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bunzip2: big style cleanup. No code changes apart from one s/write/safe_write/

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(verified with objdump).
This commit is contained in:
Denis Vlasenko 2007-04-10 17:16:33 +00:00
parent a9d7d24e1f
commit b38cf3ff8a
1 changed files with 208 additions and 190 deletions
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398
archival/libunarchive/decompress_bunzip2.c
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@ -55,7 +55,7 @@
/* This is what we know about each Huffman coding group */ /* This is what we know about each Huffman coding group */
struct group_data { struct group_data {
/* We have an extra slot at the end of limit[] for a sentinal value. */ /* We have an extra slot at the end of limit[] for a 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; int minLen, maxLen;
}; };
@ -65,13 +65,13 @@ struct group_data {
typedef struct { typedef struct {
/* State for interrupting output loop */ /* 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.) */ /* 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 char *inbuf /*,*outbuf*/;
unsigned int inbufBitCount, inbufBits; unsigned inbufBitCount, inbufBits;
/* The CRC values stored in the block header and calculated from the data */ /* The CRC values stored in the block header and calculated from the data */
@ -79,7 +79,7 @@ typedef struct {
uint32_t *crc32Table; uint32_t *crc32Table;
/* Intermediate buffer and its size (in bytes) */ /* 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 */ /* 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 /* Return the next nnn bits of input. All reads from the compressed input
are done through this function. All reads are big endian */ 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 /* 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.) */ 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 we need to read more data from file into byte buffer, do so */
if(bd->inbufPos==bd->inbufCount) { if (bd->inbufPos == bd->inbufCount) {
if((bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE)) <= 0) bd->inbufCount = read(bd->in_fd, bd->inbuf, IOBUF_SIZE);
longjmp(bd->jmpbuf,RETVAL_UNEXPECTED_INPUT_EOF); if (bd->inbufCount <= 0)
bd->inbufPos=0; longjmp(bd->jmpbuf, RETVAL_UNEXPECTED_INPUT_EOF);
bd->inbufPos = 0;
} }
/* Avoid 32-bit overflow (dump bit buffer to top of output) */ /* Avoid 32-bit overflow (dump bit buffer to top of output) */
if(bd->inbufBitCount>=24) { if (bd->inbufBitCount >= 24) {
bits=bd->inbufBits&((1<<bd->inbufBitCount)-1); bits = bd->inbufBits & ((1 << bd->inbufBitCount) - 1);
bits_wanted-=bd->inbufBitCount; bits_wanted -= bd->inbufBitCount;
bits<<=bits_wanted; bits <<= bits_wanted;
bd->inbufBitCount=0; bd->inbufBitCount = 0;
} }
/* Grab next 8 bits of input from buffer. */ /* Grab next 8 bits of input from buffer. */
bd->inbufBits=(bd->inbufBits<<8)|bd->inbuf[bd->inbufPos++]; bd->inbufBits = (bd->inbufBits<<8) | bd->inbuf[bd->inbufPos++];
bd->inbufBitCount+=8; bd->inbufBitCount += 8;
} }
/* Calculate result */ /* Calculate result */
bd->inbufBitCount-=bits_wanted; bd->inbufBitCount -= bits_wanted;
bits|=(bd->inbufBits>>bd->inbufBitCount)&((1<<bits_wanted)-1); bits |= (bd->inbufBits >> bd->inbufBitCount) & ((1 << bits_wanted) - 1);
return bits; 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) static int get_next_block(bunzip_data *bd)
{ {
struct group_data *hufGroup; struct group_data *hufGroup;
int dbufCount,nextSym,dbufSize,groupCount,*base,*limit,selector, int dbufCount, nextSym, dbufSize, groupCount, *base, *limit, selector,
i,j,k,t,runPos,symCount,symTotal,nSelectors,byteCount[256]; i, j, k, t, runPos, symCount, symTotal, nSelectors, byteCount[256];
unsigned char uc, symToByte[256], mtfSymbol[256], *selectors; unsigned char uc, symToByte[256], mtfSymbol[256], *selectors;
unsigned int *dbuf,origPtr; unsigned *dbuf, origPtr;
dbuf=bd->dbuf; dbuf = bd->dbuf;
dbufSize=bd->dbufSize; dbufSize = bd->dbufSize;
selectors=bd->selectors; selectors = bd->selectors;
/* Reset longjmp I/O error handling */ /* Reset longjmp I/O error handling */
i=setjmp(bd->jmpbuf); i = setjmp(bd->jmpbuf);
if (i) return i; if (i) return i;
/* Read in header signature and CRC, then validate signature. /* Read in header signature and CRC, then validate signature.
(last block signature means CRC is for whole file, return now) */ (last block signature means CRC is for whole file, return now) */
i = get_bits(bd,24); i = get_bits(bd, 24);
j = get_bits(bd,24); j = get_bits(bd, 24);
bd->headerCRC=get_bits(bd,32); bd->headerCRC = get_bits(bd, 32);
if ((i == 0x177245) && (j == 0x385090)) return RETVAL_LAST_BLOCK; if ((i == 0x177245) && (j == 0x385090)) return RETVAL_LAST_BLOCK;
if ((i != 0x314159) || (j != 0x265359)) return RETVAL_NOT_BZIP_DATA; 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 some code for this in busybox 1.0.0-pre3, but nobody ever noticed that
it didn't actually work. */ it didn't actually work. */
if (get_bits(bd,1)) return RETVAL_OBSOLETE_INPUT; if (get_bits(bd, 1)) return RETVAL_OBSOLETE_INPUT;
if ((origPtr=get_bits(bd,24)) > dbufSize) return RETVAL_DATA_ERROR; origPtr = get_bits(bd, 24);
if (origPtr > dbufSize) return RETVAL_DATA_ERROR;
/* mapping table: if some byte values are never used (encoding things /* mapping table: if some byte values are never used (encoding things
like ascii text), the compression code removes the gaps to have fewer 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 values were present. We make a translation table to convert the symbols
back to the corresponding bytes. */ back to the corresponding bytes. */
t=get_bits(bd, 16); t = get_bits(bd, 16);
symTotal=0; symTotal = 0;
for (i=0;i<16;i++) { for (i = 0; i < 16; i++) {
if(t&(1<<(15-i))) { if (t & (1 << (15-i))) {
k=get_bits(bd,16); k = get_bits(bd, 16);
for (j=0;j<16;j++) for (j = 0; j < 16; j++)
if(k&(1<<(15-j))) symToByte[symTotal++]=(16*i)+j; if (k & (1 << (15-j)))
symToByte[symTotal++] = (16*i) + j;
} }
} }
/* How many different Huffman coding groups does this block use? */ /* How many different Huffman coding groups does this block use? */
groupCount=get_bits(bd,3); groupCount = get_bits(bd, 3);
if (groupCount<2 || groupCount>MAX_GROUPS) return RETVAL_DATA_ERROR; if (groupCount < 2 || groupCount > MAX_GROUPS)
return RETVAL_DATA_ERROR;
/* nSelectors: Every GROUP_SIZE many symbols we select a new Huffman coding /* 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 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 bit runs. (MTF=Move To Front, as each value is used it's moved to the
start of the list.) */ start of the list.) */
if(!(nSelectors=get_bits(bd, 15))) return RETVAL_DATA_ERROR; nSelectors = get_bits(bd, 15);
for (i=0; i<groupCount; i++) mtfSymbol[i] = i; if (!nSelectors) return RETVAL_DATA_ERROR;
for (i=0; i<nSelectors; i++) { for (i = 0; i < groupCount; i++) mtfSymbol[i] = i;
for (i = 0; i < nSelectors; i++) {
/* Get next value */ /* 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 */ /* Decode MTF to get the next selector */
uc = mtfSymbol[j]; uc = mtfSymbol[j];
for (;j;j--) mtfSymbol[j] = mtfSymbol[j-1]; 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 /* Read the Huffman coding tables for each group, which code for symTotal
literal symbols, plus two run symbols (RUNA, RUNB) */ literal symbols, plus two run symbols (RUNA, RUNB) */
symCount=symTotal+2; symCount = symTotal + 2;
for (j=0; j<groupCount; j++) { for (j = 0; j < groupCount; j++) {
unsigned char length[MAX_SYMBOLS],temp[MAX_HUFCODE_BITS+1]; unsigned char length[MAX_SYMBOLS], temp[MAX_HUFCODE_BITS+1];
int minLen, maxLen, pp; int minLen, maxLen, pp;
/* Read Huffman code lengths for each symbol. They're stored in /* Read Huffman code lengths for each symbol. They're stored in
a way similar to mtf; record a starting value for the first symbol, 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 an optimization that makes the test inside the loop simpler: symbol
length 0 becomes negative, so an unsigned inequality catches it.) */ 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 (i = 0; i < symCount; i++) {
for (;;) { for (;;) {
if (((unsigned)t) > (MAX_HUFCODE_BITS-1)) if ((unsigned)t > (MAX_HUFCODE_BITS-1))
return RETVAL_DATA_ERROR; return RETVAL_DATA_ERROR;
/* If first bit is 0, stop. Else second bit indicates whether /* If first bit is 0, stop. Else second bit indicates whether
to increment or decrement the value. Optimization: grab 2 to increment or decrement the value. Optimization: grab 2
bits and unget the second if the first was 0. */ bits and unget the second if the first was 0. */
k = get_bits(bd,2); k = get_bits(bd, 2);
if (k < 2) { if (k < 2) {
bd->inbufBitCount++; bd->inbufBitCount++;
break; 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 */ /* 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 */ /* 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 */ /* Find largest and smallest lengths in this group */
minLen=maxLen=length[0]; minLen = maxLen = length[0];
for (i = 1; i < symCount; i++) { for (i = 1; i < symCount; i++) {
if(length[i] > maxLen) maxLen = length[i]; if (length[i] > maxLen) maxLen = length[i];
else if(length[i] < minLen) minLen = length[i]; else if (length[i] < minLen) minLen = length[i];
} }
/* Calculate permute[], base[], and limit[] tables from length[]. /* 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. * length: each code with a value>limit[length] needs another bit.
*/ */
hufGroup=bd->groups+j; hufGroup = bd->groups + j;
hufGroup->minLen = minLen; hufGroup->minLen = minLen;
hufGroup->maxLen = maxLen; 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 and limit array pointers so we're not always wasting the first
entry. We do this again when using them (during symbol decoding).*/ entry. We do this again when using them (during symbol decoding).*/
base=hufGroup->base-1; base = hufGroup->base - 1;
limit=hufGroup->limit-1; limit = hufGroup->limit - 1;
/* Calculate permute[]. Concurently, initialize temp[] and limit[]. */ /* Calculate permute[]. Concurently, initialize temp[] and limit[]. */
pp=0; pp = 0;
for (i=minLen;i<=maxLen;i++) { for (i = minLen; i <= maxLen; i++) {
temp[i]=limit[i]=0; temp[i] = limit[i] = 0;
for (t=0;t<symCount;t++) for (t = 0; t < symCount; t++)
if(length[t]==i) hufGroup->permute[pp++] = t; if (length[t] == i)
hufGroup->permute[pp++] = t;
} }
/* Count symbols coded for at each bit length */ /* 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 /* Calculate limit[] (the largest symbol-coding value at each bit
* length, which is (previous limit<<1)+symbols at this level), and * length, which is (previous limit<<1)+symbols at this level), and
* base[] (number of symbols to ignore at each bit length, which is * base[] (number of symbols to ignore at each bit length, which is
* limit minus the cumulative count of symbols coded for already). */ * limit minus the cumulative count of symbols coded for already). */
pp=t=0; pp = t = 0;
for (i=minLen; i<maxLen; i++) { for (i = minLen; i < maxLen; i++) {
pp+=temp[i]; pp += temp[i];
/* We read the largest possible symbol size and then unget bits /* We read the largest possible symbol size and then unget bits
after determining how many we need, and those extra bits could 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 so here we set all the trailing to-be-ignored bits to 1 so they
don't affect the value>limit[length] comparison. */ don't affect the value>limit[length] comparison. */
limit[i]= (pp << (maxLen - i)) - 1; limit[i] = (pp << (maxLen - i)) - 1;
pp<<=1; pp <<= 1;
base[i+1]=pp-(t+=temp[i]); t += temp[i];
base[i+1] = pp - t;
} }
limit[maxLen+1] = INT_MAX; /* Sentinal value for reading next sym. */ limit[maxLen+1] = INT_MAX; /* Sentinal value for reading next sym. */
limit[maxLen]=pp+temp[maxLen]-1; limit[maxLen] = pp + temp[maxLen] - 1;
base[minLen]=0; base[minLen] = 0;
} }
/* We've finished reading and digesting the block header. Now read this /* 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 */ /* 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; byteCount[i] = 0;
mtfSymbol[i]=(unsigned char)i; mtfSymbol[i] = (unsigned char)i;
} }
/* Loop through compressed symbols. */ /* Loop through compressed symbols. */
runPos=dbufCount=selector=0; runPos = dbufCount = selector = 0;
for (;;) { for (;;) {
/* fetch next Huffman coding group from list. */ /* fetch next Huffman coding group from list. */
symCount=GROUP_SIZE-1; symCount = GROUP_SIZE - 1;
if(selector>=nSelectors) return RETVAL_DATA_ERROR; if (selector >= nSelectors) return RETVAL_DATA_ERROR;
hufGroup=bd->groups+selectors[selector++]; hufGroup = bd->groups + selectors[selector++];
base=hufGroup->base-1; base = hufGroup->base - 1;
limit=hufGroup->limit-1; limit = hufGroup->limit - 1;
continue_this_group: continue_this_group:
/* Read next Huffman-coded symbol. */ /* Read next Huffman-coded symbol. */
@ -353,33 +361,34 @@ continue_this_group:
valid compressed file. As a further optimization, we do the read valid compressed file. As a further optimization, we do the read
inline (falling back to a call to get_bits if the buffer runs inline (falling back to a call to get_bits if the buffer runs
dry). The following (up to got_huff_bits:) is equivalent to 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) { while (bd->inbufBitCount < hufGroup->maxLen) {
if(bd->inbufPos==bd->inbufCount) { if (bd->inbufPos == bd->inbufCount) {
j = get_bits(bd,hufGroup->maxLen); j = get_bits(bd, hufGroup->maxLen);
goto got_huff_bits; goto got_huff_bits;
} }
bd->inbufBits=(bd->inbufBits<<8)|bd->inbuf[bd->inbufPos++]; bd->inbufBits = (bd->inbufBits << 8) | bd->inbuf[bd->inbufPos++];
bd->inbufBitCount+=8; bd->inbufBitCount += 8;
}; };
bd->inbufBitCount-=hufGroup->maxLen; bd->inbufBitCount -= hufGroup->maxLen;
j = (bd->inbufBits>>bd->inbufBitCount)&((1<<hufGroup->maxLen)-1); 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 */ /* Figure how how many bits are in next symbol and unget extras */
i=hufGroup->minLen; i = hufGroup->minLen;
while (j>limit[i]) ++i; while (j > limit[i]) ++i;
bd->inbufBitCount += (hufGroup->maxLen - i); bd->inbufBitCount += (hufGroup->maxLen - i);
/* Huffman decode value to get nextSym (with bounds checking) */ /* Huffman decode value to get nextSym (with bounds checking) */
if ((i > hufGroup->maxLen) if (i > hufGroup->maxLen)
|| (((unsigned)(j=(j>>(hufGroup->maxLen-i))-base[i])) return RETVAL_DATA_ERROR;
>= MAX_SYMBOLS)) j = (j >> (hufGroup->maxLen - i)) - base[i];
if ((unsigned)j >= MAX_SYMBOLS)
return RETVAL_DATA_ERROR; return RETVAL_DATA_ERROR;
nextSym = hufGroup->permute[j]; nextSym = hufGroup->permute[j];
@ -388,11 +397,11 @@ got_huff_bits:
check if nextSym indicates a repeated run, and if so loop collecting check if nextSym indicates a repeated run, and if so loop collecting
how many times to repeat the last literal. */ 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 this is the start of a new run, zero out counter */
if(!runPos) { if (!runPos) {
runPos = 1; runPos = 1;
t = 0; t = 0;
} }
@ -406,7 +415,7 @@ got_huff_bits:
context). Thus space is saved. */ context). Thus space is saved. */
t += (runPos << nextSym); /* +runPos if RUNA; +2*runPos if RUNB */ 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; goto end_of_huffman_loop;
} }
@ -415,18 +424,18 @@ got_huff_bits:
copies to our buffer of decoded symbols (dbuf) now. (The last copies to our buffer of decoded symbols (dbuf) now. (The last
literal used is the one at the head of the mtfSymbol array.) */ literal used is the one at the head of the mtfSymbol array.) */
if(runPos) { if (runPos) {
runPos=0; runPos = 0;
if(dbufCount+t>=dbufSize) return RETVAL_DATA_ERROR; if (dbufCount + t >= dbufSize) return RETVAL_DATA_ERROR;
uc = symToByte[mtfSymbol[0]]; uc = symToByte[mtfSymbol[0]];
byteCount[uc] += t; byteCount[uc] += t;
while (t--) dbuf[dbufCount++]=uc; while (t--) dbuf[dbufCount++] = uc;
} }
/* Is this the terminating symbol? */ /* Is this the terminating symbol? */
if(nextSym>symTotal) break; if (nextSym > symTotal) break;
/* At this point, nextSym indicates a new literal character. Subtract /* At this point, nextSym indicates a new literal character. Subtract
one to get the position in the MTF array at which this literal is 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 as part of a run above. Therefore 1 unused mtf position minus
2 non-literal nextSym values equals -1.) */ 2 non-literal nextSym values equals -1.) */
if(dbufCount>=dbufSize) return RETVAL_DATA_ERROR; if (dbufCount >= dbufSize) return RETVAL_DATA_ERROR;
i = nextSym - 1; i = nextSym - 1;
uc = mtfSymbol[i]; uc = mtfSymbol[i];
@ -449,18 +458,18 @@ got_huff_bits:
mtfSymbol[i] = mtfSymbol[i-1]; mtfSymbol[i] = mtfSymbol[i-1];
} while (--i); } while (--i);
mtfSymbol[0] = uc; mtfSymbol[0] = uc;
uc=symToByte[uc]; uc = symToByte[uc];
/* We have our literal byte. Save it into dbuf. */ /* We have our literal byte. Save it into dbuf. */
byteCount[uc]++; byteCount[uc]++;
dbuf[dbufCount++] = (unsigned int)uc; dbuf[dbufCount++] = (unsigned)uc;
/* Skip group initialization if we're not done with this group. Done /* Skip group initialization if we're not done with this group. Done
* this way to avoid compiler warning. */ * this way to avoid compiler warning. */
end_of_huffman_loop: end_of_huffman_loop:
if(symCount--) goto continue_this_group; if (symCount--) goto continue_this_group;
} }
/* At this point, we've read all the Huffman-coded symbols (and repeated /* 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. */ /* Turn byteCount into cumulative occurrence counts of 0 to n-1. */
j=0; j = 0;
for (i=0;i<256;i++) { for (i = 0; i < 256; i++) {
k=j+byteCount[i]; k = j + byteCount[i];
byteCount[i] = j; byteCount[i] = j;
j=k; j = k;
} }
/* Figure out what order dbuf would be in if we sorted it. */ /* Figure out what order dbuf would be in if we sorted it. */
for (i=0;i<dbufCount;i++) { for (i = 0; i < dbufCount; i++) {
uc=(unsigned char)(dbuf[i] & 0xff); uc = (unsigned char)(dbuf[i] & 0xff);
dbuf[byteCount[uc]] |= (i << 8); dbuf[byteCount[uc]] |= (i << 8);
byteCount[uc]++; byteCount[uc]++;
} }
@ -491,14 +500,14 @@ end_of_huffman_loop:
doesn't get output, and if the first three characters are identical doesn't get output, and if the first three characters are identical
it doesn't qualify as a run (hence writeRunCountdown=5). */ it doesn't qualify as a run (hence writeRunCountdown=5). */
if(dbufCount) { if (dbufCount) {
if(origPtr>=dbufCount) return RETVAL_DATA_ERROR; if (origPtr >= dbufCount) return RETVAL_DATA_ERROR;
bd->writePos=dbuf[origPtr]; bd->writePos = dbuf[origPtr];
bd->writeCurrent=(unsigned char)(bd->writePos&0xff); bd->writeCurrent = (unsigned char)(bd->writePos & 0xff);
bd->writePos>>=8; bd->writePos >>= 8;
bd->writeRunCountdown=5; bd->writeRunCountdown = 5;
} }
bd->writeCount=dbufCount; bd->writeCount = dbufCount;
return RETVAL_OK; return RETVAL_OK;
} }
@ -512,16 +521,16 @@ end_of_huffman_loop:
static int read_bunzip(bunzip_data *bd, char *outbuf, int len) static int read_bunzip(bunzip_data *bd, char *outbuf, int len)
{ {
const unsigned int *dbuf; const unsigned *dbuf;
int pos,current,previous,gotcount; int pos, current, previous, gotcount;
/* If last read was short due to end of file, return last block now */ /* 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; gotcount = 0;
dbuf=bd->dbuf; dbuf = bd->dbuf;
pos=bd->writePos; pos = bd->writePos;
current=bd->writeCurrent; current = bd->writeCurrent;
/* We will always have pending decoded data to write into the output /* 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 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 the output buffer is full, snapshot state and return */
if(gotcount >= len) { if (gotcount >= len) {
bd->writePos=pos; bd->writePos =pos;
bd->writeCurrent=current; bd->writeCurrent = current;
bd->writeCopies++; bd->writeCopies++;
return len; 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 */ /* Write next byte into output buffer, updating CRC */
outbuf[gotcount++] = current; outbuf[gotcount++] = current;
bd->writeCRC=(((bd->writeCRC)<<8) bd->writeCRC = (bd->writeCRC << 8)
^bd->crc32Table[((bd->writeCRC)>>24)^current]); ^ bd->crc32Table[(bd->writeCRC >> 24) ^ current];
/* Loop now if we're outputting multiple copies of this byte */ /* 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; --bd->writeCopies;
continue; continue;
} }
decode_next_byte: decode_next_byte:
if (!bd->writeCount--) break; if (!bd->writeCount--) break;
/* Follow sequence vector to undo Burrows-Wheeler transform */ /* Follow sequence vector to undo Burrows-Wheeler transform */
previous=current; previous = current;
pos=dbuf[pos]; pos = dbuf[pos];
current=pos&0xff; current = pos & 0xff;
pos>>=8; pos >>= 8;
/* After 3 consecutive copies of the same byte, the 4th is a repeat /* After 3 consecutive copies of the same byte, the 4th is a repeat
count. We count down from 4 instead count. We count down from 4 instead
* of counting up because testing for non-zero is faster */ * of counting up because testing for non-zero is faster */
if(--bd->writeRunCountdown) { if (--bd->writeRunCountdown) {
if(current!=previous) bd->writeRunCountdown=4; if (current != previous)
bd->writeRunCountdown = 4;
} else { } else {
/* We have a repeated run, this byte indicates the count */ /* We have a repeated run, this byte indicates the count */
bd->writeCopies=current; bd->writeCopies = current;
current=previous; current = previous;
bd->writeRunCountdown=5; bd->writeRunCountdown = 5;
/* Sometimes there are just 3 bytes (run length 0) */ /* 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 */ /* Subtract the 1 copy we'd output anyway to get extras */
@ -592,13 +602,13 @@ decode_next_byte:
/* Decompression of this block completed successfully */ /* Decompression of this block completed successfully */
bd->writeCRC=~bd->writeCRC; bd->writeCRC = ~bd->writeCRC;
bd->totalCRC=((bd->totalCRC<<1) | (bd->totalCRC>>31)) ^ 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 this block had a CRC error, force file level CRC error. */
if(bd->writeCRC!=bd->headerCRC) { if (bd->writeCRC != bd->headerCRC) {
bd->totalCRC=bd->headerCRC+1; bd->totalCRC = bd->headerCRC+1;
return RETVAL_LAST_BLOCK; return RETVAL_LAST_BLOCK;
} }
} }
@ -606,14 +616,14 @@ decode_next_byte:
/* Refill the intermediate buffer by Huffman-decoding next block of input */ /* Refill the intermediate buffer by Huffman-decoding next block of input */
/* (previous is just a convenient unused temp variable here) */ /* (previous is just a convenient unused temp variable here) */
previous=get_next_block(bd); previous = get_next_block(bd);
if(previous) { if (previous) {
bd->writeCount=previous; bd->writeCount = previous;
return (previous!=RETVAL_LAST_BLOCK) ? previous : gotcount; return (previous != RETVAL_LAST_BLOCK) ? previous : gotcount;
} }
bd->writeCRC=~0; bd->writeCRC = ~0;
pos=bd->writePos; pos = bd->writePos;
current=bd->writeCurrent; current = bd->writeCurrent;
goto decode_next_byte; goto decode_next_byte;
} }
@ -625,25 +635,28 @@ static int start_bunzip(bunzip_data **bdp, int in_fd, unsigned char *inbuf,
int len) int len)
{ {
bunzip_data *bd; bunzip_data *bd;
unsigned int i; unsigned i;
const unsigned int BZh0=(((unsigned int)'B')<<24)+(((unsigned int)'Z')<<16) enum {
+(((unsigned int)'h')<<8)+(unsigned int)'0'; BZh0 = ('B' << 24) + ('Z' << 16) + ('h' << 8) + '0'
};
/* Figure out how much data to allocate */ /* Figure out how much data to allocate */
i=sizeof(bunzip_data); i = sizeof(bunzip_data);
if(in_fd!=-1) i+=IOBUF_SIZE; if (in_fd != -1) i += IOBUF_SIZE;
/* Allocate bunzip_data. Most fields initialize to zero. */ /* Allocate bunzip_data. Most fields initialize to zero. */
bd=*bdp=xzalloc(i); bd = *bdp = xzalloc(i);
/* Setup input buffer */ /* Setup input buffer */
if(-1==(bd->in_fd=in_fd)) { bd->in_fd = in_fd;
bd->inbuf=inbuf; if (-1 == in_fd) {
bd->inbufCount=len; bd->inbuf = inbuf;
} else bd->inbuf=(unsigned char *)(bd+1); bd->inbufCount = len;
} else
bd->inbuf = (unsigned char *)(bd + 1);
/* Init the CRC32 table (big endian) */ /* 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 */ /* Setup for I/O error handling via longjmp */
i=setjmp(bd->jmpbuf); i = setjmp(bd->jmpbuf);
if(i) return i; if (i) return i;
/* Ensure that file starts with "BZh['1'-'9']." */ /* Ensure that file starts with "BZh['1'-'9']." */
i = get_bits(bd,32); i = get_bits(bd, 32);
if (((unsigned int)(i-BZh0-1)) >= 9) return RETVAL_NOT_BZIP_DATA; if (((unsigned)(i - BZh0 - 1)) >= 9) return RETVAL_NOT_BZIP_DATA;
/* Fourth byte (ascii '1'-'9'), indicates block size in units of 100k of /* Fourth byte (ascii '1'-'9'), indicates block size in units of 100k of
uncompressed data. Allocate intermediate buffer for block. */ 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; return RETVAL_OK;
} }
@ -679,13 +692,14 @@ uncompressStream(int src_fd, int dst_fd)
bunzip_data *bd; bunzip_data *bd;
int i; int i;
outbuf=xmalloc(IOBUF_SIZE); outbuf = xmalloc(IOBUF_SIZE);
i=start_bunzip(&bd,src_fd,0,0); i = start_bunzip(&bd, src_fd, 0, 0);
if(!i) { if (!i) {
for (;;) { for (;;) {
if((i=read_bunzip(bd,outbuf,IOBUF_SIZE)) <= 0) break; i = read_bunzip(bd, outbuf, IOBUF_SIZE);
if(i!=write(dst_fd,outbuf,i)) { if (i <= 0) break;
i=RETVAL_UNEXPECTED_OUTPUT_EOF; if (i != safe_write(dst_fd, outbuf, i)) {
i = RETVAL_UNEXPECTED_OUTPUT_EOF;
break; break;
} }
USE_DESKTOP(total_written += i;) USE_DESKTOP(total_written += i;)
@ -694,13 +708,13 @@ uncompressStream(int src_fd, int dst_fd)
/* Check CRC and release memory */ /* Check CRC and release memory */
if(i==RETVAL_LAST_BLOCK) { if (i == RETVAL_LAST_BLOCK) {
if (bd->headerCRC!=bd->totalCRC) { if (bd->headerCRC != bd->totalCRC) {
bb_error_msg("data integrity error when decompressing"); bb_error_msg("data integrity error when decompressing");
} else { } 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"); bb_error_msg("compressed file ends unexpectedly");
} else { } else {
bb_error_msg("decompression failed"); bb_error_msg("decompression failed");
@ -714,18 +728,22 @@ uncompressStream(int src_fd, int dst_fd)
#ifdef TESTING #ifdef TESTING
static char * const bunzip_errors[]={NULL,"Bad file checksum","Not bzip data", static char *const bunzip_errors[] = {
"Unexpected input EOF","Unexpected output EOF","Data error", NULL, "Bad file checksum", "Not bzip data",
"Out of memory","Obsolete (pre 0.9.5) bzip format not supported."}; "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 */ /* Dumb little test thing, decompress stdin to stdout */
int main(int argc, char **argv) int main(int argc, char **argv)
{ {
int i=uncompressStream(0,1); int i = uncompressStream(0, 1);
char c; char c;
if(i<0) fprintf(stderr,"%s\n", bunzip_errors[-i]); if (i < 0)
else if(read(0,&c,1)) fprintf(stderr,"Trailing garbage ignored\n"); fprintf(stderr,"%s\n", bunzip_errors[-i]);
else if (read(0, &c, 1))
fprintf(stderr,"Trailing garbage ignored\n");
return -i; return -i;
} }
#endif #endif