flate

commit 0415ad28bd842b0ed4e5f081d73669ceb5e254dd
parent 2dd25d387a3157e6e09d56db17ddc2a27b6d757e
Author: nsz <nszabolcs@gmail.com>
Date:   Sun, 26 Jul 2009 19:28:58 +0200

deflate_simple update
Diffstat:
Makefile
 | 
4
++--
README
 | 
10
++++++----
deflate_simple.c
 | 
10
++--------

3 files changed, 10 insertions(+), 14 deletions(-)
diff --git a/Makefile b/Makefile
@@ -1,5 +1,5 @@
-#CFLAGS=-g -Wall -ansi -pedantic
-CFLAGS=-O3 -Wall -ansi -pedantic
+CFLAGS=-g -Wall -ansi -pedantic
+#CFLAGS=-O3 -Wall -ansi -pedantic
 LDFLAGS=
 SRC=inflate.c inflate_simple.c inflate_callback.c deflate.c deflate_simple.c
 OBJ=${SRC:.c=.o}
diff --git a/README b/README
@@ -2,15 +2,17 @@ minimal deflate implementation
 
 based on:
 	rfc1951 from ietf
-	tinf from ibsensoftware
-	libflate from plan 9
 	zlib
 	puff from zlib
 	gzip
-	halibut/deflate from putty
+	tinf from ibsensoftware
+	libflate from plan 9
+	deflate from halibut
+	sshzlib from putty
 
 build:
 	make
 
 features:
-	decode raw deflate compressed data
+	inflate: decode raw deflate compressed data
+	deflate: raw deflate compression
diff --git a/deflate_simple.c b/deflate_simple.c
@@ -8,7 +8,7 @@ enum {
 	MinMatch = 3,
 	MaxMatch = 258,
 	BigDist = 1 << 12,
-	MaxChainStep = 64,
+	MaxChainStep = 128,
 	HashBits = 13,
 	HashSize = 1 << HashBits,
 	WinSize = 1 << 15,
@@ -309,7 +309,6 @@ static void deflate_block(State *s, int blocklen) {
 	int dynsize, fixsize, uncsize;
 	int *pn;
 	uchar *pc;
-/*int dyntree;*/
 
 	/* calc dynamic codes */
 	hufflens(llen, s->lfreq, Nlitlen, CodeBits-1);
@@ -340,7 +339,6 @@ static void deflate_block(State *s, int blocklen) {
 		if (c == 18)
 			dynsize += 7;
 	}
-/*dyntree = dynsize - 3;*/
 	for (pn = s->rbuf, pc = s->src; pn != s->rend;) {
 		n = *pn++;
 		if (n & RunlenFlag) {
@@ -401,10 +399,6 @@ static void deflate_block(State *s, int blocklen) {
 		memcpy(s->dst, s->src, blocklen);
 		s->dst += blocklen;
 	}
-/*
-fprintf(stderr, "blocklen: %d lzlen: %d dynsize: %d (tree: %d, rate: %.3f) fixsize: %d (rate: %.3f) uncsize: %d (rate: %.3f)\n", blocklen, s->rend - s->rbuf,
-	dynsize, dyntree, dynsize/(float)blocklen, fixsize, fixsize/(float)blocklen, uncsize, uncsize/(float)blocklen);
-*/
 }
 
 static int bisect(ushort *base, int len, int n) {
@@ -442,7 +436,7 @@ static void recordlit(State *s, int c) {
 	s->lfreq[c]++;
 }
 
-/* 32 bit multiplicative hash */
+/* multiplicative hash */
 static uint gethash(uchar *p) {
 	return 0x9e3779b1 * ((p[0]<<16) + (p[1]<<8) + p[2]) >> (32 - HashBits);
 }