* applied patch provided by Christophe Fergeau <teuf at gnome.org>

for artwork database support (read-only).

git-svn-id: https://gtkpod.svn.sf.net/svnroot/gtkpod/libgpod/trunk@1093 f01d2545-417e-4e96-918e-98f8d0dbbcb6

1 files changed, 196 insertions, 0 deletions

diff --git a/src/db-parse-context.c b/src/db-parse-context.c
new file mode 100644
index 0000000..4f4264e
--- /dev/null
+++ b/src/db-parse-context.c
@@ -0,0 +1,196 @@
+/*
+ *  Copyright (C) 2005 Christophe Fergeau
+ *
+ * 
+ *  The code contained in this file 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 file 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 code; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ * 
+ *  iTunes and iPod are trademarks of Apple
+ * 
+ *  This product is not supported/written/published by Apple!
+ *
+ */
+
+
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <glib.h>
+
+#include "db-parse-context.h"
+#include "db-itunes-parser.h"
+
+DBParseContext *
+db_parse_context_new (const unsigned char *buffer, off_t len)
+{
+	DBParseContext *result;
+
+	result = g_new0 (DBParseContext, 1);
+	if (result == NULL) {
+		return NULL;
+	}
+
+	result->buffer = buffer;
+	result->cur_pos = buffer;
+	result->total_len = len;
+
+	return result;
+}
+
+
+static void
+db_parse_context_set_header_len (DBParseContext *ctx, off_t len)
+{
+	/* FIXME: this can probably happen in malformed itunesdb files, 
+	 * don't g_assert on this, only output a warning 
+	 */
+	g_assert ((ctx->cur_pos - ctx->buffer) <= len);
+	g_assert (len <= ctx->total_len);
+	ctx->header_len = len;
+}
+
+void
+db_parse_context_set_total_len (DBParseContext *ctx, off_t len)
+{
+	/* FIXME: this can probably happen in malformed itunesdb files, 
+	 * don't g_assert on this, only output a warning 
+	 */
+	g_assert ((ctx->cur_pos - ctx->buffer) <= len);
+	if (ctx->header_len != 0) {
+		g_assert (len >= ctx->header_len);
+	}
+	ctx->total_len = len;
+}
+
+
+off_t
+db_parse_context_get_remaining_length (DBParseContext *ctx)
+{
+	if (ctx->header_len != 0) {
+		return ctx->header_len - (ctx->cur_pos - ctx->buffer); 
+	} else {
+		return ctx->total_len - (ctx->cur_pos - ctx->buffer); 
+	}
+}
+
+DBParseContext *
+db_parse_context_get_sub_context (DBParseContext *ctx, off_t offset)
+{
+	if (offset >= ctx->total_len) {
+		return NULL;
+	}
+	return db_parse_context_new (&ctx->buffer[offset], 
+				     ctx->total_len - offset);
+}
+
+
+DBParseContext *
+db_parse_context_get_next_child (DBParseContext *ctx)
+{
+	if (ctx->header_len == 0) {
+		return NULL;
+	}
+	if (ctx->header_len >= ctx->total_len) {
+		return NULL;
+	}
+
+	return db_parse_context_get_sub_context (ctx, ctx->header_len);
+}
+
+void *
+db_parse_context_get_m_header_internal (DBParseContext *ctx, const char *id, off_t size) 
+{
+	MHeader *h;
+
+	if (db_parse_context_get_remaining_length (ctx) < 8) {
+		return NULL;
+	}
+
+	h = (MHeader *)ctx->cur_pos;
+	if (strncmp (id, (char *)h->header_id, 4) != 0) {
+		return NULL;
+	}
+
+	/* FIXME: this test sucks for compat: if a field is smaller than 
+	 * expected, we probably should create a buffer of the appropriate 
+	 * size inited to 0, copy the data that is available in it and use
+	 * that buffer in the rest of the code (maybe it's harmful to have
+	 * some fields at 0 in some headers though...)
+	 */
+	if (GINT_FROM_LE (h->header_len) < size) {
+		return NULL;
+	}
+
+	db_parse_context_set_header_len (ctx, GINT_FROM_LE (h->header_len));
+
+	return h;
+}
+
+DBParseContext *
+db_parse_context_new_from_file (const char *filename)
+{
+	int fd;
+	struct stat stat_buf;
+	int result;
+	unsigned char *buffer;
+	DBParseContext *ctx;
+
+	buffer = NULL;
+	ctx = NULL;
+
+	fd = open (filename, O_RDONLY);
+	if (fd == -1) {
+		g_print ("Failed to open %s: %s\n", 
+			 filename, strerror (errno));
+		return NULL;
+	}
+
+	result = fstat (fd, &stat_buf);
+	if (result == -1) {
+		g_print ("Failed to read %s size: %s\n", 
+			 filename, strerror (errno));
+		goto error;
+	}
+
+	if (!S_ISREG (stat_buf.st_mode)) {
+		g_print ("%s is not a regular file\n", filename);
+		goto error;
+	}
+
+	if (stat_buf.st_size > ITUNESDB_MAX_SIZE) {
+		g_print ("%s is too big to be an buffer file\n", filename);
+		goto error;
+	}
+
+	buffer = mmap (NULL, stat_buf.st_size, PROT_READ, MAP_SHARED, fd, 0);
+
+	if (buffer == MAP_FAILED) {
+		g_print ("Error while mmap'ing %s: %s\n", 
+			 filename, strerror (errno));
+		goto error;
+	}
+
+	ctx = db_parse_context_new (buffer, stat_buf.st_size);
+	if (ctx == NULL) {
+		munmap (buffer, stat_buf.st_size);
+	}
+ error:
+	close (fd);
+	return ctx;
+}