Refactor code to avoid direct dependency upon ICU: phishing_term_feature_extractor

chrome/renderer/safe_browsing/phishing_term_feature_extractor.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/renderer/safe_browsing/phishing_term_feature_extractor.h"
 
 #include <list>
 #include <map>
 
 #include "base/bind.h"
 #include "base/compiler_specific.h"
+#include "base/i18n/break_iterator.h"
 #include "base/i18n/case_conversion.h"
 #include "base/logging.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
 #include "chrome/renderer/safe_browsing/feature_extractor_clock.h"
 #include "chrome/renderer/safe_browsing/features.h"
 #include "chrome/renderer/safe_browsing/murmurhash3_util.h"
 #include "crypto/sha2.h"
-#include "third_party/icu/source/common/unicode/ubrk.h"
 #include "ui/base/l10n/l10n_util.h"
 
 namespace safe_browsing {
 
 // This time should be short enough that it doesn't noticeably disrupt the
 // user's interaction with the page.
 const int PhishingTermFeatureExtractor::kMaxTimePerChunkMs = 10;
 
 // Experimenting shows that we get a reasonable gain in performance by
 // increasing this up to around 10, but there's not much benefit in
@@ skipping 11 matching lines @@
 struct PhishingTermFeatureExtractor::ExtractionState {
   // Stores up to max_words_per_term_ previous words separated by spaces.
   std::string previous_words;
 
   // Stores the sizes of the words in previous_words.  Note: the size includes
   // the space after each word.  In other words, the sum of all sizes in this
   // list is equal to the length of previous_words.
   std::list<size_t> previous_word_sizes;
 
   // An iterator for word breaking.
-  UBreakIterator* iterator;
-
-  // Our current position in the text that was passed to the ExtractionState
-  // constructor, speciailly, the most recent break position returned by our
-  // iterator.
-  int position;
-
-  // True if position has been initialized.
-  bool position_initialized;
+  scoped_ptr<base::i18n::BreakIterator> iterator;
 
   // The time at which we started feature extraction for the current page.
   base::TimeTicks start_time;
 
   // The number of iterations we've done for the current extraction.
   int num_iterations;
 
   ExtractionState(const base::string16& text, base::TimeTicks start_time_ticks)
-      : position(-1),
-        position_initialized(false),
-        start_time(start_time_ticks),
+      : start_time(start_time_ticks),
         num_iterations(0) {
-    UErrorCode status = U_ZERO_ERROR;
-    // TODO(bryner): We should pass in the language for the document.
-    iterator = ubrk_open(UBRK_WORD, NULL,
-                         text.data(), text.size(),
-                         &status);
-    if (U_FAILURE(status)) {
-      DLOG(ERROR) << "ubrk_open failed: " << status;
-      iterator = NULL;
-    }
-  }
 
-  ~ExtractionState() {
-    if (iterator) {
-      ubrk_close(iterator);
+    scoped_ptr<base::i18n::BreakIterator> i(
+        new base::i18n::BreakIterator(
+            text, base::i18n::BreakIterator::BREAK_WORD));
+
+    if (i->Init()) {
+      iterator = i.Pass();
+    } else {
+      DLOG(ERROR) << "failed to open iterator";
     }
   }
 };
 
 PhishingTermFeatureExtractor::PhishingTermFeatureExtractor(
     const base::hash_set<std::string>* page_term_hashes,
     const base::hash_set<uint32>* page_word_hashes,
     size_t max_words_per_term,
     uint32 murmurhash3_seed,
     FeatureExtractorClock* clock)
@@ skipping 39 matching lines @@
   // Cancel any pending callbacks, and clear our state.
   weak_factory_.InvalidateWeakPtrs();
   Clear();
 }
 
 void PhishingTermFeatureExtractor::ExtractFeaturesWithTimeout() {
   DCHECK(state_.get());
   ++state_->num_iterations;
   base::TimeTicks current_chunk_start_time = clock_->Now();
 
-  if (!state_->iterator) {
+  if (!state_->iterator.get()) {
     // We failed to initialize the break iterator, so stop now.
     UMA_HISTOGRAM_COUNTS("SBClientPhishing.TermFeatureBreakIterError", 1);
     RunCallback(false);
     return;
   }
 
-  if (!state_->position_initialized) {
-    state_->position = ubrk_first(state_->iterator);
-    if (state_->position == UBRK_DONE) {
-      // No words present, so we're done.
-      RunCallback(true);
-      return;
-    }
-    state_->position_initialized = true;
-  }
-
   int num_words = 0;
-  for (int next = ubrk_next(state_->iterator);
-       next != UBRK_DONE; next = ubrk_next(state_->iterator)) {
-    if (ubrk_getRuleStatus(state_->iterator) != UBRK_WORD_NONE) {
-      // next is now positioned at the end of a word.
-      HandleWord(base::StringPiece16(page_text_->data() + state_->position,
-                                     next - state_->position));
+  while (state_->iterator->Advance()) {
+    if (state_->iterator->IsWord()) {
+      const size_t start = state_->iterator->prev();
+      const size_t length = state_->iterator->pos() - start;
+      HandleWord(base::StringPiece16(page_text_->data() + start, length));
       ++num_words;
     }
-    state_->position = next;
 
     if (num_words >= kClockCheckGranularity) {
       num_words = 0;
       base::TimeTicks now = clock_->Now();
       if (now - state_->start_time >=
           base::TimeDelta::FromMilliseconds(kMaxTotalTimeMs)) {
         DLOG(ERROR) << "Feature extraction took too long, giving up";
         // We expect this to happen infrequently, so record when it does.
         UMA_HISTOGRAM_COUNTS("SBClientPhishing.TermFeatureTimeout", 1);
         RunCallback(false);
@@ skipping 116 matching lines @@
 
 void PhishingTermFeatureExtractor::Clear() {
   page_text_ = NULL;
   features_ = NULL;
   done_callback_.Reset();
   state_.reset(NULL);
   negative_word_cache_.Clear();
 }
 
 }  // namespace safe_browsing