stat.c

   1 /*
   2  * Copyright (C) 2005-2007 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /**
   8  *  \file stat.c functions used for sending/receiving the status of para_server
   9  *  and para_audiod
  10  */
  11 #include "para.h"
  12 #include "close_on_fork.h"
  13 #include "list.h"
  14 #include "error.h"
  15 #include "string.h"
  16 #include "fd.h"
  17
  18 /** the maximal number of simultaneous connections */
  19 #define MAX_STAT_CLIENTS 50
  20
  21 /**
  22  * describes a status client of para_audiod
  23  *
  24  * There's one such structure per audiod client that sent the 'stat' command.
  25  *
  26  * A status client is identified by its file descriptor.  para_audiod
  27  * keeps a list of connected status clients.
  28  */
  29 struct stat_client {
  30         /** the stat client's file descriptor */
  31         int fd;
  32         /** bitmask of those status items the client is interested in */
  33         long unsigned item_mask;
  34         /** its entry in the list of stat clients */
  35         struct list_head node;
  36 };
  37
  38 static struct list_head client_list;
  39 static int initialized;
  40 static int num_clients;
  41
  42 /**
  43  * the list of all status items sent by para_server/para_audiod
  44  */
  45 const char *status_item_list[NUM_STAT_ITEMS] = {
  46         [SI_STATUS_BAR] = "status_bar",
  47         [SI_STATUS] = "status",
  48         [SI_NUM_PLAYED] = "num_played",
  49
  50         [SI_MTIME] = "mtime",
  51         [SI_LENGTH_MIN] = "length_min",
  52         [SI_LENGTH_SEC] = "length_sec",
  53
  54         [SI_FILE_SIZE] = "file_size",
  55         [SI_STATUS_FLAGS] = "status_flags",
  56         [SI_FORMAT] = "format",
  57
  58         [SI_SCORE] = "score",
  59         [SI_AUDIO_INFO1] = "audio_file_info1",
  60         [SI_AUDIO_INFO2] = "audio_file_info2",
  61
  62         [SI_AUDIO_INFO3] = "audio_file_info3",
  63         [SI_DBINFO1] = "dbinfo1",
  64         [SI_DBINFO2] = "dbinfo2",
  65
  66         [SI_DBINFO3] = "dbinfo3",
  67         [SI_DECODER_FLAGS] = "decoder_flags",
  68         [SI_AUDIOD_STATUS] = "audiod_status",
  69
  70         [SI_PLAY_TIME] = "play_time",
  71         [SI_UPTIME] = "uptime",
  72         [SI_OFFSET] = "offset",
  73
  74         [SI_LENGTH] = "length",
  75         [SI_STREAM_START] = "stream_start",
  76         [SI_CURRENT_TIME] = "current_time",
  77
  78         [SI_AUDIOD_UPTIME] = "audiod_uptime",
  79         [SI_SELECTOR] = "dbtool"
  80 };
  81
  82 static void dump_stat_client_list(void)
  83 {
  84         struct stat_client *sc;
  85
  86         if (!initialized)
  87                 return;
  88         list_for_each_entry(sc, &client_list, node)
  89                 PARA_INFO_LOG("stat client on fd %d\n", sc->fd);
  90 }
  91 /**
  92  * add a status client to the list
  93  *
  94  * \param fd the file descriptor of the client
  95  * \param mask bitfield of status items for this client
  96  *
  97  * Only those status items having the bit set in \a mask will be
  98  * sent to the client.
  99  *
 100  * \return Positive value on success, or -E_TOO_MANY_CLIENTS if
 101  * the number of connected clients exceeds #MAX_STAT_CLIENTS.
 102  */
 103 int stat_client_add(int fd, long unsigned mask)
 104 {
 105         struct stat_client *new_client;
 106
 107         if (num_clients >= MAX_STAT_CLIENTS) {
 108                 PARA_ERROR_LOG("maximal number of stat clients (%d) exceeded\n",
 109                         MAX_STAT_CLIENTS);
 110                 return -E_TOO_MANY_CLIENTS;
 111         }
 112         if (!initialized) {
 113                 INIT_LIST_HEAD(&client_list);
 114                 initialized = 1;
 115         }
 116         PARA_INFO_LOG("adding client on fd %d\n", fd);
 117         new_client = para_malloc(sizeof(struct stat_client));
 118         new_client->fd = fd;
 119         new_client->item_mask = mask;
 120         para_list_add(&new_client->node, &client_list);
 121         dump_stat_client_list();
 122         num_clients++;
 123         return 1;
 124 }
 125 /**
 126  * write a message to all connected status clients
 127  *
 128  * \param msg a \p NULL terminated buffer
 129  * \param itemnum The number of the status item of \a msg
 130  *
 131  * On write errors, remove the status client from the client list and close its
 132  * file descriptor.
 133  */
 134 void stat_client_write(const char *msg, int itemnum)
 135 {
 136         struct stat_client *sc, *tmp;
 137         size_t len = strlen(msg);
 138         struct timeval tv = {0 , 0};
 139
 140         if (!initialized || !len)
 141                 return;
 142         list_for_each_entry_safe(sc, tmp, &client_list, node) {
 143                 int fd = sc->fd, ret;
 144                 fd_set wfds;
 145
 146                 if (!((1 << itemnum) & sc->item_mask))
 147                         continue;
 148                 FD_ZERO(&wfds);
 149                 FD_SET(fd, &wfds);
 150 //              PARA_DEBUG_LOG("%s: p=%lx\n", __func__, (long)p);
 151                 ret = para_select(fd + 1, NULL, &wfds, &tv);
 152                 if (ret > 0) {
 153                         ret = write(fd, msg, len);
 154                         PARA_DEBUG_LOG("dumped %s to fd %d, ret = %d\n", msg, fd, ret);
 155                         if (ret == len )
 156                                 continue;
 157                 }
 158                 /* write error or fd not ready for writing */
 159                 close(fd);
 160                 num_clients--;
 161                 PARA_INFO_LOG("deleting client on fd %d\n", fd);
 162                 list_del(&sc->node);
 163                 free(sc);
 164                 dump_stat_client_list();
 165         }
 166         PARA_DEBUG_LOG("%d client(s)\n", num_clients);
 167 }
 168
 169
 170 /**
 171  * check if string is a known status item.
 172  *
 173  * \param item buffer containing the text to check
 174  *
 175  * \return If \a item is a valid status item, the number of that status item is
 176  * returned. Otherwise, this function returns \p -E_UNKNOWN_STAT_ITEM.
 177  */
 178 int stat_item_valid(const char *item)
 179 {
 180         int i;
 181         if (!item || !*item) {
 182         PARA_ERROR_LOG("%s\n", "no item");
 183                 return -E_UNKNOWN_STAT_ITEM;
 184         }
 185         FOR_EACH_STAT_ITEM(i)
 186                 if (!strcmp(status_item_list[i], item))
 187                         return i;
 188         return -E_UNKNOWN_STAT_ITEM;
 189 }
 190
 191 /**
 192  * check if line starts with known status item.
 193  *
 194  * \param line buffer containing the line
 195  *
 196  * \return If the beginning of \a line matches any paraslash status item and is
 197  * followed by a colon, the number of that status item is returned. Otherwise,
 198  * this function returns \p -E_UNKNOWN_STAT_ITEM.
 199  */
 200 int stat_line_valid(const char *line)
 201 {
 202         int i;
 203         size_t line_len;
 204
 205         if (!line || !*line)
 206                 return -E_UNKNOWN_STAT_ITEM;
 207         line_len = strlen(line);
 208         FOR_EACH_STAT_ITEM(i) {
 209                 const char *s = status_item_list[i];
 210                 size_t item_len = strlen(s);
 211
 212                 if (line_len > item_len && line[item_len] == ':' &&
 213                                 !strncmp(line, s, item_len))
 214                         return i;
 215         }
 216         return -E_UNKNOWN_STAT_ITEM;
 217 }
 218