components/search/search.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/search/search.h"
   6
   7 #include "base/command_line.h"
   8 #include "base/metrics/field_trial.h"
   9 #include "base/strings/string_number_conversions.h"
  10 #include "base/strings/string_split.h"
  11 #include "base/strings/string_util.h"
  12 #include "base/strings/utf_string_conversions.h"
  13 #include "components/search/search_switches.h"
  14
  15 namespace chrome {
  16
  17 namespace {
  18
  19 // Configuration options for Embedded Search.
  20 // EmbeddedSearch field trials are named in such a way that we can parse out
  21 // the experiment configuration from the trial's group name in order to give
  22 // us maximum flexability in running experiments.
  23 // Field trial groups should be named things like "Group7 espv:2 instant:1".
  24 // The first token is always GroupN for some integer N, followed by a
  25 // space-delimited list of key:value pairs which correspond to these flags:
  26 const char kEmbeddedPageVersionFlagName[] = "espv";
  27
  28 #if defined(OS_IOS)
  29 const uint64 kEmbeddedPageVersionDefault = 1;
  30 #elif defined(OS_ANDROID)
  31 const uint64 kEmbeddedPageVersionDefault = 1;
  32 // Use this variant to enable EmbeddedSearch SearchBox API in the results page.
  33 const uint64 kEmbeddedSearchEnabledVersion = 2;
  34 #else
  35 const uint64 kEmbeddedPageVersionDefault = 2;
  36 #endif
  37
  38 const char kHideVerbatimFlagName[] = "hide_verbatim";
  39
  40 // Constants for the field trial name and group prefix.
  41 // Note in M30 and below this field trial was named "InstantExtended" and in
  42 // M31 was renamed to EmbeddedSearch for clarity and cleanliness.  Since we
  43 // can't easilly sync up Finch configs with the pushing of this change to
  44 // Dev & Canary, for now the code accepts both names.
  45 // TODO(dcblack): Remove the InstantExtended name once M31 hits the Beta
  46 // channel.
  47 const char kInstantExtendedFieldTrialName[] = "InstantExtended";
  48 const char kEmbeddedSearchFieldTrialName[] = "EmbeddedSearch";
  49
  50 // If the field trial's group name ends with this string its configuration will
  51 // be ignored and Instant Extended will not be enabled by default.
  52 const char kDisablingSuffix[] = "DISABLED";
  53
  54 }  // namespace
  55
  56 bool IsInstantExtendedAPIEnabled() {
  57 #if defined(OS_IOS)
  58   return false;
  59 #elif defined(OS_ANDROID)
  60   return EmbeddedSearchPageVersion() == kEmbeddedSearchEnabledVersion;
  61 #else
  62   return true;
  63 #endif  // defined(OS_IOS)
  64 }
  65
  66 // Determine what embedded search page version to request from the user's
  67 // default search provider. If 0, the embedded search UI should not be enabled.
  68 uint64 EmbeddedSearchPageVersion() {
  69 #if defined(OS_ANDROID)
  70   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
  71           switches::kEnableEmbeddedSearchAPI)) {
  72     return kEmbeddedSearchEnabledVersion;
  73   }
  74 #endif
  75
  76   FieldTrialFlags flags;
  77   if (GetFieldTrialInfo(&flags)) {
  78     return GetUInt64ValueForFlagWithDefault(kEmbeddedPageVersionFlagName,
  79                                             kEmbeddedPageVersionDefault,
  80                                             flags);
  81   }
  82   return kEmbeddedPageVersionDefault;
  83 }
  84
  85 bool GetFieldTrialInfo(FieldTrialFlags* flags) {
  86   // Get the group name.  If the EmbeddedSearch trial doesn't exist, look for
  87   // the older InstantExtended name.
  88   std::string group_name = base::FieldTrialList::FindFullName(
  89       kEmbeddedSearchFieldTrialName);
  90   if (group_name.empty()) {
  91     group_name = base::FieldTrialList::FindFullName(
  92         kInstantExtendedFieldTrialName);
  93   }
  94
  95   if (EndsWith(group_name, kDisablingSuffix, true))
  96     return false;
  97
  98   // We have a valid trial that isn't disabled. Extract the flags.
  99   std::string group_prefix(group_name);
 100   size_t first_space = group_name.find(" ");
 101   if (first_space != std::string::npos) {
 102     // There is a flags section of the group name. Split that out and parse it.
 103     group_prefix = group_name.substr(0, first_space);
 104     if (!base::SplitStringIntoKeyValuePairs(group_name.substr(first_space),
 105                                             ':', ' ', flags)) {
 106       // Failed to parse the flags section. Assume the whole group name is
 107       // invalid.
 108       return false;
 109     }
 110   }
 111   return true;
 112 }
 113
 114 // Given a FieldTrialFlags object, returns the string value of the provided
 115 // flag.
 116 std::string GetStringValueForFlagWithDefault(const std::string& flag,
 117                                              const std::string& default_value,
 118                                              const FieldTrialFlags& flags) {
 119   FieldTrialFlags::const_iterator i;
 120   for (i = flags.begin(); i != flags.end(); i++) {
 121     if (i->first == flag)
 122       return i->second;
 123   }
 124   return default_value;
 125 }
 126
 127 // Given a FieldTrialFlags object, returns the uint64 value of the provided
 128 // flag.
 129 uint64 GetUInt64ValueForFlagWithDefault(const std::string& flag,
 130                                         uint64 default_value,
 131                                         const FieldTrialFlags& flags) {
 132   uint64 value;
 133   std::string str_value =
 134       GetStringValueForFlagWithDefault(flag, std::string(), flags);
 135   if (base::StringToUint64(str_value, &value))
 136     return value;
 137   return default_value;
 138 }
 139
 140 // Given a FieldTrialFlags object, returns the boolean value of the provided
 141 // flag.
 142 bool GetBoolValueForFlagWithDefault(const std::string& flag,
 143                                     bool default_value,
 144                                     const FieldTrialFlags& flags) {
 145   return !!GetUInt64ValueForFlagWithDefault(flag, default_value ? 1 : 0, flags);
 146 }
 147
 148 bool ShouldHideTopVerbatimMatch() {
 149   FieldTrialFlags flags;
 150   return GetFieldTrialInfo(&flags) && GetBoolValueForFlagWithDefault(
 151       kHideVerbatimFlagName, false, flags);
 152 }
 153
 154 }  // namespace chrome