[w3m-dev 02960] inflate without memmove()release-0-2-5

* inflate.c: rewrite without memmove()
From: Hironori Sakamoto <hsaka@mth.biglobe.ne.jp>

1 files changed, 59 insertions, 150 deletions

diff --git a/inflate.c b/inflate.c
index 571a1b3..3c30af0 100644
--- a/inflate.c
+++ b/inflate.c
@@ -1,174 +1,83 @@
-#include <errno.h>
+/* $Id: inflate.c,v 1.6 2002/01/31 15:26:19 ukai Exp $ */
 #include <stdio.h>
-#include <string.h>
 #include <stdlib.h>
 #include <zlib.h>
 
-#define MYBUFSIZ (BUFSIZ * 0x10)
+#undef BUFSIZE
+#define BUFSIZE 4096
 
-/* 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)
 {
-    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;
+    z_stream s;
+    FILE *f;
+    char inbuf[BUFSIZE], outbuf[BUFSIZE];
+    int status, flush, retry = 0, len = 0;
 
     if (argc > 1) {
-	nfiles = argc - 1;
-	filev = &argv[1];
-    }
-    else {
-	static char *myargv[] = { "-", NULL };
-
-	nfiles = 1;
-	filev = myargv;
+	f = fopen(argv[1], "rb");
+	if (!f) {
+	    fprintf(stderr, "%s: cannot open %s\n", argv[0], argv[1]);
+	    exit(1);
+	}
     }
-
-    if ((err = inflateInit(&d_stream)) != Z_OK) {
-	fprintf(stderr, "%s: inflateInit(&d_stream): %d\n", me, err);
+    else
+	f = stdin;
+
+    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));
 	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));
+    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;
+	    len = s.avail_in = fread(inbuf, 1, sizeof(inbuf), f);
+	}
+	status = inflate(&s, flush);
+	if (status == Z_STREAM_END || status == Z_BUF_ERROR) {
+	    if (sizeof(outbuf) - s.avail_out)
+		fwrite(outbuf, 1, sizeof(outbuf) - s.avail_out, stdout);
+	    break;
+	}
+	if (status == Z_DATA_ERROR && ! retry++) {
+	    status = inflateReset(&s);
+	    if (status != Z_OK) {
+		fprintf(stderr, "%s: inflateReset() %s\n", argv[0],
+			zError(status));
 		exit(1);
 	    }
+	    s.next_in = (Bytef *) dummy_head;
+	    s.avail_in = sizeof(dummy_head);
+	    status = inflate(&s, flush);
+	    s.next_in = (Bytef *) inbuf;
+	    s.avail_in = len;
+	    continue;
 	}
-	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 (status != Z_OK) {
+	    fprintf(stderr, "%s: inflate() %s\n", argv[0], zError(status));
+	    exit(1);
 	}
-
-	if (in != stdin)
-	    fclose(in);
-    }
-
-    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);
+	if (s.avail_out == 0) {
+	    fwrite(outbuf, 1, sizeof(outbuf), stdout);
+	    s.next_out = (Bytef *) outbuf;
+	    s.avail_out = sizeof(outbuf);
+	}
+	retry = 1;
     }
-
+    inflateEnd(&s);
+    fclose(f);
     return 0;
 }