[NaCl SDK] Support non blocking TCP/UDP

native_client_sdk/src/libraries/nacl_io/fifo_char.h

Index: native_client_sdk/src/libraries/nacl_io/fifo_char.h
diff --git a/native_client_sdk/src/libraries/nacl_io/fifo_char.h b/native_client_sdk/src/libraries/nacl_io/fifo_char.h
new file mode 100644
index 0000000000000000000000000000000000000000..f6aa182b49f817aee181fcc2f747a856085fe58a
--- /dev/null
+++ b/native_client_sdk/src/libraries/nacl_io/fifo_char.h
@@ -0,0 +1,47 @@
+// Copyright (c) 2013 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 LIBRARIES_NACL_IO_FIFO_CHAR_H_
+#define LIBRARIES_NACL_IO_FIFO_CHAR_H_
+
+#include <stdint.h>
+#include <stdlib.h>
+
+namespace nacl_io {
+
+class  FIFOChar {

[binji, 2013/09/12 01:47:57]

nit: remove extra space

[noelallen1, 2013/09/12 23:19:03]

Done.

+ public:
+  explicit FIFOChar(size_t size);
+  virtual ~FIFOChar();

[binji, 2013/09/12 01:47:57]

why virtual? here and elsewhere.

[noelallen1, 2013/09/12 23:19:03]

The base 'interface' class has a virtual destructor.

+
+  virtual bool IsEmpty();
+  virtual bool IsFull();
+  virtual bool Resize(size_t len);
+
+  size_t ReadAvailable();
+  size_t WriteAvailable();
+
+  // Reads out no more than the requested len without updating the tail.
+  // Returns actual amount read.
+  size_t Peek(char* buf, size_t len);
+
+  // Reads out the data making room in the FIFO.  Returns actual amount
+  // read.
+  size_t Read(char* buf, size_t len);

[binji, 2013/09/12 01:47:57]

match MountNode::Read/Write?

Read(void* buf, size_t count)
Write(const void* buf, size_t count)

[noelallen1, 2013/09/12 23:19:03]

Done.

+
+  // Writes into the FIFO no more than len bytes, returns actual amount
+  // written.
+  size_t Write(const char* buf, size_t len);
+
+
+private:
+  char* buffer_;
+  size_t size_;   // Size of the FIFO
+  size_t avail_;  // How much data is currently available
+  size_t tail_;   // Next read location

[binji, 2013/09/12 01:47:57]

I usually think of the head being the start of the data, and the tail being the
end. So the head is the next read location and the tail is the next write
location.

+};
+
+}  // namespace nacl_io
+
+#endif  // LIBRARIES_NACL_IO_FIFO_CHAR_H_