stat.c

   1 /*
   2  * Copyright (C) 2005-2011 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
  12 #include <regex.h>
  13
  14 #include "para.h"
  15 #include "error.h"
  16 #include "string.h"
  17
  18
  19 /** The minimal length of a status item buffer. */
  20 #define MIN_STAT_ITEM_LEN 9 /* 5 + 2 + 2, e.g. '0005 00:\n' */
  21
  22 /**
  23  * Call a function for each complete status item of a buffer.
  24  *
  25  * \param item_buf The source buffer.
  26  * \param num_bytes The length of \a buf.
  27  * \param item_handler Function to call for each complete item.
  28  *
  29  * \return Negative on errors, the number of bytes _not_ passed to \a
  30  * item_handler on success.
  31  *
  32  * Status items are expected in the format used by parser-friendly output mode
  33  * of the stat command of para_client/para_audioc.
  34  */
  35 int for_each_stat_item(char *item_buf, size_t num_bytes,
  36         int (*item_handler)(int, char *))
  37 {
  38         char *buf = item_buf;
  39         int len = num_bytes;
  40
  41         for (;;) {
  42                 int i, ret, item_len, item_num = 0;
  43                 if (len < MIN_STAT_ITEM_LEN)
  44                         break;
  45                 ret = read_size_header(buf);
  46                 if (ret < 0)
  47                         return ret;
  48                 item_len = ret;
  49                 if (item_len > len - 5) /* item not complete */
  50                         break;
  51                 for (i = 0; i < 2; i++) {
  52                         unsigned char c = buf[5 + i];
  53                         item_num <<= 4;
  54                         if (c >= '0' && c <= '9') {
  55                                 item_num += c - '0';
  56                                 continue;
  57                         }
  58                         if (c >= 'a' && c <= 'f') {
  59                                 item_num += c - 'a' + 10;
  60                                 continue;
  61                         }
  62                         return -E_STAT_ITEM_PARSE;
  63                 }
  64                 if (buf[7] != ':' || buf[5 + item_len - 1] != '\n')
  65                         return -E_STAT_ITEM_PARSE;
  66                 buf[5 + item_len - 1] = '\0';
  67                 if (item_num >= NUM_STAT_ITEMS)
  68                         PARA_WARNING_LOG("unknown status item %d: %s\n",
  69                                 item_num, buf + 8);
  70                 else {
  71                         ret = item_handler(item_num, buf + 8);
  72                         if (ret < 0)
  73                                 return ret;
  74                 }
  75                 buf += 5 + item_len;
  76                 len -= 5 + item_len;
  77                 assert(len >= 0 && buf <= item_buf + num_bytes);
  78         }
  79         assert(len >= 0);
  80         return len;
  81 }