From 11613347bedef464029c167116d226ec3fddfdcd Mon Sep 17 00:00:00 2001 From: Max Kellermann Date: Thu, 18 Nov 2010 21:44:24 +0100 Subject: tag_ape: move code to ape.c Generic library for scanning APE tags. Eliminated one "goto"! --- src/ape.c | 113 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ src/ape.h | 42 ++++++++++++++++++++++ src/tag_ape.c | 112 ++++++++++----------------------------------------------- 3 files changed, 174 insertions(+), 93 deletions(-) create mode 100644 src/ape.c create mode 100644 src/ape.h (limited to 'src') 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 + +#include +#include +#include +#include + +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; +} diff --git a/src/ape.h b/src/ape.h new file mode 100644 index 000000000..754b9bb2d --- /dev/null +++ b/src/ape.h @@ -0,0 +1,42 @@ +/* + * 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. + */ + +#ifndef MPD_APE_H +#define MPD_APE_H + +#include "check.h" + +#include +#include + +typedef bool (*tag_ape_callback_t)(unsigned long flags, const char *key, + const char *value, size_t value_length, + void *ctx); + +/** + * Scans the APE tag values from a file. + * + * @param path_fs the path of the file in filesystem encoding + * @return false if the file could not be opened or if no APE tag is + * present + */ +bool +tag_ape_scan(const char *path_fs, tag_ape_callback_t callback, void *ctx); + +#endif diff --git a/src/tag_ape.c b/src/tag_ape.c index 4841b3138..82e36d7a4 100644 --- a/src/tag_ape.c +++ b/src/tag_ape.c @@ -21,11 +21,7 @@ #include "tag_ape.h" #include "tag.h" #include "tag_table.h" - -#include - -#include -#include +#include "ape.h" static const char *const ape_tag_names[TAG_NUM_OF_ITEM_TYPES] = { [TAG_ALBUM_ARTIST] = "album artist", @@ -61,96 +57,26 @@ tag_ape_import_item(struct tag *tag, unsigned long flags, return tag; } -struct tag * -tag_ape_load(const char *file) -{ - struct tag *ret = NULL; - FILE *fp; - int tagCount; - char *buffer = NULL; - char *p; - size_t tagLen; - size_t size; - unsigned long flags; - char *key; - - struct { - unsigned char id[8]; - uint32_t version; - uint32_t length; - uint32_t tagCount; - unsigned char flags[4]; - unsigned char reserved[8]; - } footer; - - fp = fopen(file, "rb"); - if (!fp) - return NULL; - - /* determine if file has an apeV2 tag */ - if (fseek(fp, 0, SEEK_END)) - goto fail; - size = (size_t)ftell(fp); - if (fseek(fp, size - sizeof(footer), SEEK_SET)) - goto fail; - if (fread(&footer, 1, sizeof(footer), fp) != sizeof(footer)) - goto fail; - if (memcmp(footer.id, "APETAGEX", sizeof(footer.id)) != 0) - goto fail; - if (GUINT32_FROM_LE(footer.version) != 2000) - goto fail; - - /* find beginning of ape tag */ - tagLen = GUINT32_FROM_LE(footer.length); - if (tagLen <= sizeof(footer) + 10) - goto fail; - if (tagLen > 1024 * 1024) - /* refuse to load more than one megabyte of tag data */ - goto fail; - if (fseek(fp, size - tagLen, SEEK_SET)) - goto fail; - - /* read tag into buffer */ - tagLen -= sizeof(footer); - assert(tagLen > 10); - - buffer = g_malloc(tagLen); - if (fread(buffer, 1, tagLen, fp) != tagLen) - goto fail; - - /* read tags */ - tagCount = GUINT32_FROM_LE(footer.tagCount); - p = buffer; - while (tagCount-- && tagLen > 10) { - size = GUINT32_FROM_LE(*(const uint32_t *)p); - p += 4; - tagLen -= 4; - flags = GUINT32_FROM_LE(*(const uint32_t *)p); - p += 4; - tagLen -= 4; - - /* get the key */ - key = p; - while (tagLen > size && *p != '\0') { - p++; - tagLen--; - } - p++; - tagLen--; +struct tag_ape_ctx { + struct tag *tag; +}; - /* get the value */ - if (tagLen < size) - goto fail; +static bool +tag_ape_callback(unsigned long flags, const char *key, + const char *value, size_t value_length, void *_ctx) +{ + struct tag_ape_ctx *ctx = _ctx; - ret = tag_ape_import_item(ret, flags, key, p, size); + ctx->tag = tag_ape_import_item(ctx->tag, flags, key, + value, value_length); + return true; +} - p += size; - tagLen -= size; - } +struct tag * +tag_ape_load(const char *file) +{ + struct tag_ape_ctx ctx = { .tag = NULL }; -fail: - if (fp) - fclose(fp); - g_free(buffer); - return ret; + tag_ape_scan(file, tag_ape_callback, &ctx); + return ctx.tag; } -- cgit v1.2.3