inflate.c: support raw deflate without zlib header

From: Kiyokazu SUTO <suto@ks-and-ks.ne.jp>

2 files changed, 161 insertions, 46 deletions

diff --git a/ChangeLog b/ChangeLog
index abcd444..dd0419c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2002-01-31  Kiyokazu SUTO <suto@ks-and-ks.ne.jp>
+
+	* inflate.c: support raw deflate without zlib header
+
 2002-01-31  Fumitoshi UKAI  <ukai@debian.or.jp>
 
 	* [w3m-dev 02955] compression_decoders error message
@@ -2468,4 +2472,4 @@
 	* release-0-2-1
 	* import w3m-0.2.1
 
-$Id: ChangeLog,v 1.282 2002/01/31 09:43:14 ukai Exp $
+$Id: ChangeLog,v 1.283 2002/01/31 14:03:49 ukai Exp $
diff --git a/inflate.c b/inflate.c
index 9b58101..571a1b3 100644
--- a/inflate.c
+++ b/inflate.c
@@ -1,63 +1,174 @@
-/* $Id: inflate.c,v 1.4 2002/01/31 09:43:15 ukai Exp $ */
+#include <errno.h>
 #include <stdio.h>
+#include <string.h>
 #include <stdlib.h>
 #include <zlib.h>
 
-#undef BUFSIZE
-#define BUFSIZE 4096
+#define MYBUFSIZ (BUFSIZ * 0x10)
+
+/* cf. rfc1950.txt */
+static char dummy_head[1 + 1] = {
+    0x8 + 0x7 * 0x10,
+    (((0x8 + 0x7 * 0x10) * 0x100 + 30) / 31 * 31) & 0xFF,
+};
 
 int
-main(int argc, char **argv)
+main(int argc, char *argv[])
 {
-    z_stream s;
-    FILE *f;
-    char inbuf[BUFSIZE], outbuf[BUFSIZE];
-    int status, flush;
+    int err, nfiles, i, nin, inrest, eoin, nout, outrest, eoout, ninflates,
+	raw;
+    z_stream d_stream;
+    char *me = argv[0];
+    char *inbuf, *outbuf, **filev;
+
+    if (!(inbuf = malloc(MYBUFSIZ))) {
+	fprintf(stderr, "%s: inbuf = malloc(%lu): %s\n", me,
+		(unsigned long)MYBUFSIZ, strerror(errno));
+	exit(1);
+    }
+
+    if (!(outbuf = malloc(MYBUFSIZ))) {
+	fprintf(stderr, "%s: outbuf = malloc(%lu): %s\n", me,
+		(unsigned long)MYBUFSIZ, strerror(errno));
+	exit(1);
+    }
+
+    d_stream.zalloc = NULL;
+    d_stream.zfree = NULL;
+    d_stream.opaque = NULL;
 
     if (argc > 1) {
-	f = fopen(argv[1], "rb");
-	if (!f) {
-	    fprintf(stderr, "%s: cannot open %s\n", argv[0], argv[1]);
-	    exit(1);
-	}
+	nfiles = argc - 1;
+	filev = &argv[1];
     }
-    else
-	f = stdin;
+    else {
+	static char *myargv[] = { "-", NULL };
 
-    s.zalloc = Z_NULL;
-    s.zfree = Z_NULL;
-    s.opaque = Z_NULL;
-    status = inflateInit(&s);
-    if (status != Z_OK) {
-	fprintf(stderr, "%s: inflateInit() %s\n", argv[0], zError(status));
+	nfiles = 1;
+	filev = myargv;
+    }
+
+    if ((err = inflateInit(&d_stream)) != Z_OK) {
+	fprintf(stderr, "%s: inflateInit(&d_stream): %d\n", me, err);
 	exit(1);
     }
-    s.avail_in = 0;
-    s.next_out = (Bytef *) outbuf;
-    s.avail_out = sizeof(outbuf);
-    flush = Z_NO_FLUSH;
-    while (1) {
-	if (s.avail_in == 0) {
-	    s.next_in = (Bytef *) inbuf;
-	    s.avail_in = fread(inbuf, 1, sizeof(inbuf), f);
-	}
-	status = inflate(&s, flush);
-	if (status == Z_STREAM_END) {
-	    if (sizeof(outbuf) - s.avail_out)
-		fwrite(outbuf, 1, sizeof(outbuf) - s.avail_out, stdout);
-	    break;
-	}
-	if (status != Z_OK) {
-	    fprintf(stderr, "%s: inflate() %s\n", argv[0], zError(status));
-	    exit(1);
+
+    for (raw = ninflates = i = inrest = outrest = 0, eoout = 1; i < nfiles;
+	 ++i) {
+	FILE *in;
+
+	if (strcmp(filev[i], "-")) {
+	    if (!(in = fopen(filev[i], "rb"))) {
+		fprintf(stderr, "%s: fopen(\"%s\", \"rb\"): %s\n", me,
+			filev[i], strerror(errno));
+		exit(1);
+	    }
 	}
-	if (s.avail_out == 0) {
-	    fwrite(outbuf, 1, sizeof(outbuf), stdout);
-	    s.next_out = (Bytef *) outbuf;
-	    s.avail_out = sizeof(outbuf);
+	else
+	    in = stdin;
+
+	for (eoin = 0;;) {
+	    if ((nin =
+		 fread(&inbuf[inrest], 1, MYBUFSIZ - inrest,
+		       in)) < MYBUFSIZ - inrest) {
+		if (ferror(in)) {
+		    fprintf(stderr, "%s: fread(&inbuf[%d], 1, %d, in): %s\n",
+			    me, inrest, MYBUFSIZ - inrest, strerror(errno));
+		    exit(1);
+		}
+
+		eoin = 1;
+	    }
+
+	    if (nin > 0) {
+	      retry:
+		d_stream.next_in = inbuf;
+		d_stream.avail_in = inrest + nin;
+
+		for (eoout = 0;;) {
+		    d_stream.next_out = &outbuf[outrest];
+		    d_stream.avail_out = MYBUFSIZ - outrest;
+
+		    switch (err = inflate(&d_stream, Z_NO_FLUSH)) {
+		    case Z_OK:
+			if (!
+			    ((nout =
+			      fwrite(outbuf, 1, MYBUFSIZ - d_stream.avail_out,
+				     stdout)) > 0)) {
+			    fprintf(stderr,
+				    "%s: fwrite(outbuf, 1, %d, stdout): %s\n",
+				    me, MYBUFSIZ - d_stream.avail_out,
+				    strerror(errno));
+			    exit(1);
+			}
+
+			memmove(outbuf, &outbuf[nout],
+				MYBUFSIZ - d_stream.avail_out - nout);
+			outrest = MYBUFSIZ - d_stream.avail_out - nout;
+			++ninflates;
+			break;
+		    case Z_STREAM_END:
+		    case Z_BUF_ERROR:
+			ninflates = 0;
+			outrest = MYBUFSIZ - d_stream.avail_out;
+			eoout = 1;
+			goto next_fread;
+		    case Z_DATA_ERROR:
+			if (!ninflates) {
+			    if ((err = inflateReset(&d_stream)) != Z_OK) {
+				fprintf(stderr,
+					"%s: inflateReset(&d_stream): %d\n",
+					me, err);
+				exit(1);
+			    }
+
+			    d_stream.next_in = dummy_head;
+			    d_stream.avail_in = sizeof(dummy_head);
+
+			    if ((err = inflate(&d_stream, Z_NO_FLUSH)) == Z_OK) {
+				raw = ninflates = 1;
+				goto retry;
+			    }
+			}
+		    default:
+			fprintf(stderr,
+				"%s: inflate(&d_stream, Z_NO_FLUSH): %d\n", me,
+				err);
+			exit(1);
+		    }
+		}
+	    }
+
+	  next_fread:
+	    if (d_stream.avail_in) {
+		memmove(inbuf, &inbuf[inrest + nin - d_stream.avail_in],
+			d_stream.avail_in);
+		inrest = d_stream.avail_in;
+	    }
+	    else
+		inrest = 0;
+
+	    if (eoin)
+		break;
 	}
+
+	if (in != stdin)
+	    fclose(in);
     }
-    inflateEnd(&s);
-    fclose(f);
+
+    if (!eoout && !raw) {
+	fprintf(stderr, "%s: short input\n", me);
+	exit(1);
+    }
+
+    if (inrest)
+	fprintf(stderr, "%s: trailing garbages are ignored\n", me);
+
+    if (outrest && fwrite(outbuf, 1, outrest, stdout) < outrest) {
+	fprintf(stderr, "%s: fwrite(outbuf, 1, %d, stdout): %s\n", me, outrest,
+		strerror(errno));
+	exit(1);
+    }
+
     return 0;
 }