Forwarder 2 implementation

tools/android/forwarder2/socket.h

+// Copyright (c) 2012 The Chromium 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 TOOLS_ANDROID_FORWARDER2_SOCKET_H_
+#define TOOLS_ANDROID_FORWARDER2_SOCKET_H_
+
+#include <fcntl.h>
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+
+#include <string>

[Satish, 2012/09/06 15:53:12]

move up to line 10

[felipeg, 2012/09/06 16:19:06]

But linter tool says C++ headers should come in a separate section.

+
+#include "base/basictypes.h"
+
+using std::string;
+
+namespace forwarder {
+
+class Socket {

[Satish, 2012/09/06 15:53:12]

add a comment explaining what this class does

[felipeg, 2012/09/06 16:19:06]

Done.

+ public:
+  Socket();
+  ~Socket();
+
+  bool BindUnix(const string& path, bool abstract);
+  bool BindTcp(const string& host, int port);
+  bool ConnectUnix(const string& path, bool abstract);
+  bool ConnectTcp(const string& host, int port);
+
+  void Shutdown();

[Satish, 2012/09/06 15:53:12]

please add comments explaining what these do, and what the difference between
close and shutdown is

[felipeg, 2012/09/06 16:19:06]

This is a wrapper around unix sockets.
The explanation and the difference are in the manpages.
I guess we can just let the reader to look at the manpages for explanations if
needed.

+  void Close();
+  bool IsClosed() const { return socket_ < 0; }
+
+  bool Accept(Socket* new_socket);
+
+  bool IsFdInSet(const fd_set& fds) const;
+  bool AddFdToSet(fd_set* fds) const;
+
+  // Just a wrapper around unix read() function.
+  // Reads up to buffer_size, but may read less then buffer_size.
+  // Returns the number of bytes read.
+  int Read(char* buffer, size_t buffer_size);
+  // Same as Read(), just a wrapper around write().

[Satish, 2012/09/06 15:53:12]

leave an empty line above full length comments like these for better readability

[felipeg, 2012/09/06 16:19:06]

Done.

+  int Write(const char* buffer, size_t count);
+
+  // Calls Read() multiple times until num_bytes is written to the provided
+  // buffer. No bounds checking is performed.
+  // Returns number of bytes read, which can be different from num_bytes in case
+  // of errror.
+  int ReadNumBytes(char* buffer, size_t num_bytes);
+
+  // Calls Write() multiple times until num_bytes is written. No bounds checking
+  // is performed. Returns number of bytes written, which can be different from
+  // num_bytes in case of errror.
+  int WriteNumBytes(const char* buffer, size_t num_bytes);
+
+  // Calls WriteNumBytes for the given string.
+  int WriteString(const string& buffer) {
+    return WriteNumBytes(buffer.c_str(), buffer.size());
+  }
+
+  static int GetHighestFileDescriptor(const Socket& s1, const Socket& s2);
+
+  bool HasError() const { return socket_error_; }
+
+  // |notifier_fd| must be a valid pipe file descriptor created from the
+  // PipeNotifier and must live (not be closed) at least as long as this socket
+  // is alive.
+  void set_notifier_fd(int notifier_fd) { exit_notifier_fd_ = notifier_fd; }
+  // Unset the |exit_notifier_fd_| so that it will not receive notifications
+  // anymore.
+  void unset_notifier_fd() { exit_notifier_fd_ = -1; }

[Satish, 2012/09/06 15:53:12]

unset -> reset

[felipeg, 2012/09/06 16:19:06]

Done.

+
+ private:
+  // If |host| is empty, use localhost.
+  bool InitTcpSocket(const string& host, int port);
+  bool InitUnixSocket(const string& path, bool abstract);
+  bool BindAndListen();
+  bool Connect();
+
+  bool Resolve(const string& host);
+  bool InitSocketInternal();
+  void SetSocketError();
+
+  // Waits until either the Socket or the |exit_notifier_fd_| has received a
+  // read event (accept or read). Returns false iff an exit notification was
+  // received.
+  bool WaitForEvent() const;
+
+  int socket_;
+  int port_;
+  bool socket_error_;
+
+  // Family of the socket (IF_INET, IF_INET6 or PF_UNIX).
+  int family_;
+
+  // True if this is an abstract unix domain socket.
+  bool abstract_;
+
+  typedef union {
+    // IPv4 sockaddr
+    sockaddr_in addr4;
+    // IPv6 sockaddr
+    sockaddr_in6 addr6;
+    // Unix Domain sockaddr
+    sockaddr_un addr_un;
+  } SockAddr;
+
+  SockAddr addr_;
+
+  // Points to one of the members of the above union depending on the family.
+  sockaddr* addr_ptr_;
+  // Length of one of the members of the above union depending on the family.
+  socklen_t addr_len_;
+
+  int exit_notifier_fd_;

[Satish, 2012/09/06 15:53:12]

comment please

[felipeg, 2012/09/06 16:19:06]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(Socket);
+};
+
+}  // namespace forwarder
+
+#endif  // TOOLS_ANDROID_FORWARDER2_SOCKET_H_