Add FlStandardMessageCodec (#18213)

ci/licenses_golden/licenses_flutter

@@ -1199,6 +1199,9 @@ FILE: ../../../flutter/shell/platform/linux/fl_renderer.cc
 FILE: ../../../flutter/shell/platform/linux/fl_renderer.h
 FILE: ../../../flutter/shell/platform/linux/fl_renderer_x11.cc
 FILE: ../../../flutter/shell/platform/linux/fl_renderer_x11.h
+FILE: ../../../flutter/shell/platform/linux/fl_standard_message_codec.cc
+FILE: ../../../flutter/shell/platform/linux/fl_standard_message_codec_private.h
+FILE: ../../../flutter/shell/platform/linux/fl_standard_message_codec_test.cc
 FILE: ../../../flutter/shell/platform/linux/fl_string_codec.cc
 FILE: ../../../flutter/shell/platform/linux/fl_string_codec_test.cc
 FILE: ../../../flutter/shell/platform/linux/fl_value.cc
@@ -1209,6 +1212,7 @@ FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_binary_messe
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_dart_project.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_engine.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_message_codec.h
+FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_standard_message_codec.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_string_codec.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_value.h
 FILE: ../../../flutter/shell/platform/linux/public/flutter_linux/fl_view.h

shell/platform/linux/BUILD.gn

@@ -49,6 +49,7 @@ _public_headers = [
   "public/flutter_linux/fl_dart_project.h",
   "public/flutter_linux/fl_engine.h",
   "public/flutter_linux/fl_message_codec.h",
+  "public/flutter_linux/fl_standard_message_codec.h",
   "public/flutter_linux/fl_string_codec.h",
   "public/flutter_linux/fl_value.h",
   "public/flutter_linux/fl_view.h",
@@ -70,6 +71,7 @@ source_set("flutter_linux") {
     "fl_message_codec.cc",
     "fl_renderer.cc",
     "fl_renderer_x11.cc",
+    "fl_standard_message_codec.cc",
     "fl_string_codec.cc",
     "fl_value.cc",
     "fl_view.cc",
@@ -100,6 +102,7 @@ executable("flutter_linux_unittests") {
     "fl_binary_codec_test.cc",
     "fl_dart_project_test.cc",
     "fl_message_codec_test.cc",
+    "fl_standard_message_codec_test.cc",
     "fl_string_codec_test.cc",
     "fl_value_test.cc",
     "testing/fl_test.cc",

shell/platform/linux/fl_standard_message_codec_private.h

+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_PLATFORM_LINUX_FL_STANDARD_MESSAGE_CODEC_PRIVATE_H_
+#define FLUTTER_SHELL_PLATFORM_LINUX_FL_STANDARD_MESSAGE_CODEC_PRIVATE_H_
+
+#include "flutter/shell/platform/linux/public/flutter_linux/fl_standard_message_codec.h"
+
+G_BEGIN_DECLS
+
+/**
+ * fl_standard_message_codec_write_size:
+ * @codec: a #FlStandardMessageCodec
+ * @buffer: buffer to write into
+ * @size: size value to write
+ *
+ * Writes a size field in Flutter Standard encoding.
+ */
+void fl_standard_message_codec_write_size(FlStandardMessageCodec* codec,
+                                          GByteArray* buffer,
+                                          uint32_t size);
+
+/**
+ * fl_standard_message_codec_read_size:
+ * @codec: a #FlStandardMessageCodec
+ * @buffer: buffer to read from
+ * @offset: (inout): read position in @buffer
+ * @value: location to read size
+ * @error: (allow-none): #GError location to store the error occurring, or %NULL
+ *
+ * Reads a size field in Flutter Standard encoding.
+ *
+ * Returns: %TRUE on success.
+ */
+gboolean fl_standard_message_codec_read_size(FlStandardMessageCodec* codec,
+                                             GBytes* buffer,
+                                             size_t* offset,
+                                             uint32_t* value,
+                                             GError** error);
+
+/**
+ * fl_standard_message_codec_write_value:
+ * @codec: a #FlStandardMessageCodec
+ * @buffer: buffer to write into
+ * @value: (allow-none): value to write
+ * @error: (allow-none): #GError location to store the error occurring, or %NULL
+ *
+ * Writes a #FlValue in Flutter Standard encoding.
+ *
+ * Returns: %TRUE on success.
+ */
+gboolean fl_standard_message_codec_write_value(FlStandardMessageCodec* codec,
+                                               GByteArray* buffer,
+                                               FlValue* value,
+                                               GError** error);
+
+/**
+ * fl_standard_message_codec_read_value:
+ * @codec: a #FlStandardMessageCodec
+ * @buffer: buffer to read from
+ * @offset: (inout): read position in @buffer
+ * @value: location to read size
+ * @error: (allow-none): #GError location to store the error occurring, or %NULL
+ *
+ * Reads a #FlValue in Flutter Standard encoding.
+ *
+ * Returns: a new #FlValue or %NULL on error.
+ */
+FlValue* fl_standard_message_codec_read_value(FlStandardMessageCodec* codec,
+                                              GBytes* buffer,
+                                              size_t* offset,
+                                              GError** error);
+
+G_END_DECLS
+
+#endif  // FLUTTER_SHELL_PLATFORM_LINUX_FL_STANDARD_MESSAGE_CODEC_PRIVATE_H_

shell/platform/linux/public/flutter_linux/fl_standard_message_codec.h

+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef FLUTTER_SHELL_PLATFORM_LINUX_FL_STANDARD_MESSAGE_CODEC_H_
+#define FLUTTER_SHELL_PLATFORM_LINUX_FL_STANDARD_MESSAGE_CODEC_H_
+
+#if !defined(__FLUTTER_LINUX_INSIDE__) && !defined(FLUTTER_LINUX_COMPILATION)
+#error "Only <flutter_linux/flutter_linux.h> can be included directly."
+#endif
+
+#include "fl_message_codec.h"
+
+G_BEGIN_DECLS
+
+G_DECLARE_FINAL_TYPE(FlStandardMessageCodec,
+                     fl_standard_message_codec,
+                     FL,
+                     STANDARD_CODEC,
+                     FlMessageCodec)
+
+/**
+ * FlStandardMessageCodec:
+ *
+ * #FlStandardMessageCodec is an #FlMessageCodec that implements the Flutter
+ * standard message encoding. This encodes and decodes #FlValue of type
+ * #FL_VALUE_TYPE_NULL, #FL_VALUE_TYPE_BOOL, #FL_VALUE_TYPE_INT,
+ * #FL_VALUE_TYPE_FLOAT, #FL_VALUE_TYPE_STRING, #FL_VALUE_TYPE_UINT8_LIST,
+ * #FL_VALUE_TYPE_INT32_LIST, #FL_VALUE_TYPE_INT64_LIST,
+ * #FL_VALUE_TYPE_FLOAT_LIST, #FL_VALUE_TYPE_LIST, and #FL_VALUE_TYPE_MAP
+ *
+ * #FlStandardMessageCodec matches the StandardCodec class in the Flutter
+ * services library.
+ */
+
+/*
+ * fl_standard_message_codec_new:
+ *
+ * Creates a #FlStandardMessageCodec.
+ *
+ * Returns: a new #FlStandardMessageCodec
+ */
+FlStandardMessageCodec* fl_standard_message_codec_new();
+
+G_END_DECLS
+
+#endif  // FLUTTER_SHELL_PLATFORM_LINUX_FL_STANDARD_MESSAGE_CODEC_H_

shell/platform/linux/public/flutter_linux/flutter_linux.h

@@ -12,6 +12,7 @@
 #include <flutter_linux/fl_dart_project.h>
 #include <flutter_linux/fl_engine.h>
 #include <flutter_linux/fl_message_codec.h>
+#include <flutter_linux/fl_standard_message_codec.h>
 #include <flutter_linux/fl_string_codec.h>
 #include <flutter_linux/fl_value.h>
 #include <flutter_linux/fl_view.h>