[PATCH 03/10] trace-cmd library: New API for setting a custom trace directory to an output handler

["Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com>]

The new API associates a custom tracing directory with an output file
handler. It is used when creating the trace file instead of the system
default tracing directory.
 tracecmd_output_set_trace_dir()

Signed-off-by: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
---
 .../include/private/trace-cmd-private.h       |  1 +
 lib/trace-cmd/trace-output.c                  | 27 +++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/lib/trace-cmd/include/private/trace-cmd-private.h b/lib/trace-cmd/include/private/trace-cmd-private.h
index 2f34af13..ad9d5265 100644
--- a/lib/trace-cmd/include/private/trace-cmd-private.h
+++ b/lib/trace-cmd/include/private/trace-cmd-private.h
@@ -272,6 +272,7 @@ struct tracecmd_msg_handle;
 struct tracecmd_output *tracecmd_output_allocate(int fd);
 int tracecmd_output_set_msg(struct tracecmd_output *handler,
 			    struct tracecmd_msg_handle *msg_handle);
+int tracecmd_output_set_trace_dir(struct tracecmd_output *handler, const char *tracing_dir);
 struct tracecmd_output *tracecmd_create_file_latency(const char *output_file, int cpus);
 struct tracecmd_output *
 tracecmd_create_init_file_glob(const char *output_file,
diff --git a/lib/trace-cmd/trace-output.c b/lib/trace-cmd/trace-output.c
index d73c4f99..a5d7ed5f 100644
--- a/lib/trace-cmd/trace-output.c
+++ b/lib/trace-cmd/trace-output.c
@@ -941,6 +941,33 @@ int tracecmd_output_set_msg(struct tracecmd_output *handler, struct tracecmd_msg
 	return 0;
 }
 
+/**
+ * tracecmd_output_set_trace_dir - Set a custom tracing dir, instead of system default
+ * @handle: output handler to a trace file.
+ * @tracing_dir: full path to a directory with tracing files
+ *
+ * This API associates an output file handler with a custom tracing directory, to be used when
+ * creating the trace file instead of the system default tracing directory.
+ * This API must be called before tracecmd_output_write_init().
+ *
+ * Returns 0 on success, or -1 if the output file handler is not allocated or not in expected state.
+ */
+int tracecmd_output_set_trace_dir(struct tracecmd_output *handler, const char *tracing_dir)
+{
+	if (!handler || handler->file_state != TRACECMD_FILE_ALLOCATED)
+		return -1;
+
+	free(handler->tracing_dir);
+	if (tracing_dir) {
+		handler->tracing_dir = strdup(tracing_dir);
+		if (!handler->tracing_dir)
+			return -1;
+	} else
+		handler->tracing_dir = NULL;
+
+	return 0;
+}
+
 static int select_file_version(struct tracecmd_output *handle,
 				struct tracecmd_input *ihandle)
 {
-- 
2.31.1