Introduce (private) ZLibFilter to dart:io.

runtime/bin/filter.cc

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#include "bin/filter.h"
+#include "bin/dartutils.h"
+
+#include "include/dart_api.h"
+
+static const int kFilterPointerNativeField = 0;
+
+
+void FUNCTION_NAME(Filter_CreateZLIB)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  Dart_Handle filter_obj = Dart_GetNativeArgument(args, 0);
+  Filter* filter = new ZLibFilter();
+  if (!filter->Init() ||
+      Dart_IsError(Filter::SetFilterPointerNativeField(filter_obj, filter))) {
+    OSError os_error(-1, "Failed to create ZLib filter", OSError::kUnknown);
+    Dart_Handle err = DartUtils::NewDartOSError(&os_error);
+    Dart_SetReturnValue(args, err);
+  } else {
+    Dart_SetReturnValue(args, Dart_True());
+  }
+  Dart_ExitScope();
+}
+
+
+void FUNCTION_NAME(Filter_Process)(Dart_NativeArguments args) {
+  Dart_EnterScope();
+  Dart_Handle filter_obj = Dart_GetNativeArgument(args, 0);
+  Filter* filter;
+  if (Dart_IsError(Filter::GetFilterPointerNativeField(filter_obj, &filter))) {
+    OSError os_error(-1, "Failed to get ZLib filter", OSError::kUnknown);
+    Dart_Handle err = DartUtils::NewDartOSError(&os_error);
+    Dart_SetReturnValue(args, err);
+  } else {
+    Dart_SetReturnValue(args, Dart_True());
+  }
+  Dart_ExitScope();
+}
+
+
+Dart_Handle Filter::SetFilterPointerNativeField(Dart_Handle filter,
+                                                Filter* filter_pointer) {
+  return Dart_SetNativeInstanceField(filter,
+                                     kFilterPointerNativeField,
+                                     (intptr_t)filter_pointer);
+}
+
+
+Dart_Handle Filter::GetFilterPointerNativeField(Dart_Handle filter,
+                                                Filter** filter_pointer) {
+  return Dart_GetNativeInstanceField(
+      filter,
+      kFilterPointerNativeField,
+      reinterpret_cast<intptr_t*>(filter_pointer));
+}
+
+
+ZLibFilter::~ZLibFilter() {
+  // FIXME: Change to ::End to be able to return status value?
+}
+
+
+bool ZLibFilter::Init() {
+  return true;
+}
+
+
+uint8_t* ZLibFilter::Process(uint8_t* data,
+                             intptr_t length,
+                             intptr_t& outputLength) {
+  return 0;
+}
+