WIP: DevFS initial implementation

runtime/vm/dev_fs.h

Index: runtime/vm/dev_fs.h
diff --git a/runtime/vm/dev_fs.h b/runtime/vm/dev_fs.h
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index 0000000000000000000000000000000000000000..68f925ba78d870f2a60371b8d10834fffd21ee3c
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+++ b/runtime/vm/dev_fs.h
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+// Copyright (c) 2016, 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.
+
+#ifndef VM_DEV_FS_H_
+#define VM_DEV_FS_H_
+
+#include "vm/globals.h"
+
+namespace dart {
+
+class Array;
+class JSONStream;
+class Mutex;
+class ObjectPointerVisitor;
+class RawArray;
+class RawObject;
+class String;
+
+class DevFS {
+ public:
+  static void Init();
+
+  static void ListFileSystems(JSONStream* js);
+  static void CreateFileSystem(JSONStream* js, const char* fs_name);
+  static void DeleteFileSystem(JSONStream* js, const char* fs_name);
+  static void WriteFile(JSONStream* js,
+                        const char* fs_name,
+                        const char* path,
+                        const char* file_contents);
+  static void ReadFile(JSONStream* js,
+                       const char* fs_name,
+                       const char* path);
+
+  static void VisitObjectPointers(ObjectPointerVisitor* visitor);
+
+ private:
+  static void EnsureStorage();
+  static RawArray* LookupFileSystem(const String& fs_name);
+  static bool UpdateFileSystem(const String& fs_name, const Array& fs_contents);
+
+  static Mutex* mutex_;
+
+  static RawObject** from() {
+    return reinterpret_cast<RawObject**>(&fs_map_storage_);
+  }
+  static RawArray* fs_map_storage_;
+  static RawObject** to() {
+    return reinterpret_cast<RawObject**>(&fs_map_storage_);
+  }
+};
+
+}  // namespace dart
+
+#endif  // VM_DEV_FS_H_