-struct audio_format_handler {
- /**
- * name of the audio format
- */
- const char *name;
- /**
- * typical file endings for files that can be handled by this afh.
- */
- const char **suffixes;
- /**
- * pointer to the audio format handler's init function
- *
- * Must initialize all function pointers and is assumed to succeed.
- */
- void (*init)(void*);
- /**
- * period of time between sending data chunks
- */
- struct timeval chunk_tv; /* length of one chunk of data */
- /**
- * end of file timeout - do not load new audio file until this time
- *
- */
- struct timeval eof_tv; /* timeout on eof */
- /**
- * Pointer to the optional get-header function.
- *
- * This is called from a sender in case a new client connects in the middle of
- * the stream. The audio format handler may set this to NULL to indicate that
- * this audio format does not need any special header treatment. If non-NULL,
- * the function it points to must return a pointer to a buffer holding the
- * current audio file header, together with the header length.
- */
- char *(*get_header_info)(int *header_len);
- /**
- * check if this audio format handler can handle the file
- *
- * This is a pointer to a function returning whether a given file is valid for
- * this audio format. A negative return value indicates that this audio format
- * handler did not recognize the given file. On success, the function is
- * expected to return a positive value and to fill in \arg info_str, \arg
- * chunks and \arg seconds appropriately.
- */
- int (*get_file_info)(FILE *audio_file, char *info_str,
- long unsigned *chunks, int *seconds);
- /**
- * cleanup function of this audio format handler
- *
- * This close function should deallocate any resources
- * associated with the current audio file. In particular, it is responsible
- * for closing the file handle. It is assumed to succeed.
- */
- void (*close_audio_file)(void);
- /**
- * jump to another position in the current audio file
- *
- * This is called if a client issued the ff or jmp command with \a request
- * being the number of the next chunk that should be sent out. Must return a
- * positive value on success and a negative value on errors.
- */
- int (*reposition_stream)(long unsigned request);
- /**
- * function responsible for reading one data chunk.
- *
- * \a read_chunk() must return a pointer to the next chunk of data that should
- * be sent out, or \p NULL on errors or if the end of the file was encountered.
- *
- * If it returns non-NULL, \a len must contain the length of the returned
- * buffer (which may be zero if nothing has to be sent for some reason).
- * Otherwise, \a len is used to distinguish between the eof and the error case:
- * It must be zero in the eof case, or negative if an error occcured.
- */
- char * (*read_chunk)(long unsigned chunk_num, ssize_t *len);
+void (*update_audio_file)(char *audio_file);
+/**
+ *
+ * shutdown this selector and free all resources
+ *
+ * This gets called whenever the audio file selector changes. The reason for
+ * this change might be that some user sent the chs command, that para_server
+ * receives the HUP signal, or that para_server shuts down. It is assumed to
+ * succeed.
+ */
+void (*shutdown)(void);
+/**
+ *
+ * add file descriptors to fd_sets
+ *
+ * The pre_select function of the activated selector gets called just before
+ * para_server enters its main select loop. The selector may add its own file
+ * descriptors to the \a rfds or the \a wfds set.
+ *
+ * \return The highest-numbered file descriptor which was added to either of
+ * the two fd sets (or -1 if no file descriptors were added).
+ *
+ * \sa select(2)
+ */
+int (*pre_select)(fd_set *rfds, fd_set *wfds);
+/**
+ * handle the file descriptors which are ready for I/O
+ *
+ * If the pre_select hook added one ore more file descriptors to the read or write
+ * set, this is the hook to check the result and do any I/O on those descriptors
+ * which are ready for reading/writing.
+ */
+void (*post_select)(fd_set *rfds, fd_set *wfds);
+/**
+ * each selector has its private data pointer */
+void *private_data;