Cache Autofill heuristics regexes

chrome/browser/autofill/autofill_regexes.cc

+// Copyright (c) 2011 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/autofill/autofill_regexes.h"
+
+#include <map>
+#include <utility>
+
+#include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/singleton.h"
+#include "base/stl_util-inl.h"
+#include "base/string16.h"
+#include "unicode/regex.h"
+
+namespace {
+
+// A singleton class that serves as a cache of compiled regex patterns.
+class AutofillRegexes {
+ public:
+  static AutofillRegexes* GetInstance();
+
+  // Returns the compiled regex matcher corresponding to |pattern|.
+  icu::RegexMatcher* GetMatcher(const string16& pattern);
+
+ private:
+  AutofillRegexes();
+  ~AutofillRegexes();
+  friend struct DefaultSingletonTraits<AutofillRegexes>;
+
+  // Maps patterns to their corresponding regex matchers.
+  std::map<string16, icu::RegexMatcher*> matchers_;
+
+  DISALLOW_COPY_AND_ASSIGN(AutofillRegexes);
+};
+
+// static
+AutofillRegexes* AutofillRegexes::GetInstance() {
+  return Singleton<AutofillRegexes>::get();
+}
+
+AutofillRegexes::AutofillRegexes() {
+}
+
+AutofillRegexes::~AutofillRegexes() {
+  STLDeleteContainerPairSecondPointers(matchers_.begin(),
+                                       matchers_.end());
+}
+
+icu::RegexMatcher* AutofillRegexes::GetMatcher(const string16& pattern) {
+  if (!matchers_.count(pattern)) {
+    const icu::UnicodeString icu_pattern(pattern.data(), pattern.length());
+
+    UErrorCode status = U_ZERO_ERROR;
+    icu::RegexMatcher* matcher = new icu::RegexMatcher(icu_pattern,
+                                                       UREGEX_CASE_INSENSITIVE,
+                                                       status);
+    DCHECK(U_SUCCESS(status));
+
+    matchers_.insert(std::make_pair(pattern, matcher));
+  }
+
+  return matchers_[pattern];
+}
+
+}  // namespace
+
+namespace autofill {
+
+bool MatchesPattern(const string16& input, const string16& pattern) {
+  icu::RegexMatcher* matcher =
+      AutofillRegexes::GetInstance()->GetMatcher(pattern);
+  icu::UnicodeString icu_input(input.data(), input.length());
+  matcher->reset(icu_input);
+
+  UErrorCode status = U_ZERO_ERROR;
+  UBool match = matcher->find(0, status);
+  DCHECK(U_SUCCESS(status));
+  return !!match;
+}
+
+}  // namespace autofill
+