Added simplest device mount implementation (includes NullDevice and RandomDevice)

libraries/nacl-mounts/dev/DevMount.h

+/*
+ * Copyright (c) 2012 The Native Client 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 PACKAGES_LIBRARIES_NACL_MOUNTS_DEV_DEVMOUNT_H_
+#define PACKAGES_LIBRARIES_NACL_MOUNTS_DEV_DEVMOUNT_H_
+
+#include <map>
+#include <string>
+#include "../base/BaseMount.h"
+#include "../dev/Device.h"
+#include "../util/macros.h"
+
+// DevMount
+class DevMount: public BaseMount {
+ public:
+  DevMount() {}
+  virtual ~DevMount() {}
+
+  // Creat() is successful if the path is "/dev/null", "/dev/random",
+  // or "/def/tty".  Otherwise, Creat() fails.

[Evgeniy Stepanov, 2012/05/11 08:16:37]

I'd skip this comment, or move it to .cc - it's going to change every time we
add a new device, no need to enumerate them all.

[vissi, 2012/05/11 08:31:05]

Done.

+  int Creat(const std::string& path, mode_t mode, struct stat* st);
+
+  // GetNode() is successful if the path is "/dev/null", "/dev/random",
+  // or "/def/tty".  Otherwise, GetNode() fails.
+  int GetNode(const std::string& path, struct stat* st);
+
+  int Stat(ino_t node, struct stat *buf);
+  ssize_t Read(ino_t node, off_t offset, void *buf, size_t count);
+  ssize_t Write(ino_t node, off_t offset, const void *buf, size_t count);
+  int Isatty(ino_t node) { return 0; }
+
+ private:
+  std::map<int, std::string> inode_to_path;
+  std::map<int, Device*> inode_to_dev;
+  std::map<int, int> inode_to_ref;
+  std::map<std::string, int> path_to_inode;
+  void Attach(std::string path, Device* device);
+
+  DISALLOW_COPY_AND_ASSIGN(DevMount);
+};
+
+#endif  // PACKAGES_LIBRARIES_NACL_MOUNTS_DEV_DEVMOUNT_H_
+