FCL/sf/os/kernelhwsrv: comparison brdbootldr/ubootldr/inflate.c

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--1:000000000000
+:96e5fb8b040d
+/*
+* Copyright (c) 2009 Nokia Corporation and/or its subsidiary(-ies).
+* All rights reserved.
+* This component and the accompanying materials are made available
+* under the terms of "Eclipse Public License v1.0"
+* which accompanies this distribution, and is available
+* at the URL "http://www.eclipse.org/legal/epl-v10.html".
+*
+* Initial Contributors:
+* Nokia Corporation - initial contribution.
+*
+* Contributors:
+*
+* Description:
+*
+*/
+/* inflate.c -- Not copyrighted 1992 by Mark Adler
+version c10p1, 10 January 1993 */
+/* You can do whatever you like with this source file, though I would
+prefer that if you modify it and redistribute it that you include
+comments to that effect with your name and the date.  Thank you.
+[The history has been moved to the file ChangeLog.]
+*/
+/*
+Inflate deflated (PKZIP's method 8 compressed) data.  The compression
+method searches for as much of the current string of bytes (up to a
+length of 258) in the previous 32K bytes.  If it doesn't find any
+matches (of at least length 3), it codes the next byte.  Otherwise, it
+codes the length of the matched string and its distance backwards from
+the current position.  There is a single Huffman code that codes both
+single bytes (called "literals") and match lengths.  A second Huffman
+code codes the distance information, which follows a length code.  Each
+length or distance code actually represents a base value and a number
+of "extra" (sometimes zero) bits to get to add to the base value.  At
+the end of each deflated block is a special end-of-block (EOB) literal/
+length code.  The decoding process is basically: get a literal/length
+code; if EOB then done; if a literal, emit the decoded byte; if a
+length then get the distance and emit the referred-to bytes from the
+sliding window of previously emitted data.
+There are (currently) three kinds of inflate blocks: stored, fixed, and
+dynamic.  The compressor deals with some chunk of data at a time, and
+decides which method to use on a chunk-by-chunk basis.  A chunk might
+typically be 32K or 64K.  If the chunk is uncompressible, then the
+"stored" method is used.  In this case, the bytes are simply stored as
+is, eight bits per byte, with none of the above coding.  The bytes are
+preceded by a count, since there is no longer an EOB code.
+If the data is compressible, then either the fixed or dynamic methods
+are used.  In the dynamic method, the compressed data is preceded by
+an encoding of the literal/length and distance Huffman codes that are
+to be used to decode this block.  The representation is itself Huffman
+coded, and so is preceded by a description of that code.  These code
+descriptions take up a little space, and so for small blocks, there is
+a predefined set of codes, called the fixed codes.  The fixed method is
+used if the block codes up smaller that way (usually for quite small
+chunks), otherwise the dynamic method is used.  In the latter case, the
+codes are customized to the probabilities in the current block, and so
+can code it much better than the pre-determined fixed codes.
+The Huffman codes themselves are decoded using a mutli-level table
+lookup, in order to maximize the speed of decoding plus the speed of
+building the decoding tables.  See the comments below that precede the
+lbits and dbits tuning parameters.
+*/
+/*
+Notes beyond the 1.93a appnote.txt:
+1. Distance pointers never point before the beginning of the output
+stream.
+2. Distance pointers can point back across blocks, up to 32k away.
+3. There is an implied maximum of 7 bits for the bit length table and
+15 bits for the actual data.
+4. If only one code exists, then it is encoded using one bit.  (Zero
+would be more efficient, but perhaps a little confusing.)  If two
+codes exist, they are coded using one bit each (0 and 1).
+5. There is no way of sending zero distance codes--a dummy must be
+sent if there are none.  (History: a pre 2.0 version of PKZIP would
+store blocks with no distance codes, but this was discovered to be
+too harsh a criterion.)  Valid only for 1.93a.  2.04c does allow
+zero distance codes, which is sent as one code of zero bits in
+length.
+6. There are up to 286 literal/length codes.  Code 256 represents the
+end-of-block.  Note however that the static length tree defines
+288 codes just to fill out the Huffman codes.  Codes 286 and 287
+cannot be used though, since there is no length base or extra bits
+defined for them.  Similarly, there are up to 30 distance codes.
+However, static trees define 32 codes (all 5 bits) to fill out the
+Huffman codes, but the last two had better not show up in the data.
+7. Unzip can check dynamic Huffman blocks for complete code sets.
+The exception is that a single code would not be complete (see #4).
+8. The five bits following the block type is really the number of
+literal codes sent minus 257.
+9. Length codes 8,16,16 are interpreted as 13 length codes of 8 bits
+(1+6+6).  Therefore, to output three times the length, you output
+three codes (1+1+1), whereas to output four times the same length,
+you only need two codes (1+3).  Hmm.
+10. In the tree reconstruction algorithm, Code = Code + Increment
+only if BitLength(i) is not zero.  (Pretty obvious.)
+11. Correction: 4 Bits: # of Bit Length codes - 4     (4 - 19)
+12. Note: length code 284 can represent 227-258, but length code 285
+really is 258.  The last length deserves its own, short code
+since it gets used a lot in very redundant files.  The length
+258 is special since 258 - 3 (the min match length) is 255.
+13. The literal/length and distance code bit lengths are read as a
+single stream of lengths.  It is possible (and advantageous) for
+a repeat code (16, 17, or 18) to go across the boundary between
+the two sets of lengths.
+*/
+#include "inflate.h"
+extern void* memcpy(void*, const void*, unsigned);
+extern void* memset(void*, int, unsigned);
+/* Huffman code lookup table entry--this entry is four bytes for machines
+that have 16-bit pointers (e.g. PC's in the small or medium model).
+Valid extra bits are 0..13.  e == 15 is EOB (end of block), e == 16
+means that v is a literal, 16 < e < 32 means that v is a pointer to
+the next table, which codes e - 16 bits, and lastly e == 99 indicates
+an unused code.  If a code with e == 99 is looked up, this implies an
+error in the data. */
+struct huft {
+uch e;                /* number of extra bits or operation */
+uch b;                /* number of bits in this code or subcode */
+union {
+ush n;              /* literal, length base, or distance base */
+struct huft *t;     /* pointer to next level of table */
+} v;
+};
+/* Function prototypes */
+int huft_build(unsigned *, unsigned, unsigned, const ush *, const ush *,
+struct huft **, int *);
+int huft_free(struct huft *);
+int inflate_codes(struct huft *, struct huft *, int, int);
+int inflate_stored(void);
+int inflate_fixed(void);
+int inflate_dynamic(void);
+int inflate_block(int *);
+int inflate(void);
+/* The inflate algorithm uses a sliding 32K byte window on the uncompressed
+stream to find repeated byte strings.  This is implemented here as a
+circular buffer.  The index is updated simply by incrementing and then
+and'ing with 0x7fff (32K-1). */
+/* It is left to other modules to supply the 32K area.  It is assumed
+to be usable as if it were declared "uch slide[32768];" or as just
+"uch *slide;" and then malloc'ed in the latter case.  The definition
+must be in unzip.h, included above. */
+/* unsigned wp;             current position in slide */
+/*#define wp outcnt*/
+/*#define flush_output(w) (wp=(w),flush_window())*/
+/* Tables for deflate from PKZIP's appnote.txt. */
+static const unsigned border[] = {    /* Order of the bit length code lengths */
+16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+static const ush cplens[] = {         /* Copy lengths for literal codes 257..285 */
+3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0};
+/* note: see note #13 above about the 258 in this list. */
+static const ush cplext[] = {         /* Extra bits for literal codes 257..285 */
+0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
+3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99}; /* 99==invalid */
+static const ush cpdist[] = {         /* Copy offsets for distance codes 0..29 */
+1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+8193, 12289, 16385, 24577};
+static const ush cpdext[] = {         /* Extra bits for distance codes */
+0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
+7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
+12, 12, 13, 13};
+/* Macros for inflate() bit peeking and grabbing.
+The usage is:
+NEEDBITS(j)
+x = b & mask_bits[j];
+DUMPBITS(j)
+where NEEDBITS makes sure that b has at least j bits in it, and
+DUMPBITS removes the bits from b.  The macros use the variable k
+for the number of bits in b.  Normally, b and k are register
+variables for speed, and are initialized at the beginning of a
+routine that uses these macros from a global bit buffer and count.
+If we assume that EOB will be the longest code, then we will never
+ask for bits with NEEDBITS that are beyond the end of the stream.
+So, NEEDBITS should not read any more bytes than are needed to
+meet the request.  Then no bytes need to be "returned" to the buffer
+at the end of the last block.
+However, this assumption is not true for fixed blocks--the EOB code
+is 7 bits, but the other literal/length codes can be 8 or 9 bits.
+(The EOB code is shorter than other codes because fixed blocks are
+generally short.  So, while a block always has an EOB, many other
+literal/length codes have a significantly lower probability of
+showing up at all.)  However, by making the first table have a
+lookup of seven bits, the EOB code will be found in that first
+lookup, and so will not require that too many bits be pulled from
+the stream.
+*/
+ulg bb;                         /* bit buffer */
+unsigned bk;                    /* bits in bit buffer */
+static const ush mask_bits[] = {
+0x0000,
+0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
+0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
+};
+#define get_byte()  (inptr < inbuf_end ? *inptr++ : fill_inbuf())
+#define NEXTBYTE()  (uch)get_byte()
+#define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE())<<k;k+=8;}}
+#define DUMPBITS(n) {b>>=(n);k-=(n);}
+/*
+Huffman code decoding is performed using a multi-level table lookup.
+The fastest way to decode is to simply build a lookup table whose
+size is determined by the longest code.  However, the time it takes
+to build this table can also be a factor if the data being decoded
+is not very long.  The most common codes are necessarily the
+shortest codes, so those codes dominate the decoding time, and hence
+the speed.  The idea is you can have a shorter table that decodes the
+shorter, more probable codes, and then point to subsidiary tables for
+the longer codes.  The time it costs to decode the longer codes is
+then traded against the time it takes to make longer tables.
+This results of this trade are in the variables lbits and dbits
+below.  lbits is the number of bits the first level table for literal/
+length codes can decode in one step, and dbits is the same thing for
+the distance codes.  Subsequent tables are also less than or equal to
+those sizes.  These values may be adjusted either when all of the
+codes are shorter than that, in which case the longest code length in
+bits is used, or when the shortest code is *longer* than the requested
+table size, in which case the length of the shortest code in bits is
+used.
+There are two different values for the two tables, since they code a
+different number of possibilities each.  The literal/length table
+codes 286 possible values, or in a flat code, a little over eight
+bits.  The distance table codes 30 possible values, or a little less
+than five bits, flat.  The optimum values for speed end up being
+about one bit more than those, so lbits is 8+1 and dbits is 5+1.
+The optimum values may differ though from machine to machine, and
+possibly even between compilers.  Your mileage may vary.
+*/
+static const int lbits = 9;          /* bits in base literal/length lookup table */
+static const int dbits = 6;          /* bits in base distance lookup table */
+/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
+#define BMAX 16         /* maximum bit length of any code (16 for explode) */
+#define N_MAX 288       /* maximum number of codes in any set */
+unsigned hufts;         /* track memory usage */
+int huft_build(
+unsigned *b,            /* code lengths in bits (all assumed <= BMAX) */
+unsigned n,             /* number of codes (assumed <= N_MAX) */
+unsigned s,             /* number of simple-valued codes (0..s-1) */
+const ush *d,                 /* list of base values for non-simple codes */
+const ush *e,                 /* list of extra bits for non-simple codes */
+struct huft **t,        /* result: starting table */
+int *m                 /* maximum lookup bits, returns actual */
+)
+/* Given a list of code lengths and a maximum table size, make a set of
+tables to decode that set of codes.  Return zero on success, one if
+the given code set is incomplete (the tables are still built in this
+case), two if the input is invalid (all zero length codes or an
+oversubscribed set of lengths), and three if not enough memory. */
+{
+unsigned a;                   /* counter for codes of length k */
+unsigned c[BMAX+1];           /* bit length count table */
+unsigned f;                   /* i repeats in table every f entries */
+int g;                        /* maximum code length */
+int h;                        /* table level */
+register unsigned i;          /* counter, current code */
+register unsigned j;          /* counter */
+register int k;               /* number of bits in current code */
+int l;                        /* bits per table (returned in m) */
+register unsigned *p;         /* pointer into c[], b[], or v[] */
+register struct huft *q;      /* points to current table */
+struct huft r;                /* table entry for structure assignment */
+struct huft *u[BMAX];         /* table stack */
+unsigned v[N_MAX];            /* values in order of bit length */
+register int w;               /* bits before this table == (l * h) */
+unsigned x[BMAX+1];           /* bit offsets, then code stack */
+unsigned *xp;                 /* pointer into x */
+int y;                        /* number of dummy codes added */
+unsigned z;                   /* number of entries in current table */
+/* Generate counts for each bit length */
+memset(c, 0, sizeof(c));
+p = b;  i = n;
+do {
+/*    Tracecv(*p, (stderr, (n-i >= ' ' && n-i <= '~' ? "%c %d\n" : "0x%x %d\n"),
+	    n-i, *p));*/
+c[*p]++;                    /* assume all entries <= BMAX */
+p++;                      /* Can't combine with above line (Solaris bug) */
+} while (--i);
+if (c[0] == n)                /* null input--all zero length codes */
+{
+*t = (struct huft *)NULL;
+*m = 0;
+return 0;
+}
+/* Find minimum and maximum length, bound *m by those */
+l = *m;
+for (j = 1; j <= BMAX; j++)
+if (c[j])
+break;
+k = j;                        /* minimum code length */
+if ((unsigned)l < j)
+l = j;
+for (i = BMAX; i; i--)
+if (c[i])
+break;
+g = i;                        /* maximum code length */
+if ((unsigned)l > i)
+l = i;
+*m = l;
+/* Adjust last length count to fill out codes, if needed */
+for (y = 1 << j; j < i; j++, y <<= 1)
+if ((y -= c[j]) < 0)
+return 2;                 /* bad input: more codes than bits */
+if ((y -= c[i]) < 0)
+return 2;
+c[i] += y;
+/* Generate starting offsets into the value table for each length */
+x[1] = j = 0;
+p = c + 1;  xp = x + 2;
+while (--i) {                 /* note that i == g from above */
+*xp++ = (j += *p++);
+}
+/* Make a table of values in order of bit lengths */
+p = b;  i = 0;
+do {
+if ((j = *p++) != 0)
+v[x[j]++] = i;
+} while (++i < n);
+/* Generate the Huffman codes and for each, make the table entries */
+x[0] = i = 0;                 /* first Huffman code is zero */
+p = v;                        /* grab values in bit order */
+h = -1;                       /* no tables yet--level -1 */
+w = -l;                       /* bits decoded == (l * h) */
+u[0] = (struct huft *)NULL;   /* just to keep compilers happy */
+q = (struct huft *)NULL;      /* ditto */
+z = 0;                        /* ditto */
+/* go through the bit lengths (k already is bits in shortest code) */
+for (; k <= g; k++)
+{
+a = c[k];
+while (a--)
+{
+/* here i is the Huffman code of length k bits for value *p */
+/* make tables up to required level */
+while (k > w + l)
+{
+h++;
+w += l;                 /* previous table always l bits */
+/* compute minimum size table less than or equal to l bits */
+z = (z = g - w) > (unsigned)l ? l : z;  /* upper limit on table size */
+if ((f = 1 << (j = k - w)) > a + 1)     /* try a k-w bit table */
+{                       /* too few codes for k-w bit table */
+f -= a + 1;           /* deduct codes from patterns left */
+xp = c + k;
+while (++j < z)       /* try smaller tables up to z bits */
+{
+if ((f <<= 1) <= *++xp)
+break;            /* enough codes to use up j bits */
+f -= *xp;           /* else deduct codes from patterns */
+}
+}
+z = 1 << j;             /* table entries for j-bit table */
+/* allocate and link in new table */
+if ((q = (struct huft *)malloc((z + 1)*sizeof(struct huft))) ==
+(struct huft *)NULL)
+{
+if (h)
+huft_free(u[0]);
+return 3;             /* not enough memory */
+}
+hufts += z + 1;         /* track memory usage */
+*t = q + 1;             /* link to list for huft_free() */
+*(t = &(q->v.t)) = (struct huft *)NULL;
+u[h] = ++q;             /* table starts after link */
+/* connect to last table, if there is one */
+if (h)
+{
+x[h] = i;             /* save pattern for backing up */
+r.b = (uch)l;         /* bits to dump before this table */
+r.e = (uch)(16 + j);  /* bits in this table */
+r.v.t = q;            /* pointer to this table */
+j = i >> (w - l);     /* (get around Turbo C bug) */
+u[h-1][j] = r;        /* connect to last table */
+}
+}
+/* set up table entry in r */
+r.b = (uch)(k - w);
+if (p >= v + n)
+r.e = 99;               /* out of values--invalid code */
+else if (*p < s)
+{
+r.e = (uch)(*p < 256 ? 16 : 15);    /* 256 is end-of-block code */
+r.v.n = (ush)(*p);             /* simple code is just the value */
+	p++;                           /* one compiler does not like *p++ */
+}
+else
+{
+r.e = (uch)e[*p - s];   /* non-simple--look up in lists */
+r.v.n = d[*p++ - s];
+}
+/* fill code-like entries with r */
+f = 1 << (k - w);
+for (j = i >> w; j < z; j += f)
+q[j] = r;
+/* backwards increment the k-bit code i */
+for (j = 1 << (k - 1); i & j; j >>= 1)
+i ^= j;
+i ^= j;
+/* backup over finished tables */
+while ((i & ((1 << w) - 1)) != x[h])
+{
+h--;                    /* don't need to update q */
+w -= l;
+}
+}
+}
+/* Return true (1) if we were given an incomplete table */
+return y != 0 && g != 1;
+}
+int huft_free(struct huft *t)
+/* Free the malloc'ed tables built by huft_build(), which makes a linked
+list of the tables it made, with the links in a dummy first entry of
+each table. */
+{
+register struct huft *p, *q;
+/* Go through linked list, freeing from the malloced (t[-1]) address. */
+p = t;
+while (p != (struct huft *)NULL)
+{
+q = (--p)->v.t;
+free((char*)p);
+p = q;
+}
+return 0;
+}
+int inflate_codes(
+struct huft *tl,
+struct huft *td,   /* literal/length and distance decoder tables */
+int bl,
+int bd             /* number of bits decoded by tl[] and td[] */
+)
+/* inflate (decompress) the codes in a deflated (compressed) block.
+Return an error code or zero if it all goes ok. */
+{
+register unsigned e;  /* table entry flag/number of extra bits */
+unsigned n, d;        /* length and index for copy */
+struct huft *t;       /* pointer to table entry */
+unsigned ml, md;      /* masks for bl and bd bits */
+register ulg b=bb;       /* bit buffer */
+register unsigned k=bk;  /* number of bits in bit buffer */
+register uch* p=(uch*)outptr;
+/* inflate the coded data */
+ml = mask_bits[bl];           /* precompute masks for speed */
+md = mask_bits[bd];
+for (;;)                      /* do until end of block */
+{
+NEEDBITS((unsigned)bl)
+if ((e = (t = tl + ((unsigned)b & ml))->e) > 16)
+do {
+if (e == 99)
+return 1;
+DUMPBITS(t->b)
+e -= 16;
+NEEDBITS(e)
+} while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
+DUMPBITS(t->b)
+if (e == 16)                /* then it's a literal */
+{
+*p++ = (uch)t->v.n;
+}
+else                        /* it's an EOB or a length */
+{
+/* exit if end of block */
+if (e == 15)
+break;
+/* get length of block to copy */
+NEEDBITS(e)
+n = t->v.n + ((unsigned)b & mask_bits[e]);
+DUMPBITS(e);
+/* decode distance of block to copy */
+NEEDBITS((unsigned)bd)
+if ((e = (t = td + ((unsigned)b & md))->e) > 16)
+do {
+if (e == 99)
+return 1;
+DUMPBITS(t->b)
+e -= 16;
+NEEDBITS(e)
+} while ((e = (t = t->v.t + ((unsigned)b & mask_bits[e]))->e) > 16);
+DUMPBITS(t->b)
+NEEDBITS(e)
+d = t->v.n + ((unsigned)b & mask_bits[e]);
+	  d &= ZIP_WINDOW_SIZE-1;
+DUMPBITS(e)
+/* do the copy */
+	  if (d>=n)
+		  {
+		  memcpy(p, p-d, n);
+		  p+=n;
+		  }
+	  else
+		  {
+		  uch* q=p-d;
+		  while(n--) *p++=*q++;
+		  }
+}
+}
+/* restore the globals from the locals */
+outptr=p;
+bb = b;                       /* restore global bit buffer */
+bk = k;
+/* done */
+return 0;
+}
+int inflate_stored()
+/* "decompress" an inflated type 0 (stored) block. */
+{
+unsigned n;           /* number of bytes in block */
+register ulg b;       /* bit buffer */
+register unsigned k;  /* number of bits in bit buffer */
+register uch* p=(uch*)outptr;
+/* make local copies of globals */
+b = bb;                       /* initialize bit buffer */
+k = bk;
+/* go to byte boundary */
+n = k & 7;
+DUMPBITS(n);
+/* get the length and its complement */
+NEEDBITS(16)
+n = ((unsigned)b & 0xffff);
+DUMPBITS(16)
+NEEDBITS(16)
+if (n != (unsigned)((~b) & 0xffff))
+return 1;                   /* error in compressed data */
+DUMPBITS(16)
+/* read and output the compressed data */
+while (n--)
+{
+NEEDBITS(8)
+	*p++=(uch)b;
+DUMPBITS(8)
+}
+/* restore the globals from the locals */
+outptr=p;
+bb = b;                       /* restore global bit buffer */
+bk = k;
+return 0;
+}
+int inflate_fixed()
+/* decompress an inflated type 1 (fixed Huffman codes) block.  We should
+either replace this with a custom decoder, or at least precompute the
+Huffman tables. */
+{
+int i;                /* temporary variable */
+struct huft *tl;      /* literal/length code table */
+struct huft *td;      /* distance code table */
+int bl;               /* lookup bits for tl */
+int bd;               /* lookup bits for td */
+unsigned l[288];      /* length list for huft_build */
+/* set up literal table */
+for (i = 0; i < 144; i++)
+l[i] = 8;
+for (; i < 256; i++)
+l[i] = 9;
+for (; i < 280; i++)
+l[i] = 7;
+for (; i < 288; i++)          /* make a complete, but wrong code set */
+l[i] = 8;
+bl = 7;
+// coverity[overrun-call]
+// Coverity seems to get confused - there is nothing wrong with this code
+if ((i = huft_build(l, 288, 257, cplens, cplext, &tl, &bl)) != 0)
+return i;
+/* set up distance table */
+for (i = 0; i < 30; i++)      /* make an incomplete code set */
+l[i] = 5;
+bd = 5;
+if ((i = huft_build(l, 30, 0, cpdist, cpdext, &td, &bd)) > 1)
+{
+huft_free(tl);
+return i;
+}
+/* decompress until an end-of-block code */
+if (inflate_codes(tl, td, bl, bd))
+return 1;
+/* free the decoding tables, return */
+huft_free(tl);
+huft_free(td);
+return 0;
+}
+int inflate_dynamic()
+/* decompress an inflated type 2 (dynamic Huffman codes) block. */
+{
+int i;                /* temporary variables */
+unsigned j;
+unsigned l;           /* last length */
+unsigned m;           /* mask for bit lengths table */
+unsigned n;           /* number of lengths to get */
+struct huft *tl;      /* literal/length code table */
+struct huft *td;      /* distance code table */
+int bl;               /* lookup bits for tl */
+int bd;               /* lookup bits for td */
+unsigned nb;          /* number of bit length codes */
+unsigned nl;          /* number of literal/length codes */
+unsigned nd;          /* number of distance codes */
+#ifdef PKZIP_BUG_WORKAROUND
+unsigned ll[288+32];  /* literal/length and distance code lengths */
+#else
+unsigned ll[286+30];  /* literal/length and distance code lengths */
+#endif
+register ulg b;       /* bit buffer */
+register unsigned k;  /* number of bits in bit buffer */
+/* make local bit buffer */
+b = bb;
+k = bk;
+/* read in table lengths */
+NEEDBITS(5)
+nl = 257 + ((unsigned)b & 0x1f);      /* number of literal/length codes */
+DUMPBITS(5)
+NEEDBITS(5)
+nd = 1 + ((unsigned)b & 0x1f);        /* number of distance codes */
+DUMPBITS(5)
+NEEDBITS(4)
+nb = 4 + ((unsigned)b & 0xf);         /* number of bit length codes */
+DUMPBITS(4)
+#ifdef PKZIP_BUG_WORKAROUND
+if (nl > 288 || nd > 32)
+#else
+if (nl > 286 || nd > 30)
+#endif
+return 1;                   /* bad lengths */
+/* read in bit-length-code lengths */
+for (j = 0; j < nb; j++)
+{
+NEEDBITS(3)
+ll[border[j]] = (unsigned)b & 7;
+DUMPBITS(3)
+}
+for (; j < 19; j++)
+ll[border[j]] = 0;
+/* build decoding table for trees--single level, 7 bit lookup */
+bl = 7;
+if ((i = huft_build(ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)
+{
+if (i == 1)
+huft_free(tl);
+return i;                   /* incomplete code set */
+}
+/* read in literal and distance code lengths */
+n = nl + nd;
+m = mask_bits[bl];
+i = l = 0;
+while ((unsigned)i < n)
+{
+NEEDBITS((unsigned)bl)
+j = (td = tl + ((unsigned)b & m))->b;
+DUMPBITS(j)
+j = td->v.n;
+if (j < 16)                 /* length of code in bits (0..15) */
+ll[i++] = l = j;          /* save last length in l */
+else if (j == 16)           /* repeat last length 3 to 6 times */
+{
+NEEDBITS(2)
+j = 3 + ((unsigned)b & 3);
+DUMPBITS(2)
+if ((unsigned)i + j > n)
+return 1;
+while (j--)
+ll[i++] = l;
+}
+else if (j == 17)           /* 3 to 10 zero length codes */
+{
+NEEDBITS(3)
+j = 3 + ((unsigned)b & 7);
+DUMPBITS(3)
+if ((unsigned)i + j > n)
+return 1;
+while (j--)
+ll[i++] = 0;
+l = 0;
+}
+else                        /* j == 18: 11 to 138 zero length codes */
+{
+NEEDBITS(7)
+j = 11 + ((unsigned)b & 0x7f);
+DUMPBITS(7)
+if ((unsigned)i + j > n)
+return 1;
+while (j--)
+ll[i++] = 0;
+l = 0;
+}
+}
+/* free decoding table for trees */
+huft_free(tl);
+/* restore the global bit buffer */
+bb = b;
+bk = k;
+/* build the decoding tables for literal/length and distance codes */
+bl = lbits;
+if ((i = huft_build(ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
+{
+if (i == 1) {
+/*      fprintf(stderr, " incomplete literal tree\n");*/
+huft_free(tl);
+}
+return i;                   /* incomplete code set */
+}
+bd = dbits;
+if ((i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
+{
+if (i == 1) {
+/*      fprintf(stderr, " incomplete distance tree\n");*/
+#ifdef PKZIP_BUG_WORKAROUND
+i = 0;
+}
+#else
+huft_free(td);
+}
+huft_free(tl);
+return i;                   /* incomplete code set */
+#endif
+}
+/* decompress until an end-of-block code */
+if (inflate_codes(tl, td, bl, bd))
+return 1;
+/* free the decoding tables, return */
+huft_free(tl);
+huft_free(td);
+return 0;
+}
+int inflate_block(int* e)
+/* decompress an inflated block */
+{
+unsigned t;           /* block type */
+register ulg b;       /* bit buffer */
+register unsigned k;  /* number of bits in bit buffer */
+/* make local bit buffer */
+b = bb;
+k = bk;
+/* read in last block bit */
+NEEDBITS(1)
+*e = (int)b & 1;
+DUMPBITS(1)
+/* read in block type */
+NEEDBITS(2)
+t = (unsigned)b & 3;
+DUMPBITS(2)
+/* restore the global bit buffer */
+bb = b;
+bk = k;
+/* inflate that block type */
+if (t == 2)
+return inflate_dynamic();
+if (t == 0)
+return inflate_stored();
+if (t == 1)
+return inflate_fixed();
+/* bad block type */
+return 2;
+}
+int inflate()
+/* decompress an inflated entry */
+{
+int e;                /* last block flag */
+int r;                /* result code */
+unsigned h;           /* maximum struct huft's malloc'ed */
+/* initialize window, bit buffer */
+/*  wp = 0;*/
+bk = 0;
+bb = 0;
+/* decompress until the last block */
+h = 0;
+do {
+hufts = 0;
+	r=inflate_block(&e);
+	process_block(r);
+	if (r!=0)
+		return r;
+if (hufts > h)
+h = hufts;
+} while (!e);
+/* Undo too much lookahead. The next read will be byte aligned so we
+* can discard unused bits in the last meaningful byte.
+*/
+/*  while (bk >= 8) {
+bk -= 8;
+inptr--;
+}*/
+/* flush out slide */
+/*  flush_output(wp);*/
+/* return success */
+#ifdef DEBUG
+/*  fprintf(stderr, "<%u> ", h);*/
+#endif /* DEBUG */
+return 0;
+}

changeset 43	96e5fb8b040d
child 44	36bfc973b146