commit e46afd79679b931cf1912ce2c98aa5293a3f006a
parent 92913b23713f768bc4467f5e29c9c0a4997d5b70
Author: nsz <nszabolcs@gmail.com>
Date: Fri, 1 May 2009 11:08:08 +0200
inflate with callback wip
Diffstat:
| inflate.c | | | 121 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------------------ |
1 file changed, 94 insertions(+), 27 deletions(-)
diff --git a/inflate.c b/inflate.c
@@ -11,15 +11,17 @@ typedef unsigned int uint;
enum {
CodeBits = 16, /* max number of bits in a code */
- LitlenTableBits = 9, /* log2(litlen lookup table size) */
- DistTableBits = 6, /* log2(dist lookup table size) */
- ClenTableBits = 6, /* log2(clen lookup table size) */
- TableBits = LitlenTableBits, /* log2(max lookup table size) */
+ LitlenTableBits = 9, /* litlen code bits used in lookup table */
+ DistTableBits = 6, /* dist code bits used in lookup table */
+ ClenTableBits = 6, /* clen code bits used in lookup table */
+ TableBits = LitlenTableBits, /* log2(lookup table size) */
Nlit = 256, /* number of lit codes */
Nlen = 29, /* number of len codes */
Nlitlen = Nlit+Nlen+3, /* litlen codes + block end + 2 unused */
Ndist = 30, /* number of distance codes */
- Nclen = 19 /* number of code length codes */
+ Nclen = 19, /* number of code length codes */
+ SrcSize = 32768, /* input window size */
+ DstSize = 32768 /* output window size */
};
enum {
@@ -44,12 +46,19 @@ typedef struct {
} Huff;
typedef struct {
- uchar *src;
+ int (*r)(void *, int, void *);
+ void *rdata;
+ uchar *srcbegin;
uchar *srcend;
+ uchar *src;
+ uint srcleft;
- uchar *dst;
+ int (*w)(void *, int, void *);
+ void *wdata;
uchar *dstbegin;
uchar *dstend;
+ uchar *dst;
+ uint dstleft;
uint bits;
uint nbits;
@@ -196,15 +205,36 @@ static void init_fixed_huffs(void) {
build_huff(&dhuff, lens, Ndist, 5);
}
+static int checksrc(Stream *s) {
+ if (s->src == s->srcend) {
+ s->src = s->srcbegin;
+ s->srcend = s->src + s->r(s->src, SrcSize, s->rdata);
+ if (s->src == s->srcend) {
+ s->error = FlateShortSrc;
+ return 0;
+ }
+ }
+ return 1;
+}
+
+static int checkdst(Stream *s) {
+ if (s->dst == s->dstend) {
+ s->dst = s->dstbegin;
+ if (s->w(s->dst, s->dstend - s->dst, s->wdata) <= 0) {
+ s->error = FlateShortSrc;
+ return 0;
+ }
+ }
+ return 1;
+}
+
/* get one bit from stream */
static uint getbit(Stream *s) {
uint bit;
if (!s->nbits--) {
- if (s->src == s->srcend) {
- s->error = FlateShortSrc;
+ if (!checksrc(s))
return 0;
- }
s->bits = *s->src++;
s->nbits = 7;
}
@@ -223,10 +253,8 @@ static uint getbits(Stream *s, int n) {
bits = s->bits;
nbits = s->nbits;
while (nbits < n) {
- if (s->src == s->srcend) {
- s->error = FlateShortSrc;
+ if (!checksrc(s))
return 0;
- }
bits |= (*s->src++ << nbits);
nbits += 8;
}
@@ -235,7 +263,7 @@ static uint getbits(Stream *s, int n) {
return bits & ((1 << n) - 1);
}
-/* decode a symbol from stream with tree */
+/* decode a symbol from stream with huff code */
static uint decode_symbol(Stream *s, Huff *huff) {
int sum, cur;
ushort *count;
@@ -248,10 +276,8 @@ static uint decode_symbol(Stream *s, Huff *huff) {
/* avail src should be checked outside */
while (streambits < huffbits) {
/* TODO: decode_symbol is performace bottleneck, do it faster */
- if (s->src == s->srcend) {
- s->error = FlateShortSrc;
+ if (!checksrc(s))
return 0;
- }
bits |= (*s->src++ << streambits);
streambits += 8;
}
@@ -358,10 +384,8 @@ static void decode_block(Stream *s, Huff *lhuff, Huff *dhuff) {
if (sym == 256)
return;
if (sym < 256) {
- if (s->dst == s->dstend) {
- s->error = FlateShortDst;
+ if (!checkdst(s))
return;
- }
*s->dst++ = sym;
} else {
int i, len, dist;
@@ -384,6 +408,7 @@ static void decode_block(Stream *s, Huff *lhuff, Huff *dhuff) {
return;
/* copy match */
if (s->dst + len > s->dstend) {
+ /* TODO */
s->error = FlateShortDst;
return;
}
@@ -445,7 +470,50 @@ static void inflate_dynamic_block(Stream *s) {
/* extern */
-/* inflate stream from src to dst */
+/* inflate with callbacks */
+int inflate_f(int (*r)(void *, int, void *), void *rdata, int (*w)(void *, int, void *), void *wdata) {
+ Stream s;
+ uint final;
+
+ s.r = r;
+ s.rdata = rdata;
+ s.w = w;
+ s.wdata = wdata;
+ s.srcbegin = s.srcend = s.src = malloc(SrcSize);
+ s.dst = s.dstbegin = malloc(DstSize);
+ s.dstend = s.dst + DstSize;
+ s.error = FlateOk;
+ s.nbits = 0;
+ do {
+ uint blocktype;
+
+ final = getbit(&s);
+ blocktype = getbits(&s, 2);
+ if (s.error != FlateOk)
+ return 0;
+
+ /* decompress block */
+ switch (blocktype) {
+ case 0:
+ inflate_uncompressed_block(&s);
+ break;
+ case 1:
+ inflate_fixed_block(&s);
+ break;
+ case 2:
+ inflate_dynamic_block(&s);
+ break;
+ default:
+ s.error = FlateCorrupted;
+ }
+ if (s.error != FlateOk)
+ return 0;
+ } while (!final);
+ /* TODO: errors, extra data at the end */
+ return s.dst - s.dstbegin;
+}
+
+/*
uint inflate(void *dst, uint dstlen, void *src, uint srclen) {
Stream s;
uint final;
@@ -464,7 +532,6 @@ uint inflate(void *dst, uint dstlen, void *src, uint srclen) {
if (s.error != FlateOk)
return 0;
- /* decompress block */
switch (blocktype) {
case 0:
inflate_uncompressed_block(&s);
@@ -483,15 +550,14 @@ uint inflate(void *dst, uint dstlen, void *src, uint srclen) {
} while (!final);
return s.dst - s.dstbegin;
}
-
+*/
/* simple test */
#include <stdlib.h>
#include <stdio.h>
-void *readall(FILE *in) {
- uint len = 1 << 22;
+void *readall(FILE *in, uint len) {
void *buf;
buf = malloc(len);
@@ -502,11 +568,12 @@ void *readall(FILE *in) {
int main(int argc, char **argv) {
uint len = 1 << 24;
+ uint srclen = 1 << 22;
uchar *src, *dst;
- src = readall(argc < 2 ? stdin : fopen(argv[1], "r"));
+ src = readall(argc < 2 ? stdin : fopen(argv[1], "r"), srclen);
dst = malloc(len);
- len = inflate(dst, len, src, len>>2);
+ len = inflate(dst, len, src, srclen);
fprintf(stderr, "decompressed %u bytes\n", len);
fwrite(dst, 1, len, stdout);
free(dst);
