2 * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file filter_chain.c Common helper functions for filter input/output. */
20 /** The array of supported filters. */
21 struct filter filters[NUM_SUPPORTED_FILTERS] = {FILTER_ARRAY};
24 * Call the init function of each supported filter.
26 * \param all_filters the array of all supported filters.
30 void filter_init(struct filter *all_filters)
34 FOR_EACH_SUPPORTED_FILTER(i)
35 all_filters[i].init(all_filters + i);
39 * Close and destroy a filter callback.
41 * \param fcb The filter callback to close.
43 * This removes \a fcb from the list of filter callbacks and calls
44 * the close callback associated with \a fcb.
46 static void close_filter_callback(struct filter_callback *fcb)
48 PARA_NOTICE_LOG("closing filter_callback %p, data: %p\n", fcb, fcb->data);
54 * Close all callbacks of a filter node.
56 * \param fn The filter node which contains the filter callbacks to be closed.
58 * Call close_filter_callback() for each entry in the filter callback list
61 static void close_callbacks(struct filter_node *fn)
63 struct filter_callback *fcb, *tmp;
65 list_for_each_entry_safe(fcb, tmp, &fn->callbacks, node) {
66 PARA_INFO_LOG("closing %s filter callback\n",
67 filters[fn->filter_num].name);
68 close_filter_callback(fcb);
72 static void call_callbacks(struct filter_node *fn, char *inbuf, size_t inlen,
73 char *outbuf, size_t outlen)
75 struct filter_callback *fcb, *tmp;
76 list_for_each_entry_safe(fcb, tmp, &fn->callbacks, node) {
78 if (inlen && fcb->input_cb) {
79 ret = fcb->input_cb(inbuf, inlen, fcb);
81 close_filter_callback(fcb);
85 if (!outlen || !fcb->output_cb)
87 ret = fcb->output_cb(outbuf, outlen, fcb);
89 close_filter_callback(fcb);
94 * Call the convert function of each filter.
97 * \param t The task identifying the filter chain.
99 * This is the core function of the filter subsystem. It loops over the list of
100 * filter nodes determined by \a t and calls the filter's convert function if
101 * there is input available for the filter node in question. If the convert
102 * function consumed some or all of its input data, all registered input
103 * callbacks are called. Similarly, if a convert function produced output, all
104 * registerd output callbacks get called.
106 * On errors a (negative) error code is stored in t->error.
108 * \sa filter_node, filter#convert, filter_callback.
110 void filter_pre_select(__a_unused struct sched *s, struct task *t)
112 struct filter_chain *fc = container_of(t, struct filter_chain, task);
113 struct filter_node *fn;
116 int i, conv, conv_total = 0;
118 if (fc->output_error && *fc->output_error < 0) {
119 t->error = *fc->output_error;
124 loaded = fc->in_loaded;
126 FOR_EACH_FILTER_NODE(fn, fc, i) {
127 struct filter *f = filters + fn->filter_num;
128 if (fn->loaded < fn->bufsize) {
129 size_t size, old_fn_loaded = fn->loaded;
130 // PARA_DEBUG_LOG("fc %p loaded: %zd, calling %s convert\n",
131 // fc, *loaded, fn->filter->name);
132 t->error = f->convert(ib, *loaded, fn);
136 call_callbacks(fn, ib, size, fn->buf + old_fn_loaded,
137 fn->loaded - old_fn_loaded);
140 if (*loaded && size) {
141 // PARA_DEBUG_LOG("moving %zd bytes in input "
142 // "buffer for %s filter\n",
143 // *loaded, fn->filter->name);
144 memmove(ib, ib + size, *loaded);
148 loaded = &fn->loaded;
151 // PARA_DEBUG_LOG("eof (in/out/fc): %d/%d/%d out_loaded: %zd, "
152 // "conv: %d, conv_total: %d\n", *fc->input_eof,
153 // fc->output_eof? *fc->output_eof : -42,
154 // fc->eof, *fc->out_loaded, conv, conv_total);
157 if (!*fc->input_error)
161 if (*fc->in_loaded && conv_total)
163 t->error = -E_FC_EOF;
167 * Close all filter nodes and their callbacks.
169 * \param fc The filter chain to close.
171 * For each filter node determined by \a fc, call the close function of each
172 * registered filter callback as well as the close function of the
173 * corresponding filter. Free all resources and destroy all callback lists and
174 * the filter node list.
176 * \sa filter::close, filter_callback::close
178 void close_filters(struct filter_chain *fc)
180 struct filter_node *fn;
185 PARA_NOTICE_LOG("closing filter chain %p\n", fc);
186 FOR_EACH_FILTER_NODE(fn, fc, i) {
187 struct filter *f = filters + fn->filter_num;
189 PARA_INFO_LOG("closing %s filter\n", f->name);
192 free(fc->filter_nodes);
196 * If the filter has a command line parser and options is not NULL, run it.
197 * Returns filter_num on success, negative on errors
199 static int parse_filter_args(int filter_num, char *options, void **conf)
201 struct filter *f = &filters[filter_num];
202 int ret, i, argc = 2;
205 // PARA_DEBUG_LOG("%s, options: %s, parser: %p\n", f->name,
206 // options? options : "(none)", f->parse_config);
207 if (!f->parse_config)
208 return strlen(options)? -E_BAD_FILTER_OPTIONS : filter_num;
209 // PARA_DEBUG_LOG("options: %s\n", options);
210 argc = split_args(options, &argv, " \t");
211 // PARA_DEBUG_LOG("argc = %d, argv[0]: %s\n", argc, argv[0]);
212 for (i = argc - 1; i >= 0; i--)
213 argv[i + 1] = argv[i];
214 argv[0] = para_strdup(f->name);
216 ret = f->parse_config(argc, argv, conf);
219 return ret < 0? ret : filter_num;
223 * Check the filter command line options.
225 * \param fa The command line options.
226 * \param conf Points to the filter configuration upon successful return.
228 * Check if \a fa starts with a the name of a supported filter, followed by
229 * a colon. If yes, call the command line parser of that filter.
231 * \return On success, the number of the filter is returned and \a conf
232 * is initialized to point to the filter configuration determined by \a fa.
233 * On errors, a negative value is returned.
235 * Note: If \a fa specifies a filter that has no command line parser success is
236 * returned, and \a conf is initialized to \p NULL.
238 * \sa filter::parse_config
240 int check_filter_arg(char *fa, void **conf)
245 // PARA_DEBUG_LOG("arg: %s\n", fa);
246 FOR_EACH_SUPPORTED_FILTER(j) {
247 const char *name = filters[j].name;
248 size_t len = strlen(name);
250 if (strlen(fa) < len)
252 if (strncmp(name, fa, len))
257 if (c && !filters[j].parse_config)
258 return -E_BAD_FILTER_OPTIONS;
259 return parse_filter_args(j, c? fa + len + 1 :
260 fa + strlen(fa), conf);
262 return -E_UNSUPPORTED_FILTER;