+/*****************************************************************************
+ * access.c: libarchive based access
+ *****************************************************************************
+ * Copyright (C) 2014 Videolan Team
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#include "archive.h"
+
+#include <vlc_access.h>
+#include <vlc_url.h>
+#include <vlc_stream.h>
+
+#include <archive.h>
+#include <archive_entry.h>
+
+struct access_sys_t
+{
+ struct archive *p_archive;
+ bool b_source_canseek;
+ uint8_t buffer[ARCHIVE_READ_SIZE];
+
+ struct archive_entry *p_entry;
+ stream_t *p_stream;
+ char *psz_uri;
+ bool b_seekable; /* Is our archive type seekable ? */
+};
+
+static ssize_t Read(access_t *p_access, uint8_t *p_data, size_t i_size)
+{
+ access_sys_t *p_sys = p_access->p_sys;
+
+ size_t i_read = 0;
+
+ i_read = archive_read_data(p_sys->p_archive, p_data, i_size);
+
+ if (i_read > 0)
+ p_access->info.i_pos += i_read;
+
+ if (i_size > 0 && i_read <= 0)
+ p_access->info.b_eof = true;
+
+ return i_read;
+}
+
+static int Seek(access_t *p_access, uint64_t i_pos)
+{
+ access_sys_t *p_sys = p_access->p_sys;
+
+ if (!p_sys->b_seekable)
+ return VLC_EGENERIC;
+
+ int64_t i_ret = archive_seek_data(p_sys->p_archive, i_pos, SEEK_SET);
+ if ( i_ret < ARCHIVE_OK )
+ return VLC_EGENERIC;
+ p_access->info.i_pos = i_ret;
+
+ return VLC_SUCCESS;
+}
+
+static ssize_t ReadCallback(struct archive *p_archive, void *p_object, const void **pp_buffer)
+{
+ VLC_UNUSED(p_archive);
+ access_t *p_access = (access_t*)p_object;
+ access_sys_t *p_sys = p_access->p_sys;
+
+ *pp_buffer = &p_sys->buffer;
+ return stream_Read(p_sys->p_stream, &p_sys->buffer, ARCHIVE_READ_SIZE);
+}
+
+static ssize_t SkipCallback(struct archive *p_archive, void *p_object, ssize_t i_request)
+{
+ VLC_UNUSED(p_archive);
+ access_t *p_access = (access_t*)p_object;
+ access_sys_t *p_sys = p_access->p_sys;
+ ssize_t i_skipped = 0;
+
+ /* be smart as small seeks converts to reads */
+ if (p_sys->b_source_canseek)
+ {
+ int64_t i_pos = stream_Tell(p_sys->p_stream);
+ if (i_pos >=0)
+ stream_Seek(p_sys->p_stream, i_pos + i_request);
+ i_skipped = stream_Tell(p_sys->p_stream) - i_pos;
+ }
+ else while(i_request)
+ {
+ int i_skip = __MIN(INT32_MAX, i_request);
+ int i_read = stream_Read(p_sys->p_stream, NULL, i_skip);
+ if (i_read > 0)
+ i_skipped += i_read;
+ else
+ break;
+ i_request -= i_read;
+ }
+
+ return i_skipped;
+}
+
+static ssize_t SeekCallback(struct archive *p_archive, void *p_object, ssize_t i_offset, int i_whence)
+{
+ VLC_UNUSED(p_archive);
+ access_t *p_access = (access_t*)p_object;
+ access_sys_t *p_sys = p_access->p_sys;
+
+ ssize_t i_pos;
+
+ switch(i_whence)
+ {
+ case SEEK_CUR:
+ i_pos = stream_Tell(p_sys->p_stream);
+ break;
+ case SEEK_SET:
+ i_pos = 0;
+ break;
+ case SEEK_END:
+ i_pos = stream_Size(p_sys->p_stream) - 1;
+ break;
+ default:
+ return -1;
+ }
+
+ if (i_pos < 0)
+ return -1;
+
+ stream_Seek(p_sys->p_stream, i_pos + i_offset); /* We don't care about return val */
+ return stream_Tell(p_sys->p_stream);
+}
+
+static int OpenCallback(struct archive *p_archive, void *p_object)
+{
+ VLC_UNUSED(p_archive);
+ access_t *p_access = (access_t*)p_object;
+ access_sys_t *p_sys = p_access->p_sys;
+
+ p_sys->p_stream = stream_UrlNew( p_access, p_sys->psz_uri );
+ if(!p_sys->p_stream)
+ return ARCHIVE_FATAL;
+
+ /* Seek callback must only be set if calls are guaranteed to succeed */
+ stream_Control(p_sys->p_stream, STREAM_CAN_SEEK, &p_sys->b_source_canseek);
+ if(p_sys->b_source_canseek)
+ archive_read_set_seek_callback(p_sys->p_archive, SeekCallback);
+
+ return ARCHIVE_OK;
+}
+
+static int CloseCallback(struct archive *p_archive, void *p_object)
+{
+ VLC_UNUSED(p_archive);
+ access_t *p_access = (access_t*)p_object;
+
+ if (p_access->p_sys->p_stream)
+ stream_Delete(p_access->p_sys->p_stream);
+
+ return ARCHIVE_OK;
+}
+
+static int Control(access_t *p_access, int i_query, va_list args)
+{
+ access_sys_t *p_sys = p_access->p_sys;
+
+ switch (i_query)
+ {
+
+ case ACCESS_CAN_SEEK:
+ *va_arg(args, bool *)= p_sys->b_seekable;
+ break;
+
+ case ACCESS_CAN_FASTSEEK:
+ if (!p_sys->b_seekable || !p_sys->p_stream)
+ {
+ *va_arg( args, bool* ) = false;
+ break;
+ }
+ else
+ return stream_vaControl( p_sys->p_stream, i_query, args );
+
+ case ACCESS_SET_PAUSE_STATE:
+ break;
+
+ case ACCESS_CAN_PAUSE:
+ case ACCESS_CAN_CONTROL_PACE:
+ *va_arg(args, bool *) = true;
+ break;
+
+ case ACCESS_GET_SIZE:
+ *va_arg(args, uint64_t *) = archive_entry_size(p_sys->p_entry);
+ break;
+
+ case ACCESS_GET_PTS_DELAY:
+ *va_arg(args, int64_t *) = DEFAULT_PTS_DELAY;
+ break;
+
+ default:
+ return VLC_EGENERIC;
+ }
+ return VLC_SUCCESS;
+}
+
+int AccessOpen(vlc_object_t *p_object)
+{
+ access_t *p_access = (access_t*)p_object;
+
+ if (!strchr(p_access->psz_location, ARCHIVE_SEP_CHAR))
+ return VLC_EGENERIC;
+
+ char *psz_base = strdup(p_access->psz_location);
+ if (!psz_base)
+ return VLC_EGENERIC;
+ char *psz_name = strchr(psz_base, ARCHIVE_SEP_CHAR);
+ *psz_name++ = '\0';
+
+ if (decode_URI(psz_base) == NULL)
+ {
+ free(psz_base);
+ return VLC_EGENERIC;
+ }
+
+ access_sys_t *p_sys = p_access->p_sys = calloc(1, sizeof(access_sys_t));
+ p_sys->p_archive = archive_read_new();
+ if (!p_sys->p_archive)
+ {
+ msg_Err(p_access, "can't create libarchive instance: %s",
+ archive_error_string(p_sys->p_archive));
+ free(psz_base);
+ goto error;
+ }
+
+ EnableArchiveFormats(p_sys->p_archive);
+
+ p_sys->psz_uri = psz_base;
+
+ if (archive_read_open2(p_sys->p_archive, p_access, OpenCallback, ReadCallback, SkipCallback, CloseCallback) != ARCHIVE_OK)
+ {
+ msg_Err(p_access, "can't open archive: %s",
+ archive_error_string(p_sys->p_archive));
+ AccessClose(p_object);
+ return VLC_EGENERIC;
+ }
+
+ bool b_present = false;
+ while(archive_read_next_header(p_sys->p_archive, &p_sys->p_entry) == ARCHIVE_OK)
+ {
+ if (!strcmp(archive_entry_pathname(p_sys->p_entry), psz_name))
+ {
+ b_present = true;
+ break;
+ }
+ msg_Dbg(p_access, "skipping entry %s != %s", archive_entry_pathname(p_sys->p_entry), psz_name);
+ }
+
+ if (!b_present)
+ {
+ msg_Err(p_access, "entry '%s' not found in archive", psz_name);
+ /* entry not found */
+ goto error;
+ }
+
+ msg_Dbg(p_access, "reading entry %s %"PRId64, archive_entry_pathname(p_sys->p_entry),
+ archive_entry_size(p_sys->p_entry));
+
+ /* try to guess if it is seekable or not (does not depend on backend) */
+ p_sys->b_seekable = (archive_seek_data(p_sys->p_archive, 0, SEEK_SET) >= 0);
+
+ p_access->pf_read = Read;
+ p_access->pf_block = NULL; /* libarchive's zerocopy keeps owning block :/ */
+ p_access->pf_control = Control;
+ p_access->pf_seek = Seek;
+
+ access_InitFields(p_access);
+
+ return VLC_SUCCESS;
+
+error:
+ AccessClose(p_object);
+ return VLC_EGENERIC;
+}
+
+void AccessClose(vlc_object_t *p_object)
+{
+ access_t *p_access = (access_t*)p_object;
+ access_sys_t *p_sys = p_access->p_sys;
+
+ if (p_sys->p_archive)
+ archive_read_free(p_sys->p_archive);
+
+ free(p_sys->psz_uri);
+ free(p_sys);
+}