*** empty log message ***

1 files changed, 71 insertions, 0 deletions

diff --git a/runtime/scbuf.c b/runtime/scbuf.c
new file mode 100644
index 00000000..15458bee
--- /dev/null
+++ b/runtime/scbuf.c
@@ -0,0 +1,71 @@
+#ifndef _SCBUF_C_
+#define _SCBUF_C_
+
+/* -*- linux-c -*- */
+/** @file scbuf.c
+ * @addtogroup scbuf Scratch Buffer
+ * Scratch Buffer Functions.
+ * The scratch buffer is for collecting output before storing in a map,
+ * printing, etc. This is a per-cpu static buffer.  It is necessary because 
+ * of the limited stack space available in the kernel.
+ * @{
+ */
+
+/** Maximum size of buffer, not including terminating NULL */
+#define STP_BUF_LEN 8191
+
+/** Scratch buffer for printing, building strings, etc */
+char _stp_scbuf[STP_BUF_LEN+1];
+static int _stp_scbuf_len = STP_BUF_LEN;
+
+/** Sprint into the scratch buffer.
+ * Like printf, except output goes into  #_stp_scbuf,
+ * which will contain the null-terminated output.
+ * Safe because overflowing #_stp_scbuf is not allowed.
+ * Size is limited by length of scratch buffer, STP_BUF_LEN.
+ *
+ * @param fmt A printf-style format string followed by a 
+ * variable number of args.
+ * @sa _stp_scbuf_clear
+ */
+
+void _stp_sprint (const char *fmt, ...)
+{
+  int num;
+  va_list args;
+  char *buf = _stp_scbuf + STP_BUF_LEN - _stp_scbuf_len;
+  va_start(args, fmt);
+  num = vscnprintf(buf, _stp_scbuf_len, fmt, args);
+  va_end(args);
+  if (num > 0)
+    _stp_scbuf_len -= num;
+}
+
+void _stp_sprint_str (const char *str)
+{
+  char *buf = _stp_scbuf + STP_BUF_LEN - _stp_scbuf_len;
+  int num = strlen (str);
+  if (num > _stp_scbuf_len)
+    num = _stp_scbuf_len;
+  strncpy (buf, str, num);
+  _stp_scbuf_len -= num;
+}
+
+/** Clear the scratch buffer.
+ * Output from _stp_sprint() will accumulate in the buffer
+ * until this is called.
+ */
+
+void _stp_scbuf_clear (void)
+{
+  _stp_scbuf_len = STP_BUF_LEN;
+  _stp_scbuf[0] = 0;
+}
+
+static char *_stp_scbuf_cur (void)
+{
+  return _stp_scbuf + STP_BUF_LEN - _stp_scbuf_len;
+}
+
+/** @} */
+#endif /* _SCBUF_C_ */