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

webrtc/libjingle/xmllite/xmlnsstack.cc

Index: webrtc/libjingle/xmllite/xmlnsstack.cc
diff --git a/webrtc/libjingle/xmllite/xmlnsstack.cc b/webrtc/libjingle/xmllite/xmlnsstack.cc
new file mode 100644
index 0000000000000000000000000000000000000000..bac2fc695e2210c3ed22baacca2586c6509800ad
--- /dev/null
+++ b/webrtc/libjingle/xmllite/xmlnsstack.cc
@@ -0,0 +1,178 @@
+/*
+ *  Copyright 2004 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.
+ */
+
+#include "webrtc/libjingle/xmllite/xmlnsstack.h"
+
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "webrtc/libjingle/xmllite/xmlconstants.h"
+#include "webrtc/libjingle/xmllite/xmlelement.h"
+
+namespace buzz {
+
+XmlnsStack::XmlnsStack() :
+  pxmlnsStack_(new std::vector<std::string>),
+  pxmlnsDepthStack_(new std::vector<size_t>) {
+}
+
+XmlnsStack::~XmlnsStack() {}
+
+void XmlnsStack::PushFrame() {
+  pxmlnsDepthStack_->push_back(pxmlnsStack_->size());
+}
+
+void XmlnsStack::PopFrame() {
+  size_t prev_size = pxmlnsDepthStack_->back();
+  pxmlnsDepthStack_->pop_back();
+  if (prev_size < pxmlnsStack_->size()) {
+    pxmlnsStack_->erase(pxmlnsStack_->begin() + prev_size,
+                        pxmlnsStack_->end());
+  }
+}
+
+std::pair<std::string, bool> XmlnsStack::NsForPrefix(
+    const std::string& prefix) {
+  if (prefix.length() >= 3 &&
+      (prefix[0] == 'x' || prefix[0] == 'X') &&
+      (prefix[1] == 'm' || prefix[1] == 'M') &&
+      (prefix[2] == 'l' || prefix[2] == 'L')) {
+    if (prefix == "xml")
+      return std::make_pair(NS_XML, true);
+    if (prefix == "xmlns")
+      return std::make_pair(NS_XMLNS, true);
+    // Other names with xml prefix are illegal.
+    return std::make_pair(STR_EMPTY, false);
+  }
+
+  std::vector<std::string>::iterator pos;
+  for (pos = pxmlnsStack_->end(); pos > pxmlnsStack_->begin(); ) {
+    pos -= 2;
+    if (*pos == prefix)
+      return std::make_pair(*(pos + 1), true);
+  }
+
+  if (prefix == STR_EMPTY)
+    return std::make_pair(STR_EMPTY, true);  // default namespace
+
+  return std::make_pair(STR_EMPTY, false);  // none found
+}
+
+bool XmlnsStack::PrefixMatchesNs(const std::string& prefix,
+                                 const std::string& ns) {
+  const std::pair<std::string, bool> match = NsForPrefix(prefix);
+  return match.second && (match.first == ns);
+}
+
+std::pair<std::string, bool> XmlnsStack::PrefixForNs(const std::string& ns,
+                                                     bool isattr) {
+  if (ns == NS_XML)
+    return std::make_pair(std::string("xml"), true);
+  if (ns == NS_XMLNS)
+    return std::make_pair(std::string("xmlns"), true);
+  if (isattr ? ns == STR_EMPTY : PrefixMatchesNs(STR_EMPTY, ns))
+    return std::make_pair(STR_EMPTY, true);
+
+  std::vector<std::string>::iterator pos;
+  for (pos = pxmlnsStack_->end(); pos > pxmlnsStack_->begin(); ) {
+    pos -= 2;
+    if (*(pos + 1) == ns &&
+        (!isattr || !pos->empty()) && PrefixMatchesNs(*pos, ns))
+      return std::make_pair(*pos, true);
+  }
+
+  return std::make_pair(STR_EMPTY, false); // none found
+}
+
+std::string XmlnsStack::FormatQName(const QName& name, bool isAttr) {
+  std::string prefix(PrefixForNs(name.Namespace(), isAttr).first);
+  if (prefix == STR_EMPTY)
+    return name.LocalPart();
+  else
+    return prefix + ':' + name.LocalPart();
+}
+
+void XmlnsStack::AddXmlns(const std::string & prefix, const std::string & ns) {
+  pxmlnsStack_->push_back(prefix);
+  pxmlnsStack_->push_back(ns);
+}
+
+void XmlnsStack::RemoveXmlns() {
+  pxmlnsStack_->pop_back();
+  pxmlnsStack_->pop_back();
+}
+
+static bool IsAsciiLetter(char ch) {
+  return ((ch >= 'a' && ch <= 'z') ||
+          (ch >= 'A' && ch <= 'Z'));
+}
+
+static std::string AsciiLower(const std::string & s) {
+  std::string result(s);
+  size_t i;
+  for (i = 0; i < result.length(); i++) {
+    if (result[i] >= 'A' && result[i] <= 'Z')
+      result[i] += 'a' - 'A';
+  }
+  return result;
+}
+
+static std::string SuggestPrefix(const std::string & ns) {
+  size_t len = ns.length();
+  size_t i = ns.find_last_of('.');
+  if (i != std::string::npos && len - i <= 4 + 1)
+    len = i; // chop off ".html" or ".xsd" or ".?{0,4}"
+  size_t last = len;
+  while (last > 0) {
+    last -= 1;
+    if (IsAsciiLetter(ns[last])) {
+      size_t first = last;
+      last += 1;
+      while (first > 0) {
+        if (!IsAsciiLetter(ns[first - 1]))
+          break;
+        first -= 1;
+      }
+      if (last - first > 4)
+        last = first + 3;
+      std::string candidate(AsciiLower(ns.substr(first, last - first)));
+      if (candidate.find("xml") != 0)
+        return candidate;
+      break;
+    }
+  }
+  return "ns";
+}
+
+std::pair<std::string, bool> XmlnsStack::AddNewPrefix(const std::string& ns,
+                                                      bool isAttr) {
+  if (PrefixForNs(ns, isAttr).second)
+    return std::make_pair(STR_EMPTY, false);
+
+  std::string base(SuggestPrefix(ns));
+  std::string result(base);
+  int i = 2;
+  while (NsForPrefix(result).second) {
+    std::stringstream ss;
+    ss << base;
+    ss << (i++);
+    ss >> result;
+  }
+  AddXmlns(result, ns);
+  return std::make_pair(result, true);
+}
+
+void XmlnsStack::Reset() {
+  pxmlnsStack_->clear();
+  pxmlnsDepthStack_->clear();
+}
+
+}