flate

commit c74af3ca586060b2172459ddcac6055d0358f57a
parent b4ac11e701ddfb012b25d6f77f75ab8aa4db405e
Author: nsz <nszabolcs@gmail.com>
Date:   Sat,  1 Aug 2009 19:16:25 +0200

inflate.h, example
Diffstat:
inflate.h
 | 
29
+++++++++++++++++++++++++++++
inflate_example.c
 | 
70
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

2 files changed, 99 insertions(+), 0 deletions(-)
diff --git a/inflate.h b/inflate.h
@@ -0,0 +1,29 @@
+typedef unsigned char uchar;
+typedef unsigned short ushort;
+typedef unsigned int uint;
+
+/* TODO: flatein flateout flateerr */
+
+/* return values */
+enum {
+	FlateOk         = 0,
+	FlateError      = -1,
+	FlateNeedInput  = -2,
+	FlateHasOutput  = -3
+};
+
+typedef struct {
+	uchar *in;
+	int nin;
+	uchar *out;
+	int nout;
+	char *err;
+	void *state;
+} FlateStream;
+
+/* state and err should be initialized to 0, to free internal state call s->err = ""; inflate(s) */
+/* decode from in to out, return if input is needed or output is available */
+int inflate(FlateStream *s);
+
+/* callback interface: r(buf, n, rdata) reads at most n bytes into buf */
+int inflate_callback(int (*r)(void *, int, void *), void *rdata, int (*w)(void *, int, void *), void *wdata);
diff --git a/inflate_example.c b/inflate_example.c
@@ -0,0 +1,70 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include "inflate.h"
+
+int decompress_stream(FILE *in, FILE *out) {
+	FlateStream s;
+	int n, nin, nout;
+	enum {Nin = 1<<12, Nout = 1<<15};
+
+	s.in = malloc(Nin);
+	s.out = malloc(Nout);
+	s.nout = Nout;
+	s.err = 0;
+	s.state = 0;
+	nin = nout = 0;
+
+	for (n = FlateNeedInput; ; n = inflate(&s))
+		switch (n) {
+		case FlateOk:
+		case FlateError:
+			fprintf(stderr, "in: %d out: %d err: %s\n", nin, nout, s.err);
+			return n;
+		case FlateNeedInput:
+			s.nin = fread(s.in, 1, Nin, in);
+			if (s.nin == 0)
+				s.err = "read error.";
+			nin += s.nin;
+			break;
+		case FlateHasOutput:
+			if (s.nout != fwrite(s.out, 1, s.nout, out))
+				s.err = "write error.";
+			nout += s.nout;
+			s.nout = Nout;
+			break;
+		}
+}
+
+int decompress_mem(void *src, int srclen, void *dst, int dstlen) {
+	FlateStream s;
+	int n;
+
+	s.in = src;
+	s.nin = srclen;
+	s.out = dst;
+	s.nout = dstlen;
+	s.err = 0;
+	s.state = 0;
+
+	while ((n = inflate(&s)) == FlateHasOutput) {
+		dstlen -= s.nout;
+		s.out += s.nout;
+		s.nout = dstlen;
+		if (dstlen < 0)
+			s.err = "not enough output space.";
+	}
+	if (n == FlateNeedInput) {
+		s.err = "input is not terminated.";
+		n = inflate(&s);
+	}
+	if (n == FlateOk) {
+		fprintf(stderr, "in: %d out: %d\n", srclen, (char *)s.out - (char *)dst);
+		return (char *)s.out - (char *)dst;
+	}
+	fprintf(stderr, "in: %d out: %d err: %s\n", srclen, (char *)s.out - (char *)dst, s.err);
+	return -1;
+}
+
+int main(void) {
+	return decompress_stream(stdin, stdout);
+}