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Unified Diff: chrome/browser/ui/title_prefix_matcher.cc

Issue 7067007: Remove prefix eliding (Closed) Base URL: svn://svn.chromium.org/chrome/trunk/src/
Patch Set: Created 9 years, 7 months ago
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Index: chrome/browser/ui/title_prefix_matcher.cc
===================================================================
--- chrome/browser/ui/title_prefix_matcher.cc (revision 86295)
+++ chrome/browser/ui/title_prefix_matcher.cc (working copy)
@@ -1,117 +0,0 @@
-// 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/ui/title_prefix_matcher.h"
-
-#include "base/hash_tables.h"
-#include "base/i18n/break_iterator.h"
-#include "base/logging.h"
-#include "base/utf_string_conversions.h"
-
-namespace {
-// We use this value to identify that we have already seen the title associated
-// to this value in the duplicate_titles hash_set, ans marked it as a duplicate.
-const size_t kPreviouslySeenIndex = 0xFFFFFFFF;
-}
-
-// static
-const int TitlePrefixMatcher::kCommonCharsToShow = 2;
-const size_t TitlePrefixMatcher::kMinElidingLength =
- TitlePrefixMatcher::kCommonCharsToShow + 3;
-
-TitlePrefixMatcher::TitleInfo::TitleInfo(
- const string16* title, const GURL& url, int caller_value)
- : title(title),
- url(url),
- prefix_length(0),
- caller_value(caller_value) {
- DCHECK(title != NULL);
-}
-
-TitlePrefixMatcher::TitleInfo::~TitleInfo() {
-}
-
-// static
-void TitlePrefixMatcher::CalculatePrefixLengths(
- std::vector<TitleInfo>* title_infos) {
- DCHECK(title_infos != NULL);
- // This set will contain the indexes of the TitleInfo objects in the vector
- // that have a duplicate.
- base::hash_set<size_t> duplicate_titles;
- // This map is used to identify duplicates by remembering the vector indexes
- // we have seen with a given title string. The vector index is set to
- // kPreviouslySeenIndex once we identified duplicates and placed their
- // indices in duplicate_titles.
- base::hash_map<string16, size_t> existing_title;
- // We identify if there are identical titles upfront,
- // because we don't want to remove prefixes for those at all.
- // We do it as a separate pass so that we don't need to remove
- // previously parsed titles when we find a duplicate title later on.
- for (size_t i = 0; i < title_infos->size(); ++i) {
- // We use pairs to test existence and insert in one shot.
- std::pair<base::hash_map<string16, size_t>::iterator, bool> insert_result =
- existing_title.insert(std::make_pair(*(*title_infos)[i].title, i));
- if (!insert_result.second) {
- // insert_result.second is false when we insert a duplicate in the set.
- // insert_result.first is a map iterator and thus
- // insert_result.first->first is the string title key of the map.
- DCHECK_EQ(*(*title_infos)[i].title, insert_result.first->first);
- duplicate_titles.insert(i);
- // insert_result.first->second is the value of the title index and if it's
- // not kPreviouslySeenIndex yet, we must remember it as a duplicate too.
- if (insert_result.first->second != kPreviouslySeenIndex) {
- duplicate_titles.insert(insert_result.first->second);
- insert_result.first->second = kPreviouslySeenIndex;
- }
- }
- }
-
- // This next loop accumulates all the potential prefixes,
- // and remember on which titles we saw them.
- base::hash_map<string16, std::vector<size_t> > prefixes;
- for (size_t i = 0; i < title_infos->size(); ++i) {
- // Duplicate titles are not to be included in this process.
- if (duplicate_titles.find(i) != duplicate_titles.end())
- continue;
- const TitleInfo& title_info = (*title_infos)[i];
- const string16* title = title_info.title;
- // We prefix the hostname at the beginning, so that we only group
- // titles that are from the same hostname.
- string16 hostname = ASCIIToUTF16(title_info.url.host());
- // We only create prefixes at word boundaries.
- base::i18n::BreakIterator iter(title,
- base::i18n::BreakIterator::BREAK_WORD);
- // We ignore this title if we can't break it into words, or if it only
- // contains a single word.
- if (!iter.Init() || !iter.Advance())
- continue;
- // We continue advancing even though we already advanced to the first
- // word above, so that we can use iter.prev() to identify the end of the
- // previous word and more easily ignore the last word while iterating.
- while (iter.Advance()) {
- if (iter.IsWord())
- prefixes[hostname + title->substr(0, iter.prev())].push_back(i);
- }
- }
-
- // Now we parse the map to find common prefixes
- // and keep the largest per title.
- for (base::hash_map<string16, std::vector<size_t> >::iterator iter =
- prefixes.begin(); iter != prefixes.end(); ++iter) {
- // iter->first is the prefix string, iter->second is a vector of indices.
- if (iter->second.size() > 1) {
- // We need to subtract the hostname size since we added it to the prefix.
- const TitleInfo& first_title_info = (*title_infos)[iter->second[0]];
- DCHECK_GE(iter->first.size(), first_title_info.url.host().size());
- size_t prefix_length = iter->first.size() -
- first_title_info.url.host().size();
- for (size_t i = 0; i < iter->second.size(); ++i){
- TitleInfo& title_info = (*title_infos)[iter->second[i]];
- DCHECK_EQ(first_title_info.url.host(), title_info.url.host());
- if (title_info.prefix_length < prefix_length)
- title_info.prefix_length = prefix_length;
- }
- }
- }
-}

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