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zig/std/zlib/inflate.zig

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c-to-zig: return statement
2017-09-01 00:16:35 -07:00
error Z_STREAM_ERROR;
error Z_STREAM_END;
error Z_NEED_DICT;
error Z_ERRNO;
error Z_STREAM_ERROR;
error Z_DATA_ERROR;
error Z_MEM_ERROR;
error Z_BUF_ERROR;
error Z_VERSION_ERROR;
pub Flush = enum {
NO_FLUSH,
PARTIAL_FLUSH,
SYNC_FLUSH,
FULL_FLUSH,
FINISH,
BLOCK,
TREES,
};
const code = struct {
/// operation, extra bits, table bits
op: u8,
/// bits in this part of the code
bits: u8,
/// offset in table or code value
val: u16,
};
/// State maintained between inflate() calls -- approximately 7K bytes, not
/// including the allocated sliding window, which is up to 32K bytes.
const inflate_state = struct {
z_stream * strm; /* pointer back to this zlib stream */
inflate_mode mode; /* current inflate mode */
int last; /* true if processing last block */
int wrap; /* bit 0 true for zlib, bit 1 true for gzip,
bit 2 true to validate check value */
int havedict; /* true if dictionary provided */
int flags; /* gzip header method and flags (0 if zlib) */
unsigned dmax; /* zlib header max distance (INFLATE_STRICT) */
unsigned long check; /* protected copy of check value */
unsigned long total; /* protected copy of output count */
gz_headerp head; /* where to save gzip header information */
/* sliding window */
unsigned wbits; /* log base 2 of requested window size */
unsigned wsize; /* window size or zero if not using window */
unsigned whave; /* valid bytes in the window */
unsigned wnext; /* window write index */
u8 FAR *window; /* allocated sliding window, if needed */
/* bit accumulator */
unsigned long hold; /* input bit accumulator */
unsigned bits; /* number of bits in "in" */
/* for string and stored block copying */
unsigned length; /* literal or length of data to copy */
unsigned offset; /* distance back to copy string from */
/* for table and code decoding */
unsigned extra; /* extra bits needed */
/* fixed and dynamic code tables */
code const FAR *lencode; /* starting table for length/literal codes */
code const FAR *distcode; /* starting table for distance codes */
unsigned lenbits; /* index bits for lencode */
unsigned distbits; /* index bits for distcode */
/* dynamic table building */
unsigned ncode; /* number of code length code lengths */
unsigned nlen; /* number of length code lengths */
unsigned ndist; /* number of distance code lengths */
unsigned have; /* number of code lengths in lens[] */
code FAR *next; /* next available space in codes[] */
unsigned short lens[320]; /* temporary storage for code lengths */
unsigned short work[288]; /* work area for code table building */
code codes[ENOUGH]; /* space for code tables */
int sane; /* if false, allow invalid distance too far */
int back; /* bits back of last unprocessed length/lit */
unsigned was; /* initial length of match */
};
const alloc_func = fn(opaque: &c_void, items: u16, size: u16);
const free_func = fn(opaque: &c_void, address: &c_void);
const z_stream = struct {
/// next input byte
next_in: &u8,
/// number of bytes available at next_in
avail_in: u16,
/// total number of input bytes read so far
total_in: u32,
/// next output byte will go here
next_out: &u8,
/// remaining free space at next_out
avail_out: u16,
/// total number of bytes output so far */
total_out: u32,
/// last error message, NULL if no error
msg: &const u8,
/// not visible by applications
state: &inflate_state,
/// used to allocate the internal state
zalloc: alloc_func,
/// used to free the internal state
zfree: free_func,
/// private data object passed to zalloc and zfree
opaque: &c_void,
/// best guess about the data type: binary or text
/// for deflate, or the decoding state for inflate
data_type: i32,
/// Adler-32 or CRC-32 value of the uncompressed data
adler: u32,
};
// Possible inflate modes between inflate() calls
/// i: waiting for magic header
pub const HEAD = 16180;
/// i: waiting for method and flags (gzip)
pub const FLAGS = 16181;
/// i: waiting for modification time (gzip)
pub const TIME = 16182;
/// i: waiting for extra flags and operating system (gzip)
pub const OS = 16183;
/// i: waiting for extra length (gzip)
pub const EXLEN = 16184;
/// i: waiting for extra bytes (gzip)
pub const EXTRA = 16185;
/// i: waiting for end of file name (gzip)
pub const NAME = 16186;
/// i: waiting for end of comment (gzip)
pub const COMMENT = 16187;
/// i: waiting for header crc (gzip)
pub const HCRC = 16188;
/// i: waiting for dictionary check value
pub const DICTID = 16189;
/// waiting for inflateSetDictionary() call
pub const DICT = 16190;
/// i: waiting for type bits, including last-flag bit
pub const TYPE = 16191;
/// i: same, but skip check to exit inflate on new block
pub const TYPEDO = 16192;
/// i: waiting for stored size (length and complement)
pub const STORED = 16193;
/// i/o: same as COPY below, but only first time in
pub const COPY_ = 16194;
/// i/o: waiting for input or output to copy stored block
pub const COPY = 16195;
/// i: waiting for dynamic block table lengths
pub const TABLE = 16196;
/// i: waiting for code length code lengths
pub const LENLENS = 16197;
/// i: waiting for length/lit and distance code lengths
pub const CODELENS = 16198;
/// i: same as LEN below, but only first time in
pub const LEN_ = 16199;
/// i: waiting for length/lit/eob code
pub const LEN = 16200;
/// i: waiting for length extra bits
pub const LENEXT = 16201;
/// i: waiting for distance code
pub const DIST = 16202;
/// i: waiting for distance extra bits
pub const DISTEXT = 16203;
/// o: waiting for output space to copy string
pub const MATCH = 16204;
/// o: waiting for output space to write literal
pub const LIT = 16205;
/// i: waiting for 32-bit check value
pub const CHECK = 16206;
/// i: waiting for 32-bit length (gzip)
pub const LENGTH = 16207;
/// finished check, done -- remain here until reset
pub const DONE = 16208;
/// got a data error -- remain here until reset
pub const BAD = 16209;
/// got an inflate() memory error -- remain here until reset
pub const MEM = 16210;
/// looking for synchronization bytes to restart inflate() */
pub const SYNC = 16211;
/// 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;
/// ...
/// }
///
/// 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.
pub fn inflate(strm: &z_stream, flush: Flush, gunzip: bool) -> %void {
// next input
var next: &const u8 = undefined;
// next output
var put: &u8 = undefined;
// available input and output
var have: u16 = undefined;
var left: u16 = undefined;
// bit buffer
var hold: u32 = undefined;
// bits in bit buffer
var bits: u16 = undefined;
// save starting available input and output
var in: u16 = undefined;
var out: u16 = undefined;
// number of stored or match bytes to copy
var copy: u16 = undefined;
// where to copy match bytes from
var from: &u8 = undefined;
// current decoding table entry
var here: code = undefined;
// parent table entry
var last: code = undefined;
// length to copy for repeats, bits to drop
var len: u16 = undefined;
// return code
var ret: error = undefined;
// buffer for gzip header crc calculation
var hbuf: [4]u8 = undefined;
// permutation of code lengths
const short_order = []u16 = {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
if (inflateStateCheck(strm) or strm.next_out == Z_NULL or (strm.next_in == Z_NULL and strm.avail_in != 0)) {
return error.Z_STREAM_ERROR;
}
var state: &inflate_state = strm.state;
if (state.mode == TYPE) {
state.mode = TYPEDO; // skip check
}
put = strm.next_out; \
left = strm.avail_out; \
next = strm.next_in; \
have = strm.avail_in; \
hold = state.hold; \
bits = state.bits; \
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 */
if (state.wbits == 0)
state.wbits = 15;
state.check = crc32(0L, Z_NULL, 0);
CRC2(state.check, hold);
INITBITS();
state.mode = FLAGS;
break;
}
state.flags = 0; /* expect zlib header */
if (state.head != Z_NULL)
state.head.done = -1;
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);
len = BITS(4) + 8;
if (state.wbits == 0)
state.wbits = len;
if (len > 15 || len > state.wbits) {
strm.msg = (char *)"invalid window size";
state.mode = BAD;
break;
}
state.dmax = 1U << len;
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.head != Z_NULL)
state.head.text = (int)((hold >> 8) & 1);
if ((state.flags & 0x0200) && (state.wrap & 4))
CRC2(state.check, hold);
INITBITS();
state.mode = TIME;
case TIME:
NEEDBITS(32);
if (state.head != Z_NULL)
state.head.time = hold;
if ((state.flags & 0x0200) && (state.wrap & 4))
CRC4(state.check, hold);
INITBITS();
state.mode = OS;
case OS:
NEEDBITS(16);
if (state.head != Z_NULL) {
state.head.xflags = (int)(hold & 0xff);
state.head.os = (int)(hold >> 8);
}
if ((state.flags & 0x0200) && (state.wrap & 4))
CRC2(state.check, hold);
INITBITS();
state.mode = EXLEN;
case EXLEN:
if (state.flags & 0x0400) {
NEEDBITS(16);
state.length = (unsigned)(hold);
if (state.head != Z_NULL)
state.head.extra_len = (unsigned)hold;
if ((state.flags & 0x0200) && (state.wrap & 4))
CRC2(state.check, hold);
INITBITS();
}
else if (state.head != Z_NULL)
state.head.extra = Z_NULL;
state.mode = EXTRA;
case EXTRA:
if (state.flags & 0x0400) {
copy = state.length;
if (copy > have) copy = have;
if (copy) {
if (state.head != Z_NULL &&
state.head.extra != Z_NULL) {
len = state.head.extra_len - state.length;
zmemcpy(state.head.extra + len, next,
len + copy > state.head.extra_max ?
state.head.extra_max - len : copy);
}
if ((state.flags & 0x0200) && (state.wrap & 4))
state.check = crc32(state.check, next, copy);
have -= copy;
next += copy;
state.length -= copy;
}
if (state.length) goto inf_leave;
}
state.length = 0;
state.mode = NAME;
case NAME:
if (state.flags & 0x0800) {
if (have == 0) goto inf_leave;
copy = 0;
do {
len = (unsigned)(next[copy++]);
if (state.head != Z_NULL &&
state.head.name != Z_NULL &&
state.length < state.head.name_max)
state.head.name[state.length++] = (Bytef)len;
} while (len && copy < have);
if ((state.flags & 0x0200) && (state.wrap & 4))
state.check = crc32(state.check, next, copy);
have -= copy;
next += copy;
if (len) goto inf_leave;
}
else if (state.head != Z_NULL)
state.head.name = Z_NULL;
state.length = 0;
state.mode = COMMENT;
case COMMENT:
if (state.flags & 0x1000) {
if (have == 0) goto inf_leave;
copy = 0;
do {
len = (unsigned)(next[copy++]);
if (state.head != Z_NULL &&
state.head.comment != Z_NULL &&
state.length < state.head.comm_max)
state.head.comment[state.length++] = (Bytef)len;
} while (len && copy < have);
if ((state.flags & 0x0200) && (state.wrap & 4))
state.check = crc32(state.check, next, copy);
have -= copy;
next += copy;
if (len) goto inf_leave;
}
else if (state.head != Z_NULL)
state.head.comment = Z_NULL;
state.mode = HCRC;
case HCRC:
if (state.flags & 0x0200) {
NEEDBITS(16);
if ((state.wrap & 4) && hold != (state.check & 0xffff)) {
strm.msg = (char *)"header crc mismatch";
state.mode = BAD;
break;
}
INITBITS();
}
if (state.head != Z_NULL) {
state.head.hcrc = (int)((state.flags >> 9) & 1);
state.head.done = 1;
}
strm.adler = state.check = crc32(0L, Z_NULL, 0);
state.mode = TYPE;
break;
#endif
case DICTID:
NEEDBITS(32);
strm.adler = state.check = ZSWAP32(hold);
INITBITS();
state.mode = DICT;
case DICT:
if (state.havedict == 0) {
strm.next_out = put; \
strm.avail_out = left; \
strm.next_in = next; \
strm.avail_in = have; \
state.hold = hold; \
state.bits = bits; \
return Z_NEED_DICT;
}
strm.adler = state.check = adler32(0L, Z_NULL, 0);
state.mode = TYPE;
case TYPE:
if (flush == Z_BLOCK || flush == Z_TREES) 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 */
if (flush == Z_TREES) {
DROPBITS(2);
goto inf_leave;
}
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_;
if (flush == Z_TREES) goto inf_leave;
case COPY_:
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 = (const code 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 (;;) {
here = state.lencode[BITS(state.lenbits)];
if ((unsigned)(here.bits) <= bits) break;
PULLBYTE();
}
if (here.val < 16) {
DROPBITS(here.bits);
state.lens[state.have++] = here.val;
}
else {
if (here.val == 16) {
NEEDBITS(here.bits + 2);
DROPBITS(here.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 (here.val == 17) {
NEEDBITS(here.bits + 3);
DROPBITS(here.bits);
len = 0;
copy = 3 + BITS(3);
DROPBITS(3);
}
else {
NEEDBITS(here.bits + 7);
DROPBITS(here.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;
/* check for end-of-block code (better have one) */
if (state.lens[256] == 0) {
strm.msg = (char *)"invalid code -- missing end-of-block";
state.mode = BAD;
break;
}
/* build code tables -- note: do not change the lenbits or distbits
values here (9 and 6) without reading the comments in inftrees.h
concerning the ENOUGH constants, which depend on those values */
state.next = state.codes;
state.lencode = (const code 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 = (const code 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_;
if (flush == Z_TREES) goto inf_leave;
case LEN_:
state.mode = LEN;
case LEN:
if (have >= 6 && left >= 258) {
strm.next_out = put; \
strm.avail_out = left; \
strm.next_in = next; \
strm.avail_in = have; \
state.hold = hold; \
state.bits = bits; \
inflate_fast(strm, out);
put = strm.next_out; \
left = strm.avail_out; \
next = strm.next_in; \
have = strm.avail_in; \
hold = state.hold; \
bits = state.bits; \
if (state.mode == TYPE)
state.back = -1;
break;
}
state.back = 0;
for (;;) {
here = state.lencode[BITS(state.lenbits)];
if ((unsigned)(here.bits) <= bits) break;
PULLBYTE();
}
if (here.op && (here.op & 0xf0) == 0) {
last = here;
for (;;) {
here = state.lencode[last.val +
(BITS(last.bits + last.op) >> last.bits)];
if ((unsigned)(last.bits + here.bits) <= bits) break;
PULLBYTE();
}
DROPBITS(last.bits);
state.back += last.bits;
}
DROPBITS(here.bits);
state.back += here.bits;
state.length = (unsigned)here.val;
if ((int)(here.op) == 0) {
Tracevv((stderr, here.val >= 0x20 && here.val < 0x7f ?
"inflate: literal '%c'\n" :
"inflate: literal 0x%02x\n", here.val));
state.mode = LIT;
break;
}
if (here.op & 32) {
Tracevv((stderr, "inflate: end of block\n"));
state.back = -1;
state.mode = TYPE;
break;
}
if (here.op & 64) {
strm.msg = (char *)"invalid literal/length code";
state.mode = BAD;
break;
}
state.extra = (unsigned)(here.op) & 15;
state.mode = LENEXT;
case LENEXT:
if (state.extra) {
NEEDBITS(state.extra);
state.length += BITS(state.extra);
DROPBITS(state.extra);
state.back += state.extra;
}
Tracevv((stderr, "inflate: length %u\n", state.length));
state.was = state.length;
state.mode = DIST;
case DIST:
for (;;) {
here = state.distcode[BITS(state.distbits)];
if ((unsigned)(here.bits) <= bits) break;
PULLBYTE();
}
if ((here.op & 0xf0) == 0) {
last = here;
for (;;) {
here = state.distcode[last.val +
(BITS(last.bits + last.op) >> last.bits)];
if ((unsigned)(last.bits + here.bits) <= bits) break;
PULLBYTE();
}
DROPBITS(last.bits);
state.back += last.bits;
}
DROPBITS(here.bits);
state.back += here.bits;
if (here.op & 64) {
strm.msg = (char *)"invalid distance code";
state.mode = BAD;
break;
}
state.offset = (unsigned)here.val;
state.extra = (unsigned)(here.op) & 15;
state.mode = DISTEXT;
case DISTEXT:
if (state.extra) {
NEEDBITS(state.extra);
state.offset += BITS(state.extra);
DROPBITS(state.extra);
state.back += state.extra;
}
#ifdef INFLATE_STRICT
if (state.offset > state.dmax) {
strm.msg = (char *)"invalid distance too far back";
state.mode = BAD;
break;
}
#endif
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.whave) {
if (state.sane) {
strm.msg = (char *)"invalid distance too far back";
state.mode = BAD;
break;
}
#ifdef INFLATE_ALLOW_INVALID_DISTANCE_TOOFAR_ARRR
Trace((stderr, "inflate.c too far\n"));
copy -= state.whave;
if (copy > state.length) copy = state.length;
if (copy > left) copy = left;
left -= copy;
state.length -= copy;
do {
*put++ = 0;
} while (--copy);
if (state.length == 0) state.mode = LEN;
break;
#endif
}
if (copy > state.wnext) {
copy -= state.wnext;
from = state.window + (state.wsize - copy);
}
else
from = state.window + (state.wnext - 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++ = (u8)(state.length);
left--;
state.mode = LEN;
break;
case CHECK:
if (state.wrap) {
NEEDBITS(32);
out -= left;
strm.total_out += out;
state.total += out;
if ((state.wrap & 4) && out)
strm.adler = state.check =
UPDATE(state.check, put - out, out);
out = left;
if ((state.wrap & 4) && (
#ifdef GUNZIP
state.flags ? hold :
#endif
ZSWAP32(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:
strm.next_out = put; \
strm.avail_out = left; \
strm.next_in = next; \
strm.avail_in = have; \
state.hold = hold; \
state.bits = bits; \
if (state.wsize || (out != strm.avail_out && state.mode < BAD &&
(state.mode < CHECK || flush != Z_FINISH)))
if (updatewindow(strm, strm.next_out, out - strm.avail_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 & 4) && out)
strm.adler = state.check =
UPDATE(state.check, strm.next_out - out, out);
strm.data_type = (int)state.bits + (state.last ? 64 : 0) +
(state.mode == TYPE ? 128 : 0) +
(state.mode == LEN_ || state.mode == COPY_ ? 256 : 0);
if (((in == 0 && out == 0) || flush == Z_FINISH) && ret == Z_OK)
ret = Z_BUF_ERROR;
return ret;
}
local int inflateStateCheck(z_stream * strm) {
struct inflate_state FAR *state;
if (strm == Z_NULL ||
strm.zalloc == (alloc_func)0 || strm.zfree == (free_func)0)
return 1;
state = (struct inflate_state FAR *)strm.state;
if (state == Z_NULL || state.strm != strm ||
state.mode < HEAD || state.mode > SYNC)
return 1;
return 0;
}