zip.c

   1 /* zip.c -- compress files to the gzip or pkzip format
   2
   3    Copyright (C) 1997-1999, 2006-2007, 2009-2022 Free Software Foundation, Inc.
   4    Copyright (C) 1992-1993 Jean-loup Gailly
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3, or (at your option)
   9    any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software Foundation,
  18    Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
  19
  20 #include <config.h>
  21 #include <ctype.h>
  22
  23 #include "tailor.h"
  24 #include "gzip.h"
  25
  26 off_t header_bytes;   /* number of bytes in gzip header */
  27
  28 /* Speed options for the general purpose bit flag.  */
  29 enum { SLOW = 2, FAST = 4 };
  30
  31 /* ===========================================================================
  32  * Deflate in to out.
  33  * IN assertions: the input and output buffers are cleared.
  34  *   The variables time_stamp and save_orig_name are initialized.
  35  */
  36 int zip(in, out)
  37     int in, out;            /* input and output file descriptors */
  38 {
  39     uch  flags = 0;         /* general purpose bit flags */
  40     ush  attr = 0;          /* ascii/binary flag */
  41     ush  deflate_flags = 0; /* pkzip -es, -en or -ex equivalent */
  42     ulg  stamp;
  43
  44     ifd = in;
  45     ofd = out;
  46     outcnt = 0;
  47
  48     /* Write the header to the gzip file. See algorithm.doc for the format */
  49
  50     method = DEFLATED;
  51     put_byte(GZIP_MAGIC[0]); /* magic header */
  52     put_byte(GZIP_MAGIC[1]);
  53     put_byte(DEFLATED);      /* compression method */
  54
  55     if (save_orig_name) {
  56         flags |= ORIG_NAME;
  57     }
  58     put_byte(flags);         /* general flags */
  59     if (time_stamp.tv_nsec < 0)
  60       stamp = 0;
  61     else if (0 < time_stamp.tv_sec && time_stamp.tv_sec <= 0xffffffff)
  62       stamp = time_stamp.tv_sec;
  63     else
  64       {
  65         /* It's intended that timestamp 0 generates this warning,
  66            since gzip format reserves 0 for something else.  */
  67         warning ("file timestamp out of range for gzip format");
  68         stamp = 0;
  69       }
  70     put_long (stamp);
  71
  72     /* Write deflated file to zip file */
  73     updcrc (NULL, 0);
  74
  75     bi_init(out);
  76     ct_init(&attr, &method);
  77     if (level == 1)
  78       deflate_flags |= FAST;
  79     else if (level == 9)
  80       deflate_flags |= SLOW;
  81
  82     put_byte((uch)deflate_flags); /* extra flags */
  83     put_byte(OS_CODE);            /* OS identifier */
  84
  85     if (save_orig_name) {
  86         char *p = gzip_base_name (ifname); /* Don't save the directory part. */
  87         do {
  88             put_byte (*p);
  89         } while (*p++);
  90     }
  91     header_bytes = (off_t)outcnt;
  92
  93 #ifdef IBM_Z_DFLTCC
  94     dfltcc_deflate (level);
  95 #else
  96     deflate (level);
  97 #endif
  98
  99 #ifndef NO_SIZE_CHECK
 100   /* Check input size
 101    * (but not on MSDOS -- diet in TSR mode reports an incorrect file size)
 102    */
 103     if (ifile_size != -1L && bytes_in != ifile_size) {
 104         fprintf(stderr, "%s: %s: file size changed while zipping\n",
 105                 program_name, ifname);
 106     }
 107 #endif
 108
 109     /* Write the crc and uncompressed size */
 110     put_long (getcrc ());
 111     put_long((ulg)bytes_in);
 112     header_bytes += 2*4;
 113
 114     flush_outbuf();
 115     return OK;
 116 }
 117
 118
 119 /* ===========================================================================
 120  * Read a new buffer from the current input file, perform end-of-line
 121  * translation, and update the crc and input file size.
 122  * IN assertion: size >= 2 (for end-of-line translation)
 123  */
 124 int file_read(buf, size)
 125     char *buf;
 126     unsigned size;
 127 {
 128     unsigned len;
 129
 130     Assert(insize == 0, "inbuf not empty");
 131
 132     len = read_buffer (ifd, buf, size);
 133     if (len == 0) return (int)len;
 134     if (len == (unsigned)-1) {
 135         read_error();
 136     }
 137
 138     updcrc ((uch *) buf, len);
 139     bytes_in += (off_t)len;
 140     return (int)len;
 141 }