← Commit list

52a4388d9

Denis Vlasenko

2007-10-10

FAILED Duration: 14s

Subject

bunzip: small code shrink and consmetics

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

archival/libunarchive/decompress_bunzip2.c +28 -22

archival/libunarchive/decompress_bunzip2.c+28 -22

@@ -44,7 +44,7 @@
	#define RETVAL_LAST_BLOCK (-1)
	#define RETVAL_NOT_BZIP_DATA (-2)
	#define RETVAL_UNEXPECTED_INPUT_EOF (-3)
-	#define RETVAL_UNEXPECTED_OUTPUT_EOF (-4)
+	#define RETVAL_SHORT_WRITE (-4)
	#define RETVAL_DATA_ERROR (-5)
	#define RETVAL_OUT_OF_MEMORY (-6)
	#define RETVAL_OBSOLETE_INPUT (-7)
@@ -54,22 +54,27 @@

	/* This is what we know about each Huffman coding group */
	struct group_data {
-	/* We have an extra slot at the end of limit[] for a sentinal value. */
+	/* We have an extra slot at the end of limit[] for a sentinel value. */
	int limit[MAX_HUFCODE_BITS+1], base[MAX_HUFCODE_BITS], permute[MAX_SYMBOLS];
	int minLen, maxLen;
	};

	/* Structure holding all the housekeeping data, including IO buffers and
-	memory that persists between calls to bunzip */
+	* memory that persists between calls to bunzip
+	* Found the most used member:
+	* cat this_file.c \| sed -e 's/"/ /g' -e "s/'/ /g" \| xargs -n1 \
+	* \| grep 'bd->' \| sed 's/^.*bd->/bd->/' \| sort \| $PAGER
+	* and moved it (inbufBitCount) to offset 0.
+	*/

	struct bunzip_data {
-	/* State for interrupting output loop */
-	int writeCopies, writePos, writeRunCountdown, writeCount, writeCurrent;
-
	/* I/O tracking data (file handles, buffers, positions, etc.) */
+	unsigned inbufBitCount, inbufBits;
	int in_fd, out_fd, inbufCount, inbufPos /, outbufPos/;
	unsigned char inbuf /,outbuf/;
-	unsigned inbufBitCount, inbufBits;
+
+	/* State for interrupting output loop */
+	int writeCopies, writePos, writeRunCountdown, writeCount, writeCurrent;

	/* The CRC values stored in the block header and calculated from the data */
	uint32_t headerCRC, totalCRC, writeCRC;
@@ -80,7 +85,7 @@ struct bunzip_data {
	/* For I/O error handling */
	jmp_buf jmpbuf;

-	/* Big things go last (register-relative addressing can be larger for big offsets */
+	/* Big things go last (register-relative addressing can be larger for big offsets) */
	uint32_t crc32Table[256];
	unsigned char selectors[32768]; /* nSelectors=15 bits */
	struct group_data groups[MAX_GROUPS]; /* Huffman coding tables */
@@ -91,7 +96,7 @@ struct bunzip_data {
	/* Return the next nnn bits of input. All reads from the compressed input
	are done through this function. All reads are big endian */

-	static unsigned get_bits(bunzip_data *bd, char bits_wanted)
+	static unsigned get_bits(bunzip_data *bd, int bits_wanted)
	{
	unsigned bits = 0;

@@ -121,7 +126,7 @@ static unsigned get_bits(bunzip_data *bd, char bits_wanted)

	/* Grab next 8 bits of input from buffer. */

-	bd->inbufBits = (bd->inbufBits<<8) \| bd->inbuf[bd->inbufPos++];
+	bd->inbufBits = (bd->inbufBits << 8) \| bd->inbuf[bd->inbufPos++];
	bd->inbufBitCount += 8;
	}

@@ -205,7 +210,7 @@ static int get_next_block(bunzip_data *bd)
	/* Get next value */

	for (j = 0; get_bits(bd, 1); j++)
-	if (j>=groupCount) return RETVAL_DATA_ERROR;
+	if (j >= groupCount) return RETVAL_DATA_ERROR;

	/* Decode MTF to get the next selector */

@@ -320,19 +325,20 @@ static int get_next_block(bunzip_data *bd)
	t += temp[i];
	base[i+1] = pp - t;
	}
-	limit[maxLen+1] = INT_MAX; /* Sentinal value for reading next sym. */
+	limit[maxLen+1] = INT_MAX; /* Sentinel value for reading next sym. */
	limit[maxLen] = pp + temp[maxLen] - 1;
	base[minLen] = 0;
	}

	/* We've finished reading and digesting the block header. Now read this
	block's Huffman coded symbols from the file and undo the Huffman coding
-	and run length encoding, saving the result into dbuf[dbufCount++]=uc */
+	and run length encoding, saving the result into dbuf[dbufCount++] = uc */

	/* Initialize symbol occurrence counters and symbol Move To Front table */

+	memset(byteCount, 0, sizeof(byteCount)); /* smaller, maybe slower? */
	for (i = 0; i < 256; i++) {
-	byteCount[i] = 0;
+	//byteCount[i] = 0;
	mtfSymbol[i] = (unsigned char)i;
	}

@@ -547,7 +553,7 @@ int read_bunzip(bunzip_data bd, char outbuf, int len)
	/* If the output buffer is full, snapshot state and return */

	if (gotcount >= len) {
-	bd->writePos =pos;
+	bd->writePos = pos;
	bd->writeCurrent = current;
	bd->writeCopies++;
	return len;
@@ -573,8 +579,8 @@ int read_bunzip(bunzip_data bd, char outbuf, int len)
	current = pos & 0xff;
	pos >>= 8;

-	/* After 3 consecutive copies of the same byte, the 4th is a repeat
-	count. We count down from 4 instead
+	/* After 3 consecutive copies of the same byte, the 4th
+	* is a repeat count. We count down from 4 instead
	* of counting up because testing for non-zero is faster */

	if (--bd->writeRunCountdown) {
@@ -606,7 +612,7 @@ int read_bunzip(bunzip_data bd, char outbuf, int len)
	/* If this block had a CRC error, force file level CRC error. */

	if (bd->writeCRC != bd->headerCRC) {
-	bd->totalCRC = bd->headerCRC+1;
+	bd->totalCRC = bd->headerCRC + 1;
	return RETVAL_LAST_BLOCK;
	}
	}
@@ -713,8 +719,8 @@ unpack_bz2_stream(int src_fd, int dst_fd)
	for (;;) {
	i = read_bunzip(bd, outbuf, IOBUF_SIZE);
	if (i <= 0) break;
-	if (i != safe_write(dst_fd, outbuf, i)) {
-	i = RETVAL_UNEXPECTED_OUTPUT_EOF;
+	if (i != full_write(dst_fd, outbuf, i)) {
+	i = RETVAL_SHORT_WRITE;
	break;
	}
	USE_DESKTOP(total_written += i;)
@@ -729,8 +735,8 @@ unpack_bz2_stream(int src_fd, int dst_fd)
	} else {
	i = RETVAL_OK;
	}
-	} else if (i == RETVAL_UNEXPECTED_OUTPUT_EOF) {
-	bb_error_msg("unexpected EOF");
+	} else if (i == RETVAL_SHORT_WRITE) {
+	bb_error_msg("short write");
	} else {
	bb_error_msg("bunzip error %d", i);
	}