A change for the setPause() api in chrome.sockets.tcp:

extensions/browser/api/socket/tcp_socket.cc

Index: extensions/browser/api/socket/tcp_socket.cc
diff --git a/extensions/browser/api/socket/tcp_socket.cc b/extensions/browser/api/socket/tcp_socket.cc
index 8d5257b45c3007ba9e7c0bb2bde5dc6efb2792f6..764ed6ed7bafeecbdae8776db82cf9aba89cb99b 100644
--- a/extensions/browser/api/socket/tcp_socket.cc
+++ b/extensions/browser/api/socket/tcp_socket.cc
@@ -4,6 +4,11 @@
 
 #include "extensions/browser/api/socket/tcp_socket.h"
 
+#include <ctype.h>
+#include <algorithm>
+#include <iomanip>
+#include <sstream>
+
 #include "base/lazy_instance.h"
 #include "base/logging.h"
 #include "base/macros.h"
@@ -42,6 +47,226 @@ ApiResourceManager<ResumableTCPServerSocket>::GetFactoryInstance() {
   return g_server_factory.Pointer();
 }
 
+SocketPauseBuffer::SocketPauseBuffer(
+    const SocketPauseBuffer::DownstreamReadCallback& callback)
+    : read_issued_(false),
+      downstream_read_cb_(callback),
+      downstream_read_buffer_(new net::GrowableIOBuffer),
+      upstream_data_returned_(0),
+      upstream_read_buffer_offset_(0),
+      prior_error_code_(0),
+      buffering_disabled_(false) {}
+
+SocketPauseBuffer::~SocketPauseBuffer() {}
+
+std::string SocketPauseBuffer::StatusDescription() {
+  std::stringstream status;
+  status << "\n";
+  status << static_cast<void*>(this);
+  status << " < " << upstream_data_returned_ << " | "
+         << downstream_read_buffer_->offset() << " | "
+         << downstream_read_buffer_->capacity() << ">: "
+         << ", buffered: " << BufferedDataCount() << ", "
+         << (read_issued_ ? "READING" : "not reading") << ", cb: "
+         << (upstream_read_callback_.is_null() ? "null" : "not null");
+  return status.str();
+}
+
+int SocketPauseBuffer::BufferedDataCount() const {
+  return downstream_read_buffer_->offset() - upstream_data_returned_;
+}
+
+void SocketPauseBuffer::CreditIncomingData(int count) {
+  DCHECK_GE(count, 0);
+  downstream_read_buffer_->set_offset(downstream_read_buffer_->offset() +
+                                      count);
+}
+
+void SocketPauseBuffer::ReturnDataInBuffer(net::IOBuffer* dest, int count) {
+  DCHECK_GE(count, 0);
+  memcpy(dest->data(),
+         downstream_read_buffer_->StartOfBuffer() + upstream_data_returned_,
+         count);
+  upstream_data_returned_ += count;
+}
+
+void SocketPauseBuffer::FreeReturnedBufferSpace() {
+  DCHECK(!read_issued_);
+  const int amount_to_free = upstream_data_returned_;
+
+  memmove(downstream_read_buffer_->StartOfBuffer(),
+          downstream_read_buffer_->StartOfBuffer() + upstream_data_returned_,
+          amount_to_free);
+  downstream_read_buffer_->set_offset(downstream_read_buffer_->offset() -
+                                      amount_to_free);
+  upstream_data_returned_ -= amount_to_free;
+}
+
+// Called whenever the client's callback (either upstream_read_callback_ or
+// the |callback| argument to Read()) is invoked.  Clears out state relevant
+// to the Read.
+void SocketPauseBuffer::ResetUpstreamState() {
+  upstream_read_buffer_offset_ = 0;
+  upstream_read_buffer_ = NULL;
+  upstream_read_callback_.Reset();
+}
+
+void SocketPauseBuffer::InvokeCallback(int result) {
+  DCHECK(!upstream_read_callback_.is_null());
+  net::CompletionCallback cb = upstream_read_callback_;
+  ResetUpstreamState();
+  cb.Run(result);
+}
+
+void SocketPauseBuffer::InsureBufferCanHold(int num_bytes) {
+  if (num_bytes > (downstream_read_buffer_->capacity() -
+                   downstream_read_buffer_->offset())) {
+    downstream_read_buffer_->SetCapacity(num_bytes +
+                                         downstream_read_buffer_->offset());
+  }
+}
+
+bool SocketPauseBuffer::Pause() {
+  if (buffering_disabled_) {
+    return false;
+  } else if (!upstream_read_callback_.is_null()) {
+    InvokeCallback(net::ERR_ABORTED);
+  }
+  return true;
+}
+
+void SocketPauseBuffer::DisableBuffering() {
+  buffering_disabled_ = true;
+}
+
+int SocketPauseBuffer::Read(net::IOBuffer* buffer,
+                            int buf_len,
+                            const net::CompletionCallback& callback) {
+  DVLOG(1) << "Read(" << buf_len << ") START " << StatusDescription();
+
+  if (buffering_disabled_ && BufferedDataCount() == 0) {
+    return downstream_read_cb_.Run(buffer, buf_len, callback);
+  }
+
+  // Can't buffer data and have a pending downstream Read() simultaneously.
+  DCHECK(BufferedDataCount() == 0 || !read_issued_);
+
+  // Only one upstream Read() is allowed at a time.
+  if (!upstream_read_callback_.is_null()) {
+    DVLOG(1) << "Read(" << buf_len << "):  - Returning ERR_INVALID_ARGUMENT "
+             << StatusDescription();
+    DCHECK(read_issued_);
+    return net::ERR_INVALID_ARGUMENT;  // 'this' is the invalid argument.
+  }
+
+  if (buf_len < 0) {
+    DVLOG(1) << "Read(" << buf_len << "):  - Returning ERR_INVALID_ARGUMENT "
+             << StatusDescription();
+    return net::ERR_INVALID_ARGUMENT;
+  }
+
+  if (BufferedDataCount() > 0) {
+    const int num_returned_bytes = std::min(buf_len, BufferedDataCount());
+    ReturnDataInBuffer(buffer, num_returned_bytes);
+    // Release our internal buffer once we're no longer using it.
+    if (buffering_disabled_ && BufferedDataCount() == 0) {
+      downstream_read_buffer_ = nullptr;
+    }
+    return num_returned_bytes;
+  } else {
+    DCHECK(!buffering_disabled_);
+    upstream_read_callback_ = callback;
+    upstream_read_request_size_ = buf_len;
+    upstream_read_buffer_ = buffer;
+    if (!read_issued_) {
+      // Issue a new downstream read for this request.
+      FreeReturnedBufferSpace();
+      InsureBufferCanHold(buf_len);
+      read_issued_ = true;
+      int result = downstream_read_cb_.Run(
+          downstream_read_buffer_.get(), buf_len,
+          base::Bind(&SocketPauseBuffer::ReadComplete, base::Unretained(this)));
+      if (result > 0) {
+        read_issued_ = false;
+        CreditIncomingData(result);
+        ReturnDataInBuffer(buffer, result);
+        ResetUpstreamState();
+      }
+      return result;
+    } else {
+      // We already have a downstream read pending, and now it's plumbed to
+      // invoke the callback argument.
+      return net::ERR_IO_PENDING;
+    }
+  }
+}
+
+void SocketPauseBuffer::ReadComplete(int count) {
+  read_issued_ = false;
+  if (count > 0) {
+    CreditIncomingData(count);
+  }
+  if (upstream_read_callback_.is_null()) {
+    prior_error_code_ = std::min(0, count);
+  } else {
+    int num_returned_bytes = std::min(count, upstream_read_request_size_);
+    ReturnDataInBuffer(upstream_read_buffer_.get(), num_returned_bytes);
+    InvokeCallback(num_returned_bytes);
+  }
+}
+
+BufferingStreamSocket::BufferingStreamSocket(
+    scoped_ptr<net::StreamSocket> socket)
+    : Passthrough<net::StreamSocket>(socket.Pass()),
+      pause_buffer_(base::Bind(&net::StreamSocket::Read,
+                               base::Unretained(base_socket()))) {}
+
+BufferingStreamSocket::~BufferingStreamSocket() {}
+
+bool BufferingStreamSocket::Pause() {
+  return pause_buffer_.Pause();
+}
+
+void BufferingStreamSocket::DisableBuffering() {
+  pause_buffer_.DisableBuffering();
+}
+
+int BufferingStreamSocket::Read(net::IOBuffer* buffer,
+                                int buf_len,
+                                const net::CompletionCallback& callback) {
+  return pause_buffer_.Read(buffer, buf_len, callback);
+}
+
+BufferingTCPClientSocket::BufferingTCPClientSocket(
+    scoped_ptr<net::TCPClientSocket> socket)
+    : Passthrough<net::TCPClientSocket>(socket.Pass()),
+      pause_buffer_(base::Bind(&net::TCPClientSocket::Read,
+                               base::Unretained(base_socket()))) {}
+
+BufferingTCPClientSocket::~BufferingTCPClientSocket() {}
+
+bool BufferingTCPClientSocket::Pause() {
+  return pause_buffer_.Pause();
+}
+
+void BufferingTCPClientSocket::DisableBuffering() {
+  pause_buffer_.DisableBuffering();
+}
+
+int BufferingTCPClientSocket::Read(net::IOBuffer* buffer,
+                                   int buf_len,
+                                   const net::CompletionCallback& callback) {
+  return pause_buffer_.Read(buffer, buf_len, callback);
+}
+
+bool BufferingTCPClientSocket::SetKeepAlive(bool enable, int delay) {
+  return base_socket()->SetKeepAlive(enable, delay);
+}
+
+bool BufferingTCPClientSocket::SetNoDelay(bool no_delay) {
+  return base_socket()->SetNoDelay(no_delay);
+}
+
 TCPSocket::TCPSocket(const std::string& owner_extension_id)
     : Socket(owner_extension_id), socket_mode_(UNKNOWN) {}
 
@@ -49,8 +274,9 @@ TCPSocket::TCPSocket(net::TCPClientSocket* tcp_client_socket,
                      const std::string& owner_extension_id,
                      bool is_connected)
     : Socket(owner_extension_id),
-      socket_(tcp_client_socket),
       socket_mode_(CLIENT) {
+  scoped_ptr<net::TCPClientSocket> p(tcp_client_socket);
+  socket_.reset(new BufferingTCPClientSocket(p.Pass()));
   this->is_connected_ = is_connected;
 }
 
@@ -94,9 +320,11 @@ void TCPSocket::Connect(const net::AddressList& address,
     if (is_connected_)
       break;
 
-    socket_.reset(
+    scoped_ptr<net::TCPClientSocket> internal_sock(
         new net::TCPClientSocket(address, NULL, net::NetLog::Source()));
 
+    socket_.reset(new BufferingTCPClientSocket(internal_sock.Pass()));
+
     connect_callback_ = callback;
     result = socket_->Connect(
         base::Bind(&TCPSocket::OnConnectComplete, base::Unretained(this)));
@@ -316,7 +544,7 @@ void TCPSocket::Release() {
   ignore_result(socket_.release());
 }
 
-net::TCPClientSocket* TCPSocket::ClientStream() {
+BufferingTCPClientSocket* TCPSocket::ClientStream() {
   if (socket_mode_ != CLIENT || GetSocketType() != TYPE_TCP)
     return NULL;
   return socket_.get();
@@ -340,8 +568,17 @@ ResumableTCPSocket::ResumableTCPSocket(net::TCPClientSocket* tcp_client_socket,
       buffer_size_(0),
       paused_(false) {}
 
+ResumableTCPSocket::~ResumableTCPSocket() {}
+
 bool ResumableTCPSocket::IsPersistent() const { return persistent(); }
 
+void ResumableTCPSocket::ApiPauseComplete() {
+  if (!pause_callback_.is_null()) {
+    pause_callback_.Run();
+    pause_callback_.Reset();
+  }
+}
+
 ResumableTCPServerSocket::ResumableTCPServerSocket(
     const std::string& owner_extension_id)
     : TCPSocket(owner_extension_id), persistent_(false), paused_(false) {}