stat.c

   1 /*
   2  * Copyright (C) 2005-2006 Andre Noll <maan@systemlinux.org>
   3  *
   4  *     This program is free software; you can redistribute it and/or modify
   5  *     it under the terms of the GNU General Public License as published by
   6  *     the Free Software Foundation; either version 2 of the License, or
   7  *     (at your option) any later version.
   8  *
   9  *     This program is distributed in the hope that it will be useful,
  10  *     but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  *     GNU General Public License for more details.
  13  *
  14  *     You should have received a copy of the GNU General Public License
  15  *     along with this program; if not, write to the Free Software
  16  *     Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111, USA.
  17  */
  18
  19 /**
  20  *  \file stat.c functions used for sending/receiving the status of para_server
  21  *  and para_audiod
  22  */
  23 #include "para.h"
  24 #include "close_on_fork.h"
  25 #include "list.h"
  26 #include "error.h"
  27 #include "string.h"
  28
  29 /** the maximal number of simultaneous connections */
  30 #define MAX_STAT_CLIENTS 50
  31
  32 /**
  33  * The structure associated with a connected client that sent the 'stat' command
  34 *
  35  *
  36  * A status client is identified by its file descriptor.  para_audiod
  37  * keeps a list of connected status clients.
  38  */
  39 struct stat_client {
  40 /**
  41  *
  42  *
  43  * the stat client's file descriptor
  44  */
  45 int fd;
  46 long unsigned item_mask;
  47 /**
  48  *
  49  * its entry in the list of stat clients
  50 */
  51 struct list_head node;
  52 };
  53
  54 static struct list_head client_list;
  55 static int initialized;
  56 static int num_clients;
  57
  58 /**
  59  * the list of all status items sent by para_server/para_audiod
  60  */
  61 const char *status_item_list[NUM_STAT_ITEMS] = {
  62         [SI_STATUS_BAR] = "status_bar",
  63         [SI_STATUS] = "status",
  64         [SI_NUM_PLAYED] = "num_played",
  65
  66         [SI_MTIME] = "mtime",
  67         [SI_LENGTH_MIN] = "length_min",
  68         [SI_LENGTH_SEC] = "length_sec",
  69
  70         [SI_FILE_SIZE] = "file_size",
  71         [SI_STATUS_FLAGS] = "status_flags",
  72         [SI_FORMAT] = "format",
  73
  74         [SI_SCORE] = "score",
  75         [SI_AUDIO_INFO1] = "audio_file_info1",
  76         [SI_AUDIO_INFO2] = "audio_file_info2",
  77
  78         [SI_AUDIO_INFO3] = "audio_file_info3",
  79         [SI_DBINFO1] = "dbinfo1",
  80         [SI_DBINFO2] = "dbinfo2",
  81
  82         [SI_DBINFO3] = "dbinfo3",
  83         [SI_DECODER_FLAGS] = "decoder_flags",
  84         [SI_AUDIOD_STATUS] = "audiod_status",
  85
  86         [SI_PLAY_TIME] = "play_time",
  87         [SI_UPTIME] = "uptime",
  88         [SI_OFFSET] = "offset",
  89
  90         [SI_LENGTH] = "length",
  91         [SI_STREAM_START] = "stream_start",
  92         [SI_CURRENT_TIME] = "current_time",
  93
  94         [SI_AUDIOD_UPTIME] = "audiod_uptime",
  95         [SI_SELECTOR] = "dbtool"
  96 };
  97 #define FOR_EACH_STAT_ITEM(i) for (i = 0; i < NUM_STAT_ITEMS; i++)
  98
  99 static void dump_stat_client_list(void)
 100 {
 101         struct stat_client *sc;
 102
 103         if (!initialized)
 104                 return;
 105         list_for_each_entry(sc, &client_list, node)
 106                 PARA_INFO_LOG("stat client on fd %d\n", sc->fd);
 107 }
 108 /**
 109  * add a status client to the list
 110  *
 111  * \return Positive value on success, or -E_TOO_MANY_CLIENTS if
 112  * the number of connected clients exceeds #MAX_STAT_CLIENTS
 113  */
 114 int stat_client_add(int fd, long unsigned mask)
 115 {
 116         struct stat_client *new_client;
 117
 118         if (num_clients >= MAX_STAT_CLIENTS) {
 119                 PARA_ERROR_LOG("maximal number of stat clients (%d) exceeded\n",
 120                         MAX_STAT_CLIENTS);
 121                 return -E_TOO_MANY_CLIENTS;
 122         }
 123         if (!initialized) {
 124                 INIT_LIST_HEAD(&client_list);
 125                 initialized = 1;
 126         }
 127         PARA_INFO_LOG("adding client on fd %d\n", fd);
 128         new_client = para_malloc(sizeof(struct stat_client));
 129         new_client->fd = fd;
 130         new_client->item_mask = mask;
 131         add_close_on_fork_list(fd);
 132         list_add(&new_client->node, &client_list);
 133         dump_stat_client_list();
 134         num_clients++;
 135         return 1;
 136 }
 137 /**
 138  * write a message to all connected status clients
 139  *
 140  * \param msg a \p NULL terminated buffer
 141  * \param itemnum The number of the status item of \a msg
 142  *
 143  * On write errors, remove the status client from the client list and close its
 144  * file descriptor.
 145  */
 146 void stat_client_write(char *msg, int itemnum)
 147 {
 148         struct stat_client *sc, *tmp;
 149         ssize_t len;
 150         struct timeval tv = {0 , 0};
 151
 152         if (!initialized)
 153                 return;
 154         len = strlen(msg);
 155         list_for_each_entry_safe(sc, tmp, &client_list, node) {
 156                 int fd = sc->fd, ret;
 157                 fd_set wfds;
 158
 159                 if (!((1 << itemnum) & sc->item_mask))
 160                         continue;
 161                 FD_ZERO(&wfds);
 162                 FD_SET(fd, &wfds);
 163 //              PARA_DEBUG_LOG("%s: p=%lx\n", __func__, (long)p);
 164                 do
 165                         ret = select(fd + 1, NULL, &wfds, NULL, &tv);
 166                 while (ret < 0 && errno == EINTR);
 167                 if (ret) {
 168                         ret = write(fd, msg, len);
 169                         PARA_DEBUG_LOG("dumped %s to fd %d, ret = %d\n", msg, fd, ret);
 170                         if (ret == len )
 171                                 continue;
 172                 }
 173                 /* write error or fd not ready for writing */
 174                 close(fd);
 175                 del_close_on_fork_list(fd);
 176                 num_clients--;
 177                 PARA_INFO_LOG("deleting client on fd %d\n", fd);
 178                 list_del(&sc->node);
 179                 free(sc);
 180                 dump_stat_client_list();
 181         }
 182         PARA_DEBUG_LOG("%d client(s)\n", num_clients);
 183 }
 184
 185 /**
 186  * send empty status list
 187  *
 188  * Send to  each connected client the full status item list
 189  * with empty values.
 190  */
 191 void dump_empty_status(void)
 192 {
 193         int i;
 194
 195         if (!initialized)
 196                 return;
 197         FOR_EACH_STAT_ITEM(i) {
 198                 char *tmp = make_message("%s:\n", status_item_list[i]);
 199                 stat_client_write(tmp, i);
 200                 free(tmp);
 201         }
 202 }
 203
 204 /**
 205  * check if string is a known status item.
 206  *
 207  * \param item buffer containing the text to check
 208  *
 209  * \return If \a item is a valid status item, the number of that status item is
 210  * returned. Otherwise, this function returns \p -E_UNKNOWN_STAT_ITEM.
 211  */
 212 int stat_item_valid(const char *item)
 213 {
 214         int i;
 215         if (!item || !*item)
 216                 return -E_UNKNOWN_STAT_ITEM;
 217         FOR_EACH_STAT_ITEM(i)
 218                 if (!strcmp(status_item_list[i], item))
 219                         return i;
 220         return -E_UNKNOWN_STAT_ITEM;
 221 }
 222
 223 /**
 224  * check if line starts with known status item.
 225  *
 226  * \param line buffer containing the line
 227  *
 228  * \return If the beginning of \a line matches any paraslash status item and is
 229  * followed by a colon, the number of that status item is returned. Otherwise,
 230  * this function returns \p -E_UNKNOWN_STAT_ITEM.
 231  */
 232 int stat_line_valid(const char *line)
 233 {
 234         int i;
 235         size_t line_len;
 236
 237         if (!line || !*line)
 238                 return -E_UNKNOWN_STAT_ITEM;
 239         line_len = strlen(line);
 240         FOR_EACH_STAT_ITEM(i) {
 241                 const char *s = status_item_list[i];
 242                 size_t item_len = strlen(s);
 243
 244                 if (line_len > item_len && line[item_len] == ':' &&
 245                                 !strncmp(line, s, item_len))
 246                         return i;
 247         }
 248         return -E_UNKNOWN_STAT_ITEM;
 249 }
 250
 251 /**
 252  * call a custom function for each complete line
 253  *
 254  * \param buf the buffer containing data seperated by newlines
 255  * \param n the number of bytes in \a buf
 256  * \param line_handler the custom function
 257  *
 258  * If \a line_handler is \p NULL, return number of complete lines in buf.
 259  * Otherwise, call \a line_handler for each complete line.  The rest of the
 260  * buffer (last chunk containing incomplete line is moved to the beginning of
 261  * the buffer.
 262  *
 263  * \return If line_handler is not NULL, this function returns the number
 264  * of bytes not handled to \a line_handler.
 265  */
 266 unsigned for_each_line(char *buf, int n, void (*line_handler)(char *))
 267 {
 268         char *start = buf, *end;
 269         int i, num_lines = 0;
 270
 271         while (start < buf + n) {
 272                 char *next_null;
 273                 char *next_cr;
 274
 275                 next_cr = memchr(start, '\n', buf + n - start);
 276                 next_null = memchr(start, '\0', buf + n - start);
 277                 if (!next_cr && !next_null)
 278                         break;
 279                 if (next_cr && next_null) {
 280                         end = next_cr < next_null? next_cr : next_null;
 281                 } else if (next_null) {
 282                         end = next_null;
 283                 } else
 284                         end = next_cr;
 285                 num_lines++;
 286                 if (line_handler) {
 287                         *end = '\0';
 288                         line_handler(start);
 289                         start = ++end;
 290                 } else
 291                         start = ++end;
 292         }
 293         if (!line_handler)
 294                 return num_lines;
 295         i = buf + n - start;
 296         if (i && i != n)
 297                 memmove(buf, start, i);
 298         return i;
 299 }
 300