+
+/**
+ * Determine the maximal chunk size by investigating the chunk table.
+ *
+ * \param afhi Value/result.
+ *
+ * This function iterates over the chunk table and sets ->max_chunk_size
+ * accordingly. The function exists only for backward compatibility since as of
+ * version 0.6.0, para_server stores the maximal chunk size in its database.
+ * This function is only called if the database value is zero, indicating that
+ * the file was added by an older server version.
+ */
+void set_max_chunk_size(struct afh_info *afhi)
+{
+ uint32_t n, max = 0, old = 0;
+
+ for (n = 0; n <= afhi->chunks_total; n++) {
+ uint32_t val = afhi->chunk_table[n];
+ /*
+ * If the first chunk is the header, do not consider it for the
+ * calculation of the largest chunk size.
+ */
+ if (n == 0 || (n == 1 && afhi->header_len > 0)) {
+ old = val;
+ continue;
+ }
+ max = PARA_MAX(max, val - old);
+ old = val;
+ }
+ afhi->max_chunk_size = max;
+}
+
+/**
+ * Create a copy of the given file with altered meta tags.
+ *
+ * \param audio_format_id Specifies the audio format.
+ * \param map The (read-only) memory map of the input file.
+ * \param mapsize The size of the input file in bytes.
+ * \param tags The new tags.
+ * \param output_fd Altered file is created using this file descriptor.
+ * \param filename The name of the temporary output file.
+ *
+ * This calls the ->rewrite_tags method of the audio format handler associated
+ * with \a audio_format_id to create a copy of the memory-mapped file given
+ * by \a map and \a mapsize, but with altered tags according to \a tags. If
+ * the audio format handler for \a audio_format_id lacks this optional method,
+ * the function returns (the paraslash error code of) \p ENOTSUP.
+ *
+ * \return Standard.
+ */
+int afh_rewrite_tags(int audio_format_id, void *map, size_t mapsize,
+ struct taginfo *tags, int output_fd, const char *filename)
+{
+ struct audio_format_handler *afh = afl + audio_format_id;
+
+ if (!afh->rewrite_tags)
+ return -ERRNO_TO_PARA_ERROR(ENOTSUP);
+ return afh->rewrite_tags(map, mapsize, tags, output_fd, filename);
+}