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-rw-r--r--libid3tag/file.c674
1 files changed, 674 insertions, 0 deletions
diff --git a/libid3tag/file.c b/libid3tag/file.c
new file mode 100644
index 0000000..9d7319a
--- /dev/null
+++ b/libid3tag/file.c
@@ -0,0 +1,674 @@
+/*
+ * libid3tag - ID3 tag manipulation library
+ * Copyright (C) 2000-2004 Underbit Technologies, 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 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * $Id: file.c,v 1.21 2004/01/23 09:41:32 rob Exp $
+ */
+
+# ifdef HAVE_CONFIG_H
+# include "config.h"
+# endif
+
+# include "global.h"
+
+# include <stdio.h>
+# include <stdlib.h>
+# include <string.h>
+
+# ifdef HAVE_UNISTD_H
+# include <unistd.h>
+# endif
+
+# ifdef HAVE_ASSERT_H
+# include <assert.h>
+# endif
+
+# include "id3tag.h"
+# include "file.h"
+# include "tag.h"
+# include "field.h"
+
+struct filetag {
+ struct id3_tag *tag;
+ unsigned long location;
+ id3_length_t length;
+};
+
+struct id3_file {
+ FILE *iofile;
+ enum id3_file_mode mode;
+ char *path;
+
+ int flags;
+
+ struct id3_tag *primary;
+
+ unsigned int ntags;
+ struct filetag *tags;
+};
+
+enum {
+ ID3_FILE_FLAG_ID3V1 = 0x0001
+};
+
+/*
+ * NAME: query_tag()
+ * DESCRIPTION: check for a tag at a file's current position
+ */
+static
+signed long query_tag(FILE *iofile)
+{
+ fpos_t save_position;
+ id3_byte_t query[ID3_TAG_QUERYSIZE];
+ signed long size;
+
+ if (fgetpos(iofile, &save_position) == -1)
+ return 0;
+
+ size = id3_tag_query(query, fread(query, 1, sizeof(query), iofile));
+
+ if (fsetpos(iofile, &save_position) == -1)
+ return 0;
+
+ return size;
+}
+
+/*
+ * NAME: read_tag()
+ * DESCRIPTION: read and parse a tag at a file's current position
+ */
+static
+struct id3_tag *read_tag(FILE *iofile, id3_length_t size)
+{
+ id3_byte_t *data;
+ struct id3_tag *tag = 0;
+
+ data = malloc(size);
+ if (data) {
+ if (fread(data, size, 1, iofile) == 1)
+ tag = id3_tag_parse(data, size);
+
+ free(data);
+ }
+
+ return tag;
+}
+
+/*
+ * NAME: update_primary()
+ * DESCRIPTION: update the primary tag with data from a new tag
+ */
+static
+int update_primary(struct id3_tag *tag, struct id3_tag const *new)
+{
+ unsigned int i;
+ struct id3_frame *frame;
+
+ if (new) {
+ if (!(new->extendedflags & ID3_TAG_EXTENDEDFLAG_TAGISANUPDATE))
+ id3_tag_clearframes(tag);
+
+ i = 0;
+ while ((frame = id3_tag_findframe(new, 0, i++))) {
+ if (id3_tag_attachframe(tag, frame) == -1)
+ return -1;
+ }
+ }
+
+ return 0;
+}
+
+/*
+ * NAME: tag_compare()
+ * DESCRIPTION: tag sort function for qsort()
+ */
+static
+int tag_compare(const void *a, const void *b)
+{
+ struct filetag const *tag1 = a, *tag2 = b;
+
+ if (tag1->location < tag2->location)
+ return -1;
+ else if (tag1->location > tag2->location)
+ return +1;
+
+ return 0;
+}
+
+/*
+ * NAME: add_filetag()
+ * DESCRIPTION: add a new file tag entry
+ */
+static
+int add_filetag(struct id3_file *file, struct filetag const *filetag)
+{
+ struct filetag *tags;
+
+ tags = realloc(file->tags, (file->ntags + 1) * sizeof(*tags));
+ if (tags == 0)
+ return -1;
+
+ file->tags = tags;
+ file->tags[file->ntags++] = *filetag;
+
+ /* sort tags by location */
+
+ if (file->ntags > 1)
+ qsort(file->tags, file->ntags, sizeof(file->tags[0]), tag_compare);
+
+ return 0;
+}
+
+/*
+ * NAME: del_filetag()
+ * DESCRIPTION: delete a file tag entry
+ */
+static
+void del_filetag(struct id3_file *file, unsigned int index)
+{
+ assert(index < file->ntags);
+
+ while (index < file->ntags - 1) {
+ file->tags[index] = file->tags[index + 1];
+ ++index;
+ }
+
+ --file->ntags;
+}
+
+/*
+ * NAME: add_tag()
+ * DESCRIPTION: read, parse, and add a tag to a file structure
+ */
+static
+struct id3_tag *add_tag(struct id3_file *file, id3_length_t length)
+{
+ long location;
+ unsigned int i;
+ struct filetag filetag;
+ struct id3_tag *tag;
+
+ location = ftell(file->iofile);
+ if (location == -1)
+ return 0;
+
+ /* check for duplication/overlap */
+ {
+ unsigned long begin1, end1, begin2, end2;
+
+ begin1 = location;
+ end1 = begin1 + length;
+
+ for (i = 0; i < file->ntags; ++i) {
+ begin2 = file->tags[i].location;
+ end2 = begin2 + file->tags[i].length;
+
+ if (begin1 == begin2 && end1 == end2)
+ return file->tags[i].tag; /* duplicate */
+
+ if (begin1 < end2 && end1 > begin2)
+ return 0; /* overlap */
+ }
+ }
+
+ tag = read_tag(file->iofile, length);
+
+ filetag.tag = tag;
+ filetag.location = location;
+ filetag.length = length;
+
+ if (add_filetag(file, &filetag) == -1 ||
+ update_primary(file->primary, tag) == -1) {
+ if (tag)
+ id3_tag_delete(tag);
+ return 0;
+ }
+
+ if (tag)
+ id3_tag_addref(tag);
+
+ return tag;
+}
+
+/*
+ * NAME: search_tags()
+ * DESCRIPTION: search for tags in a file
+ */
+static
+int search_tags(struct id3_file *file)
+{
+ fpos_t save_position;
+ signed long size;
+
+ /*
+ * save the current seek position
+ *
+ * We also verify the stream is seekable by calling fsetpos(), since
+ * fgetpos() alone is not reliable enough for this purpose.
+ *
+ * [Apparently not even fsetpos() is sufficient under Win32.]
+ */
+
+ if (fgetpos(file->iofile, &save_position) == -1 ||
+ fsetpos(file->iofile, &save_position) == -1)
+ return -1;
+
+ /* look for an ID3v1 tag */
+
+ if (fseek(file->iofile, -128, SEEK_END) == 0) {
+ size = query_tag(file->iofile);
+ if (size > 0) {
+ struct id3_tag const *tag;
+
+ tag = add_tag(file, size);
+
+ /* if this is indeed an ID3v1 tag, mark the file so */
+
+ if (tag && (ID3_TAG_VERSION_MAJOR(id3_tag_version(tag)) == 1))
+ file->flags |= ID3_FILE_FLAG_ID3V1;
+ }
+ }
+
+ /* look for a tag at the beginning of the file */
+
+ rewind(file->iofile);
+
+ size = query_tag(file->iofile);
+ if (size > 0) {
+ struct id3_tag const *tag;
+ struct id3_frame const *frame;
+
+ tag = add_tag(file, size);
+
+ /* locate tags indicated by SEEK frames */
+
+ while (tag && (frame = id3_tag_findframe(tag, "SEEK", 0))) {
+ long seek;
+
+ seek = id3_field_getint(id3_frame_field(frame, 0));
+ if (seek < 0 || fseek(file->iofile, seek, SEEK_CUR) == -1)
+ break;
+
+ size = query_tag(file->iofile);
+ tag = (size > 0) ? add_tag(file, size) : 0;
+ }
+ }
+
+ /* look for a tag at the end of the file (before any ID3v1 tag) */
+
+ if (fseek(file->iofile, ((file->flags & ID3_FILE_FLAG_ID3V1) ? -128 : 0) +
+ -10, SEEK_END) == 0) {
+ size = query_tag(file->iofile);
+ if (size < 0 && fseek(file->iofile, size, SEEK_CUR) == 0) {
+ size = query_tag(file->iofile);
+ if (size > 0)
+ add_tag(file, size);
+ }
+ }
+
+ clearerr(file->iofile);
+
+ /* restore seek position */
+
+ if (fsetpos(file->iofile, &save_position) == -1)
+ return -1;
+
+ /* set primary tag options and target padded length for convenience */
+
+ if ((file->ntags > 0 && !(file->flags & ID3_FILE_FLAG_ID3V1)) ||
+ (file->ntags > 1 && (file->flags & ID3_FILE_FLAG_ID3V1))) {
+ if (file->tags[0].location == 0)
+ id3_tag_setlength(file->primary, file->tags[0].length);
+ else
+ id3_tag_options(file->primary, ID3_TAG_OPTION_APPENDEDTAG, ~0);
+ }
+
+ return 0;
+}
+
+/*
+ * NAME: finish_file()
+ * DESCRIPTION: release memory associated with a file
+ */
+static
+void finish_file(struct id3_file *file)
+{
+ unsigned int i;
+
+ if (file->path)
+ free(file->path);
+
+ if (file->primary) {
+ id3_tag_delref(file->primary);
+ id3_tag_delete(file->primary);
+ }
+
+ for (i = 0; i < file->ntags; ++i) {
+ struct id3_tag *tag;
+
+ tag = file->tags[i].tag;
+ if (tag) {
+ id3_tag_delref(tag);
+ id3_tag_delete(tag);
+ }
+ }
+
+ if (file->tags)
+ free(file->tags);
+
+ free(file);
+}
+
+/*
+ * NAME: new_file()
+ * DESCRIPTION: create a new file structure and load tags
+ */
+static
+struct id3_file *new_file(FILE *iofile, enum id3_file_mode mode,
+ char const *path)
+{
+ struct id3_file *file;
+
+ file = malloc(sizeof(*file));
+ if (file == 0)
+ goto fail;
+
+ file->iofile = iofile;
+ file->mode = mode;
+ file->path = path ? strdup(path) : 0;
+
+ file->flags = 0;
+
+ file->ntags = 0;
+ file->tags = 0;
+
+ file->primary = id3_tag_new();
+ if (file->primary == 0)
+ goto fail;
+
+ id3_tag_addref(file->primary);
+
+ /* load tags from the file */
+
+ if (search_tags(file) == -1)
+ goto fail;
+
+ id3_tag_options(file->primary, ID3_TAG_OPTION_ID3V1,
+ (file->flags & ID3_FILE_FLAG_ID3V1) ? ~0 : 0);
+
+ if (0) {
+ fail:
+ if (file) {
+ finish_file(file);
+ file = 0;
+ }
+ }
+
+ return file;
+}
+
+/*
+ * NAME: file->open()
+ * DESCRIPTION: open a file given its pathname
+ */
+struct id3_file *id3_file_open(char const *path, enum id3_file_mode mode)
+{
+ FILE *iofile;
+ struct id3_file *file;
+
+ assert(path);
+
+ iofile = fopen(path, (mode == ID3_FILE_MODE_READWRITE) ? "r+b" : "rb");
+ if (iofile == 0)
+ return 0;
+
+ file = new_file(iofile, mode, path);
+ if (file == 0)
+ fclose(iofile);
+
+ return file;
+}
+
+/*
+ * NAME: file->fdopen()
+ * DESCRIPTION: open a file using an existing file descriptor
+ */
+struct id3_file *id3_file_fdopen(int fd, enum id3_file_mode mode)
+{
+# if 1 || defined(HAVE_UNISTD_H)
+ FILE *iofile;
+ struct id3_file *file;
+
+ iofile = fdopen(fd, (mode == ID3_FILE_MODE_READWRITE) ? "r+b" : "rb");
+ if (iofile == 0)
+ return 0;
+
+ file = new_file(iofile, mode, 0);
+ if (file == 0) {
+ int save_fd;
+
+ /* close iofile without closing fd */
+
+ save_fd = dup(fd);
+
+ fclose(iofile);
+
+ dup2(save_fd, fd);
+ close(save_fd);
+ }
+
+ return file;
+# else
+ return 0;
+# endif
+}
+
+/*
+ * NAME: file->close()
+ * DESCRIPTION: close a file and delete its associated tags
+ */
+int id3_file_close(struct id3_file *file)
+{
+ int result = 0;
+
+ assert(file);
+
+ if (fclose(file->iofile) == EOF)
+ result = -1;
+
+ finish_file(file);
+
+ return result;
+}
+
+/*
+ * NAME: file->tag()
+ * DESCRIPTION: return the primary tag structure for a file
+ */
+struct id3_tag *id3_file_tag(struct id3_file const *file)
+{
+ assert(file);
+
+ return file->primary;
+}
+
+/*
+ * NAME: v1_write()
+ * DESCRIPTION: write ID3v1 tag modifications to a file
+ */
+static
+int v1_write(struct id3_file *file,
+ id3_byte_t const *data, id3_length_t length)
+{
+ assert(!data || length == 128);
+
+ if (data) {
+ long location;
+
+ if (fseek(file->iofile, (file->flags & ID3_FILE_FLAG_ID3V1) ? -128 : 0,
+ SEEK_END) == -1 ||
+ (location = ftell(file->iofile)) == -1 ||
+ fwrite(data, 128, 1, file->iofile) != 1 ||
+ fflush(file->iofile) == EOF)
+ return -1;
+
+ /* add file tag reference */
+
+ if (!(file->flags & ID3_FILE_FLAG_ID3V1)) {
+ struct filetag filetag;
+
+ filetag.tag = 0;
+ filetag.location = location;
+ filetag.length = 128;
+
+ if (add_filetag(file, &filetag) == -1)
+ return -1;
+
+ file->flags |= ID3_FILE_FLAG_ID3V1;
+ }
+ }
+# if defined(HAVE_FTRUNCATE)
+ else if (file->flags & ID3_FILE_FLAG_ID3V1) {
+ long length;
+
+ if (fseek(file->iofile, 0, SEEK_END) == -1)
+ return -1;
+
+ length = ftell(file->iofile);
+ if (length == -1 ||
+ (length >= 0 && length < 128))
+ return -1;
+
+ if (ftruncate(fileno(file->iofile), length - 128) == -1)
+ return -1;
+
+ /* delete file tag reference */
+
+ del_filetag(file, file->ntags - 1);
+
+ file->flags &= ~ID3_FILE_FLAG_ID3V1;
+ }
+# endif
+
+ return 0;
+}
+
+/*
+ * NAME: v2_write()
+ * DESCRIPTION: write ID3v2 tag modifications to a file
+ */
+static
+int v2_write(struct id3_file *file,
+ id3_byte_t const *data, id3_length_t length)
+{
+ assert(!data || length > 0);
+
+ if (data &&
+ ((file->ntags == 1 && !(file->flags & ID3_FILE_FLAG_ID3V1)) ||
+ (file->ntags == 2 && (file->flags & ID3_FILE_FLAG_ID3V1))) &&
+ file->tags[0].length == length) {
+ /* easy special case: rewrite existing tag in-place */
+
+ if (fseek(file->iofile, file->tags[0].location, SEEK_SET) == -1 ||
+ fwrite(data, length, 1, file->iofile) != 1 ||
+ fflush(file->iofile) == EOF)
+ return -1;
+
+ goto done;
+ }
+
+ /* hard general case: rewrite entire file */
+
+ /* ... */
+
+ done:
+ return 0;
+}
+
+/*
+ * NAME: file->update()
+ * DESCRIPTION: rewrite tag(s) to a file
+ */
+int id3_file_update(struct id3_file *file)
+{
+ int options, result = 0;
+ id3_length_t v1size = 0, v2size = 0;
+ id3_byte_t id3v1_data[128], *id3v1 = 0, *id3v2 = 0;
+
+ assert(file);
+
+ if (file->mode != ID3_FILE_MODE_READWRITE)
+ return -1;
+
+ options = id3_tag_options(file->primary, 0, 0);
+
+ /* render ID3v1 */
+
+ if (options & ID3_TAG_OPTION_ID3V1) {
+ v1size = id3_tag_render(file->primary, 0);
+ if (v1size) {
+ assert(v1size == sizeof(id3v1_data));
+
+ v1size = id3_tag_render(file->primary, id3v1_data);
+ if (v1size) {
+ assert(v1size == sizeof(id3v1_data));
+ id3v1 = id3v1_data;
+ }
+ }
+ }
+
+ /* render ID3v2 */
+
+ id3_tag_options(file->primary, ID3_TAG_OPTION_ID3V1, 0);
+
+ v2size = id3_tag_render(file->primary, 0);
+ if (v2size) {
+ id3v2 = malloc(v2size);
+ if (id3v2 == 0)
+ goto fail;
+
+ v2size = id3_tag_render(file->primary, id3v2);
+ if (v2size == 0) {
+ free(id3v2);
+ id3v2 = 0;
+ }
+ }
+
+ /* write tags */
+
+ if (v2_write(file, id3v2, v2size) == -1 ||
+ v1_write(file, id3v1, v1size) == -1)
+ goto fail;
+
+ rewind(file->iofile);
+
+ /* update file tags array? ... */
+
+ if (0) {
+ fail:
+ result = -1;
+ }
+
+ /* clean up; restore tag options */
+
+ if (id3v2)
+ free(id3v2);
+
+ id3_tag_options(file->primary, ~0, options);
+
+ return result;
+}

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