diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2007-04-10 17:16:33 +0000 |
---|---|---|
committer | Denis Vlasenko <vda.linux@googlemail.com> | 2007-04-10 17:16:33 +0000 |
commit | b38cf3ff8a31b2b35d6bcfb1513d568d1977bcba (patch) | |
tree | 16da2cd8c469815f4506b59c73b3668b694ea316 /archival/libunarchive | |
parent | a9d7d24e1f524bb7528aa881265fe8f826023751 (diff) | |
download | busybox-b38cf3ff8a31b2b35d6bcfb1513d568d1977bcba.tar.gz |
bunzip2: big style cleanup. No code changes apart from one s/write/safe_write/
(verified with objdump).
Diffstat (limited to 'archival/libunarchive')
-rw-r--r-- | archival/libunarchive/decompress_bunzip2.c | 398 |
1 files changed, 208 insertions, 190 deletions
diff --git a/archival/libunarchive/decompress_bunzip2.c b/archival/libunarchive/decompress_bunzip2.c index dd2e1ddcb..75d225bee 100644 --- a/archival/libunarchive/decompress_bunzip2.c +++ b/archival/libunarchive/decompress_bunzip2.c @@ -55,7 +55,7 @@ /* This is what we know about each Huffman coding group */ struct group_data { /* We have an extra slot at the end of limit[] for a sentinal value. */ - int limit[MAX_HUFCODE_BITS+1],base[MAX_HUFCODE_BITS],permute[MAX_SYMBOLS]; + int limit[MAX_HUFCODE_BITS+1], base[MAX_HUFCODE_BITS], permute[MAX_SYMBOLS]; int minLen, maxLen; }; @@ -65,13 +65,13 @@ struct group_data { typedef struct { /* State for interrupting output loop */ - int writeCopies,writePos,writeRunCountdown,writeCount,writeCurrent; + int writeCopies, writePos, writeRunCountdown, writeCount, writeCurrent; /* I/O tracking data (file handles, buffers, positions, etc.) */ - int in_fd,out_fd,inbufCount,inbufPos /*,outbufPos*/; + int in_fd, out_fd, inbufCount, inbufPos /*, outbufPos*/; unsigned char *inbuf /*,*outbuf*/; - unsigned int inbufBitCount, inbufBits; + unsigned inbufBitCount, inbufBits; /* The CRC values stored in the block header and calculated from the data */ @@ -79,7 +79,7 @@ typedef struct { uint32_t *crc32Table; /* Intermediate buffer and its size (in bytes) */ - unsigned int *dbuf, dbufSize; + unsigned *dbuf, dbufSize; /* These things are a bit too big to go on the stack */ @@ -94,42 +94,43 @@ typedef struct { /* 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 int get_bits(bunzip_data *bd, char bits_wanted) +static unsigned get_bits(bunzip_data *bd, char bits_wanted) { - unsigned int bits=0; + unsigned bits = 0; /* 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 (bd->inbufBitCount<bits_wanted) { + while (bd->inbufBitCount < bits_wanted) { /* If we need to read more data from file into byte buffer, do so */ - if(bd->inbufPos==bd->inbufCount) { - if((bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE)) <= 0) - longjmp(bd->jmpbuf,RETVAL_UNEXPECTED_INPUT_EOF); - bd->inbufPos=0; + if (bd->inbufPos == bd->inbufCount) { + 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(bd->inbufBitCount>=24) { - bits=bd->inbufBits&((1<<bd->inbufBitCount)-1); - bits_wanted-=bd->inbufBitCount; - bits<<=bits_wanted; - bd->inbufBitCount=0; + if (bd->inbufBitCount >= 24) { + bits = bd->inbufBits & ((1 << bd->inbufBitCount) - 1); + bits_wanted -= bd->inbufBitCount; + bits <<= bits_wanted; + bd->inbufBitCount = 0; } /* Grab next 8 bits of input from buffer. */ - bd->inbufBits=(bd->inbufBits<<8)|bd->inbuf[bd->inbufPos++]; - bd->inbufBitCount+=8; + bd->inbufBits = (bd->inbufBits<<8) | bd->inbuf[bd->inbufPos++]; + bd->inbufBitCount += 8; } /* Calculate result */ - bd->inbufBitCount-=bits_wanted; - bits|=(bd->inbufBits>>bd->inbufBitCount)&((1<<bits_wanted)-1); + bd->inbufBitCount -= bits_wanted; + bits |= (bd->inbufBits >> bd->inbufBitCount) & ((1 << bits_wanted) - 1); return bits; } @@ -139,26 +140,26 @@ static unsigned int get_bits(bunzip_data *bd, char bits_wanted) static int get_next_block(bunzip_data *bd) { struct group_data *hufGroup; - int dbufCount,nextSym,dbufSize,groupCount,*base,*limit,selector, - i,j,k,t,runPos,symCount,symTotal,nSelectors,byteCount[256]; + int dbufCount, nextSym, dbufSize, groupCount, *base, *limit, selector, + i, j, k, t, runPos, symCount, symTotal, nSelectors, byteCount[256]; unsigned char uc, symToByte[256], mtfSymbol[256], *selectors; - unsigned int *dbuf,origPtr; + unsigned *dbuf, origPtr; - dbuf=bd->dbuf; - dbufSize=bd->dbufSize; - selectors=bd->selectors; + dbuf = bd->dbuf; + dbufSize = bd->dbufSize; + selectors = bd->selectors; /* Reset longjmp I/O error handling */ - i=setjmp(bd->jmpbuf); + i = setjmp(bd->jmpbuf); if (i) return i; /* 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); + 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; @@ -166,8 +167,9 @@ static int get_next_block(bunzip_data *bd) 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; - if ((origPtr=get_bits(bd,24)) > dbufSize) return RETVAL_DATA_ERROR; + if (get_bits(bd, 1)) return RETVAL_OBSOLETE_INPUT; + origPtr = get_bits(bd, 24); + if (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 @@ -175,48 +177,52 @@ static int get_next_block(bunzip_data *bd) values were present. We make a translation table to convert the symbols back to the corresponding bytes. */ - t=get_bits(bd, 16); - symTotal=0; - for (i=0;i<16;i++) { - if(t&(1<<(15-i))) { - k=get_bits(bd,16); - for (j=0;j<16;j++) - if(k&(1<<(15-j))) symToByte[symTotal++]=(16*i)+j; + t = get_bits(bd, 16); + symTotal = 0; + for (i = 0; i < 16; i++) { + if (t & (1 << (15-i))) { + k = get_bits(bd, 16); + for (j = 0; j < 16; j++) + if (k & (1 << (15-j))) + symToByte[symTotal++] = (16*i) + j; } } /* 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; + 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.) */ - if(!(nSelectors=get_bits(bd, 15))) return RETVAL_DATA_ERROR; - for (i=0; i<groupCount; i++) mtfSymbol[i] = i; - for (i=0; i<nSelectors; i++) { + nSelectors = get_bits(bd, 15); + if (!nSelectors) return RETVAL_DATA_ERROR; + for (i = 0; i < groupCount; i++) mtfSymbol[i] = i; + for (i = 0; i < nSelectors; i++) { /* Get next value */ - for (j=0;get_bits(bd,1);j++) if (j>=groupCount) return RETVAL_DATA_ERROR; + for (j = 0; get_bits(bd, 1); j++) + if (j>=groupCount) return RETVAL_DATA_ERROR; /* Decode MTF to get the next selector */ uc = mtfSymbol[j]; for (;j;j--) mtfSymbol[j] = mtfSymbol[j-1]; - mtfSymbol[0]=selectors[i]=uc; + mtfSymbol[0] = selectors[i] = uc; } /* 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++) { - unsigned char length[MAX_SYMBOLS],temp[MAX_HUFCODE_BITS+1]; - int minLen, maxLen, pp; + symCount = symTotal + 2; + for (j = 0; j < groupCount; j++) { + unsigned char length[MAX_SYMBOLS], temp[MAX_HUFCODE_BITS+1]; + int minLen, maxLen, pp; /* Read Huffman code lengths for each symbol. They're stored in a way similar to mtf; record a starting value for the first symbol, @@ -225,17 +231,17 @@ static int get_next_block(bunzip_data *bd) an optimization that makes the test inside the loop simpler: symbol length 0 becomes negative, so an unsigned inequality catches it.) */ - t=get_bits(bd, 5)-1; + t = get_bits(bd, 5) - 1; for (i = 0; i < symCount; i++) { for (;;) { - if (((unsigned)t) > (MAX_HUFCODE_BITS-1)) + if ((unsigned)t > (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. */ - k = get_bits(bd,2); + k = get_bits(bd, 2); if (k < 2) { bd->inbufBitCount++; break; @@ -243,20 +249,20 @@ static int get_next_block(bunzip_data *bd) /* Add one if second bit 1, else subtract 1. Avoids if/else */ - t+=(((k+1)&2)-1); + t += (((k+1) & 2) - 1); } /* Correct for the initial -1, to get the final symbol length */ - length[i]=t+1; + length[i] = t + 1; } /* Find largest and smallest lengths in this group */ - minLen=maxLen=length[0]; + 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]; + if (length[i] > maxLen) maxLen = length[i]; + else if (length[i] < minLen) minLen = length[i]; } /* Calculate permute[], base[], and limit[] tables from length[]. @@ -270,7 +276,7 @@ static int get_next_block(bunzip_data *bd) * length: each code with a value>limit[length] needs another bit. */ - hufGroup=bd->groups+j; + hufGroup = bd->groups + j; hufGroup->minLen = minLen; hufGroup->maxLen = maxLen; @@ -278,30 +284,31 @@ static int get_next_block(bunzip_data *bd) 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; + base = hufGroup->base - 1; + limit = hufGroup->limit - 1; /* Calculate permute[]. Concurently, initialize temp[] and limit[]. */ - pp=0; - for (i=minLen;i<=maxLen;i++) { - temp[i]=limit[i]=0; - for (t=0;t<symCount;t++) - if(length[t]==i) hufGroup->permute[pp++] = t; + pp = 0; + for (i = minLen; i <= maxLen; i++) { + temp[i] = limit[i] = 0; + for (t = 0; t < symCount; t++) + if (length[t] == i) + hufGroup->permute[pp++] = t; } /* Count symbols coded for at each bit length */ - for (i=0;i<symCount;i++) temp[length[i]]++; + 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; i++) { - pp+=temp[i]; + pp = t = 0; + for (i = minLen; i < maxLen; 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 @@ -310,13 +317,14 @@ static int get_next_block(bunzip_data *bd) 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; - base[i+1]=pp-(t+=temp[i]); + limit[i] = (pp << (maxLen - i)) - 1; + pp <<= 1; + t += temp[i]; + base[i+1] = pp - t; } limit[maxLen+1] = INT_MAX; /* Sentinal value for reading next sym. */ - limit[maxLen]=pp+temp[maxLen]-1; - base[minLen]=0; + limit[maxLen] = pp + temp[maxLen] - 1; + base[minLen] = 0; } /* We've finished reading and digesting the block header. Now read this @@ -325,24 +333,24 @@ static int get_next_block(bunzip_data *bd) /* Initialize symbol occurrence counters and symbol Move To Front table */ - for (i=0;i<256;i++) { + for (i = 0; i < 256; i++) { byteCount[i] = 0; - mtfSymbol[i]=(unsigned char)i; + mtfSymbol[i] = (unsigned char)i; } /* Loop through compressed symbols. */ - runPos=dbufCount=selector=0; + runPos = dbufCount = selector = 0; for (;;) { /* 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: + 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. */ @@ -353,33 +361,34 @@ continue_this_group: valid compressed file. As a further optimization, we do the read inline (falling back to a call to get_bits if the buffer runs dry). The following (up to got_huff_bits:) is equivalent to - j=get_bits(bd,hufGroup->maxLen); + j = get_bits(bd, hufGroup->maxLen); */ - while (bd->inbufBitCount<hufGroup->maxLen) { - if(bd->inbufPos==bd->inbufCount) { - j = get_bits(bd,hufGroup->maxLen); + while (bd->inbufBitCount < hufGroup->maxLen) { + if (bd->inbufPos == bd->inbufCount) { + j = get_bits(bd, hufGroup->maxLen); goto got_huff_bits; } - bd->inbufBits=(bd->inbufBits<<8)|bd->inbuf[bd->inbufPos++]; - bd->inbufBitCount+=8; + bd->inbufBits = (bd->inbufBits << 8) | bd->inbuf[bd->inbufPos++]; + bd->inbufBitCount += 8; }; - bd->inbufBitCount-=hufGroup->maxLen; - j = (bd->inbufBits>>bd->inbufBitCount)&((1<<hufGroup->maxLen)-1); + bd->inbufBitCount -= hufGroup->maxLen; + j = (bd->inbufBits >> bd->inbufBitCount) & ((1 << hufGroup->maxLen) - 1); -got_huff_bits: + got_huff_bits: /* Figure how how many bits are in next symbol and unget extras */ - i=hufGroup->minLen; - while (j>limit[i]) ++i; + i = hufGroup->minLen; + while (j > limit[i]) ++i; bd->inbufBitCount += (hufGroup->maxLen - i); /* Huffman decode value to get nextSym (with bounds checking) */ - if ((i > hufGroup->maxLen) - || (((unsigned)(j=(j>>(hufGroup->maxLen-i))-base[i])) - >= MAX_SYMBOLS)) + if (i > hufGroup->maxLen) + return RETVAL_DATA_ERROR; + j = (j >> (hufGroup->maxLen - i)) - base[i]; + if ((unsigned)j >= MAX_SYMBOLS) return RETVAL_DATA_ERROR; nextSym = hufGroup->permute[j]; @@ -388,11 +397,11 @@ got_huff_bits: 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 ((unsigned)nextSym <= SYMBOL_RUNB) { /* RUNA or RUNB */ /* If this is the start of a new run, zero out counter */ - if(!runPos) { + if (!runPos) { runPos = 1; t = 0; } @@ -406,7 +415,7 @@ got_huff_bits: context). Thus space is saved. */ t += (runPos << nextSym); /* +runPos if RUNA; +2*runPos if RUNB */ - if(runPos < dbufSize) runPos <<= 1; + if (runPos < dbufSize) runPos <<= 1; goto end_of_huffman_loop; } @@ -415,18 +424,18 @@ got_huff_bits: 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) { - runPos=0; - if(dbufCount+t>=dbufSize) return RETVAL_DATA_ERROR; + if (runPos) { + runPos = 0; + if (dbufCount + t >= dbufSize) return RETVAL_DATA_ERROR; uc = symToByte[mtfSymbol[0]]; byteCount[uc] += t; - while (t--) dbuf[dbufCount++]=uc; + while (t--) dbuf[dbufCount++] = uc; } /* Is this the terminating symbol? */ - if(nextSym>symTotal) break; + 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 @@ -436,7 +445,7 @@ got_huff_bits: 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; + if (dbufCount >= dbufSize) return RETVAL_DATA_ERROR; i = nextSym - 1; uc = mtfSymbol[i]; @@ -449,18 +458,18 @@ got_huff_bits: mtfSymbol[i] = mtfSymbol[i-1]; } while (--i); mtfSymbol[0] = uc; - uc=symToByte[uc]; + uc = symToByte[uc]; /* We have our literal byte. Save it into dbuf. */ byteCount[uc]++; - dbuf[dbufCount++] = (unsigned int)uc; + dbuf[dbufCount++] = (unsigned)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--) goto continue_this_group; + end_of_huffman_loop: + if (symCount--) goto continue_this_group; } /* At this point, we've read all the Huffman-coded symbols (and repeated @@ -472,17 +481,17 @@ end_of_huffman_loop: /* Turn byteCount into cumulative occurrence counts of 0 to n-1. */ - j=0; - for (i=0;i<256;i++) { - k=j+byteCount[i]; + j = 0; + for (i = 0; i < 256; i++) { + k = j + byteCount[i]; byteCount[i] = j; - j=k; + 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); + for (i = 0; i < dbufCount; i++) { + uc = (unsigned char)(dbuf[i] & 0xff); dbuf[byteCount[uc]] |= (i << 8); byteCount[uc]++; } @@ -491,14 +500,14 @@ end_of_huffman_loop: 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(origPtr>=dbufCount) return RETVAL_DATA_ERROR; - bd->writePos=dbuf[origPtr]; - bd->writeCurrent=(unsigned char)(bd->writePos&0xff); - bd->writePos>>=8; - bd->writeRunCountdown=5; + if (dbufCount) { + if (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; + bd->writeCount = dbufCount; return RETVAL_OK; } @@ -512,16 +521,16 @@ end_of_huffman_loop: static int read_bunzip(bunzip_data *bd, char *outbuf, int len) { - const unsigned int *dbuf; - int pos,current,previous,gotcount; + 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; + if (bd->writeCount < 0) return bd->writeCount; gotcount = 0; - dbuf=bd->dbuf; - pos=bd->writePos; - current=bd->writeCurrent; + 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 @@ -539,9 +548,9 @@ static int read_bunzip(bunzip_data *bd, char *outbuf, int len) /* If the output buffer is full, snapshot state and return */ - if(gotcount >= len) { - bd->writePos=pos; - bd->writeCurrent=current; + if (gotcount >= len) { + bd->writePos =pos; + bd->writeCurrent = current; bd->writeCopies++; return len; } @@ -549,8 +558,8 @@ static int read_bunzip(bunzip_data *bd, char *outbuf, int len) /* Write next byte into output buffer, updating CRC */ outbuf[gotcount++] = current; - bd->writeCRC=(((bd->writeCRC)<<8) - ^bd->crc32Table[((bd->writeCRC)>>24)^current]); + bd->writeCRC = (bd->writeCRC << 8) + ^ bd->crc32Table[(bd->writeCRC >> 24) ^ current]; /* Loop now if we're outputting multiple copies of this byte */ @@ -558,31 +567,32 @@ static int read_bunzip(bunzip_data *bd, char *outbuf, int len) --bd->writeCopies; continue; } -decode_next_byte: + 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; + 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; + 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; + bd->writeCopies = current; + current = previous; + bd->writeRunCountdown = 5; /* Sometimes there are just 3 bytes (run length 0) */ - if(!bd->writeCopies) goto decode_next_byte; + if (!bd->writeCopies) goto decode_next_byte; /* Subtract the 1 copy we'd output anyway to get extras */ @@ -592,13 +602,13 @@ decode_next_byte: /* Decompression of this block completed successfully */ - bd->writeCRC=~bd->writeCRC; - bd->totalCRC=((bd->totalCRC<<1) | (bd->totalCRC>>31)) ^ bd->writeCRC; + 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; + if (bd->writeCRC != bd->headerCRC) { + bd->totalCRC = bd->headerCRC+1; return RETVAL_LAST_BLOCK; } } @@ -606,14 +616,14 @@ decode_next_byte: /* 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; + 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; + bd->writeCRC = ~0; + pos = bd->writePos; + current = bd->writeCurrent; goto decode_next_byte; } @@ -625,25 +635,28 @@ static int start_bunzip(bunzip_data **bdp, int in_fd, unsigned char *inbuf, int len) { bunzip_data *bd; - unsigned int i; - const unsigned int BZh0=(((unsigned int)'B')<<24)+(((unsigned int)'Z')<<16) - +(((unsigned int)'h')<<8)+(unsigned int)'0'; + unsigned i; + enum { + BZh0 = ('B' << 24) + ('Z' << 16) + ('h' << 8) + '0' + }; /* Figure out how much data to allocate */ - i=sizeof(bunzip_data); - if(in_fd!=-1) i+=IOBUF_SIZE; + i = sizeof(bunzip_data); + if (in_fd != -1) i += IOBUF_SIZE; /* Allocate bunzip_data. Most fields initialize to zero. */ - bd=*bdp=xzalloc(i); + bd = *bdp = xzalloc(i); /* Setup input buffer */ - if(-1==(bd->in_fd=in_fd)) { - bd->inbuf=inbuf; - bd->inbufCount=len; - } else bd->inbuf=(unsigned char *)(bd+1); + bd->in_fd = in_fd; + if (-1 == in_fd) { + bd->inbuf = inbuf; + bd->inbufCount = len; + } else + bd->inbuf = (unsigned char *)(bd + 1); /* Init the CRC32 table (big endian) */ @@ -651,20 +664,20 @@ static int start_bunzip(bunzip_data **bdp, int in_fd, unsigned char *inbuf, /* Setup for I/O error handling via longjmp */ - i=setjmp(bd->jmpbuf); - if(i) return i; + 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; + i = get_bits(bd, 32); + if (((unsigned)(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->dbufSize = 100000 * (i - BZh0); - bd->dbuf=xmalloc(bd->dbufSize * sizeof(int)); + bd->dbuf = xmalloc(bd->dbufSize * sizeof(int)); return RETVAL_OK; } @@ -679,13 +692,14 @@ uncompressStream(int src_fd, int dst_fd) bunzip_data *bd; int i; - outbuf=xmalloc(IOBUF_SIZE); - i=start_bunzip(&bd,src_fd,0,0); - if(!i) { + outbuf = xmalloc(IOBUF_SIZE); + i = start_bunzip(&bd, src_fd, 0, 0); + if (!i) { for (;;) { - if((i=read_bunzip(bd,outbuf,IOBUF_SIZE)) <= 0) break; - if(i!=write(dst_fd,outbuf,i)) { - i=RETVAL_UNEXPECTED_OUTPUT_EOF; + i = read_bunzip(bd, outbuf, IOBUF_SIZE); + if (i <= 0) break; + if (i != safe_write(dst_fd, outbuf, i)) { + i = RETVAL_UNEXPECTED_OUTPUT_EOF; break; } USE_DESKTOP(total_written += i;) @@ -694,13 +708,13 @@ uncompressStream(int src_fd, int dst_fd) /* Check CRC and release memory */ - if(i==RETVAL_LAST_BLOCK) { - if (bd->headerCRC!=bd->totalCRC) { + if (i == RETVAL_LAST_BLOCK) { + if (bd->headerCRC != bd->totalCRC) { bb_error_msg("data integrity error when decompressing"); } else { - i=RETVAL_OK; + i = RETVAL_OK; } - } else if (i==RETVAL_UNEXPECTED_OUTPUT_EOF) { + } else if (i == RETVAL_UNEXPECTED_OUTPUT_EOF) { bb_error_msg("compressed file ends unexpectedly"); } else { bb_error_msg("decompression failed"); @@ -714,18 +728,22 @@ uncompressStream(int src_fd, int 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."}; +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); + int i = uncompressStream(0, 1); char c; - if(i<0) fprintf(stderr,"%s\n", bunzip_errors[-i]); - else if(read(0,&c,1)) fprintf(stderr,"Trailing garbage ignored\n"); + if (i < 0) + fprintf(stderr,"%s\n", bunzip_errors[-i]); + else if (read(0, &c, 1)) + fprintf(stderr,"Trailing garbage ignored\n"); return -i; } #endif |