[NaCl SDK] nacl_io: Add flow control the JavaScript pipes.

native_client_sdk/src/libraries/nacl_io/devfs/jspipe_node.h

Index: native_client_sdk/src/libraries/nacl_io/devfs/jspipe_node.h
diff --git a/native_client_sdk/src/libraries/nacl_io/devfs/jspipe_node.h b/native_client_sdk/src/libraries/nacl_io/devfs/jspipe_node.h
index ad7ac995477d6ebedb9d52b8efbfa09af103d025..460dd2491d63756d3ccabb360028cd1feeec5d16 100644
--- a/native_client_sdk/src/libraries/nacl_io/devfs/jspipe_node.h
+++ b/native_client_sdk/src/libraries/nacl_io/devfs/jspipe_node.h
@@ -5,27 +5,69 @@
 #ifndef LIBRARIES_NACL_IO_DEVFS_JSPIPE_NODE_H_
 #define LIBRARIES_NACL_IO_DEVFS_JSPIPE_NODE_H_
 
-#include "nacl_io/pipe/pipe_node.h"
-
+#include <ppapi/c/pp_var.h>
 #include <string>
 
+#include "nacl_io/devfs/jspipe_event_emitter.h"
+#include "nacl_io/stream/stream_node.h"
+
 namespace nacl_io {
 
-class JSPipeNode : public PipeNode {
+class MessagingInterface;
+class VarInterface;
+class VarArrayInterface;
+class VarArrayBufferInterface;
+class VarDictionaryInterface;
+
+/**
+ * JSPipeNode represents a two-way channel for communicating with JavaScript
+ * via calls to PostMessage.  In order to use these some ammount of logic on

[binji, 2014/05/01 20:22:31]

amount

[Sam Clegg, 2014/05/01 22:16:55]

Done.

+ * the JavaScript side is also required.  The protocol to the communication
+ * looks the same in both directions and consists of two message types:
+ * 'write' and 'ack'.
+ * The messages are formated as JavaScript dictionary objects and take the
+ * following form:
+ * { <pipe_name> : [ <massage_type>, <message_payload> ] }
+ * The payload for 'write' message is a ArrayBuffer containing binary data.
+ * The payload for 'ack' messages is the total number of bytes recieved at
+ * the other end.
+ * For example: { 'jspipe1' : [ 'ack', 234 ] }
+ *
+ * Messages comming from JavaScript must be delivered using the

[binji, 2014/05/01 20:22:31]

coming

[Sam Clegg, 2014/05/01 22:16:55]

Done.

+ * NACL_IOC_HANDLEMESSAGE ioctl on the file handle.
+ */
+class JSPipeNode : public Node {
  public:
-  explicit JSPipeNode(Filesystem* filesystem) : PipeNode(filesystem) {}
+  explicit JSPipeNode(Filesystem* filesystem);
+
+  virtual JSPipeEventEmitter* GetEventEmitter();
 
   virtual Error VIoctl(int request, va_list args);
 
-  // Writes go directly to PostMessage, reads come from a pipe
-  // that gets populated by incoming messages
+  virtual Error Read(const HandleAttr& attr,
+                     void* buf,
+                     size_t count,
+                     int* out_bytes);
   virtual Error Write(const HandleAttr& attr,
                       const void* buf,
                       size_t count,
                       int* out_bytes);
 
- private:
+ protected:
+  Error HandleJSWrite(PP_Var message);
+  Error HandleJSAck(PP_Var message);
+  Error HandleJSMessage(PP_Var message);
+  Error SendAck();
+
+  ScopedJSPipeEventEmitter pipe_;
+
   std::string name_;
+
+  MessagingInterface* messaging_iface_;
+  VarInterface* var_iface_;
+  VarArrayInterface* array_iface_;
+  VarArrayBufferInterface* buffer_iface_;
+  VarDictionaryInterface* dict_iface_;
 };
 
 }  // namespace nacl_io