From e8a0788b249cbac5bf5b2aa2d81bb8f6b29a7a4b Mon Sep 17 00:00:00 2001
From: Denis Vlasenko
Date: Sun, 10 Jun 2007 15:08:44 +0000
Subject: moved biggest stack buffers to malloc space, or made their size
 configurable (8k of shell line edit buffer is an overkill)

# make ARCH=i386 bloatcheck
function                                             old     new   delta
read_line_input                                     3933    3967     +34
ifaddrlist                                           348     345      -3
do_loadfont                                          208     191     -17
edit_file                                            840     819     -21
.rodata                                           129112  129080     -32
uncompress                                          1305    1268     -37
loadfont_main                                        566     495     -71
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 1/6 up/down: 34/-181)          Total: -147 bytes

---
 archival/libunarchive/decompress_uncompress.c | 98 +++++++++++++--------------
 1 file changed, 49 insertions(+), 49 deletions(-)

(limited to 'archival')

diff --git a/archival/libunarchive/decompress_uncompress.c b/archival/libunarchive/decompress_uncompress.c
index ba73f11..8c3c65d 100644
--- a/archival/libunarchive/decompress_uncompress.c
+++ b/archival/libunarchive/decompress_uncompress.c
@@ -7,7 +7,6 @@
  * (see disclaimer below)
  */
 
-
 /* (N)compress42.c - File compression ala IEEE Computer, Mar 1992.
  *
  * Authors:
@@ -34,53 +33,48 @@
 #define	OBUFSIZ	2048
 
 /* Defines for third byte of header */
-#define	MAGIC_1		(char_type)'\037'	/* First byte of compressed file               */
-#define	MAGIC_2		(char_type)'\235'	/* Second byte of compressed file              */
-#define BIT_MASK	0x1f	/* Mask for 'number of compresssion bits'       */
-							/* Masks 0x20 and 0x40 are free.                */
-							/* I think 0x20 should mean that there is       */
-							/* a fourth header byte (for expansion).        */
-#define BLOCK_MODE	0x80	/* Block compresssion if table is full and      */
-			/* compression rate is dropping flush tables    */
-			/* the next two codes should not be changed lightly, as they must not   */
-			/* lie within the contiguous general code space.                        */
-#define FIRST	257		/* first free entry                             */
-#define	CLEAR	256		/* table clear output code                      */
-
-#define INIT_BITS 9		/* initial number of bits/code */
-
+#define BIT_MASK        0x1f    /* Mask for 'number of compresssion bits'       */
+                                /* Masks 0x20 and 0x40 are free.                */
+                                /* I think 0x20 should mean that there is       */
+                                /* a fourth header byte (for expansion).        */
+#define BLOCK_MODE      0x80    /* Block compression if table is full and       */
+                                /* compression rate is dropping flush tables    */
+                                /* the next two codes should not be changed lightly, as they must not   */
+                                /* lie within the contiguous general code space.                        */
+#define FIRST   257     /* first free entry */
+#define CLEAR   256     /* table clear output code */
 
-/* machine variants which require cc -Dmachine:  pdp11, z8000, DOS */
-#define FAST
+#define INIT_BITS 9     /* initial number of bits/code */
 
-#define	HBITS		17	/* 50% occupancy */
-#define	HSIZE	   (1<<HBITS)
-#define	HMASK	   (HSIZE-1)
-#define	HPRIME		 9941
-#define	BITS		   16
-#undef	MAXSEG_64K
-#define MAXCODE(n)	(1L << (n))
-
-#define	htabof(i)				htab[i]
-#define	codetabof(i)			codetab[i]
-#define	tab_prefixof(i)			codetabof(i)
-#define	tab_suffixof(i)			((unsigned char *)(htab))[i]
-#define	de_stack				((unsigned char *)&(htab[HSIZE-1]))
-#define	clear_htab()			memset(htab, -1, HSIZE)
-#define	clear_tab_prefixof()	memset(codetab, 0, 256);
 
+/* machine variants which require cc -Dmachine:  pdp11, z8000, DOS */
+#define HBITS      17   /* 50% occupancy */
+#define HSIZE      (1<<HBITS)
+#define HMASK      (HSIZE-1)    /* unused */
+#define HPRIME     9941         /* unused */
+#define BITS       16
+#define BITS_STR   "16"
+#undef  MAXSEG_64K              /* unused */
+#define MAXCODE(n) (1L << (n))
+
+#define htabof(i)               htab[i]
+#define codetabof(i)            codetab[i]
+#define tab_prefixof(i)         codetabof(i)
+#define tab_suffixof(i)         ((unsigned char *)(htab))[i]
+#define de_stack                ((unsigned char *)&(htab[HSIZE-1]))
+#define clear_tab_prefixof()    memset(codetab, 0, 256)
 
 /*
  * Decompress stdin to stdout.  This routine adapts to the codes in the
  * file building the "string" table on-the-fly; requiring no table to
- * be stored in the compressed file.  The tables used herein are shared
- * with those of the compress() routine.  See the definitions above.
+ * be stored in the compressed file.
  */
 
 USE_DESKTOP(long long) int
 uncompress(int fd_in, int fd_out)
 {
 	USE_DESKTOP(long long total_written = 0;)
+	USE_DESKTOP(long long) int retval = -1;
 	unsigned char *stackp;
 	long code;
 	int finchar;
@@ -96,10 +90,10 @@ uncompress(int fd_in, int fd_out)
 	long maxmaxcode;
 	int n_bits;
 	int rsize = 0;
-	RESERVE_CONFIG_UBUFFER(inbuf, IBUFSIZ + 64);
-	RESERVE_CONFIG_UBUFFER(outbuf, OBUFSIZ + 2048);
-	unsigned char htab[HSIZE];
-	unsigned short codetab[HSIZE];
+	unsigned char *inbuf; /* were eating insane amounts of stack - */
+	unsigned char *outbuf; /* bad for some embedded targets */
+	unsigned char *htab;
+	unsigned short *codetab;
 
 	/* Hmm, these were statics - why?! */
 	/* user settable max # bits/code */
@@ -107,8 +101,10 @@ uncompress(int fd_in, int fd_out)
 	/* block compress mode -C compatible with 2.0 */
 	int block_mode; /* = BLOCK_MODE; */
 
-	memset(inbuf, 0, IBUFSIZ + 64);
-	memset(outbuf, 0, OBUFSIZ + 2048);
+	inbuf = xzalloc(IBUFSIZ + 64);
+	outbuf = xzalloc(OBUFSIZ + 2048);
+	htab = xzalloc(HSIZE);  /* wsn't zeroed out before, maybe can xmalloc? */
+	codetab = xzalloc(HSIZE * sizeof(codetab[0]));
 
 	insize = 0;
 
@@ -116,7 +112,7 @@ uncompress(int fd_in, int fd_out)
 	 * to do some cleanup (e.g. delete incomplete unpacked file etc) */
 	if (full_read(fd_in, inbuf, 1) != 1) {
 		bb_error_msg("short read");
-		return -1;
+		goto err;
 	}
 
 	maxbits = inbuf[0] & BIT_MASK;
@@ -125,8 +121,8 @@ uncompress(int fd_in, int fd_out)
 
 	if (maxbits > BITS) {
 		bb_error_msg("compressed with %d bits, can only handle "
-				"%d bits", maxbits, BITS);
-		return -1;
+				BITS_STR" bits", maxbits);
+		goto err;
 	}
 
 	n_bits = INIT_BITS;
@@ -140,7 +136,7 @@ uncompress(int fd_in, int fd_out)
 	free_ent = ((block_mode) ? FIRST : 256);
 
 	/* As above, initialize the first 256 entries in the table. */
-	clear_tab_prefixof();
+	/*clear_tab_prefixof(); - done by xzalloc */
 
 	for (code = 255; code >= 0; --code) {
 		tab_suffixof(code) = (unsigned char) code;
@@ -232,7 +228,7 @@ uncompress(int fd_in, int fd_out)
 						 insize, posbits, p[-1], p[0], p[1], p[2], p[3],
 						 (posbits & 07));
 					bb_error_msg("uncompress: corrupt input");
-					return -1;
+					goto err;
 				}
 
 				*--stackp = (unsigned char) finchar;
@@ -299,7 +295,11 @@ uncompress(int fd_in, int fd_out)
 		USE_DESKTOP(total_written += outpos;)
 	}
 
-	RELEASE_CONFIG_BUFFER(inbuf);
-	RELEASE_CONFIG_BUFFER(outbuf);
-	return USE_DESKTOP(total_written) + 0;
+	retval = USE_DESKTOP(total_written) + 0;
+ err:
+	free(inbuf);
+	free(outbuf);
+	free(htab);
+	free(codetab);
+	return retval;
 }
-- 
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