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<h1>scbuf.c</h1><div class="fragment"><pre class="fragment">00001 <span class="preprocessor">#ifndef _SCBUF_C_</span>
00002 <span class="preprocessor"></span><span class="preprocessor">#define _SCBUF_C_</span>
00003 <span class="preprocessor"></span>
00004 <span class="comment">/* -*- linux-c -*- */</span><span class="comment"></span>
00005 <span class="comment">/** @file scbuf.c</span>
00006 <span class="comment"> * @addtogroup scbuf Scratch Buffer</span>
00007 <span class="comment"> * Scratch Buffer Functions.</span>
00008 <span class="comment"> * The scratch buffer is for collecting output before storing in a map,</span>
00009 <span class="comment"> * printing, etc. This is a per-cpu static buffer.  It is necessary because </span>
00010 <span class="comment"> * of the limited stack space available in the kernel.</span>
00011 <span class="comment"> * @{</span>
00012 <span class="comment"> */</span>
00013 <span class="comment"></span>
00014 <span class="comment">/** Maximum size of buffer, not including terminating NULL */</span>
<a name="l00015"></a><a class="code" href="group__scbuf.html#ga6">00015</a> <span class="preprocessor">#define STP_BUF_LEN 8191</span>
00016 <span class="preprocessor"></span><span class="comment"></span>
00017 <span class="comment">/** Scratch buffer for printing, building strings, etc */</span>
<a name="l00018"></a><a class="code" href="group__scbuf.html#ga0">00018</a> <span class="keywordtype">char</span> <a class="code" href="group__scbuf.html#ga0">_stp_scbuf</a>[<a class="code" href="group__scbuf.html#ga6">STP_BUF_LEN</a>+1];
00019 <span class="keyword">static</span> <span class="keywordtype">int</span> _stp_scbuf_len = <a class="code" href="group__scbuf.html#ga6">STP_BUF_LEN</a>;
00020 <span class="comment"></span>
00021 <span class="comment">/** Sprint into the scratch buffer.</span>
00022 <span class="comment"> * Like printf, except output goes into  #_stp_scbuf,</span>
00023 <span class="comment"> * which will contain the null-terminated output.</span>
00024 <span class="comment"> * Safe because overflowing #_stp_scbuf is not allowed.</span>
00025 <span class="comment"> * Size is limited by length of scratch buffer, STP_BUF_LEN.</span>
00026 <span class="comment"> *</span>
00027 <span class="comment"> * @param fmt A printf-style format string followed by a </span>
00028 <span class="comment"> * variable number of args.</span>
00029 <span class="comment"> * @sa _stp_scbuf_clear</span>
00030 <span class="comment"> */</span>
00031 
<a name="l00032"></a><a class="code" href="group__scbuf.html#ga2">00032</a> <span class="keywordtype">void</span> <a class="code" href="group__scbuf.html#ga2">_stp_sprint</a> (<span class="keyword">const</span> <span class="keywordtype">char</span> *fmt, ...)
00033 {
00034   <span class="keywordtype">int</span> num;
00035   va_list args;
00036   <span class="keywordtype">char</span> *buf = <a class="code" href="group__scbuf.html#ga0">_stp_scbuf</a> + <a class="code" href="group__scbuf.html#ga6">STP_BUF_LEN</a> - _stp_scbuf_len;
00037   va_start(args, fmt);
00038   num = vscnprintf(buf, _stp_scbuf_len, fmt, args);
00039   va_end(args);
00040   <span class="keywordflow">if</span> (num &gt; 0)
00041     _stp_scbuf_len -= num;
00042 }
00043 
00044 <span class="keywordtype">void</span> _stp_sprint_str (<span class="keyword">const</span> <span class="keywordtype">char</span> *str)
00045 {
00046   <span class="keywordtype">char</span> *buf = <a class="code" href="group__scbuf.html#ga0">_stp_scbuf</a> + <a class="code" href="group__scbuf.html#ga6">STP_BUF_LEN</a> - _stp_scbuf_len;
00047   <span class="keywordtype">int</span> num = strlen (str);
00048   <span class="keywordflow">if</span> (num &gt; _stp_scbuf_len)
00049     num = _stp_scbuf_len;
00050   strncpy (buf, str, num);
00051   _stp_scbuf_len -= num;
00052 }
00053 <span class="comment"></span>
00054 <span class="comment">/** Clear the scratch buffer.</span>
00055 <span class="comment"> * Output from _stp_sprint() will accumulate in the buffer</span>
00056 <span class="comment"> * until this is called.</span>
00057 <span class="comment"> */</span>
00058 
<a name="l00059"></a><a class="code" href="group__scbuf.html#ga4">00059</a> <span class="keywordtype">void</span> _stp_scbuf_clear (<span class="keywordtype">void</span>)
00060 {
00061   _stp_scbuf_len = <a class="code" href="group__scbuf.html#ga6">STP_BUF_LEN</a>;
00062   <a class="code" href="group__scbuf.html#ga0">_stp_scbuf</a>[0] = 0;
00063 }
00064 
00065 <span class="keyword">static</span> <span class="keywordtype">char</span> *_stp_scbuf_cur (<span class="keywordtype">void</span>)
00066 {
00067   <span class="keywordflow">return</span> <a class="code" href="group__scbuf.html#ga0">_stp_scbuf</a> + <a class="code" href="group__scbuf.html#ga6">STP_BUF_LEN</a> - _stp_scbuf_len;
00068 }
00069 <span class="comment"></span>
00070 <span class="comment">/** @} */</span>
00071 <span class="preprocessor">#endif </span><span class="comment">/* _SCBUF_C_ */</span>
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