write_common.c

   1 /*
   2  * Copyright (C) 2006-2008 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file write_common.c common functions of para_audiod and para_write */
   8
   9 #include "para.h"
  10 #include "string.h"
  11 #include "list.h"
  12 #include "sched.h"
  13 #include "write.h"
  14 #include "error.h"
  15
  16 /** the array containing the names of all supported writers */
  17 const char *writer_names[] ={WRITER_NAMES};
  18
  19 /** the array of supported writers */
  20 struct writer writers[NUM_SUPPORTED_WRITERS] = {WRITER_ARRAY};
  21
  22 static void wng_pre_select(__a_unused struct sched *s, struct task *t)
  23 {
  24         struct writer_node_group *g = container_of(t, struct writer_node_group, task);
  25         int i;
  26
  27         FOR_EACH_WRITER_NODE(i, g) {
  28                 struct writer_node *wn = &g->writer_nodes[i];
  29                 t->error = wn->writer->pre_select(s, wn);
  30                 if (t->error < 0)
  31                         return;
  32         }
  33 }
  34
  35 static void wng_post_select(struct sched *s, struct task *t)
  36 {
  37         struct writer_node_group *g = container_of(t, struct writer_node_group, task);
  38         int i;
  39         size_t min_written = 0;
  40
  41         FOR_EACH_WRITER_NODE(i, g) {
  42                 struct writer_node *wn = &g->writer_nodes[i];
  43                 t->error = wn->writer->post_select(s, wn);
  44                 if (t->error < 0)
  45                         return;
  46                 if (!i)
  47                         min_written = wn->written;
  48                 else
  49                         min_written = PARA_MIN(min_written, wn->written);
  50         }
  51         //PARA_INFO_LOG("loaded: %zd, min_written: %zd bytes\n", *g->loaded, min_written);
  52         if (min_written) {
  53                 *g->loaded -= min_written;
  54                 FOR_EACH_WRITER_NODE(i, g)
  55                         g->writer_nodes[i].written -= min_written;
  56         }
  57         if (!*g->loaded && *g->input_error) {
  58                 t->error = *g->input_error;
  59                 return;
  60         }
  61         if (*g->loaded && min_written) {
  62 //              PARA_INFO_LOG("moving %zd bytes\n", *g->loaded);
  63                 memmove(g->buf, g->buf + min_written, *g->loaded);
  64         }
  65 }
  66
  67 /**
  68  * call the open function of each writer in the group
  69  *
  70  * \param g the writer node group
  71  *
  72  * \return If at least one open function returned an error, all successful
  73  * writer notes get closed and this error value is returned. Upon success, a
  74  * task associated with \a g is registered to the scheduler and the function
  75  * returns a positive value.
  76  * */
  77 int wng_open(struct writer_node_group *g)
  78 {
  79         int i, ret = 1;
  80
  81         PARA_NOTICE_LOG("opening wng %p with %d writer(s)\n", g, g->num_writers);
  82         FOR_EACH_WRITER_NODE(i, g) {
  83                 struct writer_node *wn = &g->writer_nodes[i];
  84                 wn->wng = g;
  85                 ret = wn->writer->open(wn);
  86                 if (ret < 0)
  87                         goto err_out;
  88                 wn->chunk_bytes = ret;
  89                 g->max_chunk_bytes = PARA_MAX(g->max_chunk_bytes, ret);
  90         }
  91         sprintf(g->task.status, "%s", "writer node group");
  92         register_task(&g->task);
  93         return 1;
  94 err_out:
  95         PARA_ERROR_LOG("%s\n", para_strerror(-ret));
  96         while (i > 0) {
  97                 struct writer_node *wn = &g->writer_nodes[--i];
  98                 wn->writer->close(wn);
  99         }
 100         g->num_writers = 0;
 101         return ret;
 102 }
 103
 104 /**
 105  * call the close function of each writer in the given group
 106  *
 107  * \param g the writer node group to close
 108  *
 109  * This function also frees all resources of the given group.
 110  */
 111 void wng_close(struct writer_node_group *g)
 112 {
 113         int i;
 114
 115         if (!g)
 116                 return;
 117         PARA_NOTICE_LOG("closing wng with %d writer(s)\n", g->num_writers);
 118         FOR_EACH_WRITER_NODE(i, g) {
 119                 struct writer_node *wn = &g->writer_nodes[i];
 120                 wn->writer->close(wn);
 121         }
 122         free(g->writer_nodes);
 123         free(g);
 124 }
 125
 126 /**
 127  * allocate and initialize a new writer_node_group struct
 128  *
 129  * \param num_writers the number of writer nodes for the new group
 130  *
 131  * \return Pointer to the new writer node group
 132  */
 133 struct writer_node_group *wng_new(unsigned num_writers)
 134 {
 135         struct writer_node_group *g = para_calloc(sizeof(struct writer_node_group));
 136         g->num_writers = num_writers;
 137         g->writer_nodes = para_calloc(num_writers
 138                 * sizeof(struct writer_node));
 139         g->task.post_select = wng_post_select;
 140         g->task.pre_select = wng_pre_select;
 141         return g;
 142 }
 143
 144 /**
 145  * call the init function of each supported paraslash writer
 146  */
 147 void init_supported_writers(void)
 148 {
 149         int i;
 150
 151         FOR_EACH_WRITER(i)
 152                 writers[i].init(&writers[i]);
 153 }
 154 /**
 155  * check if given string is a valid command line for any writer
 156  *
 157  * \param \wa string of the form writer_name:options
 158  * \param writer_num contains the number of the writer upon success
 159  *
 160  * This function checks whether \a wa starts with the name of a supported
 161  * paraslash writer, optionally followed by a colon and any options for that
 162  * writer.  If a valid writer name was found and further are present, the
 163  * remaining part of \a wa is passed to that writer's config parser.
 164  *
 165  * \return On success, a pointer to the gengetopt args info struct is returned
 166  * and \a writer_num contains the number of the writer. Otherwise this function
 167  * returns \p NULL.
 168  */
 169 void *check_writer_arg(const char *wa, int *writer_num)
 170 {
 171         int i;
 172
 173         *writer_num = -E_WRITE_COMMON_SYNTAX;
 174         PARA_INFO_LOG("checking  %s\n", wa);
 175         FOR_EACH_WRITER(i) {
 176                 const char *name = writer_names[i];
 177                 size_t len = strlen(name);
 178                 char c;
 179                 if (strlen(wa) < len)
 180                         continue;
 181                 if (strncmp(name, wa, len))
 182                         continue;
 183                 c = wa[len];
 184                 if (c && c != ' ')
 185                         continue;
 186                 if (c && !writers[i].parse_config)
 187                         return NULL;
 188                 *writer_num = i;
 189                 return writers[i].parse_config(c? wa + len + 1 : "");
 190         }
 191         PARA_ERROR_LOG("writer not found\n");
 192         return NULL;
 193 }
 194
 195 /**
 196  * setup a writer node group with only one writer, the default writer
 197  *
 198  * The writer which is set up depends on the OS. It defaults to alsa for Linux,
 199  * osx_write for OS X, file writer if neither of these is supported.
 200  *
 201  * \return pointer to the allocated writer node group
 202  */
 203 struct writer_node_group *setup_default_wng(void)
 204 {
 205         struct writer_node_group *wng = wng_new(1);
 206         wng->writer_nodes[0].writer = &writers[DEFAULT_WRITER];
 207         PARA_INFO_LOG("using default writer: %s %p\n",
 208                 writer_names[DEFAULT_WRITER], writers[DEFAULT_WRITER].parse_config);
 209         wng->writer_nodes[0].conf = writers[DEFAULT_WRITER].parse_config("");
 210         return wng;
 211 }