Implementation of a Matching strategy for URLs in the Declarative WebRequest API.

chrome/browser/extensions/api/declarative/substring_set_matcher.cc

+// Copyright (c) 2012 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 "chrome/browser/extensions/api/declarative/substring_set_matcher.h"
+
+#include "base/logging.h"
+#include "base/stl_util.h"
+
+namespace extensions {
+
+//
+// SubstringPattern
+//
+
+SubstringPattern::SubstringPattern(const std::string& pattern,
+                                   SubstringPattern::ID id)
+    : pattern_(pattern), id_(id) {}
+
+SubstringPattern::~SubstringPattern() {}
+
+bool SubstringPattern::operator<(const SubstringPattern& rhs) const {
+  if (id_ < rhs.id_) return true;
+  if (id_ > rhs.id_) return false;
+  return pattern_ < rhs.pattern_;
+}
+
+//
+// SubstringSetMatcher
+//
+
+SubstringSetMatcher::SubstringSetMatcher() {}
+
+SubstringSetMatcher::~SubstringSetMatcher() {}
+
+void SubstringSetMatcher::RegisterPatterns(
+    const std::vector<const SubstringPattern*>& rules) {
+  for (std::vector<const SubstringPattern*>::const_iterator i =
+      rules.begin(); i != rules.end(); ++i) {
+    DCHECK(patterns_.find((*i)->id()) == patterns_.end());
+    patterns_[(*i)->id()] = *i;
+  }
+}
+
+void SubstringSetMatcher::UnregisterPatterns(
+    const std::vector<const SubstringPattern*>& patterns) {
+  for (std::vector<const SubstringPattern*>::const_iterator i =
+      patterns.begin(); i != patterns.end(); ++i) {
+    patterns_.erase((*i)->id());
+  }
+}
+
+void SubstringSetMatcher::RegisterAndUnregisterPatterns(
+      const std::vector<const SubstringPattern*>& to_register,
+      const std::vector<const SubstringPattern*>& to_unregister) {
+  // In the Aho-Corasick implementation this will change, the main
+  // implementation will be here, and RegisterPatterns/UnregisterPatterns
+  // will delegate to this version.
+  RegisterPatterns(to_register);
+  UnregisterPatterns(to_unregister);
+}
+
+bool SubstringSetMatcher::Match(const std::string& text,
+                                std::set<SubstringPattern::ID>* matches) const {
+  for (SubstringPatternSet::const_iterator i = patterns_.begin();
+      i != patterns_.end(); ++i) {
+    if (text.find(i->second->pattern()) != std::string::npos) {
+      if (matches)
+        matches->insert(i->second->id());
+      else
+        return true;
+    }
+  }
+  return matches && !matches->empty();
+}
+
+}  // namespace extensions