Omnibox - Boost Frequency Scores Based on Number of Matching Pages

components/omnibox/browser/omnibox_field_trial.cc

 // Copyright 2014 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 "components/omnibox/browser/omnibox_field_trial.h"
 
+#include <algorithm>
 #include <cmath>
 #include <string>
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
@@ skipping 419 matching lines @@
   if (typed_value_str.empty())
     return 20;
   // This is a best-effort conversion; we trust the hand-crafted parameters
   // downloaded from the server to be perfect.  There's no need for handle
   // errors smartly.
   double typed_value;
   base::StringToDouble(typed_value_str, &typed_value);
   return typed_value;
 }
 
+OmniboxFieldTrial::NumMatchesScores OmniboxFieldTrial::HQPNumMatchesScores() {
+  std::string str = variations::GetVariationParamValue(
+      kBundledExperimentFieldTrialName, kHQPNumMatchesScoresRule);
+  // The parameter is a comma-separated list of (number, value) pairs, e.g.
+  // "1:3,2:2.5,3:2,4:1.5".
+  // This is a best-effort conversion; we trust the hand-crafted parameters
+  // downloaded from the server to be perfect.  There's no need to handle
+  // errors smartly.
+  base::StringPairs kv_pairs;
+  if (!base::SplitStringIntoKeyValuePairs(str, ':', ',', &kv_pairs))
+    return NumMatchesScores{};
+  NumMatchesScores num_matches_scores(kv_pairs.size());
+  for (size_t i = 0; i < kv_pairs.size(); ++i) {
+    base::StringToSizeT(kv_pairs[i].first, &num_matches_scores[i].first);
+    // Don't allow duplicates.
+    DCHECK((i == 0) ||
+           (num_matches_scores[i].first != num_matches_scores[i - 1].first));

[Peter Kasting, 2016/12/06 05:19:30]

Wouldn't using ">" here obviate the need for the is_sorted() call below?

Or, instead, you could eliminate this DCHECK entirely and replace that with:

DCHECK(std::is_sorted(num_matches_scores.begin(), num_matches_scores.end(),
[](a, b) { return a.first < b.first; }));

Note that here a and b will need type declarations of your pair type.  It might
be easier to use a type alias in the header for this.

Doing this would also allow switching the loop to use range-based for.

[Mark P, 2016/12/08 00:21:31]

Of these two suggestions, I prefer the first one.  Did the > and removed the
is_sorted() call.

+    base::StringToDouble(kv_pairs[i].second, &num_matches_scores[i].second);
+  }
+  DCHECK(std::is_sorted(num_matches_scores.begin(), num_matches_scores.end()));
+  return num_matches_scores;
+}
+
 size_t OmniboxFieldTrial::HQPNumTitleWordsToAllow() {
   // The value of the rule is a string that encodes an integer (actually
   // size_t) containing the number of words.
   size_t num_title_words;
   if (!base::StringToSizeT(
           variations::GetVariationParamValue(kBundledExperimentFieldTrialName,
                                              kHQPNumTitleWordsRule),
           &num_title_words))
     return 20;
   return num_title_words;
@@ skipping 85 matching lines @@
     "DisableResultsCaching";
 const char
 OmniboxFieldTrial::kMeasureSuggestPollingDelayFromLastKeystrokeRule[] =
     "MeasureSuggestPollingDelayFromLastKeystroke";
 const char OmniboxFieldTrial::kSuggestPollingDelayMsRule[] =
     "SuggestPollingDelayMs";
 const char OmniboxFieldTrial::kHQPFixFewVisitsBugRule[] = "HQPFixFewVisitsBug";
 const char OmniboxFieldTrial::kHQPFreqencyUsesSumRule[] = "HQPFreqencyUsesSum";
 const char OmniboxFieldTrial::kHQPMaxVisitsToScoreRule[] =
     "HQPMaxVisitsToScoreRule";
+const char OmniboxFieldTrial::kHQPNumMatchesScoresRule[] =
+    "HQPNumMatchesScores";
 const char OmniboxFieldTrial::kHQPNumTitleWordsRule[] = "HQPNumTitleWords";
 const char OmniboxFieldTrial::kHQPAlsoDoHUPLikeScoringRule[] =
     "HQPAlsoDoHUPLikeScoring";
 const char OmniboxFieldTrial::kHUPSearchDatabaseRule[] =
     "HUPSearchDatabase";
 const char OmniboxFieldTrial::kKeywordRequiresRegistryRule[] =
     "KeywordRequiresRegistry";
 const char OmniboxFieldTrial::kKeywordRequiresPrefixMatchRule[] =
     "KeywordRequiresPrefixMatch";
 const char OmniboxFieldTrial::kKeywordScoreForSufficientlyCompleteMatchRule[] =
@@ skipping 85 matching lines @@
   if (it != params.end())
     return it->second;
   // Fall back to the global instant extended context.
   it = params.find(rule + ":" + page_classification_str + ":*");
   if (it != params.end())
     return it->second;
   // Look up rule in the global context.
   it = params.find(rule + ":*:*");
   return (it != params.end()) ? it->second : std::string();
 }