects the
+ return code (per zlib.h). inflate() always writes as much as possible to
+ strm->next_out, given the space available and the provided input--the effect
+ documented in zlib.h of Z_SYNC_FLUSH. Furthermore, inflate() always defers
+ the allocation of and copying into a sliding window until necessary, which
+ provides the effect documented in zlib.h for Z_FINISH when the entire input
+ stream available. So the only thing the flush parameter actually does is:
+ when flush is set to Z_FINISH, inflate() cannot return Z_OK. Instead it
+ will return Z_BUF_ERROR if it has not reached the end of the stream.
+ */
+
+int ZEXPORT inflate(strm, flush)
+z_streamp strm;
+int flush;
+{
+ struct inflate_state FAR *state;
+ unsigned char FAR *next; /* next input */
+ unsigned char FAR *put; /* next output */
+ unsigned have, left; /* available input and output */
+ unsigned long hold; /* bit buffer */
+ unsigned bits; /* bits in bit buffer */
+ unsigned in, out; /* save starting available input and output */
+ unsigned copy; /* number of stored or match bytes to copy */
+ unsigned char FAR *from; /* where to copy match bytes from */
+ code this; /* current decoding table entry */
+ code last; /* parent table entry */
+ unsigned len; /* length to copy for repeats, bits to drop */
+ int ret; /* return code */
+#ifdef GUNZIP
+ unsigned char hbuf[4]; /* buffer for gzip header crc calculation */
#endif
+ static const unsigned short order[19] = /* permutation of code lengths */
+ {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+
+ if (strm == Z_NULL || strm->state == Z_NULL || strm->next_out == Z_NULL ||
+ (strm->next_in == Z_NULL && strm->avail_in != 0))
+ return Z_STREAM_ERROR;
+
+ state = (struct inflate_state FAR *)strm->state;
+ if (state->mode == TYPE) state->mode = TYPEDO; /* skip check */
+ LOAD();
+ in = have;
+ out = left;
+ ret = Z_OK;
+ for (;;)
+ switch (state->mode) {
+ case HEAD:
+ if (state->wrap == 0) {
+ state->mode = TYPEDO;
+ break;
+ }
+ NEEDBITS(16);
+#ifdef GUNZIP
+ if ((state->wrap & 2) && hold == 0x8b1f) { /* gzip header */
+ state->check = crc32(0L, Z_NULL, 0);
+ CRC2(state->check, hold);
+ INITBITS();
+ state->mode = FLAGS;
+ break;
+ }
+ state->flags = 0; /* expect zlib header */
+ if (!(state->wrap & 1) || /* check if zlib header allowed */
+#else
+ if (
+#endif
+ ((BITS(8) << 8) + (hold >> 8)) % 31) {
+ strm->msg = (char *)"incorrect header check";
+ state->mode = BAD;
+ break;
+ }
+ if (BITS(4) != Z_DEFLATED) {
+ strm->msg = (char *)"unknown compression method";
+ state->mode = BAD;
+ break;
+ }
+ DROPBITS(4);
+ if (BITS(4) + 8 > state->wbits) {
+ strm->msg = (char *)"invalid window size";
+ state->mode = BAD;
+ break;
+ }
+ Tracev((stderr, "inflate: zlib header ok\n"));
+ strm->adler = state->check = adler32(0L, Z_NULL, 0);
+ state->mode = hold & 0x200 ? DICTID : TYPE;
+ INITBITS();
+ break;
+#ifdef GUNZIP
+ case FLAGS:
+ NEEDBITS(16);
+ state->flags = (int)(hold);
+ if ((state->flags & 0xff) != Z_DEFLATED) {
+ strm->msg = (char *)"unknown compression method";
+ state->mode = BAD;
+ break;
+ }
+ if (state->flags & 0xe000) {
+ strm->msg = (char *)"unknown header flags set";
+ state->mode = BAD;
+ break;
+ }
+ if (state->flags & 0x0200) CRC2(state->check, hold);
+ INITBITS();
+ state->mode = TIME;
+ case TIME:
+ NEEDBITS(32);
+ if (state->flags & 0x0200) CRC4(state->check, hold);
+ INITBITS();
+ state->mode = OS;
+ case OS:
+ NEEDBITS(16);
+ if (state->flags & 0x0200) CRC2(state->check, hold);
+ INITBITS();
+ state->mode = EXLEN;
+ case EXLEN:
+ if (state->flags & 0x0400) {
+ NEEDBITS(16);
+ state->length = (unsigned)(hold);
+ if (state->flags & 0x0200) CRC2(state->check, hold);
+ INITBITS();
+ }
+ state->mode = EXTRA;
+ case EXTRA:
+ if (state->flags & 0x0400) {
+ copy = state->length;
+ if (copy > have) copy = have;
+ if (copy) {
+ if (state->flags & 0x0200)
+ state->check = crc32(state->check, next, copy);
+ have -= copy;
+ next += copy;
+ state->length -= copy;
+ }
+ if (state->length) goto inf_leave;
+ }
+ state->mode = NAME;
+ case NAME:
+ if (state->flags & 0x0800) {
+ if (have == 0) goto inf_leave;
+ copy = 0;
+ do {
+ len = (unsigned)(next[copy++]);
+ } while (len && copy < have);
+ if (state->flags & 0x02000)
+ state->check = crc32(state->check, next, copy);
+ have -= copy;
+ next += copy;
+ if (len) goto inf_leave;
+ }
+ state->mode = COMMENT;
+ case COMMENT:
+ if (state->flags & 0x1000) {
+ if (have == 0) goto inf_leave;
+ copy = 0;
+ do {
+ len = (unsigned)(next[copy++]);
+ } while (len && copy < have);
+ if (state->flags & 0x02000)
+ state->check = crc32(state->check, next, copy);
+ have -= copy;
+ next += copy;
+ if (len) goto inf_leave;
+ }
+ state->mode = HCRC;
+ case HCRC:
+ if (state->flags & 0x0200) {
+ NEEDBITS(16);
+ if (hold != (state->check & 0xffff)) {
+ strm->msg = (char *)"header crc mismatch";
+ state->mode = BAD;
+ break;
+ }
+ INITBITS();
+ }
+ strm->adler = state->check = crc32(0L, Z_NULL, 0);
+ state->mode = TYPE;
+ break;
+#endif
+ case DICTID:
+ NEEDBITS(32);
+ strm->adler = state->check = REVERSE(hold);
+ INITBITS();
+ state->mode = DICT;
+ case DICT:
+ if (state->havedict == 0) {
+ RESTORE();
+ return Z_NEED_DICT;
+ }
+ strm->adler = state->check = adler32(0L, Z_NULL, 0);
+ state->mode = TYPE;
+ case TYPE:
+ if (flush == Z_BLOCK) goto inf_leave;
+ case TYPEDO:
+ if (state->last) {
+ BYTEBITS();
+ state->mode = CHECK;
+ break;
+ }
+ NEEDBITS(3);
+ state->last = BITS(1);
+ DROPBITS(1);
+ switch (BITS(2)) {
+ case 0: /* stored block */
+ Tracev((stderr, "inflate: stored block%s\n",
+ state->last ? " (last)" : ""));
+ state->mode = STORED;
+ break;
+ case 1: /* fixed block */
+ fixedtables(state);
+ Tracev((stderr, "inflate: fixed codes block%s\n",
+ state->last ? " (last)" : ""));
+ state->mode = LEN; /* decode codes */
+ break;
+ case 2: /* dynamic block */
+ Tracev((stderr, "inflate: dynamic codes block%s\n",
+ state->last ? " (last)" : ""));
+ state->mode = TABLE;
+ break;
+ case 3:
+ strm->msg = (char *)"invalid block type";
+ state->mode = BAD;
+ }
+ DROPBITS(2);
+ break;
+ case STORED:
+ BYTEBITS(); /* go to byte boundary */
+ NEEDBITS(32);
+ if ((hold & 0xffff) != ((hold >> 16) ^ 0xffff)) {
+ strm->msg = (char *)"invalid stored block lengths";
+ state->mode = BAD;
+ break;
+ }
+ state->length = (unsigned)hold & 0xffff;
+ Tracev((stderr, "inflate: stored length %u\n",
+ state->length));
+ INITBITS();
+ state->mode = COPY;
+ case COPY:
+ copy = state->length;
+ if (copy) {
+ if (copy > have) copy = have;
+ if (copy > left) copy = left;
+ if (copy == 0) goto inf_leave;
+ zmemcpy(put, next, copy);
+ have -= copy;
+ next += copy;
+ left -= copy;
+ put += copy;
+ state->length -= copy;
+ break;
+ }
+ Tracev((stderr, "inflate: stored end\n"));
+ state->mode = TYPE;
+ break;
+ case TABLE:
+ NEEDBITS(14);
+ state->nlen = BITS(5) + 257;
+ DROPBITS(5);
+ state->ndist = BITS(5) + 1;
+ DROPBITS(5);
+ state->ncode = BITS(4) + 4;
+ DROPBITS(4);
+#ifndef PKZIP_BUG_WORKAROUND
+ if (state->nlen > 286 || state->ndist > 30) {
+ strm->msg = (char *)"too many length or distance symbols";
+ state->mode = BAD;
+ break;
+ }
+#endif
+ Tracev((stderr, "inflate: table sizes ok\n"));
+ state->have = 0;
+ state->mode = LENLENS;
+ case LENLENS:
+ while (state->have < state->ncode) {
+ NEEDBITS(3);
+ state->lens[order[state->have++]] = (unsigned short)BITS(3);
+ DROPBITS(3);
+ }
+ while (state->have < 19)
+ state->lens[order[state->have++]] = 0;
+ state->next = state->codes;
+ state->lencode = (code const FAR *)(state->next);
+ state->lenbits = 7;
+ ret = inflate_table(CODES, state->lens, 19, &(state->next),
+ &(state->lenbits), state->work);
+ if (ret) {
+ strm->msg = (char *)"invalid code lengths set";
+ state->mode = BAD;
+ break;
+ }
+ Tracev((stderr, "inflate: code lengths ok\n"));
+ state->have = 0;
+ state->mode = CODELENS;
+ case CODELENS:
+ while (state->have < state->nlen + state->ndist) {
+ for (;;) {
+ this = state->lencode[BITS(state->lenbits)];
+ if ((unsigned)(this.bits) <= bits) break;
+ PULLBYTE();
+ }
+ if (this.val < 16) {
+ NEEDBITS(this.bits);
+ DROPBITS(this.bits);
+ state->lens[state->have++] = this.val;
+ }
+ else {
+ if (this.val == 16) {
+ NEEDBITS(this.bits + 2);
+ DROPBITS(this.bits);
+ if (state->have == 0) {
+ strm->msg = (char *)"invalid bit length repeat";
+ state->mode = BAD;
+ break;
+ }
+ len = state->lens[state->have - 1];
+ copy = 3 + BITS(2);
+ DROPBITS(2);
+ }
+ else if (this.val == 17) {
+ NEEDBITS(this.bits + 3);
+ DROPBITS(this.bits);
+ len = 0;
+ copy = 3 + BITS(3);
+ DROPBITS(3);
+ }
+ else {
+ NEEDBITS(this.bits + 7);
+ DROPBITS(this.bits);
+ len = 0;
+ copy = 11 + BITS(7);
+ DROPBITS(7);
+ }
+ if (state->have + copy > state->nlen + state->ndist) {
+ strm->msg = (char *)"invalid bit length repeat";
+ state->mode = BAD;
+ break;
+ }
+ while (copy--)
+ state->lens[state->have++] = (unsigned short)len;
+ }
+ }
+
+ /* handle error breaks in while */
+ if (state->mode == BAD) break;
+
+ /* build code tables */
+ state->next = state->codes;
+ state->lencode = (code const FAR *)(state->next);
+ state->lenbits = 9;
+ ret = inflate_table(LENS, state->lens, state->nlen, &(state->next),
+ &(state->lenbits), state->work);
+ if (ret) {
+ strm->msg = (char *)"invalid literal/lengths set";
+ state->mode = BAD;
+ break;
+ }
+ state->distcode = (code const FAR *)(state->next);
+ state->distbits = 6;
+ ret = inflate_table(DISTS, state->lens + state->nlen, state->ndist,
+ &(state->next), &(state->distbits), state->work);
+ if (ret) {
+ strm->msg = (char *)"invalid distances set";
+ state->mode = BAD;
+ break;
+ }
+ Tracev((stderr, "inflate: codes ok\n"));
+ state->mode = LEN;
+ case LEN:
+ if (have >= 6 && left >= 258) {
+ RESTORE();
+ inflate_fast(strm, out);
+ LOAD();
+ break;
+ }
+ for (;;) {
+ this = state->lencode[BITS(state->lenbits)];
+ if ((unsigned)(this.bits) <= bits) break;
+ PULLBYTE();
+ }
+ if (this.op && (this.op & 0xf0) == 0) {
+ last = this;
+ for (;;) {
+ this = state->lencode[last.val +
+ (BITS(last.bits + last.op) >> last.bits)];
+ if ((unsigned)(last.bits + this.bits) <= bits) break;
+ PULLBYTE();
+ }
+ DROPBITS(last.bits);
+ }
+ DROPBITS(this.bits);
+ state->length = (unsigned)this.val;
+ if ((int)(this.op) == 0) {
+ Tracevv((stderr, this.val >= 0x20 && this.val < 0x7f ?
+ "inflate: literal '%c'\n" :
+ "inflate: literal 0x%02x\n", this.val));
+ state->mode = LIT;
+ break;
+ }
+ if (this.op & 32) {
+ Tracevv((stderr, "inflate: end of block\n"));
+ state->mode = TYPE;
+ break;
+ }
+ if (this.op & 64) {
+ strm->msg = (char *)"invalid literal/length code";
+ state->mode = BAD;
+ break;
+ }
+ state->extra = (unsigned)(this.op) & 15;
+ state->mode = LENEXT;
+ case LENEXT:
+ if (state->extra) {
+ NEEDBITS(state->extra);
+ state->length += BITS(state->extra);
+ DROPBITS(state->extra);
+ }
+ Tracevv((stderr, "inflate: length %u\n", state->length));
+ state->mode = DIST;
+ case DIST:
+ for (;;) {
+ this = state->distcode[BITS(state->distbits)];
+ if ((unsigned)(this.bits) <= bits) break;
+ PULLBYTE();
+ }
+ if ((this.op & 0xf0) == 0) {
+ last = this;
+ for (;;) {
+ this = state->distcode[last.val +
+ (BITS(last.bits + last.op) >> last.bits)];
+ if ((unsigned)(last.bits + this.bits) <= bits) break;
+ PULLBYTE();
+ }
+ DROPBITS(last.bits);
+ }
+ DROPBITS(this.bits);
+ if (this.op & 64) {
+ strm->msg = (char *)"invalid distance code";
+ state->mode = BAD;
+ break;
+ }
+ state->offset = (unsigned)this.val;
+ state->extra = (unsigned)(this.op) & 15;
+ state->mode = DISTEXT;
+ case DISTEXT:
+ if (state->extra) {
+ NEEDBITS(state->extra);
+ state->offset += BITS(state->extra);
+ DROPBITS(state->extra);
+ }
+ if (state->offset > state->whave + out - left) {
+ strm->msg = (char *)"invalid distance too far back";
+ state->mode = BAD;
+ break;
+ }
+ Tracevv((stderr, "inflate: distance %u\n", state->offset));
+ state->mode = MATCH;
+ case MATCH:
+ if (left == 0) goto inf_leave;
+ copy = out - left;
+ if (state->offset > copy) { /* copy from window */
+ copy = state->offset - copy;
+ if (copy > state->write) {
+ copy -= state->write;
+ from = state->window + (state->wsize - copy);
+ }
+ else
+ from = state->window + (state->write - copy);
+ if (copy > state->length) copy = state->length;
+ }
+ else { /* copy from output */
+ from = put - state->offset;
+ copy = state->length;
+ }
+ if (copy > left) copy = left;
+ left -= copy;
+ state->length -= copy;
+ do {
+ *put++ = *from++;
+ } while (--copy);
+ if (state->length == 0) state->mode = LEN;
+ break;
+ case LIT:
+ if (left == 0) goto inf_leave;
+ *put++ = (unsigned char)(state->length);
+ left--;
+ state->mode = LEN;
+ break;
+ case CHECK:
+ if (state->wrap) {
+ NEEDBITS(32);
+ out -= left;
+ strm->total_out += out;
+ state->total += out;
+ if (out)
+ strm->adler = state->check =
+ UPDATE(state->check, put - out, out);
+ out = left;
+ if ((
+#ifdef GUNZIP
+ state->flags ? hold :
+#endif
+ REVERSE(hold)) != state->check) {
+ strm->msg = (char *)"incorrect data check";
+ state->mode = BAD;
+ break;
+ }
+ INITBITS();
+ Tracev((stderr, "inflate: check matches trailer\n"));
+ }
+#ifdef GUNZIP
+ state->mode = LENGTH;
+ case LENGTH:
+ if (state->wrap && state->flags) {
+ NEEDBITS(32);
+ if (hold != (state->total & 0xffffffffUL)) {
+ strm->msg = (char *)"incorrect length check";
+ state->mode = BAD;
+ break;
+ }
+ INITBITS();
+ Tracev((stderr, "inflate: length matches trailer\n"));
+ }
+#endif
+ state->mode = DONE;
+ case DONE:
+ ret = Z_STREAM_END;
+ goto inf_leave;
+ case BAD:
+ ret = Z_DATA_ERROR;
+ goto inf_leave;
+ case MEM:
+ return Z_MEM_ERROR;
+ case SYNC:
+ default:
+ return Z_STREAM_ERROR;
+ }
+
+ /*
+ Return from inflate(), updating the total counts and the check value.
+ If there was no progress during the inflate() call, return a buffer
+ error. Call updatewindow() to create and/or update the window state.
+ Note: a memory error from inflate() is non-recoverable.
+ */
+ inf_leave:
+ RESTORE();
+ if (state->wsize || (state->mode < CHECK && out != strm->avail_out))
+ if (updatewindow(strm, out)) {
+ state->mode = MEM;
+ return Z_MEM_ERROR;
+ }
+ in -= strm->avail_in;
+ out -= strm->avail_out;
+ strm->total_in += in;
+ strm->total_out += out;
+ state->total += out;
+ if (state->wrap && out)
+ strm->adler = state->check =
+ UPDATE(state->check, strm->next_out - out, out);
+ strm->data_type = state->bits + (state->last ? 64 : 0) +
+ (state->mode == TYPE ? 128 : 0);
+ if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
+ ret = Z_BUF_ERROR;
+ return ret;
}
+int ZEXPORT inflateEnd(strm)
+z_streamp strm;
+{
+ struct inflate_state FAR *state;
+ if (strm == Z_NULL || strm->state == Z_NULL || strm->zfree == (free_func)0)
+ return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ if (state->window != Z_NULL) ZFREE(strm, state->window);
+ ZFREE(strm, strm->state);
+ strm->state = Z_NULL;
+ Tracev((stderr, "inflate: end\n"));
+ return Z_OK;
+}
-int ZEXPORT inflateSetDictionary(z, dictionary, dictLength)
-z_streamp z;
+int ZEXPORT inflateSetDictionary(strm, dictionary, dictLength)
+z_streamp strm;
const Bytef *dictionary;
-uInt dictLength;
+uInt dictLength;
{
- uInt length = dictLength;
-
- if (z == Z_NULL || z->state == Z_NULL || z->state->mode != DICT0)
- return Z_STREAM_ERROR;
-
- if (adler32(1L, dictionary, dictLength) != z->adler) return Z_DATA_ERROR;
- z->adler = 1L;
-
- if (length >= ((uInt)1<<z->state->wbits))
- {
- length = (1<<z->state->wbits)-1;
- dictionary += dictLength - length;
- }
- inflate_set_dictionary(z->state->blocks, dictionary, length);
- z->state->mode = BLOCKS;
- return Z_OK;
-}
+ struct inflate_state FAR *state;
+ unsigned long id;
+ /* check state */
+ if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ if (state->mode != DICT) return Z_STREAM_ERROR;
-int ZEXPORT inflateSync(z)
-z_streamp z;
+ /* check for correct dictionary id */
+ id = adler32(0L, Z_NULL, 0);
+ id = adler32(id, dictionary, dictLength);
+ if (id != state->check) return Z_DATA_ERROR;
+
+ /* copy dictionary to window */
+ if (updatewindow(strm, strm->avail_out)) {
+ state->mode = MEM;
+ return Z_MEM_ERROR;
+ }
+ if (dictLength > state->wsize) {
+ zmemcpy(state->window, dictionary + dictLength - state->wsize,
+ state->wsize);
+ state->whave = state->wsize;
+ }
+ else {
+ zmemcpy(state->window + state->wsize - dictLength, dictionary,
+ dictLength);
+ state->whave = dictLength;
+ }
+ state->havedict = 1;
+ Tracev((stderr, "inflate: dictionary set\n"));
+ return Z_OK;
+}
+
+/*
+ Search buf[0..len-1] for the pattern: 0, 0, 0xff, 0xff. Return when found
+ or when out of input. When called, *have is the number of pattern bytes
+ found in order so far, in 0..3. On return *have is updated to the new
+ state. If on return *have equals four, then the pattern was found and the
+ return value is how many bytes were read including the last byte of the
+ pattern. If *have is less than four, then the pattern has not been found
+ yet and the return value is len. In the latter case, syncsearch() can be
+ called again with more data and the *have state. *have is initialized to
+ zero for the first call.
+ */
+local unsigned syncsearch(have, buf, len)
+unsigned FAR *have;
+unsigned char FAR *buf;
+unsigned len;
{
- uInt n; /* number of bytes to look at */
- Bytef *p; /* pointer to bytes */
- uInt m; /* number of marker bytes found in a row */
- uLong r, w; /* temporaries to save total_in and total_out */
-
- /* set up */
- if (z == Z_NULL || z->state == Z_NULL)
- return Z_STREAM_ERROR;
- if (z->state->mode != BAD)
- {
- z->state->mode = BAD;
- z->state->sub.marker = 0;
- }
- if ((n = z->avail_in) == 0)
- return Z_BUF_ERROR;
- p = z->next_in;
- m = z->state->sub.marker;
-
- /* search */
- while (n && m < 4)
- {
- static const Byte mark[4] = {0, 0, 0xff, 0xff};
- if (*p == mark[m])
- m++;
- else if (*p)
- m = 0;
- else
- m = 4 - m;
- p++, n--;
- }
-
- /* restore */
- z->total_in += p - z->next_in;
- z->next_in = p;
- z->avail_in = n;
- z->state->sub.marker = m;
-
- /* return no joy or set up to restart on a new block */
- if (m != 4)
- return Z_DATA_ERROR;
- r = z->total_in; w = z->total_out;
- inflateReset(z);
- z->total_in = r; z->total_out = w;
- z->state->mode = BLOCKS;
- return Z_OK;
+ unsigned got;
+ unsigned next;
+
+ got = *have;
+ next = 0;
+ while (next < len && got < 4) {
+ if ((int)(buf[next]) == (got < 2 ? 0 : 0xff))
+ got++;
+ else if (buf[next])
+ got = 0;
+ else
+ got = 4 - got;
+ next++;
+ }
+ *have = got;
+ return next;
}
+int ZEXPORT inflateSync(strm)
+z_streamp strm;
+{
+ unsigned len; /* number of bytes to look at or looked at */
+ unsigned long in, out; /* temporary to save total_in and total_out */
+ unsigned char buf[4]; /* to restore bit buffer to byte string */
+ struct inflate_state FAR *state;
-/* Returns true if inflate is currently at the end of a block generated
- * by Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
- * implementation to provide an additional safety check. PPP uses Z_SYNC_FLUSH
- * but removes the length bytes of the resulting empty stored block. When
- * decompressing, PPP checks that at the end of input packet, inflate is
- * waiting for these length bytes.
+ /* check parameters */
+ if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ if (strm->avail_in == 0 && state->bits < 8) return Z_BUF_ERROR;
+
+ /* if first time, start search in bit buffer */
+ if (state->mode != SYNC) {
+ state->mode = SYNC;
+ state->hold <<= state->bits & 7;
+ state->bits -= state->bits & 7;
+ len = 0;
+ while (state->bits >= 8) {
+ buf[len++] = (unsigned char)(state->hold);
+ state->hold >>= 8;
+ state->bits -= 8;
+ }
+ state->have = 0;
+ syncsearch(&(state->have), buf, len);
+ }
+
+ /* search available input */
+ len = syncsearch(&(state->have), strm->next_in, strm->avail_in);
+ strm->avail_in -= len;
+ strm->next_in += len;
+ strm->total_in += len;
+
+ /* return no joy or set up to restart inflate() on a new block */
+ if (state->have != 4) return Z_DATA_ERROR;
+ in = strm->total_in; out = strm->total_out;
+ inflateReset(strm);
+ strm->total_in = in; strm->total_out = out;
+ state->mode = TYPE;
+ return Z_OK;
+}
+
+/*
+ Returns true if inflate is currently at the end of a block generated by
+ Z_SYNC_FLUSH or Z_FULL_FLUSH. This function is used by one PPP
+ implementation to provide an additional safety check. PPP uses
+ Z_SYNC_FLUSH but removes the length bytes of the resulting empty stored
+ block. When decompressing, PPP checks that at the end of input packet,
+ inflate is waiting for these length bytes.
*/
-int ZEXPORT inflateSyncPoint(z)
-z_streamp z;
+int ZEXPORT inflateSyncPoint(strm)
+z_streamp strm;
+{
+ struct inflate_state FAR *state;
+
+ if (strm == Z_NULL || strm->state == Z_NULL) return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)strm->state;
+ return state->mode == STORED && state->bits == 0;
+}
+
+int ZEXPORT inflateCopy(dest, source)
+z_streamp dest;
+z_streamp source;
{
- if (z == Z_NULL || z->state == Z_NULL || z->state->blocks == Z_NULL)
- return Z_STREAM_ERROR;
- return inflate_blocks_sync_point(z->state->blocks);
+ struct inflate_state FAR *state;
+ struct inflate_state FAR *copy;
+ unsigned char FAR *window;
+
+ /* check input */
+ if (dest == Z_NULL || source == Z_NULL || source->state == Z_NULL ||
+ source->zalloc == (alloc_func)0 || source->zfree == (free_func)0)
+ return Z_STREAM_ERROR;
+ state = (struct inflate_state FAR *)source->state;
+
+ /* allocate space */
+ copy = (struct inflate_state FAR *)
+ ZALLOC(source, 1, sizeof(struct inflate_state));
+ if (copy == Z_NULL) return Z_MEM_ERROR;
+ window = Z_NULL;
+ if (state->window != Z_NULL) {
+ window = (unsigned char FAR *)
+ ZALLOC(source, 1U << state->wbits, sizeof(unsigned char));
+ if (window == Z_NULL) {
+ ZFREE(source, copy);
+ return Z_MEM_ERROR;
+ }
+ }
+
+ /* copy state */
+ *dest = *source;
+ *copy = *state;
+ copy->lencode = copy->codes + (state->lencode - state->codes);
+ copy->distcode = copy->codes + (state->distcode - state->codes);
+ copy->next = copy->codes + (state->next - state->codes);
+ if (window != Z_NULL)
+ zmemcpy(window, state->window, 1U << state->wbits);
+ copy->window = window;
+ dest->state = (voidpf)copy;
+ return Z_OK;
}
projects / wxWidgets.git / blobdiff