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authorMax Kellermann <max@duempel.org>2010-11-18 21:44:24 +0100
committerMax Kellermann <max@duempel.org>2010-11-18 21:44:24 +0100
commit11613347bedef464029c167116d226ec3fddfdcd (patch)
tree14ddc1a52d1df90c2cd63ab5316f92254f7b77b5 /src/ape.c
parent8f46f1520cdb3e3e131b2021ac40325f6bdda2c8 (diff)
downloadmpd-11613347bedef464029c167116d226ec3fddfdcd.tar.gz
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tag_ape: move code to ape.c
Generic library for scanning APE tags. Eliminated one "goto"!
Diffstat (limited to 'src/ape.c')
-rw-r--r--src/ape.c113
1 files changed, 113 insertions, 0 deletions
diff --git a/src/ape.c b/src/ape.c
new file mode 100644
index 000000000..5fca98e28
--- /dev/null
+++ b/src/ape.c
@@ -0,0 +1,113 @@
+/*
+ * Copyright (C) 2003-2010 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "ape.h"
+
+#include <glib.h>
+
+#include <stdint.h>
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+struct ape_footer {
+ unsigned char id[8];
+ uint32_t version;
+ uint32_t length;
+ uint32_t count;
+ unsigned char flags[4];
+ unsigned char reserved[8];
+};
+
+static bool
+ape_scan_internal(FILE *fp, tag_ape_callback_t callback, void *ctx)
+{
+ /* determine if file has an apeV2 tag */
+ struct ape_footer footer;
+ if (fseek(fp, -(long)sizeof(footer), SEEK_END) ||
+ fread(&footer, 1, sizeof(footer), fp) != sizeof(footer) ||
+ memcmp(footer.id, "APETAGEX", sizeof(footer.id)) != 0 ||
+ GUINT32_FROM_LE(footer.version) != 2000)
+ return false;
+
+ /* find beginning of ape tag */
+ size_t remaining = GUINT32_FROM_LE(footer.length);
+ if (remaining <= sizeof(footer) + 10 ||
+ /* refuse to load more than one megabyte of tag data */
+ remaining > 1024 * 1024 ||
+ fseek(fp, -(long)remaining, SEEK_END))
+ return false;
+
+ /* read tag into buffer */
+ remaining -= sizeof(footer);
+ assert(remaining > 10);
+
+ char *buffer = g_malloc(remaining);
+ if (fread(buffer, 1, remaining, fp) != remaining)
+ return false;
+
+ /* read tags */
+ unsigned n = GUINT32_FROM_LE(footer.count);
+ const char *p = buffer;
+ while (n-- && remaining > 10) {
+ size_t size = GUINT32_FROM_LE(*(const uint32_t *)p);
+ p += 4;
+ remaining -= 4;
+ unsigned long flags = GUINT32_FROM_LE(*(const uint32_t *)p);
+ p += 4;
+ remaining -= 4;
+
+ /* get the key */
+ const char *key = p;
+ while (remaining > size && *p != '\0') {
+ p++;
+ remaining--;
+ }
+ p++;
+ remaining--;
+
+ /* get the value */
+ if (remaining < size)
+ break;
+
+ if (!callback(flags, key, p, size, ctx))
+ break;
+
+ p += size;
+ remaining -= size;
+ }
+
+ g_free(buffer);
+ return true;
+}
+
+bool
+tag_ape_scan(const char *path_fs, tag_ape_callback_t callback, void *ctx)
+{
+ FILE *fp;
+
+ fp = fopen(path_fs, "rb");
+ if (fp == NULL)
+ return false;
+
+ bool success = ape_scan_internal(fp, callback, ctx);
+ fclose(fp);
+ return success;
+}