Update copyright year to 2017.

[paraslash.git] / filter.h

diff --git a/filter.h b/filter.h
index 1cda119f0f3496183f0785c181f583fdd4a061b9..0bd546903927d412fccef946cf8f43783ed8bc70 100644 (file)
--- a/filter.h
+++ b/filter.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2005-2013 Andre Noll <maan@systemlinux.org>
+ * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
  *
  * Licensed under the GPL v2. For licencing details see COPYING.
  */
@@ -27,7 +27,7 @@ struct filter_node {
        /** The buffer tree node. */
        struct btr_node *btrn;
        /** The task corresponding to this filter node. */
-       struct task task;
+       struct task *task;
        /** The minimal input queue size, see \ref btr_node_status(). */
        size_t min_iqs;
 };
@@ -58,17 +58,18 @@ struct filter {
        /**
         * Open one instance of this filter.
         *
-        * This should allocate the output buffer of the given filter node and do any
-        * other filter-specific preparations like initializing the private_data member
-        * of \a fn suitably. The open function is assumed to succeed.
+        * This should allocate the output buffer of the given filter node and
+        * do any other filter-specific preparations like initializing the
+        * private_data member of \a fn suitably. The open function is
+        * optional, If it is provided, it is assumed to succeed.
         */
        void (*open)(struct filter_node *fn);
        /**
         * Close one instance of this filter.
         *
-        * Free all resources of associated with \a fn that were previously allocated
-        * by the open() function. It's OK to leave this alone if the filter does not
-        * need any cleanups.
+        * Free all resources associated with \a fn that were previously
+        * allocated by the open() function. It's OK to set this to NULL if the
+        * filter does not need to perform any cleanup operation.
         */
        void (*close)(struct filter_node *fn);
        /**
@@ -96,20 +97,21 @@ struct filter {
        /**
         * Set scheduler timeout and add file descriptors to fd sets.
         *
-        * This function is used to control the timeout value for select. It
-        * only allowed to decrease the current value. The second purpose of
-        * this function is to set file descriptors to be watched by the
-        * subsequent select call to the two 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, struct task *t);
+       void (*pre_select)(struct sched *s, void *context);
        /**
         * Convert (filter) the given data.
         *
         * Pointer to the converting function of the filter. On errors, the
-        * post_select function is supposed to set t->error to a (negative)
-        * error code.
+        * post_select function is supposed to return a negative error code.
         */
-       int (*post_select)(struct sched *s, struct task *t);
+       int (*post_select)(struct sched *s, void *context);
        /**
         * Answer a buffer tree query.
         *
@@ -120,9 +122,9 @@ struct filter {
 };
 
 void filter_init(void);
-int check_filter_arg(char *filter_arg, void **conf);
+int check_filter_arg(const char *fa, void **conf);
 void print_filter_helps(unsigned flags);
-void generic_filter_pre_select(struct sched *s, struct task *t);
+void generic_filter_pre_select(struct sched *s, void *context);
 int decoder_execute(const char *cmd, unsigned sample_rate, unsigned channels,
                char **result);
 
@@ -139,8 +141,4 @@ static inline void write_int16_host_endian(char *buf, int val)
 
 DECLARE_FILTER_INITS
 
-/** Iterate over the array of supported filters. */
-#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);