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linux/flutter/ephemeral/flutter_linux/fl_message_codec.h

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+// 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_PUBLIC_FLUTTER_LINUX_FL_MESSAGE_CODEC_H_
+#define FLUTTER_SHELL_PLATFORM_LINUX_PUBLIC_FLUTTER_LINUX_FL_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 <glib-object.h>
+#include <gmodule.h>
+
+#include "fl_value.h"
+
+G_BEGIN_DECLS
+
+/**
+ * FlMessageCodecError:
+ * @FL_MESSAGE_CODEC_ERROR_FAILED: Codec failed due to an unspecified error.
+ * @FL_MESSAGE_CODEC_ERROR_OUT_OF_DATA: Codec ran out of data reading a value.
+ * @FL_MESSAGE_CODEC_ERROR_ADDITIONAL_DATA: Additional data encountered in
+ * message.
+ * @FL_MESSAGE_CODEC_ERROR_UNSUPPORTED_TYPE: Codec encountered an unsupported
+ * #FlValue.
+ *
+ * Errors for #FlMessageCodec objects to set on failures.
+ */
+#define FL_MESSAGE_CODEC_ERROR fl_message_codec_error_quark()
+
+typedef enum {
+  // NOLINTBEGIN(readability-identifier-naming)
+  FL_MESSAGE_CODEC_ERROR_FAILED,
+  FL_MESSAGE_CODEC_ERROR_OUT_OF_DATA,
+  FL_MESSAGE_CODEC_ERROR_ADDITIONAL_DATA,
+  FL_MESSAGE_CODEC_ERROR_UNSUPPORTED_TYPE,
+  // NOLINTEND(readability-identifier-naming)
+} FlMessageCodecError;
+
+G_MODULE_EXPORT
+GQuark fl_message_codec_error_quark(void) G_GNUC_CONST;
+
+G_MODULE_EXPORT
+G_DECLARE_DERIVABLE_TYPE(FlMessageCodec,
+                         fl_message_codec,
+                         FL,
+                         MESSAGE_CODEC,
+                         GObject)
+
+/**
+ * FlMessageCodec:
+ *
+ * #FlMessageCodec is a message encoding/decoding mechanism that operates on
+ * #FlValue objects. Both operations returns errors if the conversion fails.
+ * Such situations should be treated as programming errors.
+ *
+ * #FlMessageCodec matches the MethodCodec class in the Flutter services
+ * library.
+ */
+
+struct _FlMessageCodecClass {
+  GObjectClass parent_class;
+
+  /**
+   * FlMessageCodec::encode_message:
+   * @codec: an #FlMessageCodec.
+   * @message: message to encode or %NULL to encode the null value.
+   * @error: (allow-none): #GError location to store the error occurring, or
+   * %NULL.
+   *
+   * Virtual method to encode a message. A subclass must implement this method.
+   * If the subclass cannot handle the type of @message then it must generate a
+   * FL_MESSAGE_CODEC_ERROR_UNSUPPORTED_TYPE error.
+   *
+   * Returns: a binary message or %NULL on error.
+   */
+  GBytes* (*encode_message)(FlMessageCodec* codec,
+                            FlValue* message,
+                            GError** error);
+
+  /**
+   * FlMessageCodec::decode_message:
+   * @codec: an #FlMessageCodec.
+   * @message: binary message to decode.
+   * @error: (allow-none): #GError location to store the error occurring, or
+   * %NULL.
+   *
+   * Virtual method to decode a message. A subclass must implement this method.
+   * If @message is too small then a #FL_MESSAGE_CODEC_ERROR_OUT_OF_DATA error
+   * must be generated. If @message is too large then a
+   * #FL_MESSAGE_CODEC_ERROR_ADDITIONAL_DATA error must be generated.
+   *
+   * Returns: an #FlValue or %NULL on error.
+   */
+  FlValue* (*decode_message)(FlMessageCodec* codec,
+                             GBytes* message,
+                             GError** error);
+};
+
+/**
+ * fl_message_codec_encode_message:
+ * @codec: an #FlMessageCodec.
+ * @buffer: buffer to write to.
+ * @message: message to encode or %NULL to encode the null value.
+ * @error: (allow-none): #GError location to store the error occurring, or
+ * %NULL.
+ *
+ * Encodes a message into a binary representation.
+ *
+ * Returns: a binary encoded message or %NULL on error.
+ */
+GBytes* fl_message_codec_encode_message(FlMessageCodec* codec,
+                                        FlValue* message,
+                                        GError** error);
+
+/**
+ * fl_message_codec_decode_message:
+ * @codec: an #FlMessageCodec.
+ * @message: binary message to decode.
+ * @error: (allow-none): #GError location to store the error occurring, or
+ * %NULL.
+ *
+ * Decodes a message from a binary encoding.
+ *
+ * Returns: an #FlValue or %NULL on error.
+ */
+FlValue* fl_message_codec_decode_message(FlMessageCodec* codec,
+                                         GBytes* message,
+                                         GError** error);
+
+G_END_DECLS
+
+#endif  // FLUTTER_SHELL_PLATFORM_LINUX_PUBLIC_FLUTTER_LINUX_FL_MESSAGE_CODEC_H_