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      1 /* gzwrite.c -- zlib functions for writing gzip files
      2  * Copyright (C) 2004, 2005, 2010, 2011, 2012, 2013 Mark Adler
      3  * For conditions of distribution and use, see copyright notice in zlib.h
      4  */
      5 
      6 #include "gzguts.h"
      7 
      8 /* Local functions */
      9 local int gz_init OF((gz_statep));
     10 local int gz_comp OF((gz_statep, int));
     11 local int gz_zero OF((gz_statep, z_off64_t));
     12 
     13 /* Initialize state for writing a gzip file.  Mark initialization by setting
     14    state->size to non-zero.  Return -1 on failure or 0 on success. */
     15 local int gz_init(state)
     16     gz_statep state;
     17 {
     18     int ret;
     19     z_streamp strm = &(state->strm);
     20 
     21     /* allocate input buffer */
     22     state->in = (unsigned char *)malloc(state->want);
     23     if (state->in == NULL) {
     24         gz_error(state, Z_MEM_ERROR, "out of memory");
     25         return -1;
     26     }
     27 
     28     /* only need output buffer and deflate state if compressing */
     29     if (!state->direct) {
     30         /* allocate output buffer */
     31         state->out = (unsigned char *)malloc(state->want);
     32         if (state->out == NULL) {
     33             free(state->in);
     34             gz_error(state, Z_MEM_ERROR, "out of memory");
     35             return -1;
     36         }
     37 
     38         /* allocate deflate memory, set up for gzip compression */
     39         strm->zalloc = Z_NULL;
     40         strm->zfree = Z_NULL;
     41         strm->opaque = Z_NULL;
     42         ret = deflateInit2(strm, state->level, Z_DEFLATED,
     43                            MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
     44         if (ret != Z_OK) {
     45             free(state->out);
     46             free(state->in);
     47             gz_error(state, Z_MEM_ERROR, "out of memory");
     48             return -1;
     49         }
     50     }
     51 
     52     /* mark state as initialized */
     53     state->size = state->want;
     54 
     55     /* initialize write buffer if compressing */
     56     if (!state->direct) {
     57         strm->avail_out = state->size;
     58         strm->next_out = state->out;
     59         state->x.next = strm->next_out;
     60     }
     61     return 0;
     62 }
     63 
     64 /* Compress whatever is at avail_in and next_in and write to the output file.
     65    Return -1 if there is an error writing to the output file, otherwise 0.
     66    flush is assumed to be a valid deflate() flush value.  If flush is Z_FINISH,
     67    then the deflate() state is reset to start a new gzip stream.  If gz->direct
     68    is true, then simply write to the output file without compressing, and
     69    ignore flush. */
     70 local int gz_comp(state, flush)
     71     gz_statep state;
     72     int flush;
     73 {
     74     int ret, got;
     75     unsigned have;
     76     z_streamp strm = &(state->strm);
     77 
     78     /* allocate memory if this is the first time through */
     79     if (state->size == 0 && gz_init(state) == -1)
     80         return -1;
     81 
     82     /* write directly if requested */
     83     if (state->direct) {
     84         got = write(state->fd, strm->next_in, strm->avail_in);
     85         if (got < 0 || (unsigned)got != strm->avail_in) {
     86             gz_error(state, Z_ERRNO, zstrerror());
     87             return -1;
     88         }
     89         strm->avail_in = 0;
     90         return 0;
     91     }
     92 
     93     /* run deflate() on provided input until it produces no more output */
     94     ret = Z_OK;
     95     do {
     96         /* write out current buffer contents if full, or if flushing, but if
     97            doing Z_FINISH then don't write until we get to Z_STREAM_END */
     98         if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
     99             (flush != Z_FINISH || ret == Z_STREAM_END))) {
    100             have = (unsigned)(strm->next_out - state->x.next);
    101             if (have && ((got = write(state->fd, state->x.next, have)) < 0 ||
    102                          (unsigned)got != have)) {
    103                 gz_error(state, Z_ERRNO, zstrerror());
    104                 return -1;
    105             }
    106             if (strm->avail_out == 0) {
    107                 strm->avail_out = state->size;
    108                 strm->next_out = state->out;
    109             }
    110             state->x.next = strm->next_out;
    111         }
    112 
    113         /* compress */
    114         have = strm->avail_out;
    115         ret = deflate(strm, flush);
    116         if (ret == Z_STREAM_ERROR) {
    117             gz_error(state, Z_STREAM_ERROR,
    118                       "internal error: deflate stream corrupt");
    119             return -1;
    120         }
    121         have -= strm->avail_out;
    122     } while (have);
    123 
    124     /* if that completed a deflate stream, allow another to start */
    125     if (flush == Z_FINISH)
    126         deflateReset(strm);
    127 
    128     /* all done, no errors */
    129     return 0;
    130 }
    131 
    132 /* Compress len zeros to output.  Return -1 on error, 0 on success. */
    133 local int gz_zero(state, len)
    134     gz_statep state;
    135     z_off64_t len;
    136 {
    137     int first;
    138     unsigned n;
    139     z_streamp strm = &(state->strm);
    140 
    141     /* consume whatever's left in the input buffer */
    142     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
    143         return -1;
    144 
    145     /* compress len zeros (len guaranteed > 0) */
    146     first = 1;
    147     while (len) {
    148         n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
    149             (unsigned)len : state->size;
    150         if (first) {
    151             memset(state->in, 0, n);
    152             first = 0;
    153         }
    154         strm->avail_in = n;
    155         strm->next_in = state->in;
    156         state->x.pos += n;
    157         if (gz_comp(state, Z_NO_FLUSH) == -1)
    158             return -1;
    159         len -= n;
    160     }
    161     return 0;
    162 }
    163 
    164 /* -- see zlib.h -- */
    165 int ZEXPORT gzwrite(file, buf, len)
    166     gzFile file;
    167     voidpc buf;
    168     unsigned len;
    169 {
    170     unsigned put = len;
    171     gz_statep state;
    172     z_streamp strm;
    173 
    174     /* get internal structure */
    175     if (file == NULL)
    176         return 0;
    177     state = (gz_statep)file;
    178     strm = &(state->strm);
    179 
    180     /* check that we're writing and that there's no error */
    181     if (state->mode != GZ_WRITE || state->err != Z_OK)
    182         return 0;
    183 
    184     /* since an int is returned, make sure len fits in one, otherwise return
    185        with an error (this avoids the flaw in the interface) */
    186     if ((int)len < 0) {
    187         gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
    188         return 0;
    189     }
    190 
    191     /* if len is zero, avoid unnecessary operations */
    192     if (len == 0)
    193         return 0;
    194 
    195     /* allocate memory if this is the first time through */
    196     if (state->size == 0 && gz_init(state) == -1)
    197         return 0;
    198 
    199     /* check for seek request */
    200     if (state->seek) {
    201         state->seek = 0;
    202         if (gz_zero(state, state->skip) == -1)
    203             return 0;
    204     }
    205 
    206     /* for small len, copy to input buffer, otherwise compress directly */
    207     if (len < state->size) {
    208         /* copy to input buffer, compress when full */
    209         do {
    210             unsigned have, copy;
    211 
    212             if (strm->avail_in == 0)
    213                 strm->next_in = state->in;
    214             have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
    215             copy = state->size - have;
    216             if (copy > len)
    217                 copy = len;
    218             memcpy(state->in + have, buf, copy);
    219             strm->avail_in += copy;
    220             state->x.pos += copy;
    221             buf = (const char *)buf + copy;
    222             len -= copy;
    223             if (len && gz_comp(state, Z_NO_FLUSH) == -1)
    224                 return 0;
    225         } while (len);
    226     }
    227     else {
    228         /* consume whatever's left in the input buffer */
    229         if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
    230             return 0;
    231 
    232         /* directly compress user buffer to file */
    233         strm->avail_in = len;
    234         strm->next_in = (z_const Bytef *)buf;
    235         state->x.pos += len;
    236         if (gz_comp(state, Z_NO_FLUSH) == -1)
    237             return 0;
    238     }
    239 
    240     /* input was all buffered or compressed (put will fit in int) */
    241     return (int)put;
    242 }
    243 
    244 /* -- see zlib.h -- */
    245 int ZEXPORT gzputc(file, c)
    246     gzFile file;
    247     int c;
    248 {
    249     unsigned have;
    250     unsigned char buf[1];
    251     gz_statep state;
    252     z_streamp strm;
    253 
    254     /* get internal structure */
    255     if (file == NULL)
    256         return -1;
    257     state = (gz_statep)file;
    258     strm = &(state->strm);
    259 
    260     /* check that we're writing and that there's no error */
    261     if (state->mode != GZ_WRITE || state->err != Z_OK)
    262         return -1;
    263 
    264     /* check for seek request */
    265     if (state->seek) {
    266         state->seek = 0;
    267         if (gz_zero(state, state->skip) == -1)
    268             return -1;
    269     }
    270 
    271     /* try writing to input buffer for speed (state->size == 0 if buffer not
    272        initialized) */
    273     if (state->size) {
    274         if (strm->avail_in == 0)
    275             strm->next_in = state->in;
    276         have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
    277         if (have < state->size) {
    278             state->in[have] = c;
    279             strm->avail_in++;
    280             state->x.pos++;
    281             return c & 0xff;
    282         }
    283     }
    284 
    285     /* no room in buffer or not initialized, use gz_write() */
    286     buf[0] = c;
    287     if (gzwrite(file, buf, 1) != 1)
    288         return -1;
    289     return c & 0xff;
    290 }
    291 
    292 /* -- see zlib.h -- */
    293 int ZEXPORT gzputs(file, str)
    294     gzFile file;
    295     const char *str;
    296 {
    297     int ret;
    298     unsigned len;
    299 
    300     /* write string */
    301     len = (unsigned)strlen(str);
    302     ret = gzwrite(file, str, len);
    303     return ret == 0 && len != 0 ? -1 : ret;
    304 }
    305 
    306 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
    307 #include <stdarg.h>
    308 
    309 /* -- see zlib.h -- */
    310 int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
    311 {
    312     int size, len;
    313     gz_statep state;
    314     z_streamp strm;
    315 
    316     /* get internal structure */
    317     if (file == NULL)
    318         return -1;
    319     state = (gz_statep)file;
    320     strm = &(state->strm);
    321 
    322     /* check that we're writing and that there's no error */
    323     if (state->mode != GZ_WRITE || state->err != Z_OK)
    324         return 0;
    325 
    326     /* make sure we have some buffer space */
    327     if (state->size == 0 && gz_init(state) == -1)
    328         return 0;
    329 
    330     /* check for seek request */
    331     if (state->seek) {
    332         state->seek = 0;
    333         if (gz_zero(state, state->skip) == -1)
    334             return 0;
    335     }
    336 
    337     /* consume whatever's left in the input buffer */
    338     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
    339         return 0;
    340 
    341     /* do the printf() into the input buffer, put length in len */
    342     size = (int)(state->size);
    343     state->in[size - 1] = 0;
    344 #ifdef NO_vsnprintf
    345 #  ifdef HAS_vsprintf_void
    346     (void)vsprintf((char *)(state->in), format, va);
    347     for (len = 0; len < size; len++)
    348         if (state->in[len] == 0) break;
    349 #  else
    350     len = vsprintf((char *)(state->in), format, va);
    351 #  endif
    352 #else
    353 #  ifdef HAS_vsnprintf_void
    354     (void)vsnprintf((char *)(state->in), size, format, va);
    355     len = strlen((char *)(state->in));
    356 #  else
    357     len = vsnprintf((char *)(state->in), size, format, va);
    358 #  endif
    359 #endif
    360 
    361     /* check that printf() results fit in buffer */
    362     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
    363         return 0;
    364 
    365     /* update buffer and position, defer compression until needed */
    366     strm->avail_in = (unsigned)len;
    367     strm->next_in = state->in;
    368     state->x.pos += len;
    369     return len;
    370 }
    371 
    372 int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
    373 {
    374     va_list va;
    375     int ret;
    376 
    377     va_start(va, format);
    378     ret = gzvprintf(file, format, va);
    379     va_end(va);
    380     return ret;
    381 }
    382 
    383 #else /* !STDC && !Z_HAVE_STDARG_H */
    384 
    385 /* -- see zlib.h -- */
    386 int ZEXPORTVA gzprintf (file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
    387                        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
    388     gzFile file;
    389     const char *format;
    390     int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
    391         a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
    392 {
    393     int size, len;
    394     gz_statep state;
    395     z_streamp strm;
    396 
    397     /* get internal structure */
    398     if (file == NULL)
    399         return -1;
    400     state = (gz_statep)file;
    401     strm = &(state->strm);
    402 
    403     /* check that can really pass pointer in ints */
    404     if (sizeof(int) != sizeof(void *))
    405         return 0;
    406 
    407     /* check that we're writing and that there's no error */
    408     if (state->mode != GZ_WRITE || state->err != Z_OK)
    409         return 0;
    410 
    411     /* make sure we have some buffer space */
    412     if (state->size == 0 && gz_init(state) == -1)
    413         return 0;
    414 
    415     /* check for seek request */
    416     if (state->seek) {
    417         state->seek = 0;
    418         if (gz_zero(state, state->skip) == -1)
    419             return 0;
    420     }
    421 
    422     /* consume whatever's left in the input buffer */
    423     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
    424         return 0;
    425 
    426     /* do the printf() into the input buffer, put length in len */
    427     size = (int)(state->size);
    428     state->in[size - 1] = 0;
    429 #ifdef NO_snprintf
    430 #  ifdef HAS_sprintf_void
    431     sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
    432             a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    433     for (len = 0; len < size; len++)
    434         if (state->in[len] == 0) break;
    435 #  else
    436     len = sprintf((char *)(state->in), format, a1, a2, a3, a4, a5, a6, a7, a8,
    437                   a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    438 #  endif
    439 #else
    440 #  ifdef HAS_snprintf_void
    441     snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6, a7, a8,
    442              a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
    443     len = strlen((char *)(state->in));
    444 #  else
    445     len = snprintf((char *)(state->in), size, format, a1, a2, a3, a4, a5, a6,
    446                    a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18,
    447                    a19, a20);
    448 #  endif
    449 #endif
    450 
    451     /* check that printf() results fit in buffer */
    452     if (len <= 0 || len >= (int)size || state->in[size - 1] != 0)
    453         return 0;
    454 
    455     /* update buffer and position, defer compression until needed */
    456     strm->avail_in = (unsigned)len;
    457     strm->next_in = state->in;
    458     state->x.pos += len;
    459     return len;
    460 }
    461 
    462 #endif
    463 
    464 /* -- see zlib.h -- */
    465 int ZEXPORT gzflush(file, flush)
    466     gzFile file;
    467     int flush;
    468 {
    469     gz_statep state;
    470 
    471     /* get internal structure */
    472     if (file == NULL)
    473         return -1;
    474     state = (gz_statep)file;
    475 
    476     /* check that we're writing and that there's no error */
    477     if (state->mode != GZ_WRITE || state->err != Z_OK)
    478         return Z_STREAM_ERROR;
    479 
    480     /* check flush parameter */
    481     if (flush < 0 || flush > Z_FINISH)
    482         return Z_STREAM_ERROR;
    483 
    484     /* check for seek request */
    485     if (state->seek) {
    486         state->seek = 0;
    487         if (gz_zero(state, state->skip) == -1)
    488             return -1;
    489     }
    490 
    491     /* compress remaining data with requested flush */
    492     gz_comp(state, flush);
    493     return state->err;
    494 }
    495 
    496 /* -- see zlib.h -- */
    497 int ZEXPORT gzsetparams(file, level, strategy)
    498     gzFile file;
    499     int level;
    500     int strategy;
    501 {
    502     gz_statep state;
    503     z_streamp strm;
    504 
    505     /* get internal structure */
    506     if (file == NULL)
    507         return Z_STREAM_ERROR;
    508     state = (gz_statep)file;
    509     strm = &(state->strm);
    510 
    511     /* check that we're writing and that there's no error */
    512     if (state->mode != GZ_WRITE || state->err != Z_OK)
    513         return Z_STREAM_ERROR;
    514 
    515     /* if no change is requested, then do nothing */
    516     if (level == state->level && strategy == state->strategy)
    517         return Z_OK;
    518 
    519     /* check for seek request */
    520     if (state->seek) {
    521         state->seek = 0;
    522         if (gz_zero(state, state->skip) == -1)
    523             return -1;
    524     }
    525 
    526     /* change compression parameters for subsequent input */
    527     if (state->size) {
    528         /* flush previous input with previous parameters before changing */
    529         if (strm->avail_in && gz_comp(state, Z_PARTIAL_FLUSH) == -1)
    530             return state->err;
    531         deflateParams(strm, level, strategy);
    532     }
    533     state->level = level;
    534     state->strategy = strategy;
    535     return Z_OK;
    536 }
    537 
    538 /* -- see zlib.h -- */
    539 int ZEXPORT gzclose_w(file)
    540     gzFile file;
    541 {
    542     int ret = Z_OK;
    543     gz_statep state;
    544 
    545     /* get internal structure */
    546     if (file == NULL)
    547         return Z_STREAM_ERROR;
    548     state = (gz_statep)file;
    549 
    550     /* check that we're writing */
    551     if (state->mode != GZ_WRITE)
    552         return Z_STREAM_ERROR;
    553 
    554     /* check for seek request */
    555     if (state->seek) {
    556         state->seek = 0;
    557         if (gz_zero(state, state->skip) == -1)
    558             ret = state->err;
    559     }
    560 
    561     /* flush, free memory, and close file */
    562     if (gz_comp(state, Z_FINISH) == -1)
    563         ret = state->err;
    564     if (state->size) {
    565         if (!state->direct) {
    566             (void)deflateEnd(&(state->strm));
    567             free(state->out);
    568         }
    569         free(state->in);
    570     }
    571     gz_error(state, Z_OK, NULL);
    572     free(state->path);
    573     if (close(state->fd) == -1)
    574         ret = Z_ERRNO;
    575     free(state);
    576     return ret;
    577 }
    578