diff options
Diffstat (limited to 'archival/libunarchive/decompress_bunzip2.c')
| -rw-r--r-- | archival/libunarchive/decompress_bunzip2.c | 822 |
1 files changed, 0 insertions, 822 deletions
diff --git a/archival/libunarchive/decompress_bunzip2.c b/archival/libunarchive/decompress_bunzip2.c deleted file mode 100644 index 15f08a6..0000000 --- a/archival/libunarchive/decompress_bunzip2.c +++ /dev/null @@ -1,822 +0,0 @@ -/* vi: set sw=4 ts=4: */ -/* Small bzip2 deflate implementation, by Rob Landley (rob@landley.net). - - Based on bzip2 decompression code by Julian R Seward (jseward@acm.org), - which also acknowledges contributions by Mike Burrows, David Wheeler, - Peter Fenwick, Alistair Moffat, Radford Neal, Ian H. Witten, - Robert Sedgewick, and Jon L. Bentley. - - Licensed under GPLv2 or later, see file LICENSE in this source tree. -*/ - -/* - Size and speed optimizations by Manuel Novoa III (mjn3@codepoet.org). - - More efficient reading of Huffman codes, a streamlined read_bunzip() - function, and various other tweaks. In (limited) tests, approximately - 20% faster than bzcat on x86 and about 10% faster on arm. - - Note that about 2/3 of the time is spent in read_bunzip() reversing - the Burrows-Wheeler transformation. Much of that time is delay - resulting from cache misses. - - (2010 update by vda: profiled "bzcat <84mbyte.bz2 >/dev/null" - on x86-64 CPU with L2 > 1M: get_next_block is hotter than read_bunzip: - %time seconds calls function - 71.01 12.69 444 get_next_block - 28.65 5.12 93065 read_bunzip - 00.22 0.04 7736490 get_bits - 00.11 0.02 47 dealloc_bunzip - 00.00 0.00 93018 full_write - ...) - - - I would ask that anyone benefiting from this work, especially those - using it in commercial products, consider making a donation to my local - non-profit hospice organization (www.hospiceacadiana.com) in the name of - the woman I loved, Toni W. Hagan, who passed away Feb. 12, 2003. - - Manuel - */ - -#include "libbb.h" -#include "unarchive.h" - -/* Constants for Huffman coding */ -#define MAX_GROUPS 6 -#define GROUP_SIZE 50 /* 64 would have been more efficient */ -#define MAX_HUFCODE_BITS 20 /* Longest Huffman code allowed */ -#define MAX_SYMBOLS 258 /* 256 literals + RUNA + RUNB */ -#define SYMBOL_RUNA 0 -#define SYMBOL_RUNB 1 - -/* Status return values */ -#define RETVAL_OK 0 -#define RETVAL_LAST_BLOCK (-1) -#define RETVAL_NOT_BZIP_DATA (-2) -#define RETVAL_UNEXPECTED_INPUT_EOF (-3) -#define RETVAL_SHORT_WRITE (-4) -#define RETVAL_DATA_ERROR (-5) -#define RETVAL_OUT_OF_MEMORY (-6) -#define RETVAL_OBSOLETE_INPUT (-7) - -/* Other housekeeping constants */ -#define IOBUF_SIZE 4096 - -/* 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 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 - * 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 { - /* I/O tracking data (file handles, buffers, positions, etc.) */ - unsigned inbufBitCount, inbufBits; - int in_fd, out_fd, inbufCount, inbufPos /*, outbufPos*/; - uint8_t *inbuf /*,*outbuf*/; - - /* State for interrupting output loop */ - int writeCopies, writePos, writeRunCountdown, writeCount; - int writeCurrent; /* actually a uint8_t */ - - /* The CRC values stored in the block header and calculated from the data */ - uint32_t headerCRC, totalCRC, writeCRC; - - /* Intermediate buffer and its size (in bytes) */ - uint32_t *dbuf; - unsigned dbufSize; - - /* For I/O error handling */ - jmp_buf jmpbuf; - - /* Big things go last (register-relative addressing can be larger for big offsets) */ - uint32_t crc32Table[256]; - uint8_t selectors[32768]; /* nSelectors=15 bits */ - struct group_data groups[MAX_GROUPS]; /* Huffman coding tables */ -}; -/* typedef struct bunzip_data bunzip_data; -- done in .h file */ - - -/* 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, int bits_wanted) -{ - unsigned bits = 0; - /* Cache bd->inbufBitCount in a CPU register (hopefully): */ - int bit_count = bd->inbufBitCount; - - /* If we need to get more data from the byte buffer, do so. (Loop getting - one byte at a time to enforce endianness and avoid unaligned access.) */ - while (bit_count < bits_wanted) { - - /* If we need to read more data from file into byte buffer, do so */ - if (bd->inbufPos == bd->inbufCount) { - /* if "no input fd" case: in_fd == -1, read fails, we jump */ - bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE); - if (bd->inbufCount <= 0) - longjmp(bd->jmpbuf, RETVAL_UNEXPECTED_INPUT_EOF); - bd->inbufPos = 0; - } - - /* Avoid 32-bit overflow (dump bit buffer to top of output) */ - if (bit_count >= 24) { - bits = bd->inbufBits & ((1 << bit_count) - 1); - bits_wanted -= bit_count; - bits <<= bits_wanted; - bit_count = 0; - } - - /* Grab next 8 bits of input from buffer. */ - bd->inbufBits = (bd->inbufBits << 8) | bd->inbuf[bd->inbufPos++]; - bit_count += 8; - } - - /* Calculate result */ - bit_count -= bits_wanted; - bd->inbufBitCount = bit_count; - bits |= (bd->inbufBits >> bit_count) & ((1 << bits_wanted) - 1); - - return bits; -} - -/* Unpacks the next block and sets up for the inverse Burrows-Wheeler step. */ -static int get_next_block(bunzip_data *bd) -{ - struct group_data *hufGroup; - int dbufCount, dbufSize, groupCount, *base, *limit, selector, - i, j, t, runPos, symCount, symTotal, nSelectors, byteCount[256]; - int runCnt = runCnt; /* for compiler */ - uint8_t uc, symToByte[256], mtfSymbol[256], *selectors; - uint32_t *dbuf; - unsigned origPtr; - - dbuf = bd->dbuf; - dbufSize = bd->dbufSize; - selectors = bd->selectors; - -/* In bbox, we are ok with aborting through setjmp which is set up in start_bunzip */ -#if 0 - /* Reset longjmp I/O error handling */ - i = setjmp(bd->jmpbuf); - if (i) return i; -#endif - - /* Read in header signature and CRC, then validate signature. - (last block signature means CRC is for whole file, return now) */ - i = get_bits(bd, 24); - j = get_bits(bd, 24); - bd->headerCRC = get_bits(bd, 32); - if ((i == 0x177245) && (j == 0x385090)) return RETVAL_LAST_BLOCK; - if ((i != 0x314159) || (j != 0x265359)) return RETVAL_NOT_BZIP_DATA; - - /* We can add support for blockRandomised if anybody complains. There was - some code for this in busybox 1.0.0-pre3, but nobody ever noticed that - it didn't actually work. */ - if (get_bits(bd, 1)) return RETVAL_OBSOLETE_INPUT; - origPtr = get_bits(bd, 24); - if ((int)origPtr > dbufSize) return RETVAL_DATA_ERROR; - - /* mapping table: if some byte values are never used (encoding things - like ascii text), the compression code removes the gaps to have fewer - symbols to deal with, and writes a sparse bitfield indicating which - values were present. We make a translation table to convert the symbols - back to the corresponding bytes. */ - symTotal = 0; - i = 0; - t = get_bits(bd, 16); - do { - if (t & (1 << 15)) { - unsigned inner_map = get_bits(bd, 16); - do { - if (inner_map & (1 << 15)) - symToByte[symTotal++] = i; - inner_map <<= 1; - i++; - } while (i & 15); - i -= 16; - } - t <<= 1; - i += 16; - } while (i < 256); - - /* How many different Huffman coding groups does this block use? */ - groupCount = get_bits(bd, 3); - if (groupCount < 2 || groupCount > MAX_GROUPS) - return RETVAL_DATA_ERROR; - - /* nSelectors: Every GROUP_SIZE many symbols we select a new Huffman coding - group. Read in the group selector list, which is stored as MTF encoded - bit runs. (MTF=Move To Front, as each value is used it's moved to the - start of the list.) */ - for (i = 0; i < groupCount; i++) - mtfSymbol[i] = i; - nSelectors = get_bits(bd, 15); - if (!nSelectors) - return RETVAL_DATA_ERROR; - for (i = 0; i < nSelectors; i++) { - uint8_t tmp_byte; - /* Get next value */ - int n = 0; - while (get_bits(bd, 1)) { - if (n >= groupCount) return RETVAL_DATA_ERROR; - n++; - } - /* Decode MTF to get the next selector */ - tmp_byte = mtfSymbol[n]; - while (--n >= 0) - mtfSymbol[n + 1] = mtfSymbol[n]; - mtfSymbol[0] = selectors[i] = tmp_byte; - } - - /* Read the Huffman coding tables for each group, which code for symTotal - literal symbols, plus two run symbols (RUNA, RUNB) */ - symCount = symTotal + 2; - for (j = 0; j < groupCount; j++) { - uint8_t length[MAX_SYMBOLS]; - /* 8 bits is ALMOST enough for temp[], see below */ - unsigned temp[MAX_HUFCODE_BITS+1]; - int minLen, maxLen, pp, len_m1; - - /* Read Huffman code lengths for each symbol. They're stored in - a way similar to mtf; record a starting value for the first symbol, - and an offset from the previous value for every symbol after that. - (Subtracting 1 before the loop and then adding it back at the end is - an optimization that makes the test inside the loop simpler: symbol - length 0 becomes negative, so an unsigned inequality catches it.) */ - len_m1 = get_bits(bd, 5) - 1; - for (i = 0; i < symCount; i++) { - for (;;) { - int two_bits; - if ((unsigned)len_m1 > (MAX_HUFCODE_BITS-1)) - return RETVAL_DATA_ERROR; - - /* If first bit is 0, stop. Else second bit indicates whether - to increment or decrement the value. Optimization: grab 2 - bits and unget the second if the first was 0. */ - two_bits = get_bits(bd, 2); - if (two_bits < 2) { - bd->inbufBitCount++; - break; - } - - /* Add one if second bit 1, else subtract 1. Avoids if/else */ - len_m1 += (((two_bits+1) & 2) - 1); - } - - /* Correct for the initial -1, to get the final symbol length */ - length[i] = len_m1 + 1; - } - - /* Find largest and smallest lengths in this group */ - minLen = maxLen = length[0]; - for (i = 1; i < symCount; i++) { - if (length[i] > maxLen) maxLen = length[i]; - else if (length[i] < minLen) minLen = length[i]; - } - - /* Calculate permute[], base[], and limit[] tables from length[]. - * - * permute[] is the lookup table for converting Huffman coded symbols - * into decoded symbols. base[] is the amount to subtract from the - * value of a Huffman symbol of a given length when using permute[]. - * - * limit[] indicates the largest numerical value a symbol with a given - * number of bits can have. This is how the Huffman codes can vary in - * length: each code with a value>limit[length] needs another bit. - */ - hufGroup = bd->groups + j; - hufGroup->minLen = minLen; - hufGroup->maxLen = maxLen; - - /* Note that minLen can't be smaller than 1, so we adjust the base - and limit array pointers so we're not always wasting the first - entry. We do this again when using them (during symbol decoding). */ - base = hufGroup->base - 1; - limit = hufGroup->limit - 1; - - /* Calculate permute[]. Concurently, initialize temp[] and limit[]. */ - pp = 0; - for (i = minLen; i <= maxLen; i++) { - int k; - temp[i] = limit[i] = 0; - for (k = 0; k < symCount; k++) - if (length[k] == i) - hufGroup->permute[pp++] = k; - } - - /* Count symbols coded for at each bit length */ - /* NB: in pathological cases, temp[8] can end ip being 256. - * That's why uint8_t is too small for temp[]. */ - for (i = 0; i < symCount; i++) temp[length[i]]++; - - /* Calculate limit[] (the largest symbol-coding value at each bit - * length, which is (previous limit<<1)+symbols at this level), and - * base[] (number of symbols to ignore at each bit length, which is - * limit minus the cumulative count of symbols coded for already). */ - pp = t = 0; - for (i = minLen; i < maxLen;) { - unsigned temp_i = temp[i]; - - pp += temp_i; - - /* We read the largest possible symbol size and then unget bits - after determining how many we need, and those extra bits could - be set to anything. (They're noise from future symbols.) At - each level we're really only interested in the first few bits, - so here we set all the trailing to-be-ignored bits to 1 so they - don't affect the value>limit[length] comparison. */ - limit[i] = (pp << (maxLen - i)) - 1; - pp <<= 1; - t += temp_i; - base[++i] = pp - t; - } - limit[maxLen] = pp + temp[maxLen] - 1; - limit[maxLen+1] = INT_MAX; /* Sentinel value for reading next sym. */ - 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 */ - - /* Initialize symbol occurrence counters and symbol Move To Front table */ - /*memset(byteCount, 0, sizeof(byteCount)); - smaller, but slower */ - for (i = 0; i < 256; i++) { - byteCount[i] = 0; - mtfSymbol[i] = (uint8_t)i; - } - - /* Loop through compressed symbols. */ - - runPos = dbufCount = selector = 0; - for (;;) { - int nextSym; - - /* Fetch next Huffman coding group from list. */ - symCount = GROUP_SIZE - 1; - if (selector >= nSelectors) return RETVAL_DATA_ERROR; - hufGroup = bd->groups + selectors[selector++]; - base = hufGroup->base - 1; - limit = hufGroup->limit - 1; - - continue_this_group: - /* Read next Huffman-coded symbol. */ - - /* Note: It is far cheaper to read maxLen bits and back up than it is - to read minLen bits and then add additional bit at a time, testing - as we go. Because there is a trailing last block (with file CRC), - there is no danger of the overread causing an unexpected EOF for a - valid compressed file. - */ - if (1) { - /* As a further optimization, we do the read inline - (falling back to a call to get_bits if the buffer runs dry). - */ - int new_cnt; - while ((new_cnt = bd->inbufBitCount - hufGroup->maxLen) < 0) { - /* bd->inbufBitCount < hufGroup->maxLen */ - if (bd->inbufPos == bd->inbufCount) { - nextSym = get_bits(bd, hufGroup->maxLen); - goto got_huff_bits; - } - bd->inbufBits = (bd->inbufBits << 8) | bd->inbuf[bd->inbufPos++]; - bd->inbufBitCount += 8; - }; - bd->inbufBitCount = new_cnt; /* "bd->inbufBitCount -= hufGroup->maxLen;" */ - nextSym = (bd->inbufBits >> new_cnt) & ((1 << hufGroup->maxLen) - 1); - got_huff_bits: ; - } else { /* unoptimized equivalent */ - nextSym = get_bits(bd, hufGroup->maxLen); - } - /* Figure how many bits are in next symbol and unget extras */ - i = hufGroup->minLen; - while (nextSym > limit[i]) ++i; - j = hufGroup->maxLen - i; - if (j < 0) - return RETVAL_DATA_ERROR; - bd->inbufBitCount += j; - - /* Huffman decode value to get nextSym (with bounds checking) */ - nextSym = (nextSym >> j) - base[i]; - if ((unsigned)nextSym >= MAX_SYMBOLS) - return RETVAL_DATA_ERROR; - nextSym = hufGroup->permute[nextSym]; - - /* We have now decoded the symbol, which indicates either a new literal - byte, or a repeated run of the most recent literal byte. First, - check if nextSym indicates a repeated run, and if so loop collecting - how many times to repeat the last literal. */ - if ((unsigned)nextSym <= SYMBOL_RUNB) { /* RUNA or RUNB */ - - /* If this is the start of a new run, zero out counter */ - if (runPos == 0) { - runPos = 1; - runCnt = 0; - } - - /* Neat trick that saves 1 symbol: instead of or-ing 0 or 1 at - each bit position, add 1 or 2 instead. For example, - 1011 is 1<<0 + 1<<1 + 2<<2. 1010 is 2<<0 + 2<<1 + 1<<2. - You can make any bit pattern that way using 1 less symbol than - the basic or 0/1 method (except all bits 0, which would use no - symbols, but a run of length 0 doesn't mean anything in this - context). Thus space is saved. */ - runCnt += (runPos << nextSym); /* +runPos if RUNA; +2*runPos if RUNB */ - if (runPos < dbufSize) runPos <<= 1; - goto end_of_huffman_loop; - } - - /* When we hit the first non-run symbol after a run, we now know - how many times to repeat the last literal, so append that many - copies to our buffer of decoded symbols (dbuf) now. (The last - literal used is the one at the head of the mtfSymbol array.) */ - if (runPos != 0) { - uint8_t tmp_byte; - if (dbufCount + runCnt >= dbufSize) return RETVAL_DATA_ERROR; - tmp_byte = symToByte[mtfSymbol[0]]; - byteCount[tmp_byte] += runCnt; - while (--runCnt >= 0) dbuf[dbufCount++] = (uint32_t)tmp_byte; - runPos = 0; - } - - /* Is this the terminating symbol? */ - if (nextSym > symTotal) break; - - /* At this point, nextSym indicates a new literal character. Subtract - one to get the position in the MTF array at which this literal is - currently to be found. (Note that the result can't be -1 or 0, - because 0 and 1 are RUNA and RUNB. But another instance of the - first symbol in the mtf array, position 0, would have been handled - as part of a run above. Therefore 1 unused mtf position minus - 2 non-literal nextSym values equals -1.) */ - if (dbufCount >= dbufSize) return RETVAL_DATA_ERROR; - i = nextSym - 1; - uc = mtfSymbol[i]; - - /* Adjust the MTF array. Since we typically expect to move only a - * small number of symbols, and are bound by 256 in any case, using - * memmove here would typically be bigger and slower due to function - * call overhead and other assorted setup costs. */ - do { - mtfSymbol[i] = mtfSymbol[i-1]; - } while (--i); - mtfSymbol[0] = uc; - uc = symToByte[uc]; - - /* We have our literal byte. Save it into dbuf. */ - byteCount[uc]++; - dbuf[dbufCount++] = (uint32_t)uc; - - /* Skip group initialization if we're not done with this group. Done - * this way to avoid compiler warning. */ - end_of_huffman_loop: - if (--symCount >= 0) goto continue_this_group; - } - - /* At this point, we've read all the Huffman-coded symbols (and repeated - runs) for this block from the input stream, and decoded them into the - intermediate buffer. There are dbufCount many decoded bytes in dbuf[]. - Now undo the Burrows-Wheeler transform on dbuf. - See http://dogma.net/markn/articles/bwt/bwt.htm - */ - - /* Turn byteCount into cumulative occurrence counts of 0 to n-1. */ - j = 0; - for (i = 0; i < 256; i++) { - int tmp_count = j + byteCount[i]; - byteCount[i] = j; - j = tmp_count; - } - - /* Figure out what order dbuf would be in if we sorted it. */ - for (i = 0; i < dbufCount; i++) { - uint8_t tmp_byte = (uint8_t)dbuf[i]; - int tmp_count = byteCount[tmp_byte]; - dbuf[tmp_count] |= (i << 8); - byteCount[tmp_byte] = tmp_count + 1; - } - - /* 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) { - uint32_t tmp; - if ((int)origPtr >= dbufCount) return RETVAL_DATA_ERROR; - tmp = dbuf[origPtr]; - bd->writeCurrent = (uint8_t)tmp; - bd->writePos = (tmp >> 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. - - NB: read_bunzip returns < 0 on error, or the number of *unfilled* bytes - in outbuf. IOW: on EOF returns len ("all bytes are not filled"), not 0. - (Why? This allows to get rid of one local variable) -*/ -int FAST_FUNC read_bunzip(bunzip_data *bd, char *outbuf, int len) -{ - const uint32_t *dbuf; - int pos, current, previous; - uint32_t CRC; - - /* If we already have error/end indicator, return it */ - if (bd->writeCount < 0) - return bd->writeCount; - - dbuf = bd->dbuf; - - /* Register-cached state (hopefully): */ - pos = bd->writePos; - current = bd->writeCurrent; - CRC = bd->writeCRC; /* small loss on x86-32 (not enough regs), win on x86-64 */ - - /* 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) { - - dec_writeCopies: - /* Inside the loop, writeCopies means extra copies (beyond 1) */ - --bd->writeCopies; - - /* Loop outputting bytes */ - for (;;) { - - /* If the output buffer is full, save cached state and return */ - if (--len < 0) { - /* Unlikely branch. - * Use of "goto" instead of keeping code here - * helps compiler to realize this. */ - goto outbuf_full; - } - - /* Write next byte into output buffer, updating CRC */ - *outbuf++ = current; - CRC = (CRC << 8) ^ bd->crc32Table[(CRC >> 24) ^ current]; - - /* Loop now if we're outputting multiple copies of this byte */ - if (bd->writeCopies) { - /* Unlikely branch */ - /*--bd->writeCopies;*/ - /*continue;*/ - /* Same, but (ab)using other existing --writeCopies operation - * (and this if() compiles into just test+branch pair): */ - goto dec_writeCopies; - } - decode_next_byte: - if (--bd->writeCount < 0) - break; /* input block is fully consumed, need next one */ - - /* Follow sequence vector to undo Burrows-Wheeler transform */ - previous = current; - pos = dbuf[pos]; - current = (uint8_t)pos; - 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 != 0) { - if (current != previous) - bd->writeRunCountdown = 4; - } else { - /* Unlikely branch */ - /* 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; - } - } /* for(;;) */ - - /* Decompression of this input block completed successfully */ - bd->writeCRC = CRC = ~CRC; - bd->totalCRC = ((bd->totalCRC << 1) | (bd->totalCRC >> 31)) ^ CRC; - - /* If this block had a CRC error, force file level CRC error */ - if (CRC != bd->headerCRC) { - bd->totalCRC = bd->headerCRC + 1; - return RETVAL_LAST_BLOCK; - } - } - - /* Refill the intermediate buffer by Huffman-decoding next block of input */ - { - int r = get_next_block(bd); - if (r) { /* error/end */ - bd->writeCount = r; - return (r != RETVAL_LAST_BLOCK) ? r : len; - } - } - - CRC = ~0; - pos = bd->writePos; - current = bd->writeCurrent; - goto decode_next_byte; - - outbuf_full: - /* Output buffer is full, save cached state and return */ - bd->writePos = pos; - bd->writeCurrent = current; - bd->writeCRC = CRC; - - bd->writeCopies++; - - return 0; -} - -/* 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 void *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 */ - } else { - bd->inbuf = (uint8_t*)(bd + 1); - memcpy(bd->inbuf, inbuf, len); - } - bd->inbufCount = len; - - /* 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(bd->dbuf[0])); - 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;) - bunzip_data *bd; - char *outbuf; - int i; - unsigned len; - - outbuf = xmalloc(IOBUF_SIZE); - len = 0; - while (1) { /* "Process one BZ... stream" loop */ - - i = start_bunzip(&bd, src_fd, outbuf + 2, len); - - if (i == 0) { - while (1) { /* "Produce some output bytes" loop */ - i = read_bunzip(bd, outbuf, IOBUF_SIZE); - if (i < 0) /* error? */ - break; - i = IOBUF_SIZE - i; /* number of bytes produced */ - if (i == 0) /* EOF? */ - break; - if (i != full_write(dst_fd, outbuf, i)) { - bb_error_msg("short write"); - i = RETVAL_SHORT_WRITE; - goto release_mem; - } - IF_DESKTOP(total_written += i;) - } - } - - if (i != RETVAL_LAST_BLOCK) { - bb_error_msg("bunzip error %d", i); - break; - } - if (bd->headerCRC != bd->totalCRC) { - bb_error_msg("CRC error"); - break; - } - - /* Successfully unpacked one BZ stream */ - i = RETVAL_OK; - - /* Do we have "BZ..." after last processed byte? - * pbzip2 (parallelized bzip2) produces such files. - */ - len = bd->inbufCount - bd->inbufPos; - memcpy(outbuf, &bd->inbuf[bd->inbufPos], len); - if (len < 2) { - if (safe_read(src_fd, outbuf + len, 2 - len) != 2 - len) - break; - len = 2; - } - if (*(uint16_t*)outbuf != BZIP2_MAGIC) /* "BZ"? */ - break; - dealloc_bunzip(bd); - len -= 2; - } - - release_mem: - 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) -{ - uint16_t magic2; - xread(src_fd, &magic2, 2); - if (magic2 != BZIP2_MAGIC) { - 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 |