[hackers] [flate] clean ups, -callback || nsz

changeset: 116:3ae79c6d17c5
user: nsz <nszabolcs_AT_gmail.com>
date: Sun Aug 23 19:15:58 2009 +0200
files: deflate.c
description:
clean ups, -callback

diff -r fc6500e18dd9 -r 3ae79c6d17c5 deflate.c
--- a/deflate.c Sun Aug 23 14:38:24 2009 +0200
+++ b/deflate.c Sun Aug 23 19:15:58 2009 +0200
@@ -18,11 +18,12 @@
         HashBits = 13,
         HashSize = 1 << HashBits, /* hash table size */
         BigDist = 1 << 12, /* max match distance for short match length */
- BlockSize = (1 << 15) - 300, /* TODO */
         MaxDist = WinSize,
+ BlockSize = 1 << 15, /* TODO */
         SrcSize = 2*WinSize + MaxMatch,
         DstSize = BlockSize + MaxMatch + 6, /* worst case compressed block size */
         LzSize = 1 << 13, /* lz buffer size */
+ LzGuard = LzSize - 2,
         LzLitFlag = 1 << 15 /* marks literal run length in lz buffer */
 };
 
@@ -41,24 +42,24 @@
         int startpos; /* block start pos in input src */
         int endpos; /* end of available bytes in src */
         int skip; /* skipped hash chain updates (until next iter) */
+ Match prevm; /* previous (deferred) match */
         int state; /* prev return value */
         int eof; /* end of input */
- Match prevm; /* previous (deferred) match */
- int nin;
         uchar *in; /* input data (not yet in src) */
+ uchar *inend;
+ uint bits; /* for output */
+ int nbits; /* for output */
         uchar *dst; /* compressed output (position in dstbuf) */
         uchar *dstbegin; /* start position of unflushed data in dstbuf */
- uint bits;
- int nbits;
- uchar src[SrcSize]; /* input buf */
+ LzCode *lz; /* current pos in lzbuf */
+ int nlit; /* literal run length in lzbuf */
         ushort head[HashSize]; /* position of hash chain heads */
         ushort chain[WinSize]; /* hash chain */
- LzCode lzbuf[LzSize]; /* literal run length, match len, match dist */
- LzCode *lz; /* current pos in lzbuf */
- int nlit; /* literal run length */
         ushort lfreq[Nlitlen];
         ushort dfreq[Ndist];
+ uchar src[SrcSize]; /* input buf */
         uchar dstbuf[DstSize];
+ LzCode lzbuf[LzSize]; /* literal run length, match len, match dist */
 } State;
 
 static uchar fixllen[Nlitlen]; /* fixed lit/len huffman code tree */
@@ -558,10 +559,8 @@
 }
 
 static int endblock(State *s) {
- LzCode *lzend = s->lzbuf + LzSize - 2;
-
         if ((s->pos >= 2*WinSize && !shiftwin(s)) || s->pos - s->startpos >= BlockSize ||
- s->lz >= lzend || (s->eof && s->pos == s->endpos)) {
+ s->lzbuf - s->lz >= LzGuard || (s->eof && s->pos == s->endpos)) {
                 /* deflate block */
                 flushlit(s);
                 if (s->prevm.len)
@@ -575,15 +574,15 @@
 }
 
 static int fillsrc(State *s) {
- int n;
+ int n, k;
 
         if (s->endpos < SrcSize && !s->eof) {
                 n = SrcSize - s->endpos;
- if (n > s->nin)
- n = s->nin;
+ k = s->inend - s->in;
+ if (n > k)
+ n = k;
                 memcpy(s->src + s->endpos, s->in, n);
                 s->in += n;
- s->nin -= n;
                 s->endpos += n;
                 if (s->endpos < SrcSize)
                         return 0;
@@ -603,10 +602,9 @@
         Match m;
         int next;
         int guard;
- LzCode *lzend;
 
         if (s->state == FlateIn)
- s->eof = s->nin == 0;
+ s->eof = s->in == s->inend;
         else if (s->state == FlateOut) {
                 if (s->dstbegin < s->dst)
                         return (s->state = FlateOut);
@@ -619,11 +617,10 @@
                 return s->state;
 
         guard = calcguard(s);
- lzend = s->lzbuf + LzSize - 2;
-/*fprintf(stderr,"guard:%d pos:%d nin:%d\n", guard, s->pos, s->nin);*/
+/*fprintf(stderr,"guard:%d pos:%d nin:%d\n", guard, s->pos, s->inend - s->in);*/
         for (;;) {
- if (s->pos >= guard || s->lz >= lzend) {
-/*fprintf(stderr,"guard:%d pos:%d len:%d end:%d start:%d nin:%d\n", guard, s->pos, s->pos - s->startpos, s->endpos, s->startpos, s->nin);*/
+ if (s->pos >= guard || s->lzbuf - s->lz >= LzGuard) {
+/*fprintf(stderr,"guard:%d pos:%d len:%d end:%d start:%d nin:%d\n", guard, s->pos, s->pos - s->startpos, s->endpos, s->startpos, s->inend - s->in);*/
                         if (endblock(s))
                                 return (s->state = FlateOut);
                         if (!fillsrc(s))
@@ -671,7 +668,7 @@
         huffcodes(fixlcode, fixllen, Nlitlen);
         huffcodes(fixdcode, fixdlen, Ndist);
         s->state = FlateOut;
- s->nin = 0;
+ s->in = s->inend = 0;
         s->dst = s->dstbegin = s->dstbuf;
         s->pos = s->startpos = s->endpos = WinSize;
         s->eof = 0;
@@ -699,7 +696,7 @@
         }
         if (stream->nin) {
                 s->in = stream->in;
- s->nin = stream->nin;
+ s->inend = s->in + stream->nin;
                 stream->nin = 0;
         }
         n = deflate_state(s);
@@ -716,43 +713,3 @@
         }
         return n;
 }
-
-/*
-int deflate_callback(int (*r)(void *, int, void *), void *rdata, int (*w)(void *, int, void *), void *wdata) {
- State *s;
- uchar *src;
- int len, n;
- enum {SrcSize = 1 << 13};
-
- s = alloc_state();
- if (!s)
- return FlateErr;
- src = s->src = s->srcend = malloc(SrcSize);
- if (!src) {
- free(s);
- return FlateErr;
- }
- for (;;) {
- n = deflate_state(s);
- switch (n) {
- case FlateIn:
- s->src = src;
- len = r(s->src, SrcSize, rdata);
- s->srcend = s->src + len;
- break;
- case FlateOut:
- len = w(s->dstbegin, s->dst - s->dstbegin, wdata);
- if (len == s->dst - s->dstbegin)
- s->dstbegin = s->dst;
- else
- s->state = FlateErr;
- break;
- case FlateOk:
- case FlateErr:
- free(src);
- free(s);
- return n;
- }
- }
-}
-*/
Received on Sun Aug 23 2009 - 19:00:34 UTC