stat.c

   1 /* Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
   2
   3 /**
   4  *  \file stat.c Functions used for sending/receiving the status of para_server
   5  *  and para_audiod.
   6  */
   7
   8 #include <regex.h>
   9
  10 #include "para.h"
  11 #include "error.h"
  12 #include "string.h"
  13
  14
  15 /** The minimal length of a status item buffer. */
  16 #define MIN_STAT_ITEM_LEN 9 /* 5 + 2 + 2, e.g. '0005 00:\n' */
  17
  18 /**
  19  * Call a function for each complete status item of a buffer.
  20  *
  21  * \param item_buf The source buffer.
  22  * \param num_bytes The length of \a buf.
  23  * \param item_handler Function to call for each complete item.
  24  *
  25  * \return Negative on errors, the number of bytes _not_ passed to \a
  26  * item_handler on success.
  27  *
  28  * Status items are expected in the format used by parser-friendly output mode
  29  * of the stat command of para_client/para_audioc.
  30  */
  31 int for_each_stat_item(char *item_buf, size_t num_bytes,
  32         int (*item_handler)(int, char *))
  33 {
  34         char *buf = item_buf;
  35         int len = num_bytes;
  36
  37         for (;;) {
  38                 int i, ret, item_len, item_num = 0;
  39                 if (len < MIN_STAT_ITEM_LEN)
  40                         break;
  41                 ret = read_size_header(buf);
  42                 if (ret < 0)
  43                         return ret;
  44                 item_len = ret;
  45                 if (item_len > len - 5) /* item not complete */
  46                         break;
  47                 for (i = 0; i < 2; i++) {
  48                         unsigned char c = buf[5 + i];
  49                         item_num <<= 4;
  50                         if (c >= '0' && c <= '9') {
  51                                 item_num += c - '0';
  52                                 continue;
  53                         }
  54                         if (c >= 'a' && c <= 'f') {
  55                                 item_num += c - 'a' + 10;
  56                                 continue;
  57                         }
  58                         return -E_STAT_ITEM_PARSE;
  59                 }
  60                 if (buf[7] != ':' || buf[5 + item_len - 1] != '\n')
  61                         return -E_STAT_ITEM_PARSE;
  62                 buf[5 + item_len - 1] = '\0';
  63                 if (item_num >= NUM_STAT_ITEMS)
  64                         PARA_WARNING_LOG("unknown status item %d: %s\n",
  65                                 item_num, buf + 8);
  66                 else {
  67                         ret = item_handler(item_num, buf + 8);
  68                         if (ret < 0)
  69                                 return ret;
  70                 }
  71                 buf += 5 + item_len;
  72                 len -= 5 + item_len;
  73                 assert(len >= 0 && buf <= item_buf + num_bytes);
  74         }
  75         assert(len >= 0);
  76         return len;
  77 }