weston-log-file: Introduce file type of stream

With the logging infrastructure in place this patch add a new user: file
type of stream backed-up by a std file descriptor.

Signed-off-by: Marius Vlad <marius.vlad@collabora.com>

include/libweston/weston-log.h

@@ -29,6 +29,8 @@
 #include <stdbool.h>
 #include <stdlib.h>
 #include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
 
 #ifdef  __cplusplus
 extern "C" {
@@ -104,6 +106,12 @@ weston_log_subscribe(struct weston_log_context *log_ctx,
 		     struct weston_log_subscriber *subscriber,
 		     const char *scope_name);
 
+struct weston_log_subscriber *
+weston_log_subscriber_create_log(FILE *dump_to);
+
+void
+weston_log_subscriber_destroy_log(struct weston_log_subscriber *sub);
+
 #ifdef  __cplusplus
 }
 #endif

libweston/meson.build

@@ -27,6 +27,7 @@ srcs_libweston = [
 	'timeline.c',
 	'touch-calibration.c',
 	'weston-log-wayland.c',
+	'weston-log-file.c',
 	'weston-log.c',
 	'zoom.c',
 	'../shared/matrix.c',

libweston/weston-log-file.c

@@ -0,0 +1,100 @@
+/*
+ * Copyright © 2019 Collabora Ltd.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial
+ * portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT.  IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include "config.h"
+
+#include <libweston/weston-log.h>
+#include "helpers.h"
+#include <libweston/libweston.h>
+
+#include "weston-log-internal.h"
+
+#include <stdio.h>
+
+/** File type of stream
+ */
+struct weston_debug_log_file {
+	struct weston_log_subscriber base;
+	FILE *file;
+};
+
+static struct weston_debug_log_file *
+to_weston_debug_log_file(struct weston_log_subscriber *sub)
+{
+	return container_of(sub, struct weston_debug_log_file, base);
+}
+
+static void
+weston_log_file_write(struct weston_log_subscriber *sub,
+		      const char *data, size_t len)
+{
+	struct weston_debug_log_file *stream = to_weston_debug_log_file(sub);
+	fwrite(data, len, 1, stream->file);
+}
+
+/** Creates a file type of subscriber
+ *
+ * Should be destroyed using weston_log_subscriber_destroy_log()
+ *
+ * @param dump_to if specified, used for writing data to
+ * @returns a weston_log_subscriber object or NULL in case of failure
+ *
+ * @sa weston_log_subscriber_destroy_log
+ *
+ */
+WL_EXPORT struct weston_log_subscriber *
+weston_log_subscriber_create_log(FILE *dump_to)
+{
+	struct weston_debug_log_file *file = zalloc(sizeof(*file));
+
+	if (!file)
+		return NULL;
+
+	if (dump_to)
+		file->file = dump_to;
+	else
+		file->file = stderr;
+
+
+	file->base.write = weston_log_file_write;
+	file->base.destroy = NULL;
+	file->base.complete = NULL;
+
+	wl_list_init(&file->base.subscription_list);
+
+	return &file->base;
+}
+
+/** Destroy the subscriber created with weston_log_subscriber_create_log
+ *
+ * @param subscriber the weston_log_subscriber object to destroy
+ *
+ */
+WL_EXPORT void
+weston_log_subscriber_destroy_log(struct weston_log_subscriber *subscriber)
+{
+	struct weston_debug_log_file *file = to_weston_debug_log_file(subscriber);
+	free(file);
+}