5e34ff29bc
and SKIP_XXXX to IF_NOT_XXXX - the second one was especially badly named. It was not skipping anything!
725 lines
24 KiB
C
725 lines
24 KiB
C
/* vi: set sw=4 ts=4: */
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/* Small bzip2 deflate implementation, by Rob Landley (rob@landley.net).
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Based on bzip2 decompression code by Julian R Seward (jseward@acm.org),
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which also acknowledges contributions by Mike Burrows, David Wheeler,
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Peter Fenwick, Alistair Moffat, Radford Neal, Ian H. Witten,
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Robert Sedgewick, and Jon L. Bentley.
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Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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*/
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/*
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Size and speed optimizations by Manuel Novoa III (mjn3@codepoet.org).
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More efficient reading of Huffman codes, a streamlined read_bunzip()
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function, and various other tweaks. In (limited) tests, approximately
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20% faster than bzcat on x86 and about 10% faster on arm.
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Note that about 2/3 of the time is spent in read_unzip() reversing
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the Burrows-Wheeler transformation. Much of that time is delay
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resulting from cache misses.
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I would ask that anyone benefiting from this work, especially those
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using it in commercial products, consider making a donation to my local
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non-profit hospice organization (www.hospiceacadiana.com) in the name of
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the woman I loved, Toni W. Hagan, who passed away Feb. 12, 2003.
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Manuel
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*/
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#include "libbb.h"
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#include "unarchive.h"
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/* Constants for Huffman coding */
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#define MAX_GROUPS 6
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#define GROUP_SIZE 50 /* 64 would have been more efficient */
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#define MAX_HUFCODE_BITS 20 /* Longest Huffman code allowed */
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#define MAX_SYMBOLS 258 /* 256 literals + RUNA + RUNB */
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#define SYMBOL_RUNA 0
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#define SYMBOL_RUNB 1
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/* Status return values */
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#define RETVAL_OK 0
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#define RETVAL_LAST_BLOCK (-1)
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#define RETVAL_NOT_BZIP_DATA (-2)
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#define RETVAL_UNEXPECTED_INPUT_EOF (-3)
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#define RETVAL_SHORT_WRITE (-4)
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#define RETVAL_DATA_ERROR (-5)
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#define RETVAL_OUT_OF_MEMORY (-6)
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#define RETVAL_OBSOLETE_INPUT (-7)
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/* Other housekeeping constants */
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#define IOBUF_SIZE 4096
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/* This is what we know about each Huffman coding group */
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struct group_data {
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/* We have an extra slot at the end of limit[] for a sentinel value. */
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int limit[MAX_HUFCODE_BITS+1], base[MAX_HUFCODE_BITS], permute[MAX_SYMBOLS];
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int minLen, maxLen;
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};
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/* Structure holding all the housekeeping data, including IO buffers and
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* memory that persists between calls to bunzip
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* Found the most used member:
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* cat this_file.c | sed -e 's/"/ /g' -e "s/'/ /g" | xargs -n1 \
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* | grep 'bd->' | sed 's/^.*bd->/bd->/' | sort | $PAGER
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* and moved it (inbufBitCount) to offset 0.
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*/
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struct bunzip_data {
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/* I/O tracking data (file handles, buffers, positions, etc.) */
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unsigned inbufBitCount, inbufBits;
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int in_fd, out_fd, inbufCount, inbufPos /*, outbufPos*/;
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unsigned char *inbuf /*,*outbuf*/;
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/* State for interrupting output loop */
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int writeCopies, writePos, writeRunCountdown, writeCount, writeCurrent;
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/* The CRC values stored in the block header and calculated from the data */
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uint32_t headerCRC, totalCRC, writeCRC;
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/* Intermediate buffer and its size (in bytes) */
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unsigned *dbuf, dbufSize;
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/* For I/O error handling */
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jmp_buf jmpbuf;
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/* Big things go last (register-relative addressing can be larger for big offsets) */
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uint32_t crc32Table[256];
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unsigned char selectors[32768]; /* nSelectors=15 bits */
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struct group_data groups[MAX_GROUPS]; /* Huffman coding tables */
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};
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/* typedef struct bunzip_data bunzip_data; -- done in .h file */
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/* Return the next nnn bits of input. All reads from the compressed input
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are done through this function. All reads are big endian */
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static unsigned get_bits(bunzip_data *bd, int bits_wanted)
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{
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unsigned bits = 0;
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/* If we need to get more data from the byte buffer, do so. (Loop getting
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one byte at a time to enforce endianness and avoid unaligned access.) */
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while ((int)(bd->inbufBitCount) < bits_wanted) {
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/* If we need to read more data from file into byte buffer, do so */
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if (bd->inbufPos == bd->inbufCount) {
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/* if "no input fd" case: in_fd == -1, read fails, we jump */
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bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE);
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if (bd->inbufCount <= 0)
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longjmp(bd->jmpbuf, RETVAL_UNEXPECTED_INPUT_EOF);
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bd->inbufPos = 0;
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}
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/* Avoid 32-bit overflow (dump bit buffer to top of output) */
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if (bd->inbufBitCount >= 24) {
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bits = bd->inbufBits & ((1 << bd->inbufBitCount) - 1);
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bits_wanted -= bd->inbufBitCount;
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bits <<= bits_wanted;
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bd->inbufBitCount = 0;
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}
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/* Grab next 8 bits of input from buffer. */
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bd->inbufBits = (bd->inbufBits << 8) | bd->inbuf[bd->inbufPos++];
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bd->inbufBitCount += 8;
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}
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/* Calculate result */
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bd->inbufBitCount -= bits_wanted;
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bits |= (bd->inbufBits >> bd->inbufBitCount) & ((1 << bits_wanted) - 1);
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return bits;
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}
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/* Unpacks the next block and sets up for the inverse burrows-wheeler step. */
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static int get_next_block(bunzip_data *bd)
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{
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struct group_data *hufGroup;
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int dbufCount, nextSym, dbufSize, groupCount, *base, *limit, selector,
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i, j, k, t, runPos, symCount, symTotal, nSelectors, byteCount[256];
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unsigned char uc, symToByte[256], mtfSymbol[256], *selectors;
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unsigned *dbuf, origPtr;
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dbuf = bd->dbuf;
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dbufSize = bd->dbufSize;
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selectors = bd->selectors;
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/* Reset longjmp I/O error handling */
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i = setjmp(bd->jmpbuf);
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if (i) return i;
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/* Read in header signature and CRC, then validate signature.
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(last block signature means CRC is for whole file, return now) */
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i = get_bits(bd, 24);
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j = get_bits(bd, 24);
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bd->headerCRC = get_bits(bd, 32);
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if ((i == 0x177245) && (j == 0x385090)) return RETVAL_LAST_BLOCK;
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if ((i != 0x314159) || (j != 0x265359)) return RETVAL_NOT_BZIP_DATA;
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/* We can add support for blockRandomised if anybody complains. There was
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some code for this in busybox 1.0.0-pre3, but nobody ever noticed that
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it didn't actually work. */
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if (get_bits(bd, 1)) return RETVAL_OBSOLETE_INPUT;
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origPtr = get_bits(bd, 24);
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if ((int)origPtr > dbufSize) return RETVAL_DATA_ERROR;
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/* mapping table: if some byte values are never used (encoding things
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like ascii text), the compression code removes the gaps to have fewer
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symbols to deal with, and writes a sparse bitfield indicating which
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values were present. We make a translation table to convert the symbols
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back to the corresponding bytes. */
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t = get_bits(bd, 16);
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symTotal = 0;
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for (i = 0; i < 16; i++) {
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if (t & (1 << (15-i))) {
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k = get_bits(bd, 16);
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for (j = 0; j < 16; j++)
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if (k & (1 << (15-j)))
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symToByte[symTotal++] = (16*i) + j;
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}
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}
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/* How many different Huffman coding groups does this block use? */
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groupCount = get_bits(bd, 3);
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if (groupCount < 2 || groupCount > MAX_GROUPS)
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return RETVAL_DATA_ERROR;
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/* nSelectors: Every GROUP_SIZE many symbols we select a new Huffman coding
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group. Read in the group selector list, which is stored as MTF encoded
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bit runs. (MTF=Move To Front, as each value is used it's moved to the
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start of the list.) */
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nSelectors = get_bits(bd, 15);
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if (!nSelectors) return RETVAL_DATA_ERROR;
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for (i = 0; i < groupCount; i++) mtfSymbol[i] = i;
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for (i = 0; i < nSelectors; i++) {
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/* Get next value */
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for (j = 0; get_bits(bd, 1); j++)
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if (j >= groupCount) return RETVAL_DATA_ERROR;
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/* Decode MTF to get the next selector */
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uc = mtfSymbol[j];
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for (;j;j--) mtfSymbol[j] = mtfSymbol[j-1];
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mtfSymbol[0] = selectors[i] = uc;
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}
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/* Read the Huffman coding tables for each group, which code for symTotal
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literal symbols, plus two run symbols (RUNA, RUNB) */
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symCount = symTotal + 2;
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for (j = 0; j < groupCount; j++) {
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unsigned char length[MAX_SYMBOLS];
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/* 8 bits is ALMOST enough for temp[], see below */
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unsigned temp[MAX_HUFCODE_BITS+1];
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int minLen, maxLen, pp;
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/* Read Huffman code lengths for each symbol. They're stored in
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a way similar to mtf; record a starting value for the first symbol,
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and an offset from the previous value for everys symbol after that.
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(Subtracting 1 before the loop and then adding it back at the end is
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an optimization that makes the test inside the loop simpler: symbol
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length 0 becomes negative, so an unsigned inequality catches it.) */
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t = get_bits(bd, 5) - 1;
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for (i = 0; i < symCount; i++) {
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for (;;) {
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if ((unsigned)t > (MAX_HUFCODE_BITS-1))
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return RETVAL_DATA_ERROR;
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/* If first bit is 0, stop. Else second bit indicates whether
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to increment or decrement the value. Optimization: grab 2
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bits and unget the second if the first was 0. */
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k = get_bits(bd, 2);
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if (k < 2) {
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bd->inbufBitCount++;
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break;
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}
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/* Add one if second bit 1, else subtract 1. Avoids if/else */
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t += (((k+1) & 2) - 1);
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}
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/* Correct for the initial -1, to get the final symbol length */
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length[i] = t + 1;
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}
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/* Find largest and smallest lengths in this group */
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minLen = maxLen = length[0];
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for (i = 1; i < symCount; i++) {
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if (length[i] > maxLen) maxLen = length[i];
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else if (length[i] < minLen) minLen = length[i];
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}
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/* Calculate permute[], base[], and limit[] tables from length[].
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*
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* permute[] is the lookup table for converting Huffman coded symbols
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* into decoded symbols. base[] is the amount to subtract from the
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* value of a Huffman symbol of a given length when using permute[].
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*
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* limit[] indicates the largest numerical value a symbol with a given
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* number of bits can have. This is how the Huffman codes can vary in
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* length: each code with a value>limit[length] needs another bit.
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*/
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hufGroup = bd->groups + j;
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hufGroup->minLen = minLen;
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hufGroup->maxLen = maxLen;
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/* Note that minLen can't be smaller than 1, so we adjust the base
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and limit array pointers so we're not always wasting the first
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entry. We do this again when using them (during symbol decoding).*/
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base = hufGroup->base - 1;
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limit = hufGroup->limit - 1;
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/* Calculate permute[]. Concurently, initialize temp[] and limit[]. */
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pp = 0;
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for (i = minLen; i <= maxLen; i++) {
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temp[i] = limit[i] = 0;
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for (t = 0; t < symCount; t++)
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if (length[t] == i)
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hufGroup->permute[pp++] = t;
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}
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/* Count symbols coded for at each bit length */
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/* NB: in pathological cases, temp[8] can end ip being 256.
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* That's why uint8_t is too small for temp[]. */
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for (i = 0; i < symCount; i++) temp[length[i]]++;
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/* Calculate limit[] (the largest symbol-coding value at each bit
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* length, which is (previous limit<<1)+symbols at this level), and
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* base[] (number of symbols to ignore at each bit length, which is
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* limit minus the cumulative count of symbols coded for already). */
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pp = t = 0;
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for (i = minLen; i < maxLen; i++) {
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pp += temp[i];
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/* We read the largest possible symbol size and then unget bits
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after determining how many we need, and those extra bits could
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be set to anything. (They're noise from future symbols.) At
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each level we're really only interested in the first few bits,
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so here we set all the trailing to-be-ignored bits to 1 so they
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don't affect the value>limit[length] comparison. */
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limit[i] = (pp << (maxLen - i)) - 1;
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pp <<= 1;
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t += temp[i];
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base[i+1] = pp - t;
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}
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limit[maxLen+1] = INT_MAX; /* Sentinel value for reading next sym. */
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limit[maxLen] = pp + temp[maxLen] - 1;
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base[minLen] = 0;
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}
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/* We've finished reading and digesting the block header. Now read this
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block's Huffman coded symbols from the file and undo the Huffman coding
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and run length encoding, saving the result into dbuf[dbufCount++] = uc */
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/* Initialize symbol occurrence counters and symbol Move To Front table */
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memset(byteCount, 0, sizeof(byteCount)); /* smaller, maybe slower? */
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for (i = 0; i < 256; i++) {
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//byteCount[i] = 0;
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mtfSymbol[i] = (unsigned char)i;
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}
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/* Loop through compressed symbols. */
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runPos = dbufCount = selector = 0;
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for (;;) {
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/* Fetch next Huffman coding group from list. */
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symCount = GROUP_SIZE - 1;
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if (selector >= nSelectors) return RETVAL_DATA_ERROR;
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hufGroup = bd->groups + selectors[selector++];
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base = hufGroup->base - 1;
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limit = hufGroup->limit - 1;
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continue_this_group:
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/* Read next Huffman-coded symbol. */
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/* Note: It is far cheaper to read maxLen bits and back up than it is
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to read minLen bits and then an additional bit at a time, testing
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as we go. Because there is a trailing last block (with file CRC),
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there is no danger of the overread causing an unexpected EOF for a
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valid compressed file. As a further optimization, we do the read
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inline (falling back to a call to get_bits if the buffer runs
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dry). The following (up to got_huff_bits:) is equivalent to
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j = get_bits(bd, hufGroup->maxLen);
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*/
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while ((int)(bd->inbufBitCount) < hufGroup->maxLen) {
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if (bd->inbufPos == bd->inbufCount) {
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j = get_bits(bd, hufGroup->maxLen);
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goto got_huff_bits;
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}
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bd->inbufBits = (bd->inbufBits << 8) | bd->inbuf[bd->inbufPos++];
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bd->inbufBitCount += 8;
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};
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bd->inbufBitCount -= hufGroup->maxLen;
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j = (bd->inbufBits >> bd->inbufBitCount) & ((1 << hufGroup->maxLen) - 1);
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got_huff_bits:
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/* Figure how how many bits are in next symbol and unget extras */
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i = hufGroup->minLen;
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while (j > limit[i]) ++i;
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bd->inbufBitCount += (hufGroup->maxLen - i);
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/* Huffman decode value to get nextSym (with bounds checking) */
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if (i > hufGroup->maxLen)
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return RETVAL_DATA_ERROR;
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j = (j >> (hufGroup->maxLen - i)) - base[i];
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if ((unsigned)j >= MAX_SYMBOLS)
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return RETVAL_DATA_ERROR;
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nextSym = hufGroup->permute[j];
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/* We have now decoded the symbol, which indicates either a new literal
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byte, or a repeated run of the most recent literal byte. First,
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check if nextSym indicates a repeated run, and if so loop collecting
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how many times to repeat the last literal. */
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if ((unsigned)nextSym <= SYMBOL_RUNB) { /* RUNA or RUNB */
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/* If this is the start of a new run, zero out counter */
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if (!runPos) {
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runPos = 1;
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t = 0;
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}
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/* Neat trick that saves 1 symbol: instead of or-ing 0 or 1 at
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each bit position, add 1 or 2 instead. For example,
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1011 is 1<<0 + 1<<1 + 2<<2. 1010 is 2<<0 + 2<<1 + 1<<2.
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You can make any bit pattern that way using 1 less symbol than
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the basic or 0/1 method (except all bits 0, which would use no
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symbols, but a run of length 0 doesn't mean anything in this
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context). Thus space is saved. */
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t += (runPos << nextSym); /* +runPos if RUNA; +2*runPos if RUNB */
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if (runPos < dbufSize) runPos <<= 1;
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goto end_of_huffman_loop;
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}
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/* When we hit the first non-run symbol after a run, we now know
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how many times to repeat the last literal, so append that many
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copies to our buffer of decoded symbols (dbuf) now. (The last
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literal used is the one at the head of the mtfSymbol array.) */
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if (runPos) {
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runPos = 0;
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if (dbufCount + t >= dbufSize) return RETVAL_DATA_ERROR;
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uc = symToByte[mtfSymbol[0]];
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byteCount[uc] += t;
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while (t--) dbuf[dbufCount++] = uc;
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}
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/* Is this the terminating symbol? */
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if (nextSym > symTotal) break;
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/* At this point, nextSym indicates a new literal character. Subtract
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one to get the position in the MTF array at which this literal is
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currently to be found. (Note that the result can't be -1 or 0,
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because 0 and 1 are RUNA and RUNB. But another instance of the
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first symbol in the mtf array, position 0, would have been handled
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as part of a run above. Therefore 1 unused mtf position minus
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2 non-literal nextSym values equals -1.) */
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if (dbufCount >= dbufSize) return RETVAL_DATA_ERROR;
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i = nextSym - 1;
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uc = mtfSymbol[i];
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/* Adjust the MTF array. Since we typically expect to move only a
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* small number of symbols, and are bound by 256 in any case, using
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* memmove here would typically be bigger and slower due to function
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* call overhead and other assorted setup costs. */
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do {
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mtfSymbol[i] = mtfSymbol[i-1];
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} while (--i);
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mtfSymbol[0] = uc;
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uc = symToByte[uc];
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/* We have our literal byte. Save it into dbuf. */
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byteCount[uc]++;
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dbuf[dbufCount++] = (unsigned)uc;
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/* Skip group initialization if we're not done with this group. Done
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* this way to avoid compiler warning. */
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end_of_huffman_loop:
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if (symCount--) goto continue_this_group;
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}
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/* At this point, we've read all the Huffman-coded symbols (and repeated
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runs) for this block from the input stream, and decoded them into the
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intermediate buffer. There are dbufCount many decoded bytes in dbuf[].
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Now undo the Burrows-Wheeler transform on dbuf.
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See http://dogma.net/markn/articles/bwt/bwt.htm
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*/
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|
|
/* Turn byteCount into cumulative occurrence counts of 0 to n-1. */
|
|
j = 0;
|
|
for (i = 0; i < 256; i++) {
|
|
k = j + byteCount[i];
|
|
byteCount[i] = j;
|
|
j = k;
|
|
}
|
|
|
|
/* Figure out what order dbuf would be in if we sorted it. */
|
|
for (i = 0; i < dbufCount; i++) {
|
|
uc = (unsigned char)(dbuf[i] & 0xff);
|
|
dbuf[byteCount[uc]] |= (i << 8);
|
|
byteCount[uc]++;
|
|
}
|
|
|
|
/* Decode first byte by hand to initialize "previous" byte. Note that it
|
|
doesn't get output, and if the first three characters are identical
|
|
it doesn't qualify as a run (hence writeRunCountdown=5). */
|
|
if (dbufCount) {
|
|
if ((int)origPtr >= dbufCount) return RETVAL_DATA_ERROR;
|
|
bd->writePos = dbuf[origPtr];
|
|
bd->writeCurrent = (unsigned char)(bd->writePos & 0xff);
|
|
bd->writePos >>= 8;
|
|
bd->writeRunCountdown = 5;
|
|
}
|
|
bd->writeCount = dbufCount;
|
|
|
|
return RETVAL_OK;
|
|
}
|
|
|
|
/* Undo burrows-wheeler transform on intermediate buffer to produce output.
|
|
If start_bunzip was initialized with out_fd=-1, then up to len bytes of
|
|
data are written to outbuf. Return value is number of bytes written or
|
|
error (all errors are negative numbers). If out_fd!=-1, outbuf and len
|
|
are ignored, data is written to out_fd and return is RETVAL_OK or error.
|
|
*/
|
|
int FAST_FUNC read_bunzip(bunzip_data *bd, char *outbuf, int len)
|
|
{
|
|
const unsigned *dbuf;
|
|
int pos, current, previous, gotcount;
|
|
|
|
/* If last read was short due to end of file, return last block now */
|
|
if (bd->writeCount < 0) return bd->writeCount;
|
|
|
|
gotcount = 0;
|
|
dbuf = bd->dbuf;
|
|
pos = bd->writePos;
|
|
current = bd->writeCurrent;
|
|
|
|
/* We will always have pending decoded data to write into the output
|
|
buffer unless this is the very first call (in which case we haven't
|
|
Huffman-decoded a block into the intermediate buffer yet). */
|
|
if (bd->writeCopies) {
|
|
|
|
/* Inside the loop, writeCopies means extra copies (beyond 1) */
|
|
--bd->writeCopies;
|
|
|
|
/* Loop outputting bytes */
|
|
for (;;) {
|
|
|
|
/* If the output buffer is full, snapshot state and return */
|
|
if (gotcount >= len) {
|
|
bd->writePos = pos;
|
|
bd->writeCurrent = current;
|
|
bd->writeCopies++;
|
|
return len;
|
|
}
|
|
|
|
/* Write next byte into output buffer, updating CRC */
|
|
outbuf[gotcount++] = current;
|
|
bd->writeCRC = (bd->writeCRC << 8)
|
|
^ bd->crc32Table[(bd->writeCRC >> 24) ^ current];
|
|
|
|
/* Loop now if we're outputting multiple copies of this byte */
|
|
if (bd->writeCopies) {
|
|
--bd->writeCopies;
|
|
continue;
|
|
}
|
|
decode_next_byte:
|
|
if (!bd->writeCount--) break;
|
|
/* Follow sequence vector to undo Burrows-Wheeler transform */
|
|
previous = current;
|
|
pos = dbuf[pos];
|
|
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
|
|
* of counting up because testing for non-zero is faster */
|
|
if (--bd->writeRunCountdown) {
|
|
if (current != previous)
|
|
bd->writeRunCountdown = 4;
|
|
} else {
|
|
|
|
/* We have a repeated run, this byte indicates the count */
|
|
bd->writeCopies = current;
|
|
current = previous;
|
|
bd->writeRunCountdown = 5;
|
|
|
|
/* Sometimes there are just 3 bytes (run length 0) */
|
|
if (!bd->writeCopies) goto decode_next_byte;
|
|
|
|
/* Subtract the 1 copy we'd output anyway to get extras */
|
|
--bd->writeCopies;
|
|
}
|
|
}
|
|
|
|
/* Decompression of this block completed successfully */
|
|
bd->writeCRC = ~bd->writeCRC;
|
|
bd->totalCRC = ((bd->totalCRC << 1) | (bd->totalCRC >> 31)) ^ bd->writeCRC;
|
|
|
|
/* If this block had a CRC error, force file level CRC error. */
|
|
if (bd->writeCRC != bd->headerCRC) {
|
|
bd->totalCRC = bd->headerCRC + 1;
|
|
return RETVAL_LAST_BLOCK;
|
|
}
|
|
}
|
|
|
|
/* Refill the intermediate buffer by Huffman-decoding next block of input */
|
|
/* (previous is just a convenient unused temp variable here) */
|
|
previous = get_next_block(bd);
|
|
if (previous) {
|
|
bd->writeCount = previous;
|
|
return (previous != RETVAL_LAST_BLOCK) ? previous : gotcount;
|
|
}
|
|
bd->writeCRC = ~0;
|
|
pos = bd->writePos;
|
|
current = bd->writeCurrent;
|
|
goto decode_next_byte;
|
|
}
|
|
|
|
/* Allocate the structure, read file header. If in_fd==-1, inbuf must contain
|
|
a complete bunzip file (len bytes long). If in_fd!=-1, inbuf and len are
|
|
ignored, and data is read from file handle into temporary buffer. */
|
|
|
|
/* Because bunzip2 is used for help text unpacking, and because bb_show_usage()
|
|
should work for NOFORK applets too, we must be extremely careful to not leak
|
|
any allocations! */
|
|
int FAST_FUNC start_bunzip(bunzip_data **bdp, int in_fd, const unsigned char *inbuf,
|
|
int len)
|
|
{
|
|
bunzip_data *bd;
|
|
unsigned i;
|
|
enum {
|
|
BZh0 = ('B' << 24) + ('Z' << 16) + ('h' << 8) + '0',
|
|
h0 = ('h' << 8) + '0',
|
|
};
|
|
|
|
/* Figure out how much data to allocate */
|
|
i = sizeof(bunzip_data);
|
|
if (in_fd != -1) i += IOBUF_SIZE;
|
|
|
|
/* Allocate bunzip_data. Most fields initialize to zero. */
|
|
bd = *bdp = xzalloc(i);
|
|
|
|
/* Setup input buffer */
|
|
bd->in_fd = in_fd;
|
|
if (-1 == in_fd) {
|
|
/* in this case, bd->inbuf is read-only */
|
|
bd->inbuf = (void*)inbuf; /* cast away const-ness */
|
|
bd->inbufCount = len;
|
|
} else
|
|
bd->inbuf = (unsigned char *)(bd + 1);
|
|
|
|
/* Init the CRC32 table (big endian) */
|
|
crc32_filltable(bd->crc32Table, 1);
|
|
|
|
/* Setup for I/O error handling via longjmp */
|
|
i = setjmp(bd->jmpbuf);
|
|
if (i) return i;
|
|
|
|
/* Ensure that file starts with "BZh['1'-'9']." */
|
|
/* Update: now caller verifies 1st two bytes, makes .gz/.bz2
|
|
* integration easier */
|
|
/* was: */
|
|
/* i = get_bits(bd, 32); */
|
|
/* if ((unsigned)(i - BZh0 - 1) >= 9) return RETVAL_NOT_BZIP_DATA; */
|
|
i = get_bits(bd, 16);
|
|
if ((unsigned)(i - h0 - 1) >= 9) return RETVAL_NOT_BZIP_DATA;
|
|
|
|
/* Fourth byte (ascii '1'-'9') indicates block size in units of 100k of
|
|
uncompressed data. Allocate intermediate buffer for block. */
|
|
/* bd->dbufSize = 100000 * (i - BZh0); */
|
|
bd->dbufSize = 100000 * (i - h0);
|
|
|
|
/* Cannot use xmalloc - may leak bd in NOFORK case! */
|
|
bd->dbuf = malloc_or_warn(bd->dbufSize * sizeof(int));
|
|
if (!bd->dbuf) {
|
|
free(bd);
|
|
xfunc_die();
|
|
}
|
|
return RETVAL_OK;
|
|
}
|
|
|
|
void FAST_FUNC dealloc_bunzip(bunzip_data *bd)
|
|
{
|
|
free(bd->dbuf);
|
|
free(bd);
|
|
}
|
|
|
|
|
|
/* Decompress src_fd to dst_fd. Stops at end of bzip data, not end of file. */
|
|
IF_DESKTOP(long long) int FAST_FUNC
|
|
unpack_bz2_stream(int src_fd, int dst_fd)
|
|
{
|
|
IF_DESKTOP(long long total_written = 0;)
|
|
char *outbuf;
|
|
bunzip_data *bd;
|
|
int i;
|
|
|
|
outbuf = xmalloc(IOBUF_SIZE);
|
|
i = start_bunzip(&bd, src_fd, NULL, 0);
|
|
if (!i) {
|
|
for (;;) {
|
|
i = read_bunzip(bd, outbuf, IOBUF_SIZE);
|
|
if (i <= 0) break;
|
|
if (i != full_write(dst_fd, outbuf, i)) {
|
|
i = RETVAL_SHORT_WRITE;
|
|
break;
|
|
}
|
|
IF_DESKTOP(total_written += i;)
|
|
}
|
|
}
|
|
|
|
/* Check CRC and release memory */
|
|
|
|
if (i == RETVAL_LAST_BLOCK) {
|
|
if (bd->headerCRC != bd->totalCRC) {
|
|
bb_error_msg("CRC error");
|
|
} else {
|
|
i = RETVAL_OK;
|
|
}
|
|
} else if (i == RETVAL_SHORT_WRITE) {
|
|
bb_error_msg("short write");
|
|
} else {
|
|
bb_error_msg("bunzip error %d", i);
|
|
}
|
|
dealloc_bunzip(bd);
|
|
free(outbuf);
|
|
|
|
return i ? i : IF_DESKTOP(total_written) + 0;
|
|
}
|
|
|
|
IF_DESKTOP(long long) int FAST_FUNC
|
|
unpack_bz2_stream_prime(int src_fd, int dst_fd)
|
|
{
|
|
unsigned char magic[2];
|
|
xread(src_fd, magic, 2);
|
|
if (magic[0] != 'B' || magic[1] != 'Z') {
|
|
bb_error_msg_and_die("invalid magic");
|
|
}
|
|
return unpack_bz2_stream(src_fd, dst_fd);
|
|
}
|
|
|
|
#ifdef TESTING
|
|
|
|
static char *const bunzip_errors[] = {
|
|
NULL, "Bad file checksum", "Not bzip data",
|
|
"Unexpected input EOF", "Unexpected output EOF", "Data error",
|
|
"Out of memory", "Obsolete (pre 0.9.5) bzip format not supported"
|
|
};
|
|
|
|
/* Dumb little test thing, decompress stdin to stdout */
|
|
int main(int argc, char **argv)
|
|
{
|
|
int i;
|
|
char c;
|
|
|
|
int i = unpack_bz2_stream_prime(0, 1);
|
|
if (i < 0)
|
|
fprintf(stderr, "%s\n", bunzip_errors[-i]);
|
|
else if (read(STDIN_FILENO, &c, 1))
|
|
fprintf(stderr, "Trailing garbage ignored\n");
|
|
return -i;
|
|
}
|
|
#endif
|