Remove dependency on XMPP implementation in WebRTC

remoting/signaling/xmpp_stream_parser.cc

+// Copyright 2015 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.
+
+#include "remoting/signaling/xmpp_stream_parser.h"
+
+#include "base/location.h"
+#include "base/single_thread_task_runner.h"
+#include "base/thread_task_runner_handle.h"
+#include "third_party/webrtc/libjingle/xmllite/xmlbuilder.h"
+#include "third_party/webrtc/libjingle/xmllite/xmlelement.h"
+#include "third_party/webrtc/libjingle/xmllite/xmlparser.h"
+
+namespace remoting {
+
+class XmppStreamParser::Core : public buzz::XmlParseHandler {
+ public:
+  typedef base::Callback<void(scoped_ptr<buzz::XmlElement> stanza)>
+      OnStanzaCallback;
+
+  Core();
+  ~Core() override;
+
+  void SetCallbacks(const OnStanzaCallback& on_stanza_callback,
+                    const base::Closure& on_error_callback);
+
+  void AppendData(const std::string& data);
+
+ private:
+  // buzz::XmlParseHandler interface.
+  void StartElement(buzz::XmlParseContext* context,
+                    const char* name,
+                    const char** atts) override;
+  void EndElement(buzz::XmlParseContext* context, const char* name) override;
+  void CharacterData(buzz::XmlParseContext* context,
+                     const char* text,
+                     int len) override;
+  void Error(buzz::XmlParseContext* context, XML_Error error_code) override;
+
+  void ProcessError();
+
+  OnStanzaCallback on_stanza_callback_;
+  base::Closure on_error_callback_;
+
+  buzz::XmlParser parser_;
+  int depth_;
+  buzz::XmlBuilder builder_;
+
+  bool error_;
+
+  DISALLOW_COPY_AND_ASSIGN(Core);
+};
+
+XmppStreamParser::Core::Core()
+    : parser_(this),
+      depth_(0),
+      error_(false) {
+}
+
+XmppStreamParser::Core::~Core() {
+}
+
+void XmppStreamParser::Core::SetCallbacks(
+    const OnStanzaCallback& on_stanza_callback,
+    const base::Closure& on_error_callback) {
+  on_stanza_callback_ = on_stanza_callback;
+  on_error_callback_ = on_error_callback;
+}
+
+void XmppStreamParser::Core::AppendData(const std::string& data) {
+  if (error_)
+    return;
+  parser_.Parse(data.data(), data.size(), false);
+}
+
+void XmppStreamParser::Core::StartElement(buzz::XmlParseContext* context,
+                                    const char* name,
+                                    const char** atts) {
+  DCHECK(!error_);
+
+  ++depth_;
+  if (depth_ == 1) {
+    scoped_ptr<buzz::XmlElement> header(
+        buzz::XmlBuilder::BuildElement(context, name, atts));
+    if (!header) {
+      LOG(ERROR) << "Failed to parse XMPP stream header.";
+      ProcessError();
+    }
+    return;
+  }
+
+  builder_.StartElement(context, name, atts);
+}
+
+void XmppStreamParser::Core::EndElement(buzz::XmlParseContext* context,
+                                        const char* name) {
+  DCHECK(!error_);
+
+  --depth_;
+  if (depth_ == 0) {
+    LOG(ERROR) << "XMPP stream ended unexpectedly.";
+    ProcessError();
+    return;
+  }
+
+  builder_.EndElement(context, name);
+
+  if (depth_ == 1) {
+    if (!on_stanza_callback_.is_null())
+      on_stanza_callback_.Run(make_scoped_ptr(builder_.CreateElement()));
+  }
+}
+
+void XmppStreamParser::Core::CharacterData(buzz::XmlParseContext* context,
+                                     const char* text,
+                                     int len) {
+  DCHECK(!error_);
+
+  // Ignore data between stanzas.
+  if (depth_ <= 1) {
+    // Only whitespace is allowed outside of the stanzas.
+    bool all_spaces = true;
+    for (char c: std::string(text, len)) {
+      if (c != ' ') {
+        all_spaces = false;
+        break;
+      }
+    }
+    if (!all_spaces) {
+      LOG(ERROR) << "Received unexpected string: " << std::string(text,
+                                                                  text + len);
+      ProcessError();
+    }
+  } else if (depth_ > 1) {
+    builder_.CharacterData(context, text, len);
+  }
+}
+
+void XmppStreamParser::Core::Error(buzz::XmlParseContext* context,
+                             XML_Error error_code) {
+  LOG(ERROR) << "XMPP parser error: " << error_code;
+  ProcessError();
+}
+
+void XmppStreamParser::Core::ProcessError() {
+  error_ = true;
+  if (!on_error_callback_.is_null())
+    on_error_callback_.Run();
+}
+
+XmppStreamParser::XmppStreamParser() : core_(new Core()) {
+}
+
+XmppStreamParser::~XmppStreamParser() {
+  // Set null callbacks and delete |core_| asynchronously to make sure it's not
+  // deleted from a callback.
+  core_->SetCallbacks(OnStanzaCallback(), base::Closure());
+  base::ThreadTaskRunnerHandle::Get()->DeleteSoon(FROM_HERE, core_.release());
+}
+
+void XmppStreamParser::SetCallbacks(const OnStanzaCallback& on_stanza_callback,
+                  const base::Closure& on_error_callback) {
+  core_->SetCallbacks(on_stanza_callback, on_error_callback);
+}
+
+void XmppStreamParser::AppendData(const std::string& data) {
+  core_->AppendData(data);
+}
+
+}  // namespace remoting