Constify argument of check_filter_arg().

[paraslash.git] / filter.h

diff --git a/filter.h b/filter.h
index a11cad50d272981c21d986f6381d3dd41a823c25..937bb42bc610e65d371ff8787a6e701c240c558a 100644 (file)
--- a/filter.h
+++ b/filter.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2009 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -24,8 +24,11 @@ struct filter_node {
        struct list_head callbacks;
        /** A pointer to the configuration of this instance. */
        void *conf;
+       /** The buffer tree node. */
        struct btr_node *btrn;
-       struct task task;
+       /** The task corresponding to this filter node. */
+       struct task *task;
+       /** The minimal input queue size, see \ref btr_node_status(). */
        size_t min_iqs;
 };
 
@@ -81,26 +84,48 @@ struct filter {
         * argv. On failure, a negative paraslash error code must be returned.
         */
        int (*parse_config)(int argc, char **argv, void **config);
+       /**
+        * Deallocate the memory for the configuration.
+        *
+        * This is called to free whatever ->parse_config() has allocated.
+        */
        void (*free_config)(void *conf);
 
        /** The help texts for this filter. */
        struct ggo_help help;
-       void (*pre_select)(struct sched *s, struct task *t);
+       /**
+        * Set scheduler timeout and add file descriptors to fd sets.
+        *
+        * This function controls the timeout value for the next call to
+        * select(2). It may decrease the current timeout but shall never
+        * increase it. The second purpose of this function is to add file
+        * descriptors to the two fd sets of the sched structure. The
+        * descriptors in these sets will be watched by the subsequent
+        * select(2) call.
+        */
+       void (*pre_select)(struct sched *s, void *context);
        /**
         * Convert (filter) the given data.
         *
-        * Pointer to the converting function of the filter. It should convert as
-        * input data as possible. On errors, the post_select function is supposed
-        * to set t->error to a (negative) error code.
+        * Pointer to the converting function of the filter. On errors, the
+        * post_select function is supposed to return a negative error code.
+        */
+       int (*post_select)(struct sched *s, void *context);
+       /**
+        * Answer a buffer tree query.
+        *
+        * This optional function pointer is used for inter node communications
+        * of the buffer tree nodes. See \ref btr_command_handler for details.
         */
-       void (*post_select)(struct sched *s, struct task *t);
        btr_command_handler execute;
 };
 
 void filter_init(void);
-int check_filter_arg(char *filter_arg, void **conf);
-void print_filter_helps(int detailed);
-void generic_filter_pre_select(struct sched *s, struct task *t);
+int check_filter_arg(const char *fa, void **conf);
+void print_filter_helps(unsigned flags);
+void generic_filter_pre_select(struct sched *s, void *context);
+int decoder_execute(const char *cmd, unsigned sample_rate, unsigned channels,
+               char **result);
 
 static inline void write_int16_host_endian(char *buf, int val)
 {
@@ -115,7 +140,4 @@ static inline void write_int16_host_endian(char *buf, int val)
 
 DECLARE_FILTER_INITS
 
-#define FOR_EACH_SUPPORTED_FILTER(j)  for (j = 0; j < NUM_SUPPORTED_FILTERS; j++)
-
-/** The filter array, one structure for each supported filter. */
-extern struct filter filters[NUM_SUPPORTED_FILTERS];
+const struct filter *filter_get(int filter_num);