lib/deflate.c

   1 /*
   2  * Copyright (c) 2019 Stefan Sperling <stsp@openbsd.org>
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17
  18 #include <errno.h>
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <zlib.h>
  23 #include <time.h>
  24
  25 #include "got_error.h"
  26 #include "got_object.h"
  27 #include "got_path.h"
  28
  29 #include "got_lib_deflate.h"
  30
  31 #ifndef MIN
  32 #define MIN(_a,_b) ((_a) < (_b) ? (_a) : (_b))
  33 #endif
  34
  35 const struct got_error *
  36 got_deflate_init(struct got_deflate_buf *zb, uint8_t *outbuf, size_t bufsize)
  37 {
  38         const struct got_error *err = NULL;
  39         int zerr;
  40
  41         memset(&zb->z, 0, sizeof(zb->z));
  42
  43         zb->z.zalloc = Z_NULL;
  44         zb->z.zfree = Z_NULL;
  45         zerr = deflateInit(&zb->z, Z_DEFAULT_COMPRESSION);
  46         if (zerr != Z_OK) {
  47                 if  (zerr == Z_ERRNO)
  48                         return got_error_from_errno("deflateInit");
  49                 if  (zerr == Z_MEM_ERROR) {
  50                         errno = ENOMEM;
  51                         return got_error_from_errno("deflateInit");
  52                 }
  53                 return got_error(GOT_ERR_COMPRESSION);
  54         }
  55
  56         zb->inlen = zb->outlen = bufsize;
  57
  58         zb->inbuf = calloc(1, zb->inlen);
  59         if (zb->inbuf == NULL) {
  60                 err = got_error_from_errno("calloc");
  61                 goto done;
  62         }
  63
  64         zb->flags = 0;
  65         if (outbuf == NULL) {
  66                 zb->outbuf = calloc(1, zb->outlen);
  67                 if (zb->outbuf == NULL) {
  68                         err = got_error_from_errno("calloc");
  69                         goto done;
  70                 }
  71                 zb->flags |= GOT_DEFLATE_F_OWN_OUTBUF;
  72         } else
  73                 zb->outbuf = outbuf;
  74 done:
  75         if (err)
  76                 got_deflate_end(zb);
  77         return err;
  78 }
  79
  80 static void
  81 csum_output(struct got_deflate_checksum *csum, const uint8_t *buf, size_t len)
  82 {
  83         if (csum->output_crc)
  84                 *csum->output_crc = crc32(*csum->output_crc, buf, len);
  85
  86         if (csum->output_sha1)
  87                 SHA1Update(csum->output_sha1, buf, len);
  88 }
  89
  90 const struct got_error *
  91 got_deflate_read(struct got_deflate_buf *zb, FILE *f, size_t *outlenp)
  92 {
  93         size_t last_total_out = zb->z.total_out;
  94         z_stream *z = &zb->z;
  95         int ret = Z_ERRNO;
  96
  97         z->next_out = zb->outbuf;
  98         z->avail_out = zb->outlen;
  99
 100         *outlenp = 0;
 101         do {
 102                 if (z->avail_in == 0) {
 103                         size_t n = fread(zb->inbuf, 1, zb->inlen, f);
 104                         if (n == 0) {
 105                                 if (ferror(f))
 106                                         return got_ferror(f, GOT_ERR_IO);
 107                                 /* EOF */
 108                                 ret = deflate(z, Z_FINISH);
 109                                 break;
 110                         }
 111                         z->next_in = zb->inbuf;
 112                         z->avail_in = n;
 113                 }
 114                 ret = deflate(z, Z_NO_FLUSH);
 115         } while (ret == Z_OK && z->avail_out > 0);
 116
 117         if (ret == Z_OK) {
 118                 zb->flags |= GOT_DEFLATE_F_HAVE_MORE;
 119         } else {
 120                 if (ret != Z_STREAM_END)
 121                         return got_error(GOT_ERR_COMPRESSION);
 122                 zb->flags &= ~GOT_DEFLATE_F_HAVE_MORE;
 123         }
 124
 125         *outlenp = z->total_out - last_total_out;
 126         return NULL;
 127 }
 128
 129 void
 130 got_deflate_end(struct got_deflate_buf *zb)
 131 {
 132         free(zb->inbuf);
 133         if (zb->flags & GOT_DEFLATE_F_OWN_OUTBUF)
 134                 free(zb->outbuf);
 135         deflateEnd(&zb->z);
 136 }
 137
 138 const struct got_error *
 139 got_deflate_to_file(size_t *outlen, FILE *infile, FILE *outfile,
 140     struct got_deflate_checksum *csum)
 141 {
 142         const struct got_error *err;
 143         size_t avail;
 144         struct got_deflate_buf zb;
 145
 146         err = got_deflate_init(&zb, NULL, GOT_DEFLATE_BUFSIZE);
 147         if (err)
 148                 goto done;
 149
 150         *outlen = 0;
 151
 152         do {
 153                 err = got_deflate_read(&zb, infile, &avail);
 154                 if (err)
 155                         goto done;
 156                 if (avail > 0) {
 157                         size_t n;
 158                         n = fwrite(zb.outbuf, avail, 1, outfile);
 159                         if (n != 1) {
 160                                 err = got_ferror(outfile, GOT_ERR_IO);
 161                                 goto done;
 162                         }
 163                         if (csum)
 164                                 csum_output(csum, zb.outbuf, avail);
 165                         *outlen += avail;
 166                 }
 167         } while (zb.flags & GOT_DEFLATE_F_HAVE_MORE);
 168
 169 done:
 170         got_deflate_end(&zb);
 171         return err;
 172 }