-/* PSPP - a program for statistical analysis.
- Copyright (C) 2011, 2013 Free Software Foundation, Inc.
-
- This program is free software: you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation, either version 3 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>. */
-
-
-#include <config.h>
-
-#include "inflate.h"
-
-#include <xalloc.h>
-#include <zlib.h>
-#include <stdio.h>
-#include <stdlib.h>
-#include "zip-reader.h"
-
-#include "str.h"
-
-#include "gettext.h"
-#define _(msgid) gettext (msgid)
-#define N_(msgid) (msgid)
-
-#define UCOMPSIZE 4096
-
-struct inflator
-{
- z_stream zss;
- int state;
- unsigned char ucomp[UCOMPSIZE];
- size_t bytes_uncomp;
- size_t ucomp_bytes_read;
-
- /* Two bitfields as defined by RFC1950 */
- uint16_t cmf_flg ;
-};
-
-void
-inflate_finish (struct zip_member *zm)
-{
- struct inflator *inf = zm->aux;
-
- inflateEnd (&inf->zss);
-
- free (inf);
-}
-
-bool
-inflate_init (struct zip_member *zm)
-{
- int r;
- struct inflator *inf = xzalloc (sizeof *inf);
-
- uint16_t flg = 0 ;
- uint16_t cmf = 0x8; /* Always 8 for inflate */
-
- const uint16_t cinfo = 7; /* log_2(Window size) - 8 */
-
- cmf |= cinfo << 4; /* Put cinfo into the high nibble */
-
- /* make these into a 16 bit word */
- inf->cmf_flg = (cmf << 8 ) | flg;
-
- /* Set the check bits */
- inf->cmf_flg += 31 - (inf->cmf_flg % 31);
- assert (inf->cmf_flg % 31 == 0);
-
- inf->zss.next_in = Z_NULL;
- inf->zss.avail_in = 0;
- inf->zss.zalloc = Z_NULL;
- inf->zss.zfree = Z_NULL;
- inf->zss.opaque = Z_NULL;
- r = inflateInit (&inf->zss);
-
- if ( Z_OK != r)
- {
- ds_put_format (zm->errmsgs, _("Cannot initialize inflator: %s"), zError (r));
- return false;
- }
-
- zm->aux = inf;
-
- return true;
-}
-
-
-int
-inflate_read (struct zip_member *zm, void *buf, size_t n)
-{
- int r;
- struct inflator *inf = zm->aux;
-
- if (inf->zss.avail_in == 0)
- {
- int bytes_read;
- int bytes_to_read;
- int pad = 0;
-
- if ( inf->state == 0)
- {
- inf->ucomp[1] = inf->cmf_flg ;
- inf->ucomp[0] = inf->cmf_flg >> 8 ;
-
- pad = 2;
- inf->state++;
- }
-
- bytes_to_read = zm->comp_size - inf->ucomp_bytes_read;
-
- if (bytes_to_read == 0)
- return 0;
-
- if (bytes_to_read > UCOMPSIZE)
- bytes_to_read = UCOMPSIZE;
-
- bytes_read = fread (inf->ucomp + pad, 1, bytes_to_read - pad, zm->fp);
-
- inf->ucomp_bytes_read += bytes_read;
-
- inf->zss.avail_in = bytes_read + pad;
- inf->zss.next_in = inf->ucomp;
- }
- inf->zss.avail_out = n;
- inf->zss.next_out = buf;
-
- r = inflate (&inf->zss, Z_NO_FLUSH);
- if ( Z_OK == r)
- {
- return n - inf->zss.avail_out;
- }
-
- ds_put_format (zm->errmsgs, _("Error inflating: %s"), zError (r));
-
- return -1;
-}