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Linux/lib/decompress_bunzip2.c

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Diff markup

Differences between /lib/decompress_bunzip2.c (Architecture alpha) and /lib/decompress_bunzip2.c (Architecture ppc)


  1 /*      Small bzip2 deflate implementation, by      1 /*      Small bzip2 deflate implementation, by Rob Landley (rob@landley.net).
  2                                                     2 
  3         Based on bzip2 decompression code by J      3         Based on bzip2 decompression code by Julian R Seward (jseward@acm.org),
  4         which also acknowledges contributions       4         which also acknowledges contributions by Mike Burrows, David Wheeler,
  5         Peter Fenwick, Alistair Moffat, Radfor      5         Peter Fenwick, Alistair Moffat, Radford Neal, Ian H. Witten,
  6         Robert Sedgewick, and Jon L. Bentley.       6         Robert Sedgewick, and Jon L. Bentley.
  7                                                     7 
  8         This code is licensed under the LGPLv2      8         This code is licensed under the LGPLv2:
  9                 LGPL (http://www.gnu.org/copyl      9                 LGPL (http://www.gnu.org/copyleft/lgpl.html
 10 */                                                 10 */
 11                                                    11 
 12 /*                                                 12 /*
 13         Size and speed optimizations by Manuel     13         Size and speed optimizations by Manuel Novoa III  (mjn3@codepoet.org).
 14                                                    14 
 15         More efficient reading of Huffman code     15         More efficient reading of Huffman codes, a streamlined read_bunzip()
 16         function, and various other tweaks.  I     16         function, and various other tweaks.  In (limited) tests, approximately
 17         20% faster than bzcat on x86 and about     17         20% faster than bzcat on x86 and about 10% faster on arm.
 18                                                    18 
 19         Note that about 2/3 of the time is spe     19         Note that about 2/3 of the time is spent in read_unzip() reversing
 20         the Burrows-Wheeler transformation.  M     20         the Burrows-Wheeler transformation.  Much of that time is delay
 21         resulting from cache misses.               21         resulting from cache misses.
 22                                                    22 
 23         I would ask that anyone benefiting fro     23         I would ask that anyone benefiting from this work, especially those
 24         using it in commercial products, consi     24         using it in commercial products, consider making a donation to my local
 25         non-profit hospice organization in the     25         non-profit hospice organization in the name of the woman I loved, who
 26         passed away Feb. 12, 2003.                 26         passed away Feb. 12, 2003.
 27                                                    27 
 28                 In memory of Toni W. Hagan         28                 In memory of Toni W. Hagan
 29                                                    29 
 30                 Hospice of Acadiana, Inc.          30                 Hospice of Acadiana, Inc.
 31                 2600 Johnston St., Suite 200       31                 2600 Johnston St., Suite 200
 32                 Lafayette, LA 70503-3240           32                 Lafayette, LA 70503-3240
 33                                                    33 
 34                 Phone (337) 232-1234 or 1-800-     34                 Phone (337) 232-1234 or 1-800-738-2226
 35                 Fax   (337) 232-1297               35                 Fax   (337) 232-1297
 36                                                    36 
 37                 https://www.hospiceacadiana.co     37                 https://www.hospiceacadiana.com/
 38                                                    38 
 39         Manuel                                     39         Manuel
 40  */                                                40  */
 41                                                    41 
 42 /*                                                 42 /*
 43         Made it fit for running in Linux Kerne     43         Made it fit for running in Linux Kernel by Alain Knaff (alain@knaff.lu)
 44 */                                                 44 */
 45                                                    45 
 46                                                    46 
 47 #ifdef STATIC                                      47 #ifdef STATIC
 48 #define PREBOOT                                    48 #define PREBOOT
 49 #else                                              49 #else
 50 #include <linux/decompress/bunzip2.h>              50 #include <linux/decompress/bunzip2.h>
 51 #endif /* STATIC */                                51 #endif /* STATIC */
 52                                                    52 
 53 #include <linux/decompress/mm.h>                   53 #include <linux/decompress/mm.h>
 54 #include <linux/crc32poly.h>                       54 #include <linux/crc32poly.h>
 55                                                    55 
 56 #ifndef INT_MAX                                    56 #ifndef INT_MAX
 57 #define INT_MAX 0x7fffffff                         57 #define INT_MAX 0x7fffffff
 58 #endif                                             58 #endif
 59                                                    59 
 60 /* Constants for Huffman coding */                 60 /* Constants for Huffman coding */
 61 #define MAX_GROUPS              6                  61 #define MAX_GROUPS              6
 62 #define GROUP_SIZE              50      /* 64      62 #define GROUP_SIZE              50      /* 64 would have been more efficient */
 63 #define MAX_HUFCODE_BITS        20      /* Lon     63 #define MAX_HUFCODE_BITS        20      /* Longest Huffman code allowed */
 64 #define MAX_SYMBOLS             258     /* 256     64 #define MAX_SYMBOLS             258     /* 256 literals + RUNA + RUNB */
 65 #define SYMBOL_RUNA             0                  65 #define SYMBOL_RUNA             0
 66 #define SYMBOL_RUNB             1                  66 #define SYMBOL_RUNB             1
 67                                                    67 
 68 /* Status return values */                         68 /* Status return values */
 69 #define RETVAL_OK                       0          69 #define RETVAL_OK                       0
 70 #define RETVAL_LAST_BLOCK               (-1)       70 #define RETVAL_LAST_BLOCK               (-1)
 71 #define RETVAL_NOT_BZIP_DATA            (-2)       71 #define RETVAL_NOT_BZIP_DATA            (-2)
 72 #define RETVAL_UNEXPECTED_INPUT_EOF     (-3)       72 #define RETVAL_UNEXPECTED_INPUT_EOF     (-3)
 73 #define RETVAL_UNEXPECTED_OUTPUT_EOF    (-4)       73 #define RETVAL_UNEXPECTED_OUTPUT_EOF    (-4)
 74 #define RETVAL_DATA_ERROR               (-5)       74 #define RETVAL_DATA_ERROR               (-5)
 75 #define RETVAL_OUT_OF_MEMORY            (-6)       75 #define RETVAL_OUT_OF_MEMORY            (-6)
 76 #define RETVAL_OBSOLETE_INPUT           (-7)       76 #define RETVAL_OBSOLETE_INPUT           (-7)
 77                                                    77 
 78 /* Other housekeeping constants */                 78 /* Other housekeeping constants */
 79 #define BZIP2_IOBUF_SIZE                4096       79 #define BZIP2_IOBUF_SIZE                4096
 80                                                    80 
 81 /* This is what we know about each Huffman cod     81 /* This is what we know about each Huffman coding group */
 82 struct group_data {                                82 struct group_data {
 83         /* We have an extra slot at the end of     83         /* We have an extra slot at the end of limit[] for a sentinel value. */
 84         int limit[MAX_HUFCODE_BITS+1];             84         int limit[MAX_HUFCODE_BITS+1];
 85         int base[MAX_HUFCODE_BITS];                85         int base[MAX_HUFCODE_BITS];
 86         int permute[MAX_SYMBOLS];                  86         int permute[MAX_SYMBOLS];
 87         int minLen, maxLen;                        87         int minLen, maxLen;
 88 };                                                 88 };
 89                                                    89 
 90 /* Structure holding all the housekeeping data     90 /* Structure holding all the housekeeping data, including IO buffers and
 91    memory that persists between calls to bunzi     91    memory that persists between calls to bunzip */
 92 struct bunzip_data {                               92 struct bunzip_data {
 93         /* State for interrupting output loop      93         /* State for interrupting output loop */
 94         int writeCopies, writePos, writeRunCou     94         int writeCopies, writePos, writeRunCountdown, writeCount, writeCurrent;
 95         /* I/O tracking data (file handles, bu     95         /* I/O tracking data (file handles, buffers, positions, etc.) */
 96         long (*fill)(void*, unsigned long);        96         long (*fill)(void*, unsigned long);
 97         long inbufCount, inbufPos /*, outbufPo     97         long inbufCount, inbufPos /*, outbufPos*/;
 98         unsigned char *inbuf /*,*outbuf*/;         98         unsigned char *inbuf /*,*outbuf*/;
 99         unsigned int inbufBitCount, inbufBits;     99         unsigned int inbufBitCount, inbufBits;
100         /* The CRC values stored in the block     100         /* The CRC values stored in the block header and calculated from the
101         data */                                   101         data */
102         unsigned int crc32Table[256], headerCR    102         unsigned int crc32Table[256], headerCRC, totalCRC, writeCRC;
103         /* Intermediate buffer and its size (i    103         /* Intermediate buffer and its size (in bytes) */
104         unsigned int *dbuf, dbufSize;             104         unsigned int *dbuf, dbufSize;
105         /* These things are a bit too big to g    105         /* These things are a bit too big to go on the stack */
106         unsigned char selectors[32768];           106         unsigned char selectors[32768];         /* nSelectors = 15 bits */
107         struct group_data groups[MAX_GROUPS];     107         struct group_data groups[MAX_GROUPS];   /* Huffman coding tables */
108         int io_error;                   /* non    108         int io_error;                   /* non-zero if we have IO error */
109         int byteCount[256];                       109         int byteCount[256];
110         unsigned char symToByte[256], mtfSymbo    110         unsigned char symToByte[256], mtfSymbol[256];
111 };                                                111 };
112                                                   112 
113                                                   113 
114 /* Return the next nnn bits of input.  All rea    114 /* Return the next nnn bits of input.  All reads from the compressed input
115    are done through this function.  All reads     115    are done through this function.  All reads are big endian */
116 static unsigned int INIT get_bits(struct bunzi    116 static unsigned int INIT get_bits(struct bunzip_data *bd, char bits_wanted)
117 {                                                 117 {
118         unsigned int bits = 0;                    118         unsigned int bits = 0;
119                                                   119 
120         /* If we need to get more data from th    120         /* If we need to get more data from the byte buffer, do so.
121            (Loop getting one byte at a time to    121            (Loop getting one byte at a time to enforce endianness and avoid
122            unaligned access.) */                  122            unaligned access.) */
123         while (bd->inbufBitCount < bits_wanted    123         while (bd->inbufBitCount < bits_wanted) {
124                 /* If we need to read more dat    124                 /* If we need to read more data from file into byte buffer, do
125                    so */                          125                    so */
126                 if (bd->inbufPos == bd->inbufC    126                 if (bd->inbufPos == bd->inbufCount) {
127                         if (bd->io_error)         127                         if (bd->io_error)
128                                 return 0;         128                                 return 0;
129                         bd->inbufCount = bd->f    129                         bd->inbufCount = bd->fill(bd->inbuf, BZIP2_IOBUF_SIZE);
130                         if (bd->inbufCount <=     130                         if (bd->inbufCount <= 0) {
131                                 bd->io_error =    131                                 bd->io_error = RETVAL_UNEXPECTED_INPUT_EOF;
132                                 return 0;         132                                 return 0;
133                         }                         133                         }
134                         bd->inbufPos = 0;         134                         bd->inbufPos = 0;
135                 }                                 135                 }
136                 /* Avoid 32-bit overflow (dump    136                 /* Avoid 32-bit overflow (dump bit buffer to top of output) */
137                 if (bd->inbufBitCount >= 24) {    137                 if (bd->inbufBitCount >= 24) {
138                         bits = bd->inbufBits&(    138                         bits = bd->inbufBits&((1 << bd->inbufBitCount)-1);
139                         bits_wanted -= bd->inb    139                         bits_wanted -= bd->inbufBitCount;
140                         bits <<= bits_wanted;     140                         bits <<= bits_wanted;
141                         bd->inbufBitCount = 0;    141                         bd->inbufBitCount = 0;
142                 }                                 142                 }
143                 /* Grab next 8 bits of input f    143                 /* Grab next 8 bits of input from buffer. */
144                 bd->inbufBits = (bd->inbufBits    144                 bd->inbufBits = (bd->inbufBits << 8)|bd->inbuf[bd->inbufPos++];
145                 bd->inbufBitCount += 8;           145                 bd->inbufBitCount += 8;
146         }                                         146         }
147         /* Calculate result */                    147         /* Calculate result */
148         bd->inbufBitCount -= bits_wanted;         148         bd->inbufBitCount -= bits_wanted;
149         bits |= (bd->inbufBits >> bd->inbufBit    149         bits |= (bd->inbufBits >> bd->inbufBitCount)&((1 << bits_wanted)-1);
150                                                   150 
151         return bits;                              151         return bits;
152 }                                                 152 }
153                                                   153 
154 /* Unpacks the next block and sets up for the     154 /* Unpacks the next block and sets up for the inverse burrows-wheeler step. */
155                                                   155 
156 static int INIT get_next_block(struct bunzip_d    156 static int INIT get_next_block(struct bunzip_data *bd)
157 {                                                 157 {
158         struct group_data *hufGroup = NULL;       158         struct group_data *hufGroup = NULL;
159         int *base = NULL;                         159         int *base = NULL;
160         int *limit = NULL;                        160         int *limit = NULL;
161         int dbufCount, nextSym, dbufSize, grou    161         int dbufCount, nextSym, dbufSize, groupCount, selector,
162                 i, j, k, t, runPos, symCount,     162                 i, j, k, t, runPos, symCount, symTotal, nSelectors, *byteCount;
163         unsigned char uc, *symToByte, *mtfSymb    163         unsigned char uc, *symToByte, *mtfSymbol, *selectors;
164         unsigned int *dbuf, origPtr;              164         unsigned int *dbuf, origPtr;
165                                                   165 
166         dbuf = bd->dbuf;                          166         dbuf = bd->dbuf;
167         dbufSize = bd->dbufSize;                  167         dbufSize = bd->dbufSize;
168         selectors = bd->selectors;                168         selectors = bd->selectors;
169         byteCount = bd->byteCount;                169         byteCount = bd->byteCount;
170         symToByte = bd->symToByte;                170         symToByte = bd->symToByte;
171         mtfSymbol = bd->mtfSymbol;                171         mtfSymbol = bd->mtfSymbol;
172                                                   172 
173         /* Read in header signature and CRC, t    173         /* Read in header signature and CRC, then validate signature.
174            (last block signature means CRC is     174            (last block signature means CRC is for whole file, return now) */
175         i = get_bits(bd, 24);                     175         i = get_bits(bd, 24);
176         j = get_bits(bd, 24);                     176         j = get_bits(bd, 24);
177         bd->headerCRC = get_bits(bd, 32);         177         bd->headerCRC = get_bits(bd, 32);
178         if ((i == 0x177245) && (j == 0x385090)    178         if ((i == 0x177245) && (j == 0x385090))
179                 return RETVAL_LAST_BLOCK;         179                 return RETVAL_LAST_BLOCK;
180         if ((i != 0x314159) || (j != 0x265359)    180         if ((i != 0x314159) || (j != 0x265359))
181                 return RETVAL_NOT_BZIP_DATA;      181                 return RETVAL_NOT_BZIP_DATA;
182         /* We can add support for blockRandomi    182         /* We can add support for blockRandomised if anybody complains.
183            There was some code for this in bus    183            There was some code for this in busybox 1.0.0-pre3, but nobody ever
184            noticed that it didn't actually wor    184            noticed that it didn't actually work. */
185         if (get_bits(bd, 1))                      185         if (get_bits(bd, 1))
186                 return RETVAL_OBSOLETE_INPUT;     186                 return RETVAL_OBSOLETE_INPUT;
187         origPtr = get_bits(bd, 24);               187         origPtr = get_bits(bd, 24);
188         if (origPtr >= dbufSize)                  188         if (origPtr >= dbufSize)
189                 return RETVAL_DATA_ERROR;         189                 return RETVAL_DATA_ERROR;
190         /* mapping table: if some byte values     190         /* mapping table: if some byte values are never used (encoding things
191            like ascii text), the compression c    191            like ascii text), the compression code removes the gaps to have fewer
192            symbols to deal with, and writes a     192            symbols to deal with, and writes a sparse bitfield indicating which
193            values were present.  We make a tra    193            values were present.  We make a translation table to convert the
194            symbols back to the corresponding b    194            symbols back to the corresponding bytes. */
195         t = get_bits(bd, 16);                     195         t = get_bits(bd, 16);
196         symTotal = 0;                             196         symTotal = 0;
197         for (i = 0; i < 16; i++) {                197         for (i = 0; i < 16; i++) {
198                 if (t&(1 << (15-i))) {            198                 if (t&(1 << (15-i))) {
199                         k = get_bits(bd, 16);     199                         k = get_bits(bd, 16);
200                         for (j = 0; j < 16; j+    200                         for (j = 0; j < 16; j++)
201                                 if (k&(1 << (1    201                                 if (k&(1 << (15-j)))
202                                         symToB    202                                         symToByte[symTotal++] = (16*i)+j;
203                 }                                 203                 }
204         }                                         204         }
205         /* How many different Huffman coding g    205         /* How many different Huffman coding groups does this block use? */
206         groupCount = get_bits(bd, 3);             206         groupCount = get_bits(bd, 3);
207         if (groupCount < 2 || groupCount > MAX    207         if (groupCount < 2 || groupCount > MAX_GROUPS)
208                 return RETVAL_DATA_ERROR;         208                 return RETVAL_DATA_ERROR;
209         /* nSelectors: Every GROUP_SIZE many s    209         /* nSelectors: Every GROUP_SIZE many symbols we select a new
210            Huffman coding group.  Read in the     210            Huffman coding group.  Read in the group selector list,
211            which is stored as MTF encoded bit     211            which is stored as MTF encoded bit runs.  (MTF = Move To
212            Front, as each value is used it's m    212            Front, as each value is used it's moved to the start of the
213            list.) */                              213            list.) */
214         nSelectors = get_bits(bd, 15);            214         nSelectors = get_bits(bd, 15);
215         if (!nSelectors)                          215         if (!nSelectors)
216                 return RETVAL_DATA_ERROR;         216                 return RETVAL_DATA_ERROR;
217         for (i = 0; i < groupCount; i++)          217         for (i = 0; i < groupCount; i++)
218                 mtfSymbol[i] = i;                 218                 mtfSymbol[i] = i;
219         for (i = 0; i < nSelectors; i++) {        219         for (i = 0; i < nSelectors; i++) {
220                 /* Get next value */              220                 /* Get next value */
221                 for (j = 0; get_bits(bd, 1); j    221                 for (j = 0; get_bits(bd, 1); j++)
222                         if (j >= groupCount)      222                         if (j >= groupCount)
223                                 return RETVAL_    223                                 return RETVAL_DATA_ERROR;
224                 /* Decode MTF to get the next     224                 /* Decode MTF to get the next selector */
225                 uc = mtfSymbol[j];                225                 uc = mtfSymbol[j];
226                 for (; j; j--)                    226                 for (; j; j--)
227                         mtfSymbol[j] = mtfSymb    227                         mtfSymbol[j] = mtfSymbol[j-1];
228                 mtfSymbol[0] = selectors[i] =     228                 mtfSymbol[0] = selectors[i] = uc;
229         }                                         229         }
230         /* Read the Huffman coding tables for     230         /* Read the Huffman coding tables for each group, which code
231            for symTotal literal symbols, plus     231            for symTotal literal symbols, plus two run symbols (RUNA,
232            RUNB) */                               232            RUNB) */
233         symCount = symTotal+2;                    233         symCount = symTotal+2;
234         for (j = 0; j < groupCount; j++) {        234         for (j = 0; j < groupCount; j++) {
235                 unsigned char length[MAX_SYMBO    235                 unsigned char length[MAX_SYMBOLS];
236                 unsigned short temp[MAX_HUFCOD    236                 unsigned short temp[MAX_HUFCODE_BITS+1];
237                 int     minLen, maxLen, pp;       237                 int     minLen, maxLen, pp;
238                 /* Read Huffman code lengths f    238                 /* Read Huffman code lengths for each symbol.  They're
239                    stored in a way similar to     239                    stored in a way similar to mtf; record a starting
240                    value for the first symbol,    240                    value for the first symbol, and an offset from the
241                    previous value for everys s    241                    previous value for everys symbol after that.
242                    (Subtracting 1 before the l    242                    (Subtracting 1 before the loop and then adding it
243                    back at the end is an optim    243                    back at the end is an optimization that makes the
244                    test inside the loop simple    244                    test inside the loop simpler: symbol length 0
245                    becomes negative, so an uns    245                    becomes negative, so an unsigned inequality catches
246                    it.) */                        246                    it.) */
247                 t = get_bits(bd, 5)-1;            247                 t = get_bits(bd, 5)-1;
248                 for (i = 0; i < symCount; i++)    248                 for (i = 0; i < symCount; i++) {
249                         for (;;) {                249                         for (;;) {
250                                 if (((unsigned    250                                 if (((unsigned)t) > (MAX_HUFCODE_BITS-1))
251                                         return    251                                         return RETVAL_DATA_ERROR;
252                                                   252 
253                                 /* If first bi    253                                 /* If first bit is 0, stop.  Else
254                                    second bit     254                                    second bit indicates whether to
255                                    increment o    255                                    increment or decrement the value.
256                                    Optimizatio    256                                    Optimization: grab 2 bits and unget
257                                    the second     257                                    the second if the first was 0. */
258                                                   258 
259                                 k = get_bits(b    259                                 k = get_bits(bd, 2);
260                                 if (k < 2) {      260                                 if (k < 2) {
261                                         bd->in    261                                         bd->inbufBitCount++;
262                                         break;    262                                         break;
263                                 }                 263                                 }
264                                 /* Add one if     264                                 /* Add one if second bit 1, else
265                                  * subtract 1.    265                                  * subtract 1.  Avoids if/else */
266                                 t += (((k+1)&2    266                                 t += (((k+1)&2)-1);
267                         }                         267                         }
268                         /* Correct for the ini    268                         /* Correct for the initial -1, to get the
269                          * final symbol length    269                          * final symbol length */
270                         length[i] = t+1;          270                         length[i] = t+1;
271                 }                                 271                 }
272                 /* Find largest and smallest l    272                 /* Find largest and smallest lengths in this group */
273                 minLen = maxLen = length[0];      273                 minLen = maxLen = length[0];
274                                                   274 
275                 for (i = 1; i < symCount; i++)    275                 for (i = 1; i < symCount; i++) {
276                         if (length[i] > maxLen    276                         if (length[i] > maxLen)
277                                 maxLen = lengt    277                                 maxLen = length[i];
278                         else if (length[i] < m    278                         else if (length[i] < minLen)
279                                 minLen = lengt    279                                 minLen = length[i];
280                 }                                 280                 }
281                                                   281 
282                 /* Calculate permute[], base[]    282                 /* Calculate permute[], base[], and limit[] tables from
283                  * length[].                      283                  * length[].
284                  *                                284                  *
285                  * permute[] is the lookup tab    285                  * permute[] is the lookup table for converting
286                  * Huffman coded symbols into     286                  * Huffman coded symbols into decoded symbols.  base[]
287                  * is the amount to subtract f    287                  * is the amount to subtract from the value of a
288                  * Huffman symbol of a given l    288                  * Huffman symbol of a given length when using
289                  * permute[].                     289                  * permute[].
290                  *                                290                  *
291                  * limit[] indicates the large    291                  * limit[] indicates the largest numerical value a
292                  * symbol with a given number     292                  * symbol with a given number of bits can have.  This
293                  * is how the Huffman codes ca    293                  * is how the Huffman codes can vary in length: each
294                  * code with a value > limit[l    294                  * code with a value > limit[length] needs another
295                  * bit.                           295                  * bit.
296                  */                               296                  */
297                 hufGroup = bd->groups+j;          297                 hufGroup = bd->groups+j;
298                 hufGroup->minLen = minLen;        298                 hufGroup->minLen = minLen;
299                 hufGroup->maxLen = maxLen;        299                 hufGroup->maxLen = maxLen;
300                 /* Note that minLen can't be s    300                 /* Note that minLen can't be smaller than 1, so we
301                    adjust the base and limit a    301                    adjust the base and limit array pointers so we're
302                    not always wasting the firs    302                    not always wasting the first entry.  We do this
303                    again when using them (duri    303                    again when using them (during symbol decoding).*/
304                 base = hufGroup->base-1;          304                 base = hufGroup->base-1;
305                 limit = hufGroup->limit-1;        305                 limit = hufGroup->limit-1;
306                 /* Calculate permute[].  Concu    306                 /* Calculate permute[].  Concurrently, initialize
307                  * temp[] and limit[]. */         307                  * temp[] and limit[]. */
308                 pp = 0;                           308                 pp = 0;
309                 for (i = minLen; i <= maxLen;     309                 for (i = minLen; i <= maxLen; i++) {
310                         temp[i] = limit[i] = 0    310                         temp[i] = limit[i] = 0;
311                         for (t = 0; t < symCou    311                         for (t = 0; t < symCount; t++)
312                                 if (length[t]     312                                 if (length[t] == i)
313                                         hufGro    313                                         hufGroup->permute[pp++] = t;
314                 }                                 314                 }
315                 /* Count symbols coded for at     315                 /* Count symbols coded for at each bit length */
316                 for (i = 0; i < symCount; i++)    316                 for (i = 0; i < symCount; i++)
317                         temp[length[i]]++;        317                         temp[length[i]]++;
318                 /* Calculate limit[] (the larg    318                 /* Calculate limit[] (the largest symbol-coding value
319                  *at each bit length, which is    319                  *at each bit length, which is (previous limit <<
320                  *1)+symbols at this level), a    320                  *1)+symbols at this level), and base[] (number of
321                  *symbols to ignore at each bi    321                  *symbols to ignore at each bit length, which is limit
322                  *minus the cumulative count o    322                  *minus the cumulative count of symbols coded for
323                  *already). */                    323                  *already). */
324                 pp = t = 0;                       324                 pp = t = 0;
325                 for (i = minLen; i < maxLen; i    325                 for (i = minLen; i < maxLen; i++) {
326                         pp += temp[i];            326                         pp += temp[i];
327                         /* We read the largest    327                         /* We read the largest possible symbol size
328                            and then unget bits    328                            and then unget bits after determining how
329                            many we need, and t    329                            many we need, and those extra bits could be
330                            set to anything.  (    330                            set to anything.  (They're noise from
331                            future symbols.)  A    331                            future symbols.)  At each level we're
332                            really only interes    332                            really only interested in the first few
333                            bits, so here we se    333                            bits, so here we set all the trailing
334                            to-be-ignored bits     334                            to-be-ignored bits to 1 so they don't
335                            affect the value >     335                            affect the value > limit[length]
336                            comparison. */         336                            comparison. */
337                         limit[i] = (pp << (max    337                         limit[i] = (pp << (maxLen - i)) - 1;
338                         pp <<= 1;                 338                         pp <<= 1;
339                         base[i+1] = pp-(t += t    339                         base[i+1] = pp-(t += temp[i]);
340                 }                                 340                 }
341                 limit[maxLen+1] = INT_MAX; /*     341                 limit[maxLen+1] = INT_MAX; /* Sentinel value for
342                                             *     342                                             * reading next sym. */
343                 limit[maxLen] = pp+temp[maxLen    343                 limit[maxLen] = pp+temp[maxLen]-1;
344                 base[minLen] = 0;                 344                 base[minLen] = 0;
345         }                                         345         }
346         /* We've finished reading and digestin    346         /* We've finished reading and digesting the block header.  Now
347            read this block's Huffman coded sym    347            read this block's Huffman coded symbols from the file and
348            undo the Huffman coding and run len    348            undo the Huffman coding and run length encoding, saving the
349            result into dbuf[dbufCount++] = uc     349            result into dbuf[dbufCount++] = uc */
350                                                   350 
351         /* Initialize symbol occurrence counte    351         /* Initialize symbol occurrence counters and symbol Move To
352          * Front table */                         352          * Front table */
353         for (i = 0; i < 256; i++) {               353         for (i = 0; i < 256; i++) {
354                 byteCount[i] = 0;                 354                 byteCount[i] = 0;
355                 mtfSymbol[i] = (unsigned char)    355                 mtfSymbol[i] = (unsigned char)i;
356         }                                         356         }
357         /* Loop through compressed symbols. */    357         /* Loop through compressed symbols. */
358         runPos = dbufCount = symCount = select    358         runPos = dbufCount = symCount = selector = 0;
359         for (;;) {                                359         for (;;) {
360                 /* Determine which Huffman cod    360                 /* Determine which Huffman coding group to use. */
361                 if (!(symCount--)) {              361                 if (!(symCount--)) {
362                         symCount = GROUP_SIZE-    362                         symCount = GROUP_SIZE-1;
363                         if (selector >= nSelec    363                         if (selector >= nSelectors)
364                                 return RETVAL_    364                                 return RETVAL_DATA_ERROR;
365                         hufGroup = bd->groups+    365                         hufGroup = bd->groups+selectors[selector++];
366                         base = hufGroup->base-    366                         base = hufGroup->base-1;
367                         limit = hufGroup->limi    367                         limit = hufGroup->limit-1;
368                 }                                 368                 }
369                 /* Read next Huffman-coded sym    369                 /* Read next Huffman-coded symbol. */
370                 /* Note: It is far cheaper to     370                 /* Note: It is far cheaper to read maxLen bits and
371                    back up than it is to read     371                    back up than it is to read minLen bits and then an
372                    additional bit at a time, t    372                    additional bit at a time, testing as we go.
373                    Because there is a trailing    373                    Because there is a trailing last block (with file
374                    CRC), there is no danger of    374                    CRC), there is no danger of the overread causing an
375                    unexpected EOF for a valid     375                    unexpected EOF for a valid compressed file.  As a
376                    further optimization, we do    376                    further optimization, we do the read inline
377                    (falling back to a call to     377                    (falling back to a call to get_bits if the buffer
378                    runs dry).  The following (    378                    runs dry).  The following (up to got_huff_bits:) is
379                    equivalent to j = get_bits(    379                    equivalent to j = get_bits(bd, hufGroup->maxLen);
380                  */                               380                  */
381                 while (bd->inbufBitCount < huf    381                 while (bd->inbufBitCount < hufGroup->maxLen) {
382                         if (bd->inbufPos == bd    382                         if (bd->inbufPos == bd->inbufCount) {
383                                 j = get_bits(b    383                                 j = get_bits(bd, hufGroup->maxLen);
384                                 goto got_huff_    384                                 goto got_huff_bits;
385                         }                         385                         }
386                         bd->inbufBits =           386                         bd->inbufBits =
387                                 (bd->inbufBits    387                                 (bd->inbufBits << 8)|bd->inbuf[bd->inbufPos++];
388                         bd->inbufBitCount += 8    388                         bd->inbufBitCount += 8;
389                 }                                 389                 }
390                 bd->inbufBitCount -= hufGroup-    390                 bd->inbufBitCount -= hufGroup->maxLen;
391                 j = (bd->inbufBits >> bd->inbu    391                 j = (bd->inbufBits >> bd->inbufBitCount)&
392                         ((1 << hufGroup->maxLe    392                         ((1 << hufGroup->maxLen)-1);
393 got_huff_bits:                                    393 got_huff_bits:
394                 /* Figure how many bits are in    394                 /* Figure how many bits are in next symbol and
395                  * unget extras */                395                  * unget extras */
396                 i = hufGroup->minLen;             396                 i = hufGroup->minLen;
397                 while (j > limit[i])              397                 while (j > limit[i])
398                         ++i;                      398                         ++i;
399                 bd->inbufBitCount += (hufGroup    399                 bd->inbufBitCount += (hufGroup->maxLen - i);
400                 /* Huffman decode value to get    400                 /* Huffman decode value to get nextSym (with bounds checking) */
401                 if ((i > hufGroup->maxLen)        401                 if ((i > hufGroup->maxLen)
402                         || (((unsigned)(j = (j    402                         || (((unsigned)(j = (j>>(hufGroup->maxLen-i))-base[i]))
403                                 >= MAX_SYMBOLS    403                                 >= MAX_SYMBOLS))
404                         return RETVAL_DATA_ERR    404                         return RETVAL_DATA_ERROR;
405                 nextSym = hufGroup->permute[j]    405                 nextSym = hufGroup->permute[j];
406                 /* We have now decoded the sym    406                 /* We have now decoded the symbol, which indicates
407                    either a new literal byte,     407                    either a new literal byte, or a repeated run of the
408                    most recent literal byte.      408                    most recent literal byte.  First, check if nextSym
409                    indicates a repeated run, a    409                    indicates a repeated run, and if so loop collecting
410                    how many times to repeat th    410                    how many times to repeat the last literal. */
411                 if (((unsigned)nextSym) <= SYM    411                 if (((unsigned)nextSym) <= SYMBOL_RUNB) { /* RUNA or RUNB */
412                         /* If this is the star    412                         /* If this is the start of a new run, zero out
413                          * counter */             413                          * counter */
414                         if (!runPos) {            414                         if (!runPos) {
415                                 runPos = 1;       415                                 runPos = 1;
416                                 t = 0;            416                                 t = 0;
417                         }                         417                         }
418                         /* Neat trick that sav    418                         /* Neat trick that saves 1 symbol: instead of
419                            or-ing 0 or 1 at ea    419                            or-ing 0 or 1 at each bit position, add 1
420                            or 2 instead.  For     420                            or 2 instead.  For example, 1011 is 1 << 0
421                            + 1 << 1 + 2 << 2.     421                            + 1 << 1 + 2 << 2.  1010 is 2 << 0 + 2 << 1
422                            + 1 << 2.  You can     422                            + 1 << 2.  You can make any bit pattern
423                            that way using 1 le    423                            that way using 1 less symbol than the basic
424                            or 0/1 method (exce    424                            or 0/1 method (except all bits 0, which
425                            would use no symbol    425                            would use no symbols, but a run of length 0
426                            doesn't mean anythi    426                            doesn't mean anything in this context).
427                            Thus space is saved    427                            Thus space is saved. */
428                         t += (runPos << nextSy    428                         t += (runPos << nextSym);
429                         /* +runPos if RUNA; +2    429                         /* +runPos if RUNA; +2*runPos if RUNB */
430                                                   430 
431                         runPos <<= 1;             431                         runPos <<= 1;
432                         continue;                 432                         continue;
433                 }                                 433                 }
434                 /* When we hit the first non-r    434                 /* When we hit the first non-run symbol after a run,
435                    we now know how many times     435                    we now know how many times to repeat the last
436                    literal, so append that man    436                    literal, so append that many copies to our buffer
437                    of decoded symbols (dbuf) n    437                    of decoded symbols (dbuf) now.  (The last literal
438                    used is the one at the head    438                    used is the one at the head of the mtfSymbol
439                    array.) */                     439                    array.) */
440                 if (runPos) {                     440                 if (runPos) {
441                         runPos = 0;               441                         runPos = 0;
442                         if (dbufCount+t >= dbu    442                         if (dbufCount+t >= dbufSize)
443                                 return RETVAL_    443                                 return RETVAL_DATA_ERROR;
444                                                   444 
445                         uc = symToByte[mtfSymb    445                         uc = symToByte[mtfSymbol[0]];
446                         byteCount[uc] += t;       446                         byteCount[uc] += t;
447                         while (t--)               447                         while (t--)
448                                 dbuf[dbufCount    448                                 dbuf[dbufCount++] = uc;
449                 }                                 449                 }
450                 /* Is this the terminating sym    450                 /* Is this the terminating symbol? */
451                 if (nextSym > symTotal)           451                 if (nextSym > symTotal)
452                         break;                    452                         break;
453                 /* At this point, nextSym indi    453                 /* At this point, nextSym indicates a new literal
454                    character.  Subtract one to    454                    character.  Subtract one to get the position in the
455                    MTF array at which this lit    455                    MTF array at which this literal is currently to be
456                    found.  (Note that the resu    456                    found.  (Note that the result can't be -1 or 0,
457                    because 0 and 1 are RUNA an    457                    because 0 and 1 are RUNA and RUNB.  But another
458                    instance of the first symbo    458                    instance of the first symbol in the mtf array,
459                    position 0, would have been    459                    position 0, would have been handled as part of a
460                    run above.  Therefore 1 unu    460                    run above.  Therefore 1 unused mtf position minus 2
461                    non-literal nextSym values     461                    non-literal nextSym values equals -1.) */
462                 if (dbufCount >= dbufSize)        462                 if (dbufCount >= dbufSize)
463                         return RETVAL_DATA_ERR    463                         return RETVAL_DATA_ERROR;
464                 i = nextSym - 1;                  464                 i = nextSym - 1;
465                 uc = mtfSymbol[i];                465                 uc = mtfSymbol[i];
466                 /* Adjust the MTF array.  Sinc    466                 /* Adjust the MTF array.  Since we typically expect to
467                  *move only a small number of     467                  *move only a small number of symbols, and are bound
468                  *by 256 in any case, using me    468                  *by 256 in any case, using memmove here would
469                  *typically be bigger and slow    469                  *typically be bigger and slower due to function call
470                  *overhead and other assorted     470                  *overhead and other assorted setup costs. */
471                 do {                              471                 do {
472                         mtfSymbol[i] = mtfSymb    472                         mtfSymbol[i] = mtfSymbol[i-1];
473                 } while (--i);                    473                 } while (--i);
474                 mtfSymbol[0] = uc;                474                 mtfSymbol[0] = uc;
475                 uc = symToByte[uc];               475                 uc = symToByte[uc];
476                 /* We have our literal byte.      476                 /* We have our literal byte.  Save it into dbuf. */
477                 byteCount[uc]++;                  477                 byteCount[uc]++;
478                 dbuf[dbufCount++] = (unsigned     478                 dbuf[dbufCount++] = (unsigned int)uc;
479         }                                         479         }
480         /* At this point, we've read all the H    480         /* At this point, we've read all the Huffman-coded symbols
481            (and repeated runs) for this block     481            (and repeated runs) for this block from the input stream,
482            and decoded them into the intermedi    482            and decoded them into the intermediate buffer.  There are
483            dbufCount many decoded bytes in dbu    483            dbufCount many decoded bytes in dbuf[].  Now undo the
484            Burrows-Wheeler transform on dbuf.     484            Burrows-Wheeler transform on dbuf.  See
485            http://dogma.net/markn/articles/bwt    485            http://dogma.net/markn/articles/bwt/bwt.htm
486          */                                       486          */
487         /* Turn byteCount into cumulative occu    487         /* Turn byteCount into cumulative occurrence counts of 0 to n-1. */
488         j = 0;                                    488         j = 0;
489         for (i = 0; i < 256; i++) {               489         for (i = 0; i < 256; i++) {
490                 k = j+byteCount[i];               490                 k = j+byteCount[i];
491                 byteCount[i] = j;                 491                 byteCount[i] = j;
492                 j = k;                            492                 j = k;
493         }                                         493         }
494         /* Figure out what order dbuf would be    494         /* Figure out what order dbuf would be in if we sorted it. */
495         for (i = 0; i < dbufCount; i++) {         495         for (i = 0; i < dbufCount; i++) {
496                 uc = (unsigned char)(dbuf[i] &    496                 uc = (unsigned char)(dbuf[i] & 0xff);
497                 dbuf[byteCount[uc]] |= (i << 8    497                 dbuf[byteCount[uc]] |= (i << 8);
498                 byteCount[uc]++;                  498                 byteCount[uc]++;
499         }                                         499         }
500         /* Decode first byte by hand to initia    500         /* Decode first byte by hand to initialize "previous" byte.
501            Note that it doesn't get output, an    501            Note that it doesn't get output, and if the first three
502            characters are identical it doesn't    502            characters are identical it doesn't qualify as a run (hence
503            writeRunCountdown = 5). */             503            writeRunCountdown = 5). */
504         if (dbufCount) {                          504         if (dbufCount) {
505                 if (origPtr >= dbufCount)         505                 if (origPtr >= dbufCount)
506                         return RETVAL_DATA_ERR    506                         return RETVAL_DATA_ERROR;
507                 bd->writePos = dbuf[origPtr];     507                 bd->writePos = dbuf[origPtr];
508                 bd->writeCurrent = (unsigned c    508                 bd->writeCurrent = (unsigned char)(bd->writePos&0xff);
509                 bd->writePos >>= 8;               509                 bd->writePos >>= 8;
510                 bd->writeRunCountdown = 5;        510                 bd->writeRunCountdown = 5;
511         }                                         511         }
512         bd->writeCount = dbufCount;               512         bd->writeCount = dbufCount;
513                                                   513 
514         return RETVAL_OK;                         514         return RETVAL_OK;
515 }                                                 515 }
516                                                   516 
517 /* Undo burrows-wheeler transform on intermedi    517 /* Undo burrows-wheeler transform on intermediate buffer to produce output.
518    If start_bunzip was initialized with out_fd    518    If start_bunzip was initialized with out_fd =-1, then up to len bytes of
519    data are written to outbuf.  Return value i    519    data are written to outbuf.  Return value is number of bytes written or
520    error (all errors are negative numbers).  I    520    error (all errors are negative numbers).  If out_fd!=-1, outbuf and len
521    are ignored, data is written to out_fd and     521    are ignored, data is written to out_fd and return is RETVAL_OK or error.
522 */                                                522 */
523                                                   523 
524 static int INIT read_bunzip(struct bunzip_data    524 static int INIT read_bunzip(struct bunzip_data *bd, char *outbuf, int len)
525 {                                                 525 {
526         const unsigned int *dbuf;                 526         const unsigned int *dbuf;
527         int pos, xcurrent, previous, gotcount;    527         int pos, xcurrent, previous, gotcount;
528                                                   528 
529         /* If last read was short due to end o    529         /* If last read was short due to end of file, return last block now */
530         if (bd->writeCount < 0)                   530         if (bd->writeCount < 0)
531                 return bd->writeCount;            531                 return bd->writeCount;
532                                                   532 
533         gotcount = 0;                             533         gotcount = 0;
534         dbuf = bd->dbuf;                          534         dbuf = bd->dbuf;
535         pos = bd->writePos;                       535         pos = bd->writePos;
536         xcurrent = bd->writeCurrent;              536         xcurrent = bd->writeCurrent;
537                                                   537 
538         /* We will always have pending decoded    538         /* We will always have pending decoded data to write into the output
539            buffer unless this is the very firs    539            buffer unless this is the very first call (in which case we haven't
540            Huffman-decoded a block into the in    540            Huffman-decoded a block into the intermediate buffer yet). */
541                                                   541 
542         if (bd->writeCopies) {                    542         if (bd->writeCopies) {
543                 /* Inside the loop, writeCopie    543                 /* Inside the loop, writeCopies means extra copies (beyond 1) */
544                 --bd->writeCopies;                544                 --bd->writeCopies;
545                 /* Loop outputting bytes */       545                 /* Loop outputting bytes */
546                 for (;;) {                        546                 for (;;) {
547                         /* If the output buffe    547                         /* If the output buffer is full, snapshot
548                          * state and return */    548                          * state and return */
549                         if (gotcount >= len) {    549                         if (gotcount >= len) {
550                                 bd->writePos =    550                                 bd->writePos = pos;
551                                 bd->writeCurre    551                                 bd->writeCurrent = xcurrent;
552                                 bd->writeCopie    552                                 bd->writeCopies++;
553                                 return len;       553                                 return len;
554                         }                         554                         }
555                         /* Write next byte int    555                         /* Write next byte into output buffer, updating CRC */
556                         outbuf[gotcount++] = x    556                         outbuf[gotcount++] = xcurrent;
557                         bd->writeCRC = (((bd->    557                         bd->writeCRC = (((bd->writeCRC) << 8)
558                                 ^bd->crc32Tabl    558                                 ^bd->crc32Table[((bd->writeCRC) >> 24)
559                                 ^xcurrent]);      559                                 ^xcurrent]);
560                         /* Loop now if we're o    560                         /* Loop now if we're outputting multiple
561                          * copies of this byte    561                          * copies of this byte */
562                         if (bd->writeCopies) {    562                         if (bd->writeCopies) {
563                                 --bd->writeCop    563                                 --bd->writeCopies;
564                                 continue;         564                                 continue;
565                         }                         565                         }
566 decode_next_byte:                                 566 decode_next_byte:
567                         if (!bd->writeCount--)    567                         if (!bd->writeCount--)
568                                 break;            568                                 break;
569                         /* Follow sequence vec    569                         /* Follow sequence vector to undo
570                          * Burrows-Wheeler tra    570                          * Burrows-Wheeler transform */
571                         previous = xcurrent;      571                         previous = xcurrent;
572                         pos = dbuf[pos];          572                         pos = dbuf[pos];
573                         xcurrent = pos&0xff;      573                         xcurrent = pos&0xff;
574                         pos >>= 8;                574                         pos >>= 8;
575                         /* After 3 consecutive    575                         /* After 3 consecutive copies of the same
576                            byte, the 4th is a     576                            byte, the 4th is a repeat count.  We count
577                            down from 4 instead    577                            down from 4 instead *of counting up because
578                            testing for non-zer    578                            testing for non-zero is faster */
579                         if (--bd->writeRunCoun    579                         if (--bd->writeRunCountdown) {
580                                 if (xcurrent !    580                                 if (xcurrent != previous)
581                                         bd->wr    581                                         bd->writeRunCountdown = 4;
582                         } else {                  582                         } else {
583                                 /* We have a r    583                                 /* We have a repeated run, this byte
584                                  * indicates t    584                                  * indicates the count */
585                                 bd->writeCopie    585                                 bd->writeCopies = xcurrent;
586                                 xcurrent = pre    586                                 xcurrent = previous;
587                                 bd->writeRunCo    587                                 bd->writeRunCountdown = 5;
588                                 /* Sometimes t    588                                 /* Sometimes there are just 3 bytes
589                                  * (run length    589                                  * (run length 0) */
590                                 if (!bd->write    590                                 if (!bd->writeCopies)
591                                         goto d    591                                         goto decode_next_byte;
592                                 /* Subtract th    592                                 /* Subtract the 1 copy we'd output
593                                  * anyway to g    593                                  * anyway to get extras */
594                                 --bd->writeCop    594                                 --bd->writeCopies;
595                         }                         595                         }
596                 }                                 596                 }
597                 /* Decompression of this block    597                 /* Decompression of this block completed successfully */
598                 bd->writeCRC = ~bd->writeCRC;     598                 bd->writeCRC = ~bd->writeCRC;
599                 bd->totalCRC = ((bd->totalCRC     599                 bd->totalCRC = ((bd->totalCRC << 1) |
600                                 (bd->totalCRC     600                                 (bd->totalCRC >> 31)) ^ bd->writeCRC;
601                 /* If this block had a CRC err    601                 /* If this block had a CRC error, force file level CRC error. */
602                 if (bd->writeCRC != bd->header    602                 if (bd->writeCRC != bd->headerCRC) {
603                         bd->totalCRC = bd->hea    603                         bd->totalCRC = bd->headerCRC+1;
604                         return RETVAL_LAST_BLO    604                         return RETVAL_LAST_BLOCK;
605                 }                                 605                 }
606         }                                         606         }
607                                                   607 
608         /* Refill the intermediate buffer by H    608         /* Refill the intermediate buffer by Huffman-decoding next
609          * block of input */                      609          * block of input */
610         /* (previous is just a convenient unus    610         /* (previous is just a convenient unused temp variable here) */
611         previous = get_next_block(bd);            611         previous = get_next_block(bd);
612         if (previous) {                           612         if (previous) {
613                 bd->writeCount = previous;        613                 bd->writeCount = previous;
614                 return (previous != RETVAL_LAS    614                 return (previous != RETVAL_LAST_BLOCK) ? previous : gotcount;
615         }                                         615         }
616         bd->writeCRC = 0xffffffffUL;              616         bd->writeCRC = 0xffffffffUL;
617         pos = bd->writePos;                       617         pos = bd->writePos;
618         xcurrent = bd->writeCurrent;              618         xcurrent = bd->writeCurrent;
619         goto decode_next_byte;                    619         goto decode_next_byte;
620 }                                                 620 }
621                                                   621 
622 static long INIT nofill(void *buf, unsigned lo    622 static long INIT nofill(void *buf, unsigned long len)
623 {                                                 623 {
624         return -1;                                624         return -1;
625 }                                                 625 }
626                                                   626 
627 /* Allocate the structure, read file header.      627 /* Allocate the structure, read file header.  If in_fd ==-1, inbuf must contain
628    a complete bunzip file (len bytes long).  I    628    a complete bunzip file (len bytes long).  If in_fd!=-1, inbuf and len are
629    ignored, and data is read from file handle     629    ignored, and data is read from file handle into temporary buffer. */
630 static int INIT start_bunzip(struct bunzip_dat    630 static int INIT start_bunzip(struct bunzip_data **bdp, void *inbuf, long len,
631                              long (*fill)(void    631                              long (*fill)(void*, unsigned long))
632 {                                                 632 {
633         struct bunzip_data *bd;                   633         struct bunzip_data *bd;
634         unsigned int i, j, c;                     634         unsigned int i, j, c;
635         const unsigned int BZh0 =                 635         const unsigned int BZh0 =
636                 (((unsigned int)'B') << 24)+((    636                 (((unsigned int)'B') << 24)+(((unsigned int)'Z') << 16)
637                 +(((unsigned int)'h') << 8)+(u    637                 +(((unsigned int)'h') << 8)+(unsigned int)'';
638                                                   638 
639         /* Figure out how much data to allocat    639         /* Figure out how much data to allocate */
640         i = sizeof(struct bunzip_data);           640         i = sizeof(struct bunzip_data);
641                                                   641 
642         /* Allocate bunzip_data.  Most fields     642         /* Allocate bunzip_data.  Most fields initialize to zero. */
643         bd = *bdp = malloc(i);                    643         bd = *bdp = malloc(i);
644         if (!bd)                                  644         if (!bd)
645                 return RETVAL_OUT_OF_MEMORY;      645                 return RETVAL_OUT_OF_MEMORY;
646         memset(bd, 0, sizeof(struct bunzip_dat    646         memset(bd, 0, sizeof(struct bunzip_data));
647         /* Setup input buffer */                  647         /* Setup input buffer */
648         bd->inbuf = inbuf;                        648         bd->inbuf = inbuf;
649         bd->inbufCount = len;                     649         bd->inbufCount = len;
650         if (fill != NULL)                         650         if (fill != NULL)
651                 bd->fill = fill;                  651                 bd->fill = fill;
652         else                                      652         else
653                 bd->fill = nofill;                653                 bd->fill = nofill;
654                                                   654 
655         /* Init the CRC32 table (big endian) *    655         /* Init the CRC32 table (big endian) */
656         for (i = 0; i < 256; i++) {               656         for (i = 0; i < 256; i++) {
657                 c = i << 24;                      657                 c = i << 24;
658                 for (j = 8; j; j--)               658                 for (j = 8; j; j--)
659                         c = c&0x80000000 ? (c     659                         c = c&0x80000000 ? (c << 1)^(CRC32_POLY_BE) : (c << 1);
660                 bd->crc32Table[i] = c;            660                 bd->crc32Table[i] = c;
661         }                                         661         }
662                                                   662 
663         /* Ensure that file starts with "BZh['    663         /* Ensure that file starts with "BZh['1'-'9']." */
664         i = get_bits(bd, 32);                     664         i = get_bits(bd, 32);
665         if (((unsigned int)(i-BZh0-1)) >= 9)      665         if (((unsigned int)(i-BZh0-1)) >= 9)
666                 return RETVAL_NOT_BZIP_DATA;      666                 return RETVAL_NOT_BZIP_DATA;
667                                                   667 
668         /* Fourth byte (ascii '1'-'9'), indica    668         /* Fourth byte (ascii '1'-'9'), indicates block size in units of 100k of
669            uncompressed data.  Allocate interm    669            uncompressed data.  Allocate intermediate buffer for block. */
670         bd->dbufSize = 100000*(i-BZh0);           670         bd->dbufSize = 100000*(i-BZh0);
671                                                   671 
672         bd->dbuf = large_malloc(bd->dbufSize *    672         bd->dbuf = large_malloc(bd->dbufSize * sizeof(int));
673         if (!bd->dbuf)                            673         if (!bd->dbuf)
674                 return RETVAL_OUT_OF_MEMORY;      674                 return RETVAL_OUT_OF_MEMORY;
675         return RETVAL_OK;                         675         return RETVAL_OK;
676 }                                                 676 }
677                                                   677 
678 /* Example usage: decompress src_fd to dst_fd.    678 /* Example usage: decompress src_fd to dst_fd.  (Stops at end of bzip2 data,
679    not end of file.) */                           679    not end of file.) */
680 STATIC int INIT bunzip2(unsigned char *buf, lo    680 STATIC int INIT bunzip2(unsigned char *buf, long len,
681                         long (*fill)(void*, un    681                         long (*fill)(void*, unsigned long),
682                         long (*flush)(void*, u    682                         long (*flush)(void*, unsigned long),
683                         unsigned char *outbuf,    683                         unsigned char *outbuf,
684                         long *pos,                684                         long *pos,
685                         void(*error)(char *x))    685                         void(*error)(char *x))
686 {                                                 686 {
687         struct bunzip_data *bd;                   687         struct bunzip_data *bd;
688         int i = -1;                               688         int i = -1;
689         unsigned char *inbuf;                     689         unsigned char *inbuf;
690                                                   690 
691         if (flush)                                691         if (flush)
692                 outbuf = malloc(BZIP2_IOBUF_SI    692                 outbuf = malloc(BZIP2_IOBUF_SIZE);
693                                                   693 
694         if (!outbuf) {                            694         if (!outbuf) {
695                 error("Could not allocate outp    695                 error("Could not allocate output buffer");
696                 return RETVAL_OUT_OF_MEMORY;      696                 return RETVAL_OUT_OF_MEMORY;
697         }                                         697         }
698         if (buf)                                  698         if (buf)
699                 inbuf = buf;                      699                 inbuf = buf;
700         else                                      700         else
701                 inbuf = malloc(BZIP2_IOBUF_SIZ    701                 inbuf = malloc(BZIP2_IOBUF_SIZE);
702         if (!inbuf) {                             702         if (!inbuf) {
703                 error("Could not allocate inpu    703                 error("Could not allocate input buffer");
704                 i = RETVAL_OUT_OF_MEMORY;         704                 i = RETVAL_OUT_OF_MEMORY;
705                 goto exit_0;                      705                 goto exit_0;
706         }                                         706         }
707         i = start_bunzip(&bd, inbuf, len, fill    707         i = start_bunzip(&bd, inbuf, len, fill);
708         if (!i) {                                 708         if (!i) {
709                 for (;;) {                        709                 for (;;) {
710                         i = read_bunzip(bd, ou    710                         i = read_bunzip(bd, outbuf, BZIP2_IOBUF_SIZE);
711                         if (i <= 0)               711                         if (i <= 0)
712                                 break;            712                                 break;
713                         if (!flush)               713                         if (!flush)
714                                 outbuf += i;      714                                 outbuf += i;
715                         else                      715                         else
716                                 if (i != flush    716                                 if (i != flush(outbuf, i)) {
717                                         i = RE    717                                         i = RETVAL_UNEXPECTED_OUTPUT_EOF;
718                                         break;    718                                         break;
719                                 }                 719                                 }
720                 }                                 720                 }
721         }                                         721         }
722         /* Check CRC and release memory */        722         /* Check CRC and release memory */
723         if (i == RETVAL_LAST_BLOCK) {             723         if (i == RETVAL_LAST_BLOCK) {
724                 if (bd->headerCRC != bd->total    724                 if (bd->headerCRC != bd->totalCRC)
725                         error("Data integrity     725                         error("Data integrity error when decompressing.");
726                 else                              726                 else
727                         i = RETVAL_OK;            727                         i = RETVAL_OK;
728         } else if (i == RETVAL_UNEXPECTED_OUTP    728         } else if (i == RETVAL_UNEXPECTED_OUTPUT_EOF) {
729                 error("Compressed file ends un    729                 error("Compressed file ends unexpectedly");
730         }                                         730         }
731         if (!bd)                                  731         if (!bd)
732                 goto exit_1;                      732                 goto exit_1;
733         if (bd->dbuf)                             733         if (bd->dbuf)
734                 large_free(bd->dbuf);             734                 large_free(bd->dbuf);
735         if (pos)                                  735         if (pos)
736                 *pos = bd->inbufPos;              736                 *pos = bd->inbufPos;
737         free(bd);                                 737         free(bd);
738 exit_1:                                           738 exit_1:
739         if (!buf)                                 739         if (!buf)
740                 free(inbuf);                      740                 free(inbuf);
741 exit_0:                                           741 exit_0:
742         if (flush)                                742         if (flush)
743                 free(outbuf);                     743                 free(outbuf);
744         return i;                                 744         return i;
745 }                                                 745 }
746                                                   746 
747 #ifdef PREBOOT                                    747 #ifdef PREBOOT
748 STATIC int INIT __decompress(unsigned char *bu    748 STATIC int INIT __decompress(unsigned char *buf, long len,
749                         long (*fill)(void*, un    749                         long (*fill)(void*, unsigned long),
750                         long (*flush)(void*, u    750                         long (*flush)(void*, unsigned long),
751                         unsigned char *outbuf,    751                         unsigned char *outbuf, long olen,
752                         long *pos,                752                         long *pos,
753                         void (*error)(char *x)    753                         void (*error)(char *x))
754 {                                                 754 {
755         return bunzip2(buf, len - 4, fill, flu    755         return bunzip2(buf, len - 4, fill, flush, outbuf, pos, error);
756 }                                                 756 }
757 #endif                                            757 #endif
758                                                   758 

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