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614 lines
22 KiB
C
614 lines
22 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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This code is licensed under the LGPLv2:
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LGPL (http://www.gnu.org/copyleft/lgpl.html
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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 in the name of the woman I loved, who
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passed away Feb. 12, 2003.
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In memory of Toni W. Hagan
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Hospice of Acadiana, Inc.
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2600 Johnston St., Suite 200
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Lafayette, LA 70503-3240
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Phone (337) 232-1234 or 1-800-738-2226
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Fax (337) 232-1297
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http://www.hospiceacadiana.com/
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Manuel
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*/
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#include <setjmp.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include <limits.h>
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#include "libbb.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_UNEXPECTED_OUTPUT_EOF (-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 sentinal 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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typedef struct {
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/* State for interrupting output loop */
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int writeCopies,writePos,writeRunCountdown,writeCount,writeCurrent;
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/* I/O tracking data (file handles, buffers, positions, etc.) */
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int in_fd,out_fd,inbufCount,inbufPos /*,outbufPos*/;
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unsigned char *inbuf /*,*outbuf*/;
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unsigned int inbufBitCount, inbufBits;
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/* The CRC values stored in the block header and calculated from the data */
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unsigned int crc32Table[256],headerCRC, totalCRC, writeCRC;
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/* Intermediate buffer and its size (in bytes) */
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unsigned int *dbuf, dbufSize;
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/* These things are a bit too big to go on the stack */
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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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/* For I/O error handling */
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jmp_buf jmpbuf;
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} bunzip_data;
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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 int get_bits(bunzip_data *bd, char bits_wanted)
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{
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unsigned int 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 (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((bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE)) <= 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 int *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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if((origPtr=get_bits(bd,24)) > 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))) 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) 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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if(!(nSelectors=get_bits(bd, 15))) 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++) 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],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) hufGroup->permute[pp++] = t;
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}
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/* Count symbols coded for at each bit length */
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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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base[i+1]=pp-(t+=temp[i]);
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}
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limit[maxLen+1] = INT_MAX; /* Sentinal 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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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 (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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|| (((unsigned)(j=(j>>(hufGroup->maxLen-i))-base[i]))
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>= 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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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 int)uc;
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/* Skip group initialization if we're not done with this group. Done this
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* 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. */
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j=0;
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for(i=0;i<256;i++) {
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k=j+byteCount[i];
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byteCount[i] = j;
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j=k;
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}
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/* Figure out what order dbuf would be in if we sorted it. */
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for (i=0;i<dbufCount;i++) {
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uc=(unsigned char)(dbuf[i] & 0xff);
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dbuf[byteCount[uc]] |= (i << 8);
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byteCount[uc]++;
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}
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/* Decode first byte by hand to initialize "previous" byte. Note that it
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doesn't get output, and if the first three characters are identical
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it doesn't qualify as a run (hence writeRunCountdown=5). */
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if(dbufCount) {
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if(origPtr>=dbufCount) return RETVAL_DATA_ERROR;
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bd->writePos=dbuf[origPtr];
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bd->writeCurrent=(unsigned char)(bd->writePos&0xff);
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bd->writePos>>=8;
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bd->writeRunCountdown=5;
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}
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bd->writeCount=dbufCount;
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return RETVAL_OK;
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}
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/* Undo burrows-wheeler transform on intermediate buffer to produce output.
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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.
|
|
*/
|
|
|
|
static int read_bunzip(bunzip_data *bd, char *outbuf, int len)
|
|
{
|
|
const unsigned int *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=0xffffffffUL;
|
|
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. */
|
|
static int start_bunzip(bunzip_data **bdp, int in_fd, unsigned char *inbuf,
|
|
int len)
|
|
{
|
|
bunzip_data *bd;
|
|
unsigned int i,j,c;
|
|
const unsigned int BZh0=(((unsigned int)'B')<<24)+(((unsigned int)'Z')<<16)
|
|
+(((unsigned int)'h')<<8)+(unsigned int)'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=xmalloc(i);
|
|
memset(bd,0,sizeof(bunzip_data));
|
|
/* Setup input buffer */
|
|
if(-1==(bd->in_fd=in_fd)) {
|
|
bd->inbuf=inbuf;
|
|
bd->inbufCount=len;
|
|
} else bd->inbuf=(unsigned char *)(bd+1);
|
|
/* Init the CRC32 table (big endian) */
|
|
for(i=0;i<256;i++) {
|
|
c=i<<24;
|
|
for(j=8;j;j--)
|
|
c=c&0x80000000 ? (c<<1)^0x04c11db7 : (c<<1);
|
|
bd->crc32Table[i]=c;
|
|
}
|
|
/* Setup for I/O error handling via longjmp */
|
|
i=setjmp(bd->jmpbuf);
|
|
if(i) return i;
|
|
|
|
/* Ensure that file starts with "BZh['1'-'9']." */
|
|
i = get_bits(bd,32);
|
|
if (((unsigned int)(i-BZh0-1)) >= 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->dbuf=xmalloc(bd->dbufSize * sizeof(int));
|
|
return RETVAL_OK;
|
|
}
|
|
|
|
/* Example usage: decompress src_fd to dst_fd. (Stops at end of bzip data,
|
|
not end of file.) */
|
|
extern int uncompressStream(int src_fd, int dst_fd)
|
|
{
|
|
char *outbuf;
|
|
bunzip_data *bd;
|
|
int i;
|
|
|
|
outbuf=xmalloc(IOBUF_SIZE);
|
|
if(!(i=start_bunzip(&bd,src_fd,0,0))) {
|
|
for(;;) {
|
|
if((i=read_bunzip(bd,outbuf,IOBUF_SIZE)) <= 0) break;
|
|
if(i!=write(dst_fd,outbuf,i)) {
|
|
i=RETVAL_UNEXPECTED_OUTPUT_EOF;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
/* Check CRC and release memory */
|
|
if(i==RETVAL_LAST_BLOCK) {
|
|
if (bd->headerCRC!=bd->totalCRC) {
|
|
bb_error_msg("Data integrity error when decompressing.");
|
|
} else {
|
|
i=RETVAL_OK;
|
|
}
|
|
}
|
|
else if (i==RETVAL_UNEXPECTED_OUTPUT_EOF) {
|
|
bb_error_msg("Compressed file ends unexpectedly");
|
|
} else {
|
|
bb_error_msg("Decompression failed");
|
|
}
|
|
if(bd->dbuf) free(bd->dbuf);
|
|
free(bd);
|
|
free(outbuf);
|
|
|
|
return i;
|
|
}
|
|
|
|
#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=uncompressStream(0,1);
|
|
char c;
|
|
|
|
if(i) fprintf(stderr,"%s\n", bunzip_errors[-i]);
|
|
else if(read(0,&c,1)) fprintf(stderr,"Trailing garbage ignored\n");
|
|
return -i;
|
|
}
|
|
#endif
|