+/* PSPP - a program for statistical analysis.
+ Copyright (C) 2010 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 "libpspp/zip-writer.h"
+
+#include <errno.h>
+#include <stdlib.h>
+#include <time.h>
+
+#include "libpspp/integer-format.h"
+
+#include "gl/crc.h"
+#include "gl/error.h"
+#include "gl/fwriteerror.h"
+#include "gl/xalloc.h"
+
+#include "gettext.h"
+#define _(msgid) gettext (msgid)
+
+struct zip_writer
+ {
+ char *file_name; /* File name, for use in error mesages. */
+ FILE *file; /* Output stream. */
+
+ uint16_t date, time; /* Date and time in MS-DOS format. */
+
+ /* Members already added to the file, so that we can summarize them to the
+ central directory at the end of the ZIP file. */
+ struct zip_member *members;
+ size_t n_members, allocated_members;
+ };
+
+struct zip_member
+ {
+ uint32_t offset; /* Starting offset in file. */
+ uint32_t size; /* Length of member file data, in bytes. */
+ uint32_t crc; /* CRC-32 of member file data.. */
+ char *name; /* Name of member file. */
+ };
+
+static void
+put_bytes (struct zip_writer *zw, const void *p, size_t n)
+{
+ fwrite (p, 1, n, zw->file);
+}
+
+static void
+put_u16 (struct zip_writer *zw, uint16_t x)
+{
+ if (INTEGER_NATIVE != INTEGER_LSB_FIRST)
+ integer_convert (INTEGER_NATIVE, &x, INTEGER_MSB_FIRST, &x, sizeof x);
+ put_bytes (zw, &x, sizeof x);
+}
+
+static void
+put_u32 (struct zip_writer *zw, uint32_t x)
+{
+ if (INTEGER_NATIVE != INTEGER_LSB_FIRST)
+ integer_convert (INTEGER_NATIVE, &x, INTEGER_MSB_FIRST, &x, sizeof x);
+ put_bytes (zw, &x, sizeof x);
+}
+
+/* Starts writing a new ZIP file named FILE_NAME. Returns a new zip_writer if
+ successful, otherwise a null pointer. */
+struct zip_writer *
+zip_writer_create (const char *file_name)
+{
+ struct zip_writer *zw;
+ struct tm *tm;
+ time_t now;
+ FILE *file;
+
+ file = fopen (file_name, "wb");
+ if (file == NULL)
+ {
+ error (0, errno, _("%s: error opening output file"), file_name);
+ return NULL;
+ }
+
+ zw = xmalloc (sizeof *zw);
+ zw->file_name = xstrdup (file_name);
+ zw->file = file;
+
+ now = time (NULL);
+ tm = localtime (&now);
+ zw->date = tm->tm_mday + ((tm->tm_mon + 1) << 5) + ((tm->tm_year - 80) << 9);
+ zw->time = tm->tm_sec / 2 + (tm->tm_min << 5) + (tm->tm_hour << 11);
+
+ zw->members = NULL;
+ zw->n_members = 0;
+ zw->allocated_members = 0;
+
+ return zw;
+}
+
+/* Adds the contents of FILE, with name MEMBER_NAME, to ZW. */
+void
+zip_writer_add (struct zip_writer *zw, FILE *file, const char *member_name)
+{
+ struct zip_member *member;
+ uint32_t offset, size;
+ size_t bytes_read;
+ uint32_t crc;
+ char buf[4096];
+
+ /* Local file header. */
+ offset = ftell (zw->file);
+ put_u32 (zw, 0x04034b50); /* local file header signature */
+ put_u16 (zw, 10); /* version needed to extract */
+ put_u16 (zw, 1 << 3); /* general purpose bit flag */
+ put_u16 (zw, 0); /* compression method */
+ put_u16 (zw, zw->time); /* last mod file time */
+ put_u16 (zw, zw->date); /* last mod file date */
+ put_u32 (zw, 0); /* crc-32 */
+ put_u32 (zw, 0); /* compressed size */
+ put_u32 (zw, 0); /* uncompressed size */
+ put_u16 (zw, strlen (member_name)); /* file name length */
+ put_u16 (zw, 0); /* extra field length */
+ put_bytes (zw, member_name, strlen (member_name));
+
+ /* File data. */
+ size = crc = 0;
+ fseek (file, 0, SEEK_SET);
+ while ((bytes_read = fread (buf, 1, sizeof buf, file)) > 0)
+ {
+ put_bytes (zw, buf, bytes_read);
+ size += bytes_read;
+ crc = crc32_update (crc, buf, bytes_read);
+ }
+
+ /* Data descriptor. */
+ put_u32 (zw, 0x08074b50);
+ put_u32 (zw, crc);
+ put_u32 (zw, size);
+ put_u32 (zw, size);
+
+ /* Add to set of members. */
+ if (zw->n_members >= zw->allocated_members)
+ zw->members = x2nrealloc (zw->members, &zw->allocated_members,
+ sizeof *zw->members);
+ member = &zw->members[zw->n_members++];
+ member->offset = offset;
+ member->size = size;
+ member->crc = crc;
+ member->name = xstrdup (member_name);
+}
+
+/* Finalizes the contents of ZW and closes it. Returns true if successful,
+ false if a write error occurred while finalizing the file or at any earlier
+ time. */
+bool
+zip_writer_close (struct zip_writer *zw)
+{
+ uint32_t dir_start, dir_end;
+ size_t i;
+ bool ok;
+
+ if (zw == NULL)
+ return true;
+
+ dir_start = ftell (zw->file);
+ for (i = 0; i < zw->n_members; i++)
+ {
+ struct zip_member *m = &zw->members[i];
+
+ /* Central directory file header. */
+ put_u32 (zw, 0x02014b50); /* central file header signature */
+ put_u16 (zw, 63); /* version made by */
+ put_u16 (zw, 10); /* version needed to extract */
+ put_u16 (zw, 1 << 3); /* general purpose bit flag */
+ put_u16 (zw, 0); /* compression method */
+ put_u16 (zw, zw->time); /* last mod file time */
+ put_u16 (zw, zw->date); /* last mod file date */
+ put_u32 (zw, m->crc); /* crc-32 */
+ put_u32 (zw, m->size); /* compressed size */
+ put_u32 (zw, m->size); /* uncompressed size */
+ put_u16 (zw, strlen (m->name)); /* file name length */
+ put_u16 (zw, 0); /* extra field length */
+ put_u16 (zw, 0); /* file comment length */
+ put_u16 (zw, 0); /* disk number start */
+ put_u16 (zw, 0); /* internal file attributes */
+ put_u32 (zw, 0); /* external file attributes */
+ put_u32 (zw, m->offset); /* relative offset of local header */
+ put_bytes (zw, m->name, strlen (m->name));
+ free (m->name);
+ }
+ free (zw->members);
+ dir_end = ftell (zw->file);
+
+ /* End of central directory record. */
+ put_u32 (zw, 0x06054b50); /* end of central dir signature */
+ put_u16 (zw, 0); /* number of this disk */
+ put_u16 (zw, 0); /* number of the disk with the
+ start of the central directory */
+ put_u16 (zw, zw->n_members); /* total number of entries in the
+ central directory on this disk */
+ put_u16 (zw, zw->n_members); /* total number of entries in
+ the central directory */
+ put_u32 (zw, dir_end - dir_start); /* size of the central directory */
+ put_u32 (zw, dir_start); /* offset of start of central
+ directory with respect to
+ the starting disk number */
+ put_u16 (zw, 0); /* .ZIP file comment length */
+
+ if (!fwriteerror (zw->file))
+ ok = true;
+ else
+ {
+ error (0, errno, _("%s: write failed"), zw->file_name);
+ ok = false;
+ }
+
+ free (zw->file_name);
+ free (zw);
+
+ return ok;
+}