1 files changed, 200 insertions, 0 deletions

diff --git a/tools/lib/traceevent/trace-seq.c b/tools/lib/traceevent/trace-seq.c
new file mode 100644
index 000000000000..b1ccc923e8a5
--- /dev/null
+++ b/tools/lib/traceevent/trace-seq.c
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 2009 Red Hat Inc, Steven Rostedt <srostedt@redhat.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License (not later!)
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdarg.h>
+
+#include "event-parse.h"
+#include "event-utils.h"
+
+/*
+ * The TRACE_SEQ_POISON is to catch the use of using
+ * a trace_seq structure after it was destroyed.
+ */
+#define TRACE_SEQ_POISON        ((void *)0xdeadbeef)
+#define TRACE_SEQ_CHECK(s)                                              \
+do {                                                                    \
+        if ((s)->buffer == TRACE_SEQ_POISON)                    \
+                die("Usage of trace_seq after it was destroyed");       \
+} while (0)
+
+/**
+ * trace_seq_init - initialize the trace_seq structure
+ * @s: a pointer to the trace_seq structure to initialize
+ */
+void trace_seq_init(struct trace_seq *s)
+{
+        s->len = 0;
+        s->readpos = 0;
+        s->buffer_size = TRACE_SEQ_BUF_SIZE;
+        s->buffer = malloc_or_die(s->buffer_size);
+}
+
+/**
+ * trace_seq_destroy - free up memory of a trace_seq
+ * @s: a pointer to the trace_seq to free the buffer
+ *
+ * Only frees the buffer, not the trace_seq struct itself.
+ */
+void trace_seq_destroy(struct trace_seq *s)
+{
+        if (!s)
+                return;
+        TRACE_SEQ_CHECK(s);
+        free(s->buffer);
+        s->buffer = TRACE_SEQ_POISON;
+}
+
+static void expand_buffer(struct trace_seq *s)
+{
+        s->buffer_size += TRACE_SEQ_BUF_SIZE;
+        s->buffer = realloc(s->buffer, s->buffer_size);
+        if (!s->buffer)
+                die("Can't allocate trace_seq buffer memory");
+}
+
+/**
+ * trace_seq_printf - sequence printing of trace information
+ * @s: trace sequence descriptor
+ * @fmt: printf format string
+ *
+ * It returns 0 if the trace oversizes the buffer's free
+ * space, 1 otherwise.
+ *
+ * The tracer may use either sequence operations or its own
+ * copy to user routines. To simplify formating of a trace
+ * trace_seq_printf is used to store strings into a special
+ * buffer (@s). Then the output may be either used by
+ * the sequencer or pulled into another buffer.
+ */
+int
+trace_seq_printf(struct trace_seq *s, const char *fmt, ...)
+{
+        va_list ap;
+        int len;
+        int ret;
+
+        TRACE_SEQ_CHECK(s);
+
+ try_again:
+        len = (s->buffer_size - 1) - s->len;
+
+        va_start(ap, fmt);
+        ret = vsnprintf(s->buffer + s->len, len, fmt, ap);
+        va_end(ap);
+
+        if (ret >= len) {
+                expand_buffer(s);
+                goto try_again;
+        }
+
+        s->len += ret;
+
+        return 1;
+}
+
+/**
+ * trace_seq_vprintf - sequence printing of trace information
+ * @s: trace sequence descriptor
+ * @fmt: printf format string
+ *
+ * The tracer may use either sequence operations or its own
+ * copy to user routines. To simplify formating of a trace
+ * trace_seq_printf is used to store strings into a special
+ * buffer (@s). Then the output may be either used by
+ * the sequencer or pulled into another buffer.
+ */
+int
+trace_seq_vprintf(struct trace_seq *s, const char *fmt, va_list args)
+{
+        int len;
+        int ret;
+
+        TRACE_SEQ_CHECK(s);
+
+ try_again:
+        len = (s->buffer_size - 1) - s->len;
+
+        ret = vsnprintf(s->buffer + s->len, len, fmt, args);
+
+        if (ret >= len) {
+                expand_buffer(s);
+                goto try_again;
+        }
+
+        s->len += ret;
+
+        return len;
+}
+
+/**
+ * trace_seq_puts - trace sequence printing of simple string
+ * @s: trace sequence descriptor
+ * @str: simple string to record
+ *
+ * The tracer may use either the sequence operations or its own
+ * copy to user routines. This function records a simple string
+ * into a special buffer (@s) for later retrieval by a sequencer
+ * or other mechanism.
+ */
+int trace_seq_puts(struct trace_seq *s, const char *str)
+{
+        int len;
+
+        TRACE_SEQ_CHECK(s);
+
+        len = strlen(str);
+
+        while (len > ((s->buffer_size - 1) - s->len))
+                expand_buffer(s);
+
+        memcpy(s->buffer + s->len, str, len);
+        s->len += len;
+
+        return len;
+}
+
+int trace_seq_putc(struct trace_seq *s, unsigned char c)
+{
+        TRACE_SEQ_CHECK(s);
+
+        while (s->len >= (s->buffer_size - 1))
+                expand_buffer(s);
+
+        s->buffer[s->len++] = c;
+
+        return 1;
+}
+
+void trace_seq_terminate(struct trace_seq *s)
+{
+        TRACE_SEQ_CHECK(s);
+
+        /* There's always one character left on the buffer */
+        s->buffer[s->len] = 0;
+}
+
+int trace_seq_do_printf(struct trace_seq *s)
+{
+        TRACE_SEQ_CHECK(s);
+        return printf("%.*s", s->len, s->buffer);
+}