compression/zlib/gzwrite.c

0001 /* gzwrite.c -- zlib functions for writing gzip files
0002  * Copyright (C) 2004-2019 Mark Adler
0003  * For conditions of distribution and use, see copyright notice in zlib.h
0004  */
0005
0006 #include "gzguts.h"
0007
0008 /* Local functions */
0009 local int gz_init OF((gz_statep));
0010 local int gz_comp OF((gz_statep, int));
0011 local int gz_zero OF((gz_statep, z_off64_t));
0012 local z_size_t gz_write OF((gz_statep, voidpc, z_size_t));
0013
0014 /* Initialize state for writing a gzip file.  Mark initialization by setting
0015    state->size to non-zero.  Return -1 on a memory allocation failure, or 0 on
0016    success. */
0017 local int gz_init(state)
0018     gz_statep state;
0019 {
0020     int ret;
0021     z_streamp strm = &(state->strm);
0022
0023     /* allocate input buffer (double size for gzprintf) */
0024     state->in = (unsigned char *)malloc(state->want << 1);
0025     if (state->in == NULL) {
0026         gz_error(state, Z_MEM_ERROR, "out of memory");
0027         return -1;
0028     }
0029
0030     /* only need output buffer and deflate state if compressing */
0031     if (!state->direct) {
0032         /* allocate output buffer */
0033         state->out = (unsigned char *)malloc(state->want);
0034         if (state->out == NULL) {
0035             free(state->in);
0036             gz_error(state, Z_MEM_ERROR, "out of memory");
0037             return -1;
0038         }
0039
0040         /* allocate deflate memory, set up for gzip compression */
0041         strm->zalloc = Z_NULL;
0042         strm->zfree = Z_NULL;
0043         strm->opaque = Z_NULL;
0044         ret = deflateInit2(strm, state->level, Z_DEFLATED,
0045                            MAX_WBITS + 16, DEF_MEM_LEVEL, state->strategy);
0046         if (ret != Z_OK) {
0047             free(state->out);
0048             free(state->in);
0049             gz_error(state, Z_MEM_ERROR, "out of memory");
0050             return -1;
0051         }
0052         strm->next_in = NULL;
0053     }
0054
0055     /* mark state as initialized */
0056     state->size = state->want;
0057
0058     /* initialize write buffer if compressing */
0059     if (!state->direct) {
0060         strm->avail_out = state->size;
0061         strm->next_out = state->out;
0062         state->x.next = strm->next_out;
0063     }
0064     return 0;
0065 }
0066
0067 /* Compress whatever is at avail_in and next_in and write to the output file.
0068    Return -1 if there is an error writing to the output file or if gz_init()
0069    fails to allocate memory, otherwise 0.  flush is assumed to be a valid
0070    deflate() flush value.  If flush is Z_FINISH, then the deflate() state is
0071    reset to start a new gzip stream.  If gz->direct is true, then simply write
0072    to the output file without compressing, and ignore flush. */
0073 local int gz_comp(state, flush)
0074     gz_statep state;
0075     int flush;
0076 {
0077     int ret, writ;
0078     unsigned have, put, max = ((unsigned)-1 >> 2) + 1;
0079     z_streamp strm = &(state->strm);
0080
0081     /* allocate memory if this is the first time through */
0082     if (state->size == 0 && gz_init(state) == -1)
0083         return -1;
0084
0085     /* write directly if requested */
0086     if (state->direct) {
0087         while (strm->avail_in) {
0088             put = strm->avail_in > max ? max : strm->avail_in;
0089             writ = write(state->fd, strm->next_in, put);
0090             if (writ < 0) {
0091                 gz_error(state, Z_ERRNO, zstrerror());
0092                 return -1;
0093             }
0094             strm->avail_in -= (unsigned)writ;
0095             strm->next_in += writ;
0096         }
0097         return 0;
0098     }
0099
0100     /* check for a pending reset */
0101     if (state->reset) {
0102         /* don't start a new gzip member unless there is data to write */
0103         if (strm->avail_in == 0)
0104             return 0;
0105         deflateReset(strm);
0106         state->reset = 0;
0107     }
0108
0109     /* run deflate() on provided input until it produces no more output */
0110     ret = Z_OK;
0111     do {
0112         /* write out current buffer contents if full, or if flushing, but if
0113            doing Z_FINISH then don't write until we get to Z_STREAM_END */
0114         if (strm->avail_out == 0 || (flush != Z_NO_FLUSH &&
0115             (flush != Z_FINISH || ret == Z_STREAM_END))) {
0116             while (strm->next_out > state->x.next) {
0117                 put = strm->next_out - state->x.next > (int)max ? max :
0118                       (unsigned)(strm->next_out - state->x.next);
0119                 writ = write(state->fd, state->x.next, put);
0120                 if (writ < 0) {
0121                     gz_error(state, Z_ERRNO, zstrerror());
0122                     return -1;
0123                 }
0124                 state->x.next += writ;
0125             }
0126             if (strm->avail_out == 0) {
0127                 strm->avail_out = state->size;
0128                 strm->next_out = state->out;
0129                 state->x.next = state->out;
0130             }
0131         }
0132
0133         /* compress */
0134         have = strm->avail_out;
0135         ret = deflate(strm, flush);
0136         if (ret == Z_STREAM_ERROR) {
0137             gz_error(state, Z_STREAM_ERROR,
0138                       "internal error: deflate stream corrupt");
0139             return -1;
0140         }
0141         have -= strm->avail_out;
0142     } while (have);
0143
0144     /* if that completed a deflate stream, allow another to start */
0145     if (flush == Z_FINISH)
0146         state->reset = 1;
0147
0148     /* all done, no errors */
0149     return 0;
0150 }
0151
0152 /* Compress len zeros to output.  Return -1 on a write error or memory
0153    allocation failure by gz_comp(), or 0 on success. */
0154 local int gz_zero(state, len)
0155     gz_statep state;
0156     z_off64_t len;
0157 {
0158     int first;
0159     unsigned n;
0160     z_streamp strm = &(state->strm);
0161
0162     /* consume whatever's left in the input buffer */
0163     if (strm->avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
0164         return -1;
0165
0166     /* compress len zeros (len guaranteed > 0) */
0167     first = 1;
0168     while (len) {
0169         n = GT_OFF(state->size) || (z_off64_t)state->size > len ?
0170             (unsigned)len : state->size;
0171         if (first) {
0172             memset(state->in, 0, n);
0173             first = 0;
0174         }
0175         strm->avail_in = n;
0176         strm->next_in = state->in;
0177         state->x.pos += n;
0178         if (gz_comp(state, Z_NO_FLUSH) == -1)
0179             return -1;
0180         len -= n;
0181     }
0182     return 0;
0183 }
0184
0185 /* Write len bytes from buf to file.  Return the number of bytes written.  If
0186    the returned value is less than len, then there was an error. */
0187 local z_size_t gz_write(state, buf, len)
0188     gz_statep state;
0189     voidpc buf;
0190     z_size_t len;
0191 {
0192     z_size_t put = len;
0193
0194     /* if len is zero, avoid unnecessary operations */
0195     if (len == 0)
0196         return 0;
0197
0198     /* allocate memory if this is the first time through */
0199     if (state->size == 0 && gz_init(state) == -1)
0200         return 0;
0201
0202     /* check for seek request */
0203     if (state->seek) {
0204         state->seek = 0;
0205         if (gz_zero(state, state->skip) == -1)
0206             return 0;
0207     }
0208
0209     /* for small len, copy to input buffer, otherwise compress directly */
0210     if (len < state->size) {
0211         /* copy to input buffer, compress when full */
0212         do {
0213             unsigned have, copy;
0214
0215             if (state->strm.avail_in == 0)
0216                 state->strm.next_in = state->in;
0217             have = (unsigned)((state->strm.next_in + state->strm.avail_in) -
0218                               state->in);
0219             copy = state->size - have;
0220             if (copy > len)
0221                 copy = (unsigned)len;
0222             memcpy(state->in + have, buf, copy);
0223             state->strm.avail_in += copy;
0224             state->x.pos += copy;
0225             buf = (const char *)buf + copy;
0226             len -= copy;
0227             if (len && gz_comp(state, Z_NO_FLUSH) == -1)
0228                 return 0;
0229         } while (len);
0230     }
0231     else {
0232         /* consume whatever's left in the input buffer */
0233         if (state->strm.avail_in && gz_comp(state, Z_NO_FLUSH) == -1)
0234             return 0;
0235
0236         /* directly compress user buffer to file */
0237         state->strm.next_in = (z_const Bytef *)buf;
0238         do {
0239             unsigned n = (unsigned)-1;
0240             if (n > len)
0241                 n = (unsigned)len;
0242             state->strm.avail_in = n;
0243             state->x.pos += n;
0244             if (gz_comp(state, Z_NO_FLUSH) == -1)
0245                 return 0;
0246             len -= n;
0247         } while (len);
0248     }
0249
0250     /* input was all buffered or compressed */
0251     return put;
0252 }
0253
0254 /* -- see zlib.h -- */
0255 int ZEXPORT gzwrite(file, buf, len)
0256     gzFile file;
0257     voidpc buf;
0258     unsigned len;
0259 {
0260     gz_statep state;
0261
0262     /* get internal structure */
0263     if (file == NULL)
0264         return 0;
0265     state = (gz_statep)file;
0266
0267     /* check that we're writing and that there's no error */
0268     if (state->mode != GZ_WRITE || state->err != Z_OK)
0269         return 0;
0270
0271     /* since an int is returned, make sure len fits in one, otherwise return
0272        with an error (this avoids a flaw in the interface) */
0273     if ((int)len < 0) {
0274         gz_error(state, Z_DATA_ERROR, "requested length does not fit in int");
0275         return 0;
0276     }
0277
0278     /* write len bytes from buf (the return value will fit in an int) */
0279     return (int)gz_write(state, buf, len);
0280 }
0281
0282 /* -- see zlib.h -- */
0283 z_size_t ZEXPORT gzfwrite(buf, size, nitems, file)
0284     voidpc buf;
0285     z_size_t size;
0286     z_size_t nitems;
0287     gzFile file;
0288 {
0289     z_size_t len;
0290     gz_statep state;
0291
0292     /* get internal structure */
0293     if (file == NULL)
0294         return 0;
0295     state = (gz_statep)file;
0296
0297     /* check that we're writing and that there's no error */
0298     if (state->mode != GZ_WRITE || state->err != Z_OK)
0299         return 0;
0300
0301     /* compute bytes to read -- error on overflow */
0302     len = nitems * size;
0303     if (size && len / size != nitems) {
0304         gz_error(state, Z_STREAM_ERROR, "request does not fit in a size_t");
0305         return 0;
0306     }
0307
0308     /* write len bytes to buf, return the number of full items written */
0309     return len ? gz_write(state, buf, len) / size : 0;
0310 }
0311
0312 /* -- see zlib.h -- */
0313 int ZEXPORT gzputc(file, c)
0314     gzFile file;
0315     int c;
0316 {
0317     unsigned have;
0318     unsigned char buf[1];
0319     gz_statep state;
0320     z_streamp strm;
0321
0322     /* get internal structure */
0323     if (file == NULL)
0324         return -1;
0325     state = (gz_statep)file;
0326     strm = &(state->strm);
0327
0328     /* check that we're writing and that there's no error */
0329     if (state->mode != GZ_WRITE || state->err != Z_OK)
0330         return -1;
0331
0332     /* check for seek request */
0333     if (state->seek) {
0334         state->seek = 0;
0335         if (gz_zero(state, state->skip) == -1)
0336             return -1;
0337     }
0338
0339     /* try writing to input buffer for speed (state->size == 0 if buffer not
0340        initialized) */
0341     if (state->size) {
0342         if (strm->avail_in == 0)
0343             strm->next_in = state->in;
0344         have = (unsigned)((strm->next_in + strm->avail_in) - state->in);
0345         if (have < state->size) {
0346             state->in[have] = (unsigned char)c;
0347             strm->avail_in++;
0348             state->x.pos++;
0349             return c & 0xff;
0350         }
0351     }
0352
0353     /* no room in buffer or not initialized, use gz_write() */
0354     buf[0] = (unsigned char)c;
0355     if (gz_write(state, buf, 1) != 1)
0356         return -1;
0357     return c & 0xff;
0358 }
0359
0360 /* -- see zlib.h -- */
0361 int ZEXPORT gzputs(file, s)
0362     gzFile file;
0363     const char *s;
0364 {
0365     z_size_t len, put;
0366     gz_statep state;
0367
0368     /* get internal structure */
0369     if (file == NULL)
0370         return -1;
0371     state = (gz_statep)file;
0372
0373     /* check that we're writing and that there's no error */
0374     if (state->mode != GZ_WRITE || state->err != Z_OK)
0375         return -1;
0376
0377     /* write string */
0378     len = strlen(s);
0379     if ((int)len < 0 || (unsigned)len != len) {
0380         gz_error(state, Z_STREAM_ERROR, "string length does not fit in int");
0381         return -1;
0382     }
0383     put = gz_write(state, s, len);
0384     return put < len ? -1 : (int)len;
0385 }
0386
0387 #if defined(STDC) || defined(Z_HAVE_STDARG_H)
0388 #include <stdarg.h>
0389
0390 /* -- see zlib.h -- */
0391 int ZEXPORTVA gzvprintf(gzFile file, const char *format, va_list va)
0392 {
0393     int len;
0394     unsigned left;
0395     char *next;
0396     gz_statep state;
0397     z_streamp strm;
0398
0399     /* get internal structure */
0400     if (file == NULL)
0401         return Z_STREAM_ERROR;
0402     state = (gz_statep)file;
0403     strm = &(state->strm);
0404
0405     /* check that we're writing and that there's no error */
0406     if (state->mode != GZ_WRITE || state->err != Z_OK)
0407         return Z_STREAM_ERROR;
0408
0409     /* make sure we have some buffer space */
0410     if (state->size == 0 && gz_init(state) == -1)
0411         return state->err;
0412
0413     /* check for seek request */
0414     if (state->seek) {
0415         state->seek = 0;
0416         if (gz_zero(state, state->skip) == -1)
0417             return state->err;
0418     }
0419
0420     /* do the printf() into the input buffer, put length in len -- the input
0421        buffer is double-sized just for this function, so there is guaranteed to
0422        be state->size bytes available after the current contents */
0423     if (strm->avail_in == 0)
0424         strm->next_in = state->in;
0425     next = (char *)(state->in + (strm->next_in - state->in) + strm->avail_in);
0426     next[state->size - 1] = 0;
0427 #ifdef NO_vsnprintf
0428 #  ifdef HAS_vsprintf_void
0429     (void)vsprintf(next, format, va);
0430     for (len = 0; len < state->size; len++)
0431         if (next[len] == 0) break;
0432 #  else
0433     len = vsprintf(next, format, va);
0434 #  endif
0435 #else
0436 #  ifdef HAS_vsnprintf_void
0437     (void)vsnprintf(next, state->size, format, va);
0438     len = strlen(next);
0439 #  else
0440     len = vsnprintf(next, state->size, format, va);
0441 #  endif
0442 #endif
0443
0444     /* check that printf() results fit in buffer */
0445     if (len == 0 || (unsigned)len >= state->size || next[state->size - 1] != 0)
0446         return 0;
0447
0448     /* update buffer and position, compress first half if past that */
0449     strm->avail_in += (unsigned)len;
0450     state->x.pos += len;
0451     if (strm->avail_in >= state->size) {
0452         left = strm->avail_in - state->size;
0453         strm->avail_in = state->size;
0454         if (gz_comp(state, Z_NO_FLUSH) == -1)
0455             return state->err;
0456         memmove(state->in, state->in + state->size, left);
0457         strm->next_in = state->in;
0458         strm->avail_in = left;
0459     }
0460     return len;
0461 }
0462
0463 int ZEXPORTVA gzprintf(gzFile file, const char *format, ...)
0464 {
0465     va_list va;
0466     int ret;
0467
0468     va_start(va, format);
0469     ret = gzvprintf(file, format, va);
0470     va_end(va);
0471     return ret;
0472 }
0473
0474 #else /* !STDC && !Z_HAVE_STDARG_H */
0475
0476 /* -- see zlib.h -- */
0477 int ZEXPORTVA gzprintf(file, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
0478                        a11, a12, a13, a14, a15, a16, a17, a18, a19, a20)
0479     gzFile file;
0480     const char *format;
0481     int a1, a2, a3, a4, a5, a6, a7, a8, a9, a10,
0482         a11, a12, a13, a14, a15, a16, a17, a18, a19, a20;
0483 {
0484     unsigned len, left;
0485     char *next;
0486     gz_statep state;
0487     z_streamp strm;
0488
0489     /* get internal structure */
0490     if (file == NULL)
0491         return Z_STREAM_ERROR;
0492     state = (gz_statep)file;
0493     strm = &(state->strm);
0494
0495     /* check that can really pass pointer in ints */
0496     if (sizeof(int) != sizeof(void *))
0497         return Z_STREAM_ERROR;
0498
0499     /* check that we're writing and that there's no error */
0500     if (state->mode != GZ_WRITE || state->err != Z_OK)
0501         return Z_STREAM_ERROR;
0502
0503     /* make sure we have some buffer space */
0504     if (state->size == 0 && gz_init(state) == -1)
0505         return state->error;
0506
0507     /* check for seek request */
0508     if (state->seek) {
0509         state->seek = 0;
0510         if (gz_zero(state, state->skip) == -1)
0511             return state->error;
0512     }
0513
0514     /* do the printf() into the input buffer, put length in len -- the input
0515        buffer is double-sized just for this function, so there is guaranteed to
0516        be state->size bytes available after the current contents */
0517     if (strm->avail_in == 0)
0518         strm->next_in = state->in;
0519     next = (char *)(strm->next_in + strm->avail_in);
0520     next[state->size - 1] = 0;
0521 #ifdef NO_snprintf
0522 #  ifdef HAS_sprintf_void
0523     sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12,
0524             a13, a14, a15, a16, a17, a18, a19, a20);
0525     for (len = 0; len < size; len++)
0526         if (next[len] == 0)
0527             break;
0528 #  else
0529     len = sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
0530                   a12, a13, a14, a15, a16, a17, a18, a19, a20);
0531 #  endif
0532 #else
0533 #  ifdef HAS_snprintf_void
0534     snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
0535              a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
0536     len = strlen(next);
0537 #  else
0538     len = snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8,
0539                    a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
0540 #  endif
0541 #endif
0542
0543     /* check that printf() results fit in buffer */
0544     if (len == 0 || len >= state->size || next[state->size - 1] != 0)
0545         return 0;
0546
0547     /* update buffer and position, compress first half if past that */
0548     strm->avail_in += len;
0549     state->x.pos += len;
0550     if (strm->avail_in >= state->size) {
0551         left = strm->avail_in - state->size;
0552         strm->avail_in = state->size;
0553         if (gz_comp(state, Z_NO_FLUSH) == -1)
0554             return state->err;
0555         memmove(state->in, state->in + state->size, left);
0556         strm->next_in = state->in;
0557         strm->avail_in = left;
0558     }
0559     return (int)len;
0560 }
0561
0562 #endif
0563
0564 /* -- see zlib.h -- */
0565 int ZEXPORT gzflush(file, flush)
0566     gzFile file;
0567     int flush;
0568 {
0569     gz_statep state;
0570
0571     /* get internal structure */
0572     if (file == NULL)
0573         return Z_STREAM_ERROR;
0574     state = (gz_statep)file;
0575
0576     /* check that we're writing and that there's no error */
0577     if (state->mode != GZ_WRITE || state->err != Z_OK)
0578         return Z_STREAM_ERROR;
0579
0580     /* check flush parameter */
0581     if (flush < 0 || flush > Z_FINISH)
0582         return Z_STREAM_ERROR;
0583
0584     /* check for seek request */
0585     if (state->seek) {
0586         state->seek = 0;
0587         if (gz_zero(state, state->skip) == -1)
0588             return state->err;
0589     }
0590
0591     /* compress remaining data with requested flush */
0592     (void)gz_comp(state, flush);
0593     return state->err;
0594 }
0595
0596 /* -- see zlib.h -- */
0597 int ZEXPORT gzsetparams(file, level, strategy)
0598     gzFile file;
0599     int level;
0600     int strategy;
0601 {
0602     gz_statep state;
0603     z_streamp strm;
0604
0605     /* get internal structure */
0606     if (file == NULL)
0607         return Z_STREAM_ERROR;
0608     state = (gz_statep)file;
0609     strm = &(state->strm);
0610
0611     /* check that we're writing and that there's no error */
0612     if (state->mode != GZ_WRITE || state->err != Z_OK)
0613         return Z_STREAM_ERROR;
0614
0615     /* if no change is requested, then do nothing */
0616     if (level == state->level && strategy == state->strategy)
0617         return Z_OK;
0618
0619     /* check for seek request */
0620     if (state->seek) {
0621         state->seek = 0;
0622         if (gz_zero(state, state->skip) == -1)
0623             return state->err;
0624     }
0625
0626     /* change compression parameters for subsequent input */
0627     if (state->size) {
0628         /* flush previous input with previous parameters before changing */
0629         if (strm->avail_in && gz_comp(state, Z_BLOCK) == -1)
0630             return state->err;
0631         deflateParams(strm, level, strategy);
0632     }
0633     state->level = level;
0634     state->strategy = strategy;
0635     return Z_OK;
0636 }
0637
0638 /* -- see zlib.h -- */
0639 int ZEXPORT gzclose_w(file)
0640     gzFile file;
0641 {
0642     int ret = Z_OK;
0643     gz_statep state;
0644
0645     /* get internal structure */
0646     if (file == NULL)
0647         return Z_STREAM_ERROR;
0648     state = (gz_statep)file;
0649
0650     /* check that we're writing */
0651     if (state->mode != GZ_WRITE)
0652         return Z_STREAM_ERROR;
0653
0654     /* check for seek request */
0655     if (state->seek) {
0656         state->seek = 0;
0657         if (gz_zero(state, state->skip) == -1)
0658             ret = state->err;
0659     }
0660
0661     /* flush, free memory, and close file */
0662     if (gz_comp(state, Z_FINISH) == -1)
0663         ret = state->err;
0664     if (state->size) {
0665         if (!state->direct) {
0666             (void)deflateEnd(&(state->strm));
0667             free(state->out);
0668         }
0669         free(state->in);
0670     }
0671     gz_error(state, Z_OK, NULL);
0672     free(state->path);
0673     if (close(state->fd) == -1)
0674         ret = Z_ERRNO;
0675     free(state);
0676     return ret;
0677 }