1 files changed, 130 insertions, 0 deletions
diff --git a/runtime/string.c b/runtime/string.c
new file mode 100644
index 00000000..a44cabc1
--- /dev/null
+++ b/runtime/string.c
@@ -0,0 +1,130 @@
+#ifndef _STRING_C_ /* -*- linux-c -*- */
+#define _STRING_C_
+
+#include <linux/config.h>
+
+/** @file string.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.
+ * @todo Need careful review of these to insure safety.
+ * @{
+ */
+
+#ifndef STP_STRING_SIZE
+#define STP_STRING_SIZE 2048
+#endif
+
+struct string {
+	short len;
+	short global;
+	char buf[STP_STRING_SIZE];
+};
+
+static struct string _stp_string[STP_NUM_STRINGS][NR_CPUS];
+
+typedef struct string *String;
+
+String _stp_string_init (int num)
+{
+	int global = 0;
+	String str;
+
+	if (num  < 0) {
+		num = -num;
+		global = 1;
+	}
+	
+	if (num >= STP_NUM_STRINGS) {
+		_stp_log ("_stp_string_init internal error: requested string exceeded allocated number");
+		return NULL;
+	}
+
+	if (global)
+		str = &_stp_string[num][0];
+	else
+		str = &_stp_string[num][smp_processor_id()];
+
+	str->global = global;
+	str->len = 0;
+	return str;
+}
+
+
+/** Sprint into the scratch buffer.
+ * Like printf, except output goes into a global scratch buffer
+ * which will contain the null-terminated output.
+ * Safe because overflowing the buffer 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_sprintf (String str, const char *fmt, ...)
+{
+	int num;
+	va_list args;
+	va_start(args, fmt);
+	num = vscnprintf(str->buf + str->len, STP_STRING_SIZE - str->len - 1, fmt, args);
+	va_end(args);
+	if (num > 0)
+		str->len += num;
+}
+
+void _stp_vsprintf (String str, const char *fmt, va_list args)
+{
+	int num;
+	num = vscnprintf(str->buf + str->len, STP_STRING_SIZE - str->len - 1, fmt, args);
+	if (num > 0)
+		str->len += num;
+}
+
+/** Write a string into the scratch buffer.
+ * Copies a string into a global scratch buffer.
+ * Safe because overflowing the buffer is not allowed.
+ * Size is limited by length of scratch buffer, STP_BUF_LEN.
+ * This is more efficient than using _stp_sprint().
+ *
+ * @param str A string.
+ */
+
+void _stp_string_cat_cstr (String str, const char *newstr)
+{
+	int num = strlen (newstr);
+	if (num > STP_STRING_SIZE - str->len - 1)
+		num = STP_STRING_SIZE - str->len - 1;
+	strncpy (str->buf + str->len, newstr, num+1);
+	str->len += num;
+}
+
+void _stp_string_cat_string (String str1, String str2)
+{
+	int num = str2->len;
+	if (num > STP_STRING_SIZE - str1->len - 1)
+		num = STP_STRING_SIZE - str1->len - 1;
+	strncpy (str1->buf + str1->len, str2->buf, num);
+	str1->len += num;
+}
+
+char * _stp_string_ptr (String str)
+{
+	return str->buf;
+}
+
+#define _stp_string_cat(str1, str2)					\
+  ({                                                            \
+	  if (__builtin_types_compatible_p (typeof (str2), char[])) {	\
+		  char *x = (char *)str2;				\
+		  _str_string_cat_cstr(str1,x);				\
+	  } else {							\
+		  String x = (String)str2;				\
+		  _str_string_cat_string(str1,x);			\
+	  }								\
+  })
+
+/** @} */
+#endif /* _STRING_C_ */