Revert of Remove webrtc/libjingle/{xmllite,xmpp}

webrtc/libjingle/xmpp/pubsubstateclient.h

Index: webrtc/libjingle/xmpp/pubsubstateclient.h
diff --git a/webrtc/libjingle/xmpp/pubsubstateclient.h b/webrtc/libjingle/xmpp/pubsubstateclient.h
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+++ b/webrtc/libjingle/xmpp/pubsubstateclient.h
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+/*
+ *  Copyright 2011 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_LIBJINGLE_XMPP_PUBSUBSTATECLIENT_H_
+#define WEBRTC_LIBJINGLE_XMPP_PUBSUBSTATECLIENT_H_
+
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "webrtc/libjingle/xmllite/qname.h"
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+#include "webrtc/libjingle/xmpp/constants.h"
+#include "webrtc/libjingle/xmpp/jid.h"
+#include "webrtc/libjingle/xmpp/pubsubclient.h"
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/base/sigslot.h"
+#include "webrtc/base/sigslotrepeater.h"
+
+namespace buzz {
+
+// To handle retracts correctly, we need to remember certain details
+// about an item.  We could just cache the entire XML element, but
+// that would take more memory and require re-parsing.
+struct StateItemInfo {
+  std::string published_nick;
+  std::string publisher_nick;
+};
+
+// Represents a PubSub state change.  Usually, the key is the nick,
+// but not always.  It's a per-state-type thing.  Look below on how keys are
+// computed.
+template <typename C>
+struct PubSubStateChange {
+  // The nick of the user changing the state.
+  std::string publisher_nick;
+  // The nick of the user whose state is changing.
+  std::string published_nick;
+  C old_state;
+  C new_state;
+};
+
+// Knows how to handle specific states and XML.
+template <typename C>
+class PubSubStateSerializer {
+ public:
+  virtual ~PubSubStateSerializer() {}
+  virtual XmlElement* Write(const QName& state_name, const C& state) = 0;
+  virtual void Parse(const XmlElement* state_elem, C* state_out) = 0;
+};
+
+// Knows how to create "keys" for states, which determines their
+// uniqueness.  Most states are per-nick, but block is
+// per-blocker-and-blockee.  This is independent of itemid, especially
+// in the case of presenter state.
+class PubSubStateKeySerializer {
+ public:
+  virtual ~PubSubStateKeySerializer() {}
+  virtual std::string GetKey(const std::string& publisher_nick,
+                             const std::string& published_nick) = 0;
+};
+
+class PublishedNickKeySerializer : public PubSubStateKeySerializer {
+ public:
+  virtual std::string GetKey(const std::string& publisher_nick,
+                             const std::string& published_nick);
+};
+
+class PublisherAndPublishedNicksKeySerializer
+  : public PubSubStateKeySerializer {
+ public:
+  virtual std::string GetKey(const std::string& publisher_nick,
+                             const std::string& published_nick);
+};
+
+// Adapts PubSubClient to be specifically suited for pub sub call
+// states.  Signals state changes and keeps track of keys, which are
+// normally nicks.
+template <typename C>
+class PubSubStateClient : public sigslot::has_slots<> {
+ public:
+  // Gets ownership of the serializers, but not the client.
+  PubSubStateClient(const std::string& publisher_nick,
+                    PubSubClient* client,
+                    const QName& state_name,
+                    C default_state,
+                    PubSubStateKeySerializer* key_serializer,
+                    PubSubStateSerializer<C>* state_serializer)
+      : publisher_nick_(publisher_nick),
+        client_(client),
+        state_name_(state_name),
+        default_state_(default_state) {
+    key_serializer_.reset(key_serializer);
+    state_serializer_.reset(state_serializer);
+    client_->SignalItems.connect(
+        this, &PubSubStateClient<C>::OnItems);
+    client_->SignalPublishResult.connect(
+        this, &PubSubStateClient<C>::OnPublishResult);
+    client_->SignalPublishError.connect(
+        this, &PubSubStateClient<C>::OnPublishError);
+    client_->SignalRetractResult.connect(
+        this, &PubSubStateClient<C>::OnRetractResult);
+    client_->SignalRetractError.connect(
+        this, &PubSubStateClient<C>::OnRetractError);
+  }
+
+  virtual ~PubSubStateClient() {}
+
+  virtual void Publish(const std::string& published_nick,
+                       const C& state,
+                       std::string* task_id_out) {
+    std::string key = key_serializer_->GetKey(publisher_nick_, published_nick);
+    std::string itemid = state_name_.LocalPart() + ":" + key;
+    if (StatesEqual(state, default_state_)) {
+      client_->RetractItem(itemid, task_id_out);
+    } else {
+      XmlElement* state_elem = state_serializer_->Write(state_name_, state);
+      state_elem->AddAttr(QN_NICK, published_nick);
+      client_->PublishItem(itemid, state_elem, task_id_out);
+    }
+  }
+
+  sigslot::signal1<const PubSubStateChange<C>&> SignalStateChange;
+  // Signal (task_id, item).  item is NULL for retract.
+  sigslot::signal2<const std::string&,
+  const XmlElement*> SignalPublishResult;
+  // Signal (task_id, item, error stanza).  item is NULL for retract.
+  sigslot::signal3<const std::string&,
+  const XmlElement*,
+  const XmlElement*> SignalPublishError;
+
+ protected:
+  // return false if retracted item (no info or state given)
+  virtual bool ParseStateItem(const PubSubItem& item,
+                              StateItemInfo* info_out,
+                              C* state_out) {
+    const XmlElement* state_elem = item.elem->FirstNamed(state_name_);
+    if (state_elem == NULL) {
+      return false;
+    }
+
+    info_out->publisher_nick =
+        client_->GetPublisherNickFromPubSubItem(item.elem);
+    info_out->published_nick = state_elem->Attr(QN_NICK);
+    state_serializer_->Parse(state_elem, state_out);
+    return true;
+  }
+
+  virtual bool StatesEqual(const C& state1, const C& state2) {
+    return state1 == state2;
+  }
+
+  PubSubClient* client() { return client_; }
+  const QName& state_name() { return state_name_; }
+
+ private:
+  void OnItems(PubSubClient* pub_sub_client,
+               const std::vector<PubSubItem>& items) {
+    for (std::vector<PubSubItem>::const_iterator item = items.begin();
+         item != items.end(); ++item) {
+      OnItem(*item);
+    }
+  }
+
+  void OnItem(const PubSubItem& item) {
+    const std::string& itemid = item.itemid;
+    StateItemInfo info;
+    C new_state;
+
+    bool retracted = !ParseStateItem(item, &info, &new_state);
+    if (retracted) {
+      bool known_itemid =
+          (info_by_itemid_.find(itemid) != info_by_itemid_.end());
+      if (!known_itemid) {
+        // Nothing to retract, and nothing to publish.
+        // Probably a different state type.
+        return;
+      } else {
+        info = info_by_itemid_[itemid];
+        info_by_itemid_.erase(itemid);
+        new_state = default_state_;
+      }
+    } else {
+      // TODO: Assert new key matches the known key. It
+      // shouldn't change!
+      info_by_itemid_[itemid] = info;
+    }
+
+    std::string key = key_serializer_->GetKey(
+        info.publisher_nick, info.published_nick);
+    bool has_old_state = (state_by_key_.find(key) != state_by_key_.end());
+    C old_state = has_old_state ? state_by_key_[key] : default_state_;
+    if ((retracted && !has_old_state) || StatesEqual(new_state, old_state)) {
+      // Nothing change, so don't bother signalling.
+      return;
+    }
+
+    if (retracted || StatesEqual(new_state, default_state_)) {
+      // We treat a default state similar to a retract.
+      state_by_key_.erase(key);
+    } else {
+      state_by_key_[key] = new_state;
+    }
+
+    PubSubStateChange<C> change;
+    if (!retracted) {
+      // Retracts do not have publisher information.
+      change.publisher_nick = info.publisher_nick;
+    }
+    change.published_nick = info.published_nick;
+    change.old_state = old_state;
+    change.new_state = new_state;
+    SignalStateChange(change);
+  }
+
+  void OnPublishResult(PubSubClient* pub_sub_client,
+                       const std::string& task_id,
+                       const XmlElement* item) {
+    SignalPublishResult(task_id, item);
+  }
+
+  void OnPublishError(PubSubClient* pub_sub_client,
+                      const std::string& task_id,
+                      const buzz::XmlElement* item,
+                      const buzz::XmlElement* stanza) {
+    SignalPublishError(task_id, item, stanza);
+  }
+
+  void OnRetractResult(PubSubClient* pub_sub_client,
+                       const std::string& task_id) {
+    // There's no point in differentiating between publish and retract
+    // errors, so we simplify by making them both signal a publish
+    // result.
+    const XmlElement* item = NULL;
+    SignalPublishResult(task_id, item);
+  }
+
+  void OnRetractError(PubSubClient* pub_sub_client,
+                      const std::string& task_id,
+                      const buzz::XmlElement* stanza) {
+    // There's no point in differentiating between publish and retract
+    // errors, so we simplify by making them both signal a publish
+    // error.
+    const XmlElement* item = NULL;
+    SignalPublishError(task_id, item, stanza);
+  }
+
+  std::string publisher_nick_;
+  PubSubClient* client_;
+  const QName state_name_;
+  C default_state_;
+  std::unique_ptr<PubSubStateKeySerializer> key_serializer_;
+  std::unique_ptr<PubSubStateSerializer<C> > state_serializer_;
+  // key => state
+  std::map<std::string, C> state_by_key_;
+  // itemid => StateItemInfo
+  std::map<std::string, StateItemInfo> info_by_itemid_;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(PubSubStateClient);
+};
+}  // namespace buzz
+
+#endif  // WEBRTC_LIBJINGLE_XMPP_PUBSUBSTATECLIENT_H_