[llvm-commits] [parallel] CVS: llvm/runtime/zlib/contrib/puff/Makefile README puff.c puff.h zeros.raw

Misha Brukman brukman at cs.uiuc.edu
Mon Mar 1 18:19:29 PST 2004


Changes in directory llvm/runtime/zlib/contrib/puff:

Makefile added (r1.1.2.1)
README added (r1.1.2.1)
puff.c added (r1.1.2.1)
puff.h added (r1.1.2.1)
zeros.raw added (r1.1.2.1)

---
Log message:

Merge from trunk

---
Diffs of the changes:  (+935 -0)

Index: llvm/runtime/zlib/contrib/puff/Makefile
diff -c /dev/null llvm/runtime/zlib/contrib/puff/Makefile:1.1.2.1
*** /dev/null	Mon Mar  1 17:58:58 2004
--- llvm/runtime/zlib/contrib/puff/Makefile	Mon Mar  1 17:58:48 2004
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*** 0 ****
--- 1,8 ----
+ puff: puff.c puff.h
+ 	cc -DTEST -o puff puff.c
+ 
+ test: puff
+ 	puff zeros.raw
+ 
+ clean:
+ 	rm -f puff puff.o


Index: llvm/runtime/zlib/contrib/puff/README
diff -c /dev/null llvm/runtime/zlib/contrib/puff/README:1.1.2.1
*** /dev/null	Mon Mar  1 17:58:58 2004
--- llvm/runtime/zlib/contrib/puff/README	Mon Mar  1 17:58:48 2004
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*** 0 ****
--- 1,63 ----
+ Puff -- A Simple Inflate
+ 3 Mar 2003
+ Mark Adler
+ madler at alumni.caltech.edu
+ 
+ What this is --
+ 
+ puff.c provides the routine puff() to decompress the deflate data format.  It
+ does so more slowly than zlib, but the code is about one-fifth the size of the
+ inflate code in zlib, and written to be very easy to read.
+ 
+ Why I wrote this --
+ 
+ puff.c was written to document the deflate format unambiguously, by virtue of
+ being working C code.  It is meant to supplement RFC 1951, which formally
+ describes the deflate format.  I have received many questions on details of the
+ deflate format, and I hope that reading this code will answer those questions.
+ puff.c is heavily commented with details of the deflate format, especially
+ those little nooks and cranies of the format that might not be obvious from a
+ specification.
+ 
+ puff.c may also be useful in applications where code size or memory usage is a
+ very limited resource, and speed is not as important.
+ 
+ How to use it --
+ 
+ Well, most likely you should just be reading puff.c and using zlib for actual
+ applications, but if you must ...
+ 
+ Include puff.h in your code, which provides this prototype:
+ 
+ int puff(unsigned char *dest,           /* pointer to destination pointer */
+          unsigned long *destlen,        /* amount of output space */
+          unsigned char *source,         /* pointer to source data pointer */
+          unsigned long *sourcelen);     /* amount of input available */
+ 
+ Then you can call puff() to decompress a deflate stream that is in memory in
+ its entirety at source, to a sufficiently sized block of memory for the
+ decompressed data at dest.  puff() is the only external symbol in puff.c  The
+ only C library functions that puff.c needs are setjmp() and longjmp(), which
+ are used to simplify error checking in the code to improve readabilty.  puff.c
+ does no memory allocation, and uses less than 2K bytes off of the stack.
+ 
+ If destlen is not enough space for the uncompressed data, then inflate will
+ return an error without writing more than destlen bytes.  Note that this means
+ that in order to decompress the deflate data successfully, you need to know
+ the size of the uncompressed data ahead of time.
+ 
+ If needed, puff() can determine the size of the uncompressed data with no
+ output space.  This is done by passing dest equal to (unsigned char *)0.  Then
+ the initial value of *destlen is ignored and *destlen is set to the length of
+ the uncompressed data.  So if the size of the uncompressed data is not known,
+ then two passes of puff() can be used--first to determine the size, and second
+ to do the actual inflation after allocating the appropriate memory.  Not
+ pretty, but it works.  (This is one of the reasons you should be using zlib.)
+ 
+ The deflate format is self-terminating.  If the deflate stream does not end
+ in *sourcelen bytes, puff() will return an error without reading at or past
+ endsource.
+ 
+ On return, *sourcelen is updated to the amount of input data consumed, and
+ *destlen is updated to the size of the uncompressed data.  See the comments
+ in puff.c for the possible return codes for puff().


Index: llvm/runtime/zlib/contrib/puff/puff.c
diff -c /dev/null llvm/runtime/zlib/contrib/puff/puff.c:1.1.2.1
*** /dev/null	Mon Mar  1 17:58:59 2004
--- llvm/runtime/zlib/contrib/puff/puff.c	Mon Mar  1 17:58:48 2004
***************
*** 0 ****
--- 1,833 ----
+ /*
+  * puff.c
+  * Copyright (C) 2002, 2003 Mark Adler
+  * For conditions of distribution and use, see copyright notice in puff.h
+  * version 1.7, 3 Mar 2003
+  *
+  * puff.c is a simple inflate written to be an unambiguous way to specify the
+  * deflate format.  It is not written for speed but rather simplicity.  As a
+  * side benefit, this code might actually be useful when small code is more
+  * important than speed, such as bootstrap applications.  For typical deflate
+  * data, zlib's inflate() is about four times as fast as puff().  zlib's
+  * inflate compiles to around 20K on my machine, whereas puff.c compiles to
+  * around 4K on my machine (a PowerPC using GNU cc).  If the faster decode()
+  * function here is used, then puff() is only twice as slow as zlib's
+  * inflate().
+  *
+  * All dynamically allocated memory comes from the stack.  The stack required
+  * is less than 2K bytes.  This code is compatible with 16-bit int's and
+  * assumes that long's are at least 32 bits.  puff.c uses the short data type,
+  * assumed to be 16 bits, for arrays in order to to conserve memory.  The code
+  * works whether integers are stored big endian or little endian.
+  *
+  * In the comments below are "Format notes" that describe the inflate process
+  * and document some of the less obvious aspects of the format.  This source
+  * code is meant to supplement RFC 1951, which formally describes the deflate
+  * format:
+  *
+  *    http://www.zlib.org/rfc-deflate.html
+  */
+ 
+ /*
+  * Change history:
+  *
+  * 1.0  10 Feb 2002     - First version
+  * 1.1  17 Feb 2002     - Clarifications of some comments and notes
+  *                      - Update puff() dest and source pointers on negative
+  *                        errors to facilitate debugging deflators
+  *                      - Remove longest from struct huffman -- not needed
+  *                      - Simplify offs[] index in construct()
+  *                      - Add input size and checking, using longjmp() to
+  *                        maintain easy readability
+  *                      - Use short data type for large arrays
+  *                      - Use pointers instead of long to specify source and
+  *                        destination sizes to avoid arbitrary 4 GB limits
+  * 1.2  17 Mar 2002     - Add faster version of decode(), doubles speed (!),
+  *                        but leave simple version for readabilty
+  *                      - Make sure invalid distances detected if pointers
+  *                        are 16 bits
+  *                      - Fix fixed codes table error
+  *                      - Provide a scanning mode for determining size of
+  *                        uncompressed data
+  * 1.3  20 Mar 2002     - Go back to lengths for puff() parameters [Jean-loup]
+  *                      - Add a puff.h file for the interface
+  *                      - Add braces in puff() for else do [Jean-loup]
+  *                      - Use indexes instead of pointers for readability
+  * 1.4  31 Mar 2002     - Simplify construct() code set check
+  *                      - Fix some comments
+  *                      - Add FIXLCODES #define
+  * 1.5   6 Apr 2002     - Minor comment fixes
+  * 1.6   7 Aug 2002     - Minor format changes
+  * 1.7   3 Mar 2003     - Added test code for distribution
+  *                      - Added zlib-like license
+  */
+ 
+ #include <setjmp.h>             /* for setjmp(), longjmp(), and jmp_buf */
+ #include "puff.h"               /* prototype for puff() */
+ 
+ #define local static            /* for local function definitions */
+ #define NIL ((unsigned char *)0)        /* for no output option */
+ 
+ /*
+  * Maximums for allocations and loops.  It is not useful to change these --
+  * they are fixed by the deflate format.
+  */
+ #define MAXBITS 15              /* maximum bits in a code */
+ #define MAXLCODES 286           /* maximum number of literal/length codes */
+ #define MAXDCODES 30            /* maximum number of distance codes */
+ #define MAXCODES (MAXLCODES+MAXDCODES)  /* maximum codes lengths to read */
+ #define FIXLCODES 288           /* number of fixed literal/length codes */
+ 
+ /* input and output state */
+ struct state {
+     /* output state */
+     unsigned char *out;         /* output buffer */
+     unsigned long outlen;       /* available space at out */
+     unsigned long outcnt;       /* bytes written to out so far */
+ 
+     /* input state */
+     unsigned char *in;          /* input buffer */
+     unsigned long inlen;        /* available input at in */
+     unsigned long incnt;        /* bytes read so far */
+     int bitbuf;                 /* bit buffer */
+     int bitcnt;                 /* number of bits in bit buffer */
+ 
+     /* input limit error return state for bits() and decode() */
+     jmp_buf env;
+ };
+ 
+ /*
+  * Return need bits from the input stream.  This always leaves less than
+  * eight bits in the buffer.  bits() works properly for need == 0.
+  *
+  * Format notes:
+  *
+  * - Bits are stored in bytes from the least significant bit to the most
+  *   significant bit.  Therefore bits are dropped from the bottom of the bit
+  *   buffer, using shift right, and new bytes are appended to the top of the
+  *   bit buffer, using shift left.
+  */
+ local int bits(struct state *s, int need)
+ {
+     long val;           /* bit accumulator (can use up to 20 bits) */
+ 
+     /* load at least need bits into val */
+     val = s->bitbuf;
+     while (s->bitcnt < need) {
+         if (s->incnt == s->inlen) longjmp(s->env, 1);   /* out of input */
+         val |= (long)(s->in[s->incnt++]) << s->bitcnt;  /* load eight bits */
+         s->bitcnt += 8;
+     }
+ 
+     /* drop need bits and update buffer, always zero to seven bits left */
+     s->bitbuf = (int)(val >> need);
+     s->bitcnt -= need;
+ 
+     /* return need bits, zeroing the bits above that */
+     return (int)(val & ((1L << need) - 1));
+ }
+ 
+ /*
+  * Process a stored block.
+  *
+  * Format notes:
+  *
+  * - After the two-bit stored block type (00), the stored block length and
+  *   stored bytes are byte-aligned for fast copying.  Therefore any leftover
+  *   bits in the byte that has the last bit of the type, as many as seven, are
+  *   discarded.  The value of the discarded bits are not defined and should not
+  *   be checked against any expectation.
+  *
+  * - The second inverted copy of the stored block length does not have to be
+  *   checked, but it's probably a good idea to do so anyway.
+  *
+  * - A stored block can have zero length.  This is sometimes used to byte-align
+  *   subsets of the compressed data for random access or partial recovery.
+  */
+ local int stored(struct state *s)
+ {
+     unsigned len;       /* length of stored block */
+ 
+     /* discard leftover bits from current byte (assumes s->bitcnt < 8) */
+     s->bitbuf = 0;
+     s->bitcnt = 0;
+ 
+     /* get length and check against its one's complement */
+     if (s->incnt + 4 > s->inlen) return 2;      /* not enough input */
+     len = s->in[s->incnt++];
+     len |= s->in[s->incnt++] << 8;
+     if (s->in[s->incnt++] != (~len & 0xff) ||
+         s->in[s->incnt++] != ((~len >> 8) & 0xff))
+         return -2;                              /* didn't match complement! */
+ 
+     /* copy len bytes from in to out */
+     if (s->incnt + len > s->inlen) return 2;    /* not enough input */
+     if (s->out != NIL) {
+         if (s->outcnt + len > s->outlen)
+             return 1;                           /* not enough output space */
+         while (len--)
+             s->out[s->outcnt++] = s->in[s->incnt++];
+     }
+     else {                                      /* just scanning */
+         s->outcnt += len;
+         s->incnt += len;
+     }
+ 
+     /* done with a valid stored block */
+     return 0;
+ }
+ 
+ /*
+  * Huffman code decoding tables.  count[1..MAXBITS] is the number of symbols of
+  * each length, which for a canonical code are stepped through in order.
+  * symbol[] are the symbol values in canonical order, where the number of
+  * entries is the sum of the counts in count[].  The decoding process can be
+  * seen in the function decode() below.
+  */
+ struct huffman {
+     short *count;       /* number of symbols of each length */
+     short *symbol;      /* canonically ordered symbols */
+ };
+ 
+ /*
+  * Decode a code from the stream s using huffman table h.  Return the symbol or
+  * a negative value if there is an error.  If all of the lengths are zero, i.e.
+  * an empty code, or if the code is incomplete and an invalid code is received,
+  * then -9 is returned after reading MAXBITS bits.
+  *
+  * Format notes:
+  *
+  * - The codes as stored in the compressed data are bit-reversed relative to
+  *   a simple integer ordering of codes of the same lengths.  Hence below the
+  *   bits are pulled from the compressed data one at a time and used to
+  *   build the code value reversed from what is in the stream in order to
+  *   permit simple integer comparisons for decoding.  A table-based decoding
+  *   scheme (as used in zlib) does not need to do this reversal.
+  *
+  * - The first code for the shortest length is all zeros.  Subsequent codes of
+  *   the same length are simply integer increments of the previous code.  When
+  *   moving up a length, a zero bit is appended to the code.  For a complete
+  *   code, the last code of the longest length will be all ones.
+  *
+  * - Incomplete codes are handled by this decoder, since they are permitted
+  *   in the deflate format.  See the format notes for fixed() and dynamic().
+  */
+ #ifdef SLOW
+ local int decode(struct state *s, struct huffman *h)
+ {
+     int len;            /* current number of bits in code */
+     int code;           /* len bits being decoded */
+     int first;          /* first code of length len */
+     int count;          /* number of codes of length len */
+     int index;          /* index of first code of length len in symbol table */
+ 
+     code = first = index = 0;
+     for (len = 1; len <= MAXBITS; len++) {
+         code |= bits(s, 1);             /* get next bit */
+         count = h->count[len];
+         if (code < first + count)       /* if length len, return symbol */
+             return h->symbol[index + (code - first)];
+         index += count;                 /* else update for next length */
+         first += count;
+         first <<= 1;
+         code <<= 1;
+     }
+     return -9;                          /* ran out of codes */
+ }
+ 
+ /*
+  * A faster version of decode() for real applications of this code.   It's not
+  * as readable, but it makes puff() twice as fast.  And it only makes the code
+  * a few percent larger.
+  */
+ #else /* !SLOW */
+ local int decode(struct state *s, struct huffman *h)
+ {
+     int len;            /* current number of bits in code */
+     int code;           /* len bits being decoded */
+     int first;          /* first code of length len */
+     int count;          /* number of codes of length len */
+     int index;          /* index of first code of length len in symbol table */
+     int bitbuf;         /* bits from stream */
+     int left;           /* bits left in next or left to process */
+     short *next;        /* next number of codes */
+ 
+     bitbuf = s->bitbuf;
+     left = s->bitcnt;
+     code = first = index = 0;
+     len = 1;
+     next = h->count + 1;
+     while (1) {
+         while (left--) {
+             code |= bitbuf & 1;
+             bitbuf >>= 1;
+             count = *next++;
+             if (code < first + count) { /* if length len, return symbol */
+                 s->bitbuf = bitbuf;
+                 s->bitcnt = (s->bitcnt - len) & 7;
+                 return h->symbol[index + (code - first)];
+             }
+             index += count;             /* else update for next length */
+             first += count;
+             first <<= 1;
+             code <<= 1;
+             len++;
+         }
+         left = (MAXBITS+1) - len;
+         if (left == 0) break;
+         if (s->incnt == s->inlen) longjmp(s->env, 1);   /* out of input */
+         bitbuf = s->in[s->incnt++];
+         if (left > 8) left = 8;
+     }
+     return -9;                          /* ran out of codes */
+ }
+ #endif /* SLOW */
+ 
+ /*
+  * Given the list of code lengths length[0..n-1] representing a canonical
+  * Huffman code for n symbols, construct the tables required to decode those
+  * codes.  Those tables are the number of codes of each length, and the symbols
+  * sorted by length, retaining their original order within each length.  The
+  * return value is zero for a complete code set, negative for an over-
+  * subscribed code set, and positive for an incomplete code set.  The tables
+  * can be used if the return value is zero or positive, but they cannot be used
+  * if the return value is negative.  If the return value is zero, it is not
+  * possible for decode() using that table to return an error--any stream of
+  * enough bits will resolve to a symbol.  If the return value is positive, then
+  * it is possible for decode() using that table to return an error for received
+  * codes past the end of the incomplete lengths.
+  *
+  * Not used by decode(), but used for error checking, h->count[0] is the number
+  * of the n symbols not in the code.  So n - h->count[0] is the number of
+  * codes.  This is useful for checking for incomplete codes that have more than
+  * one symbol, which is an error in a dynamic block.
+  *
+  * Assumption: for all i in 0..n-1, 0 <= length[i] <= MAXBITS
+  * This is assured by the construction of the length arrays in dynamic() and
+  * fixed() and is not verified by construct().
+  *
+  * Format notes:
+  *
+  * - Permitted and expected examples of incomplete codes are one of the fixed
+  *   codes and any code with a single symbol which in deflate is coded as one
+  *   bit instead of zero bits.  See the format notes for fixed() and dynamic().
+  *
+  * - Within a given code length, the symbols are kept in ascending order for
+  *   the code bits definition.
+  */
+ local int construct(struct huffman *h, short *length, int n)
+ {
+     int symbol;         /* current symbol when stepping through length[] */
+     int len;            /* current length when stepping through h->count[] */
+     int left;           /* number of possible codes left of current length */
+     short offs[MAXBITS+1];      /* offsets in symbol table for each length */
+ 
+     /* count number of codes of each length */
+     for (len = 0; len <= MAXBITS; len++)
+         h->count[len] = 0;
+     for (symbol = 0; symbol < n; symbol++)
+         (h->count[length[symbol]])++;   /* assumes lengths are within bounds */
+     if (h->count[0] == n)               /* no codes! */
+         return 0;                       /* complete, but decode() will fail */
+ 
+     /* check for an over-subscribed or incomplete set of lengths */
+     left = 1;                           /* one possible code of zero length */
+     for (len = 1; len <= MAXBITS; len++) {
+         left <<= 1;                     /* one more bit, double codes left */
+         left -= h->count[len];          /* deduct count from possible codes */
+         if (left < 0) return left;      /* over-subscribed--return negative */
+     }                                   /* left > 0 means incomplete */
+ 
+     /* generate offsets into symbol table for each length for sorting */
+     offs[1] = 0;
+     for (len = 1; len < MAXBITS; len++)
+         offs[len + 1] = offs[len] + h->count[len];
+ 
+     /*
+      * put symbols in table sorted by length, by symbol order within each
+      * length
+      */
+     for (symbol = 0; symbol < n; symbol++)
+         if (length[symbol] != 0)
+             h->symbol[offs[length[symbol]]++] = symbol;
+ 
+     /* return zero for complete set, positive for incomplete set */
+     return left;
+ }
+ 
+ /*
+  * Decode literal/length and distance codes until an end-of-block code.
+  *
+  * Format notes:
+  *
+  * - Compressed data that is after the block type if fixed or after the code
+  *   description if dynamic is a combination of literals and length/distance
+  *   pairs terminated by and end-of-block code.  Literals are simply Huffman
+  *   coded bytes.  A length/distance pair is a coded length followed by a
+  *   coded distance to represent a string that occurs earlier in the
+  *   uncompressed data that occurs again at the current location.
+  *
+  * - Literals, lengths, and the end-of-block code are combined into a single
+  *   code of up to 286 symbols.  They are 256 literals (0..255), 29 length
+  *   symbols (257..285), and the end-of-block symbol (256).
+  *
+  * - There are 256 possible lengths (3..258), and so 29 symbols are not enough
+  *   to represent all of those.  Lengths 3..10 and 258 are in fact represented
+  *   by just a length symbol.  Lengths 11..257 are represented as a symbol and
+  *   some number of extra bits that are added as an integer to the base length
+  *   of the length symbol.  The number of extra bits is determined by the base
+  *   length symbol.  These are in the static arrays below, lens[] for the base
+  *   lengths and lext[] for the corresponding number of extra bits.
+  *
+  * - The reason that 258 gets its own symbol is that the longest length is used
+  *   often in highly redundant files.  Note that 258 can also be coded as the
+  *   base value 227 plus the maximum extra value of 31.  While a good deflate
+  *   should never do this, it is not an error, and should be decoded properly.
+  *
+  * - If a length is decoded, including its extra bits if any, then it is
+  *   followed a distance code.  There are up to 30 distance symbols.  Again
+  *   there are many more possible distances (1..32768), so extra bits are added
+  *   to a base value represented by the symbol.  The distances 1..4 get their
+  *   own symbol, but the rest require extra bits.  The base distances and
+  *   corresponding number of extra bits are below in the static arrays dist[]
+  *   and dext[].
+  *
+  * - Literal bytes are simply written to the output.  A length/distance pair is
+  *   an instruction to copy previously uncompressed bytes to the output.  The
+  *   copy is from distance bytes back in the output stream, copying for length
+  *   bytes.
+  *
+  * - Distances pointing before the beginning of the output data are not
+  *   permitted.
+  *
+  * - Overlapped copies, where the length is greater than the distance, are
+  *   allowed and common.  For example, a distance of one and a length of 258
+  *   simply copies the last byte 258 times.  A distance of four and a length of
+  *   twelve copies the last four bytes three times.  A simple forward copy
+  *   ignoring whether the length is greater than the distance or not implements
+  *   this correctly.  You should not use memcpy() since its behavior is not
+  *   defined for overlapped arrays.  You should not use memmove() or bcopy()
+  *   since though their behavior -is- defined for overlapping arrays, it is
+  *   defined to do the wrong thing in this case.
+  */
+ local int codes(struct state *s,
+                 struct huffman *lencode,
+                 struct huffman *distcode)
+ {
+     int symbol;         /* decoded symbol */
+     int len;            /* length for copy */
+     unsigned dist;      /* distance for copy */
+     static const short lens[29] = { /* Size base for length 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};
+     static const short lext[29] = { /* Extra bits for length 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};
+     static const short dists[30] = { /* Offset base 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 short dext[30] = { /* Extra bits for distance codes 0..29 */
+         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};
+ 
+     /* decode literals and length/distance pairs */
+     do {
+         symbol = decode(s, lencode);
+         if (symbol < 0) return symbol;  /* invalid symbol */
+         if (symbol < 256) {             /* literal: symbol is the byte */
+             /* write out the literal */
+             if (s->out != NIL) {
+                 if (s->outcnt == s->outlen) return 1;
+                 s->out[s->outcnt] = symbol;
+             }
+             s->outcnt++;
+         }
+         else if (symbol > 256) {        /* length */
+             /* get and compute length */
+             symbol -= 257;
+             if (symbol >= 29) return -9;        /* invalid fixed code */
+             len = lens[symbol] + bits(s, lext[symbol]);
+ 
+             /* get and check distance */
+             symbol = decode(s, distcode);
+             if (symbol < 0) return symbol;      /* invalid symbol */
+             dist = dists[symbol] + bits(s, dext[symbol]);
+             if (dist > s->outcnt)
+                 return -10;     /* distance too far back */
+ 
+             /* copy length bytes from distance bytes back */
+             if (s->out != NIL) {
+                 if (s->outcnt + len > s->outlen) return 1;
+                 while (len--) {
+                     s->out[s->outcnt] = s->out[s->outcnt - dist];
+                     s->outcnt++;
+                 }
+             }
+             else
+                 s->outcnt += len;
+         }
+     } while (symbol != 256);            /* end of block symbol */
+ 
+     /* done with a valid fixed or dynamic block */
+     return 0;
+ }
+ 
+ /*
+  * Process a fixed codes block.
+  *
+  * Format notes:
+  *
+  * - This block type can be useful for compressing small amounts of data for
+  *   which the size of the code descriptions in a dynamic block exceeds the
+  *   benefit of custom codes for that block.  For fixed codes, no bits are
+  *   spent on code descriptions.  Instead the code lengths for literal/length
+  *   codes and distance codes are fixed.  The specific lengths for each symbol
+  *   can be seen in the "for" loops below.
+  *
+  * - The literal/length code is complete, but has two symbols that are invalid
+  *   and should result in an error if received.  This cannot be implemented
+  *   simply as an incomplete code since those two symbols are in the "middle"
+  *   of the code.  They are eight bits long and the longest literal/length\
+  *   code is nine bits.  Therefore the code must be constructed with those
+  *   symbols, and the invalid symbols must be detected after decoding.
+  *
+  * - The fixed distance codes also have two invalid symbols that should result
+  *   in an error if received.  Since all of the distance codes are the same
+  *   length, this can be implemented as an incomplete code.  Then the invalid
+  *   codes are detected while decoding.
+  */
+ local int fixed(struct state *s)
+ {
+     static int virgin = 1;
+     static short lencnt[MAXBITS+1], lensym[FIXLCODES];
+     static short distcnt[MAXBITS+1], distsym[MAXDCODES];
+     static struct huffman lencode = {lencnt, lensym};
+     static struct huffman distcode = {distcnt, distsym};
+ 
+     /* build fixed huffman tables if first call (may not be thread safe) */
+     if (virgin) {
+         int symbol;
+         short lengths[FIXLCODES];
+ 
+         /* literal/length table */
+         for (symbol = 0; symbol < 144; symbol++)
+             lengths[symbol] = 8;
+         for (; symbol < 256; symbol++)
+             lengths[symbol] = 9;
+         for (; symbol < 280; symbol++)
+             lengths[symbol] = 7;
+         for (; symbol < FIXLCODES; symbol++)
+             lengths[symbol] = 8;
+         construct(&lencode, lengths, FIXLCODES);
+ 
+         /* distance table */
+         for (symbol = 0; symbol < MAXDCODES; symbol++)
+             lengths[symbol] = 5;
+         construct(&distcode, lengths, MAXDCODES);
+ 
+         /* do this just once */
+         virgin = 0;
+     }
+ 
+     /* decode data until end-of-block code */
+     return codes(s, &lencode, &distcode);
+ }
+ 
+ /*
+  * Process a dynamic codes block.
+  *
+  * Format notes:
+  *
+  * - A dynamic block starts with a description of the literal/length and
+  *   distance codes for that block.  New dynamic blocks allow the compressor to
+  *   rapidly adapt to changing data with new codes optimized for that data.
+  *
+  * - The codes used by the deflate format are "canonical", which means that
+  *   the actual bits of the codes are generated in an unambiguous way simply
+  *   from the number of bits in each code.  Therefore the code descriptions
+  *   are simply a list of code lengths for each symbol.
+  *
+  * - The code lengths are stored in order for the symbols, so lengths are
+  *   provided for each of the literal/length symbols, and for each of the
+  *   distance symbols.
+  *
+  * - If a symbol is not used in the block, this is represented by a zero as
+  *   as the code length.  This does not mean a zero-length code, but rather
+  *   that no code should be created for this symbol.  There is no way in the
+  *   deflate format to represent a zero-length code.
+  *
+  * - The maximum number of bits in a code is 15, so the possible lengths for
+  *   any code are 1..15.
+  *
+  * - The fact that a length of zero is not permitted for a code has an
+  *   interesting consequence.  Normally if only one symbol is used for a given
+  *   code, then in fact that code could be represented with zero bits.  However
+  *   in deflate, that code has to be at least one bit.  So for example, if
+  *   only a single distance base symbol appears in a block, then it will be
+  *   represented by a single code of length one, in particular one 0 bit.  This
+  *   is an incomplete code, since if a 1 bit is received, it has no meaning,
+  *   and should result in an error.  So incomplete distance codes of one symbol
+  *   should be permitted, and the receipt of invalid codes should be handled.
+  *
+  * - It is also possible to have a single literal/length code, but that code
+  *   must be the end-of-block code, since every dynamic block has one.  This
+  *   is not the most efficient way to create an empty block (an empty fixed
+  *   block is fewer bits), but it is allowed by the format.  So incomplete
+  *   literal/length codes of one symbol should also be permitted.
+  *
+  * - The list of up to 286 length/literal lengths and up to 30 distance lengths
+  *   are themselves compressed using Huffman codes and run-length encoding.  In
+  *   the list of code lengths, a 0 symbol means no code, a 1..15 symbol means
+  *   that length, and the symbols 16, 17, and 18 are run-length instructions.
+  *   Each of 16, 17, and 18 are follwed by extra bits to define the length of
+  *   the run.  16 copies the last length 3 to 6 times.  17 represents 3 to 10
+  *   zero lengths, and 18 represents 11 to 138 zero lengths.  Unused symbols
+  *   are common, hence the special coding for zero lengths.
+  *
+  * - The symbols for 0..18 are Huffman coded, and so that code must be
+  *   described first.  This is simply a sequence of up to 19 three-bit values
+  *   representing no code (0) or the code length for that symbol (1..7).
+  *
+  * - A dynamic block starts with three fixed-size counts from which is computed
+  *   the number of literal/length code lengths, the number of distance code
+  *   lengths, and the number of code length code lengths (ok, you come up with
+  *   a better name!) in the code descriptions.  For the literal/length and
+  *   distance codes, lengths after those provided are considered zero, i.e. no
+  *   code.  The code length code lengths are received in a permuted order (see
+  *   the order[] array below) to make a short code length code length list more
+  *   likely.  As it turns out, very short and very long codes are less likely
+  *   to be seen in a dynamic code description, hence what may appear initially
+  *   to be a peculiar ordering.
+  *
+  * - Given the number of literal/length code lengths (nlen) and distance code
+  *   lengths (ndist), then they are treated as one long list of nlen + ndist
+  *   code lengths.  Therefore run-length coding can and often does cross the
+  *   boundary between the two sets of lengths.
+  *
+  * - So to summarize, the code description at the start of a dynamic block is
+  *   three counts for the number of code lengths for the literal/length codes,
+  *   the distance codes, and the code length codes.  This is followed by the
+  *   code length code lengths, three bits each.  This is used to construct the
+  *   code length code which is used to read the remainder of the lengths.  Then
+  *   the literal/length code lengths and distance lengths are read as a single
+  *   set of lengths using the code length codes.  Codes are constructed from
+  *   the resulting two sets of lengths, and then finally you can start
+  *   decoding actual compressed data in the block.
+  *
+  * - For reference, a "typical" size for the code description in a dynamic
+  *   block is around 80 bytes.
+  */
+ local int dynamic(struct state *s)
+ {
+     int nlen, ndist, ncode;             /* number of lengths in descriptor */
+     int index;                          /* index of lengths[] */
+     int err;                            /* construct() return value */
+     short lengths[MAXCODES];            /* descriptor code lengths */
+     short lencnt[MAXBITS+1], lensym[MAXLCODES];         /* lencode memory */
+     short distcnt[MAXBITS+1], distsym[MAXDCODES];       /* distcode memory */
+     struct huffman lencode = {lencnt, lensym};          /* length code */
+     struct huffman distcode = {distcnt, distsym};       /* distance code */
+     static const short order[19] =      /* permutation of code length codes */
+         {16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15};
+ 
+     /* get number of lengths in each table, check lengths */
+     nlen = bits(s, 5) + 257;
+     ndist = bits(s, 5) + 1;
+     ncode = bits(s, 4) + 4;
+     if (nlen > MAXLCODES || ndist > MAXDCODES)
+         return -3;                      /* bad counts */
+ 
+     /* read code length code lengths (really), missing lengths are zero */
+     for (index = 0; index < ncode; index++)
+         lengths[order[index]] = bits(s, 3);
+     for (; index < 19; index++)
+         lengths[order[index]] = 0;
+ 
+     /* build huffman table for code lengths codes (use lencode temporarily) */
+     err = construct(&lencode, lengths, 19);
+     if (err != 0) return -4;            /* require complete code set here */
+ 
+     /* read length/literal and distance code length tables */
+     index = 0;
+     while (index < nlen + ndist) {
+         int symbol;             /* decoded value */
+         int len;                /* last length to repeat */
+ 
+         symbol = decode(s, &lencode);
+         if (symbol < 16)                /* length in 0..15 */
+             lengths[index++] = symbol;
+         else {                          /* repeat instruction */
+             len = 0;                    /* assume repeating zeros */
+             if (symbol == 16) {         /* repeat last length 3..6 times */
+                 if (index == 0) return -5;      /* no last length! */
+                 len = lengths[index - 1];       /* last length */
+                 symbol = 3 + bits(s, 2);
+             }
+             else if (symbol == 17)      /* repeat zero 3..10 times */
+                 symbol = 3 + bits(s, 3);
+             else                        /* == 18, repeat zero 11..138 times */
+                 symbol = 11 + bits(s, 7);
+             if (index + symbol > nlen + ndist)
+                 return -6;              /* too many lengths! */
+             while (symbol--)            /* repeat last or zero symbol times */
+                 lengths[index++] = len;
+         }
+     }
+ 
+     /* build huffman table for literal/length codes */
+     err = construct(&lencode, lengths, nlen);
+     if (err < 0 || (err > 0 && nlen - lencode.count[0] != 1))
+         return -7;      /* only allow incomplete codes if just one code */
+ 
+     /* build huffman table for distance codes */
+     err = construct(&distcode, lengths + nlen, ndist);
+     if (err < 0 || (err > 0 && ndist - distcode.count[0] != 1))
+         return -8;      /* only allow incomplete codes if just one code */
+ 
+     /* decode data until end-of-block code */
+     return codes(s, &lencode, &distcode);
+ }
+ 
+ /*
+  * Inflate source to dest.  On return, destlen and sourcelen are updated to the
+  * size of the uncompressed data and the size of the deflate data respectively.
+  * On success, the return value of puff() is zero.  If there is an error in the
+  * source data, i.e. it is not in the deflate format, then a negative value is
+  * returned.  If there is not enough input available or there is not enough
+  * output space, then a positive error is returned.  In that case, destlen and
+  * sourcelen are not updated to facilitate retrying from the beginning with the
+  * provision of more input data or more output space.  In the case of invalid
+  * inflate data (a negative error), the dest and source pointers are updated to
+  * facilitate the debugging of deflators.
+  *
+  * puff() also has a mode to determine the size of the uncompressed output with
+  * no output written.  For this dest must be (unsigned char *)0.  In this case,
+  * the input value of *destlen is ignored, and on return *destlen is set to the
+  * size of the uncompressed output.
+  *
+  * The return codes are:
+  *
+  *   2:  available inflate data did not terminate
+  *   1:  output space exhausted before completing inflate
+  *   0:  successful inflate
+  *  -1:  invalid block type (type == 3)
+  *  -2:  stored block length did not match one's complement
+  *  -3:  dynamic block code description: too many length or distance codes
+  *  -4:  dynamic block code description: code lengths codes incomplete
+  *  -5:  dynamic block code description: repeat lengths with no first length
+  *  -6:  dynamic block code description: repeat more than specified lengths
+  *  -7:  dynamic block code description: invalid literal/length code lengths
+  *  -8:  dynamic block code description: invalid distance code lengths
+  *  -9:  invalid literal/length or distance code in fixed or dynamic block
+  * -10:  distance is too far back in fixed or dynamic block
+  *
+  * Format notes:
+  *
+  * - Three bits are read for each block to determine the kind of block and
+  *   whether or not it is the last block.  Then the block is decoded and the
+  *   process repeated if it was not the last block.
+  *
+  * - The leftover bits in the last byte of the deflate data after the last
+  *   block (if it was a fixed or dynamic block) are undefined and have no
+  *   expected values to check.
+  */
+ int puff(unsigned char *dest,           /* pointer to destination pointer */
+          unsigned long *destlen,        /* amount of output space */
+          unsigned char *source,         /* pointer to source data pointer */
+          unsigned long *sourcelen)      /* amount of input available */
+ {
+     struct state s;             /* input/output state */
+     int last, type;             /* block information */
+     int err;                    /* return value */
+ 
+     /* initialize output state */
+     s.out = dest;
+     s.outlen = *destlen;                /* ignored if dest is NIL */
+     s.outcnt = 0;
+ 
+     /* initialize input state */
+     s.in = source;
+     s.inlen = *sourcelen;
+     s.incnt = 0;
+     s.bitbuf = 0;
+     s.bitcnt = 0;
+ 
+     /* return if bits() or decode() tries to read past available input */
+     if (setjmp(s.env) != 0)             /* if came back here via longjmp() */
+         err = 2;                        /* then skip do-loop, return error */
+     else {
+         /* process blocks until last block or error */
+         do {
+             last = bits(&s, 1);         /* one if last block */
+             type = bits(&s, 2);         /* block type 0..3 */
+             err = type == 0 ? stored(&s) :
+                   (type == 1 ? fixed(&s) :
+                    (type == 2 ? dynamic(&s) :
+                     -1));               /* type == 3, invalid */
+             if (err != 0) break;        /* return with error */
+         } while (!last);
+     }
+ 
+     /* update the lengths and return */
+     if (err <= 0) {
+         *destlen = s.outcnt;
+         *sourcelen = s.incnt;
+     }
+     return err;
+ }
+ 
+ #ifdef TEST
+ /* Example of how to use puff() */
+ #include <stdio.h>
+ #include <stdlib.h>
+ #include <sys/types.h>
+ #include <sys/stat.h>
+ 
+ local unsigned char *yank(char *name, unsigned long *len)
+ {
+     unsigned long size;
+     unsigned char *buf;
+     FILE *in;
+     struct stat s;
+ 
+     *len = 0;
+     if (stat(name, &s)) return NULL;
+     if ((s.st_mode & S_IFMT) != S_IFREG) return NULL;
+     size = (unsigned long)(s.st_size);
+     if (size == 0 || (off_t)size != s.st_size) return NULL;
+     in = fopen(name, "r");
+     if (in == NULL) return NULL;
+     buf = malloc(size);
+     if (buf != NULL && fread(buf, 1, size, in) != size) {
+         free(buf);
+         buf = NULL;
+     }
+     fclose(in);
+     *len = size;
+     return buf;
+ }
+ 
+ int main(int argc, char **argv)
+ {
+     int ret;
+     unsigned char *source;
+     unsigned long len, sourcelen, destlen;
+ 
+     if (argc < 2) return 2;
+     source = yank(argv[1], &len);
+     if (source == NULL) return 2;
+     sourcelen = len;
+     ret = puff(NIL, &destlen, source, &sourcelen);
+     if (ret)
+         printf("puff() failed with return code %d\n", ret);
+     else {
+         printf("puff() succeeded uncompressing %lu bytes\n", destlen);
+         if (sourcelen < len) printf("%lu compressed bytes unused\n",
+                                     len - sourcelen);
+     }
+     free(source);
+     return ret;
+ }
+ #endif


Index: llvm/runtime/zlib/contrib/puff/puff.h
diff -c /dev/null llvm/runtime/zlib/contrib/puff/puff.h:1.1.2.1
*** /dev/null	Mon Mar  1 17:58:59 2004
--- llvm/runtime/zlib/contrib/puff/puff.h	Mon Mar  1 17:58:48 2004
***************
*** 0 ****
--- 1,31 ----
+ /* puff.h
+   Copyright (C) 2002, 2003 Mark Adler, all rights reserved
+   version 1.7, 3 Mar 2002
+ 
+   This software is provided 'as-is', without any express or implied
+   warranty.  In no event will the author be held liable for any damages
+   arising from the use of this software.
+ 
+   Permission is granted to anyone to use this software for any purpose,
+   including commercial applications, and to alter it and redistribute it
+   freely, subject to the following restrictions:
+ 
+   1. The origin of this software must not be misrepresented; you must not
+      claim that you wrote the original software. If you use this software
+      in a product, an acknowledgment in the product documentation would be
+      appreciated but is not required.
+   2. Altered source versions must be plainly marked as such, and must not be
+      misrepresented as being the original software.
+   3. This notice may not be removed or altered from any source distribution.
+ 
+   Mark Adler    madler at alumni.caltech.edu
+  */
+ 
+ 
+ /*
+  * See puff.c for purpose and usage.
+  */
+ int puff(unsigned char *dest,           /* pointer to destination pointer */
+          unsigned long *destlen,        /* amount of output space */
+          unsigned char *source,         /* pointer to source data pointer */
+          unsigned long *sourcelen);     /* amount of input available */


Index: llvm/runtime/zlib/contrib/puff/zeros.raw





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