flate

commit 0c8559e47e28462e087102babc34257c9b1aa30f
parent 2dd84d164143d185cb9edd664bed5f2a4e71c969
Author: nsz <nszabolcs@gmail.com>
Date:   Sun, 16 Aug 2009 13:53:56 +0200

deflate clean up
Diffstat:
deflate.c
 | 
18
+++++++-----------

1 file changed, 7 insertions(+), 11 deletions(-)
diff --git a/deflate.c b/deflate.c
@@ -2,8 +2,6 @@
 #include <string.h>
 #include "flate.h"
 
-#include <stdio.h>
-
 enum {
 	CodeBits    = 16,      /* max number of bits in a code + 1 */
 	EOB         = 256,     /* end of block symbol */
@@ -328,7 +326,7 @@ static void deflate_block(State *s) {
 	uchar *h;
 	int dynsize, fixsize, uncsize;
 	int blocklen = s->pos - s->startpos;
-int dyntree;
+/* int dyntree; */
 
 	/* calc dynamic codes */
 	hufflens(llen, s->lfreq, Nlitlen, CodeBits-1);
@@ -359,7 +357,7 @@ int dyntree;
 		if (c == 18)
 			dynsize += 7;
 	}
-dyntree = dynsize - 3;
+/* dyntree = dynsize - 3; */
 	for (lz = s->lzbuf, h = s->hist + s->startpos; lz != s->lz; lz++)
 		if (lz->bits & LzLitFlag)
 			for (n = lz->n; n > 0; n--, h++) {
@@ -416,11 +414,11 @@ dyntree = dynsize - 3;
 		memcpy(s->dst, s->hist + s->startpos, blocklen);
 		s->dst += blocklen;
 	}
-
+/*
 fprintf(stderr, "blen:%d [%d,%d] lzlen:%d dynlen:%d (tree:%d rate:%.3f) fixlen:%d (rate:%.3f) unclen:%d (rate:%.3f) avail:%d\n",
 	blocklen, s->startpos, s->pos, s->lz - s->lzbuf, dynsize, dyntree, dynsize/(float)blocklen,
 	fixsize, fixsize/(float)blocklen, uncsize, uncsize/(float)blocklen, s->avail);
-
+*/
 }
 
 /* find n in base */
@@ -539,7 +537,7 @@ static void newblock(State *s) {
 correctness assertions:
 	- pos < 64K in updatechain (head and chain is ushort)
 	- updatechain has at least MinMatch input (except at eof)
-	- getmatch has at least MaxMatch input
+	- getmatch has at least MaxMatch input in hist
 	- getmatch has at least HistSafe history
 	- lzbuf does not overflow before endblock
 	- dstbuf does not overflow before endblock
@@ -551,8 +549,6 @@ correctness assertions:
 static int updatehist(State *s) {
 	int n, k;
 
-	if (s->avail > HistEnd)
-		return 1;
 	if (s->pos >= HistSize - HistEnd) {
 		/* shift hist */
 		memcpy(s->hist, s->hist + WinSize, HistSize - WinSize);
@@ -563,10 +559,10 @@ static int updatehist(State *s) {
 		s->startpos -= WinSize;
 		s->pos -= WinSize;
 	}
-	if (!s->eof) {
+	if (s->avail <= HistEnd && !s->eof) {
 		/* fill hist */
 		k = s->srcend - s->src;
-		n = HistSize - s->pos - s->avail; /* s->avail + n >= MaxMatch */
+		n = HistSize - s->pos - s->avail; /* s->avail + n > HistEnd */
 		if (k > n)
 			k = n;
 		memcpy(s->hist + s->pos + s->avail, s->src, k);