2 * Copyright (C) 2005-2008 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file filter_common.c Common helper functions for filter input/output. */
21 /** The array of supported filters. */
22 struct filter filters[NUM_SUPPORTED_FILTERS] = {FILTER_ARRAY};
25 * Call the init function of each supported filter.
27 * \param all_filters the array of all supported filters.
31 void filter_init(struct filter *all_filters)
35 FOR_EACH_SUPPORTED_FILTER(i)
36 all_filters[i].init(all_filters + i);
40 * Close and destroy a filter callback.
42 * \param fcb The filter callback to close.
44 * This removes \a fcb from the list of filter callbacks and calls
45 * the close callback associated with \a fcb.
47 static void close_filter_callback(struct filter_callback *fcb)
49 PARA_NOTICE_LOG("closing filter_callback %p, data: %p\n", fcb, fcb->data);
55 * Close all callbacks of a filter node.
57 * \param fn The filter node which contains the filter callbacks to be closed.
59 * Call close_filter_callback() for each entry in the filter callback list
62 static void close_callbacks(struct filter_node *fn)
64 struct filter_callback *fcb, *tmp;
66 list_for_each_entry_safe(fcb, tmp, &fn->callbacks, node) {
67 PARA_INFO_LOG("closing %s filter callback\n",
68 filters[fn->filter_num].name);
69 close_filter_callback(fcb);
73 static void call_callbacks(struct filter_node *fn, char *inbuf, size_t inlen,
74 char *outbuf, size_t outlen)
76 struct filter_callback *fcb, *tmp;
77 list_for_each_entry_safe(fcb, tmp, &fn->callbacks, node) {
79 if (inlen && fcb->input_cb) {
80 ret = fcb->input_cb(inbuf, inlen, fcb);
82 close_filter_callback(fcb);
86 if (!outlen || !fcb->output_cb)
88 ret = fcb->output_cb(outbuf, outlen, fcb);
90 close_filter_callback(fcb);
95 * Call the convert function of each filter.
98 * \param t The task identifying the filter chain.
100 * This is the core function of the filter subsystem. It loops over the list of
101 * filter nodes determined by \a t and calls the filter's convert function if
102 * there is input available for the filter node in question. If the convert
103 * function consumed some or all of its input data, all registered input
104 * callbacks are called. Similarly, if a convert function produced output, all
105 * registerd output callbacks get called.
107 * On errors a (negative) error code is stored in t->error.
109 * \sa filter_node, filter#convert, filter_callback.
111 void filter_pre_select(__a_unused struct sched *s, struct task *t)
113 struct filter_chain *fc = container_of(t, struct filter_chain, task);
114 struct filter_node *fn;
117 int i, conv, conv_total = 0;
119 if (fc->output_error && *fc->output_error < 0) {
120 t->error = *fc->output_error;
125 loaded = fc->in_loaded;
127 FOR_EACH_FILTER_NODE(fn, fc, i) {
128 struct filter *f = filters + fn->filter_num;
129 if (fn->loaded < fn->bufsize) {
130 size_t size, old_fn_loaded = fn->loaded;
131 // PARA_DEBUG_LOG("fc %p loaded: %zd, calling %s convert\n",
132 // fc, *loaded, fn->filter->name);
133 t->error = f->convert(ib, *loaded, fn);
137 call_callbacks(fn, ib, size, fn->buf + old_fn_loaded,
138 fn->loaded - old_fn_loaded);
141 if (*loaded && size) {
142 // PARA_DEBUG_LOG("moving %zd bytes in input "
143 // "buffer for %s filter\n",
144 // *loaded, fn->filter->name);
145 memmove(ib, ib + size, *loaded);
149 loaded = &fn->loaded;
152 // PARA_DEBUG_LOG("eof (in/out/fc): %d/%d/%d out_loaded: %zd, "
153 // "conv: %d, conv_total: %d\n", *fc->input_eof,
154 // fc->output_eof? *fc->output_eof : -42,
155 // fc->eof, *fc->out_loaded, conv, conv_total);
158 if (!*fc->input_error)
162 if (*fc->in_loaded && conv_total)
164 t->error = -E_FC_EOF;
168 * Close all filter nodes and their callbacks.
170 * \param fc The filter chain to close.
172 * For each filter node determined by \a fc, call the close function of each
173 * registered filter callback as well as the close function of the
174 * corresponding filter. Free all resources and destroy all callback lists and
175 * the filter node list.
177 * \sa filter::close, filter_callback::close
179 void close_filters(struct filter_chain *fc)
181 struct filter_node *fn;
186 PARA_NOTICE_LOG("closing filter chain %p\n", fc);
187 FOR_EACH_FILTER_NODE(fn, fc, i) {
188 struct filter *f = filters + fn->filter_num;
190 PARA_INFO_LOG("closing %s filter\n", f->name);
193 free(fc->filter_nodes);
197 * If the filter has a command line parser and options is not NULL, run it.
198 * Returns filter_num on success, negative on errors
200 static int parse_filter_args(int filter_num, char *options, void **conf)
202 struct filter *f = &filters[filter_num];
203 int ret, i, argc = 2;
206 // PARA_DEBUG_LOG("%s, options: %s, parser: %p\n", f->name,
207 // options? options : "(none)", f->parse_config);
208 if (!f->parse_config)
209 return strlen(options)? -E_BAD_FILTER_OPTIONS : filter_num;
210 // PARA_DEBUG_LOG("options: %s\n", options);
211 argc = split_args(options, &argv, " \t");
212 // PARA_DEBUG_LOG("argc = %d, argv[0]: %s\n", argc, argv[0]);
213 for (i = argc - 1; i >= 0; i--)
214 argv[i + 1] = argv[i];
215 argv[0] = para_strdup(f->name);
217 ret = f->parse_config(argc, argv, conf);
220 return ret < 0? ret : filter_num;
224 * Check the filter command line options.
226 * \param fa The command line options.
227 * \param conf Points to the filter configuration upon successful return.
229 * Check if \a fa starts with a the name of a supported filter, followed by
230 * a colon. If yes, call the command line parser of that filter.
232 * \return On success, the number of the filter is returned and \a conf
233 * is initialized to point to the filter configuration determined by \a fa.
234 * On errors, a negative value is returned.
236 * Note: If \a fa specifies a filter that has no command line parser success is
237 * returned, and \a conf is initialized to \p NULL.
239 * \sa filter::parse_config
241 int check_filter_arg(char *fa, void **conf)
246 // PARA_DEBUG_LOG("arg: %s\n", fa);
247 FOR_EACH_SUPPORTED_FILTER(j) {
248 const char *name = filters[j].name;
249 size_t len = strlen(name);
251 if (strlen(fa) < len)
253 if (strncmp(name, fa, len))
258 if (c && !filters[j].parse_config)
259 return -E_BAD_FILTER_OPTIONS;
260 return parse_filter_args(j, c? fa + len + 1 :
261 fa + strlen(fa), conf);
263 return -E_UNSUPPORTED_FILTER;