Redirect handling in resource prefetch predictor

chrome/browser/predictors/resource_prefetch_predictor_tables.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 "chrome/browser/predictors/resource_prefetch_predictor_tables.h"
 
 #include <stdint.h>
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/stringprintf.h"
 #include "content/public/browser/browser_thread.h"
 #include "sql/meta_table.h"
 #include "sql/statement.h"
 #include "sql/transaction.h"
 
 using content::BrowserThread;
 using sql::Statement;
 
 namespace {
 
 using ResourceRow = predictors::ResourcePrefetchPredictorTables::ResourceRow;
+using RedirectRow = predictors::ResourcePrefetchPredictorTables::RedirectRow;
+using RedirectData = predictors::ResourcePrefetchPredictorTables::RedirectData;
 
 const char kMetadataTableName[] = "resource_prefetch_predictor_metadata";
-const char kUrlResourceTableName[] = "resource_prefetch_predictor_url";
+const char kUrlResourceTableName[] = "resource_prefetch_predictor_url_resource";
 const char kUrlMetadataTableName[] = "resource_prefetch_predictor_url_metadata";
-const char kHostResourceTableName[] = "resource_prefetch_predictor_host";
+const char kUrlRedirectTableName[] = "resource_prefetch_predictor_url_redirect";
+const char kHostResourceTableName[] =
+    "resource_prefetch_predictor_host_resource";
 const char kHostMetadataTableName[] =
     "resource_prefetch_predictor_host_metadata";
+const char kHostRedirectTableName[] =
+    "resource_prefetch_predictor_host_redirect";
 
 const char kCreateGlobalMetadataStatementTemplate[] =
     "CREATE TABLE %s ( "
     "key TEXT, value INTEGER, "
     "PRIMARY KEY (key))";
 const char kCreateResourceTableStatementTemplate[] =
     "CREATE TABLE %s ( "
     "main_page_url TEXT, "
     "resource_url TEXT, "
     "proto BLOB, "
     "PRIMARY KEY(main_page_url, resource_url))";
 const char kCreateMetadataTableStatementTemplate[] =
     "CREATE TABLE %s ( "
     "main_page_url TEXT, "
     "last_visit_time INTEGER, "
     "PRIMARY KEY(main_page_url))";
+const char kCreateRedirectTableStatementTemplate[] =
+    "CREATE TABLE %s ( "
+    "main_page_url TEXT, "
+    "proto BLOB, "
+    "PRIMARY KEY(main_page_url))";
 
 const char kInsertResourceTableStatementTemplate[] =
     "INSERT INTO %s (main_page_url, resource_url, proto) VALUES (?,?,?)";
+const char kInsertRedirectTableStatementTemplate[] =
+    "INSERT INTO %s (main_page_url, proto) VALUES (?,?)";
 const char kInsertMetadataTableStatementTemplate[] =
     "INSERT INTO %s (main_page_url, last_visit_time) VALUES (?,?)";
 const char kDeleteStatementTemplate[] = "DELETE FROM %s WHERE main_page_url=?";
 
 void BindResourceRowToStatement(const ResourceRow& row,
                                 const std::string& primary_key,
                                 Statement* statement) {
   chrome_browser_predictors::ResourceData proto;
   row.ToProto(&proto);
   int size = proto.ByteSize();
   std::vector<char> proto_buffer(size);
   proto.SerializeToArray(&proto_buffer[0], size);
 
   statement->BindString(0, primary_key);
   statement->BindString(1, row.resource_url.spec());
   statement->BindBlob(2, &proto_buffer[0], size);
 }
 
+void BindRedirectDataToStatement(const RedirectData& data,
+                                 Statement* statement) {
+  chrome_browser_predictors::RedirectProto proto;
+  data.ToProto(&proto);
+  int size = proto.ByteSize();
+  std::vector<char> proto_buffer(size);
+  proto.SerializeToArray(&proto_buffer[0], size);
+
+  statement->BindString(0, data.primary_key);
+  statement->BindBlob(1, &proto_buffer[0], size);
+}
+
 bool StepAndInitializeResourceRow(Statement* statement,
                                   ResourceRow* row,
                                   std::string* primary_key) {
   if (!statement->Step())
     return false;
 
   *primary_key = statement->ColumnString(0);
 
   int size = statement->ColumnByteLength(2);
   const void* data = statement->ColumnBlob(2);
   DCHECK(data);
   chrome_browser_predictors::ResourceData proto;
   proto.ParseFromArray(data, size);
   ResourceRow::FromProto(proto, row);
 
   GURL resource_url(statement->ColumnString(1));
   DCHECK(resource_url == row->resource_url);
 
   return true;
 }
 
+bool StepAndInitializeRedirectData(Statement* statement,
+                                   RedirectData* redirect_data,
+                                   std::string* primary_key) {
+  if (!statement->Step())
+    return false;
+
+  *primary_key = statement->ColumnString(0);
+  redirect_data->primary_key = *primary_key;
+
+  int size = statement->ColumnByteLength(1);
+  const void* data = statement->ColumnBlob(1);
+  DCHECK(data);
+  chrome_browser_predictors::RedirectProto proto;
+  proto.ParseFromArray(data, size);
+  RedirectData::FromProto(proto, redirect_data);
+
+  return true;
+}
+
 }  // namespace
 
 namespace predictors {
 
 ResourceRow::ResourceRow()
     : resource_type(content::RESOURCE_TYPE_LAST_TYPE),
       number_of_hits(0),
       number_of_misses(0),
       consecutive_misses(0),
       average_position(0.0),
@@ skipping 59 matching lines @@
   return resource_url == rhs.resource_url &&
          resource_type == rhs.resource_type &&
          number_of_hits == rhs.number_of_hits &&
          number_of_misses == rhs.number_of_misses &&
          consecutive_misses == rhs.consecutive_misses &&
          average_position == rhs.average_position && priority == rhs.priority &&
          has_validators == rhs.has_validators &&
          always_revalidate == rhs.always_revalidate && score == rhs.score;
 }
 
+// static
+void ResourceRow::FromProto(const ResourceData& proto, ResourceRow* row) {
+  row->resource_url = GURL(proto.resource_url());
+  row->resource_type =
+      static_cast<content::ResourceType>(proto.resource_type());
+  row->number_of_hits = proto.number_of_hits();
+  row->number_of_misses = proto.number_of_misses();
+  row->consecutive_misses = proto.consecutive_misses();
+  row->average_position = proto.average_position();
+  row->priority = static_cast<net::RequestPriority>(proto.priority());
+  row->has_validators = proto.has_validators();
+  row->always_revalidate = proto.always_revalidate();
+  row->UpdateScore();
+}
+
 void ResourceRow::ToProto(ResourceData* resource_data) const {
   using chrome_browser_predictors::ResourceData_Priority;
   using chrome_browser_predictors::ResourceData_ResourceType;
 
   resource_data->set_resource_url(resource_url.spec());
   resource_data->set_resource_type(
       static_cast<ResourceData_ResourceType>(resource_type));
   resource_data->set_number_of_hits(number_of_hits);
   resource_data->set_number_of_misses(number_of_misses);
   resource_data->set_consecutive_misses(consecutive_misses);
   resource_data->set_average_position(average_position);
   resource_data->set_priority(static_cast<ResourceData_Priority>(priority));
   resource_data->set_has_validators(has_validators);
   resource_data->set_always_revalidate(always_revalidate);
 }
 
 // static
-void ResourceRow::FromProto(const ResourceData& proto, ResourceRow* row) {
-  row->resource_url = GURL(proto.resource_url());
-  row->resource_type =
-      static_cast<content::ResourceType>(proto.resource_type());
-  row->number_of_hits = proto.number_of_hits();
-  row->number_of_misses = proto.number_of_misses();
-  row->consecutive_misses = proto.consecutive_misses();
-  row->average_position = proto.average_position();
-  row->priority = static_cast<net::RequestPriority>(proto.priority());
-  row->has_validators = proto.has_validators();
-  row->always_revalidate = proto.always_revalidate();
-  row->UpdateScore();
-}
-
-// static
-void ResourcePrefetchPredictorTables::SortResourceRows(ResourceRows* rows) {
+void ResourcePrefetchPredictorTables::SortResourceRows(
+    std::vector<ResourceRow>* rows) {
   std::sort(rows->begin(), rows->end(),
             [](const ResourceRow& x, const ResourceRow& y) {
               return x.score > y.score;
             });
 }
 
 ResourcePrefetchPredictorTables::PrefetchData::PrefetchData(
     PrefetchKeyType i_key_type,
     const std::string& i_primary_key)
     : key_type(i_key_type),
@@ skipping 10 matching lines @@
 
 ResourcePrefetchPredictorTables::PrefetchData::~PrefetchData() {
 }
 
 bool ResourcePrefetchPredictorTables::PrefetchData::operator==(
     const PrefetchData& rhs) const {
   return key_type == rhs.key_type && primary_key == rhs.primary_key &&
       resources == rhs.resources;
 }
 
+RedirectRow::RedirectRow()
+    : number_of_hits(0),
+      number_of_misses(0),
+      consecutive_misses(0),
+      score(0.0) {}
+
+RedirectRow::RedirectRow(const RedirectRow& other)
+    : url(other.url),
+      number_of_hits(other.number_of_hits),
+      number_of_misses(other.number_of_misses),
+      consecutive_misses(other.consecutive_misses),
+      score(other.score) {}
+
+RedirectRow::RedirectRow(const std::string& i_url,
+                         size_t i_number_of_hits,
+                         size_t i_number_of_misses,
+                         size_t i_consecutive_misses)
+    : url(i_url),
+      number_of_hits(i_number_of_hits),
+      number_of_misses(i_number_of_misses),
+      consecutive_misses(i_consecutive_misses),
+      score(0.0) {}
+
+void RedirectRow::UpdateScore() {
+  // TODO(alexilin): invent some scoring
+}
+
+bool RedirectRow::operator==(const RedirectRow& rhs) const {
+  return url == rhs.url && number_of_hits == rhs.number_of_hits &&
+         number_of_misses == rhs.number_of_misses &&
+         consecutive_misses == rhs.consecutive_misses;
+}
+
+// static
+void RedirectRow::FromProto(const RedirectStat& proto, RedirectRow* row) {
+  row->url = proto.url();
+  row->number_of_hits = proto.number_of_hits();
+  row->number_of_misses = proto.number_of_misses();
+  row->consecutive_misses = proto.consecutive_misses();
+  row->UpdateScore();
+}
+
+void RedirectRow::ToProto(RedirectStat* redirect_stat) const {
+  redirect_stat->set_url(url);
+  redirect_stat->set_number_of_hits(number_of_hits);
+  redirect_stat->set_number_of_misses(number_of_misses);
+  redirect_stat->set_consecutive_misses(consecutive_misses);
+}
+
+// static
+void ResourcePrefetchPredictorTables::SortRedirectRows(
+    std::vector<RedirectRow>* rows) {
+  std::sort(rows->begin(), rows->end(),
+            [](const RedirectRow& x, const RedirectRow& y) {
+              return x.score > y.score;
+            });
+}
+
+ResourcePrefetchPredictorTables::RedirectData::RedirectData(
+    PrefetchKeyType i_key_type,
+    const std::string& i_primary_key)
+    : key_type(i_key_type), primary_key(i_primary_key) {}
+
+ResourcePrefetchPredictorTables::RedirectData::RedirectData(
+    const RedirectData& other)
+    : key_type(other.key_type),
+      primary_key(other.primary_key),
+      last_visit(other.last_visit),
+      redirects(other.redirects) {}
+
+ResourcePrefetchPredictorTables::RedirectData::~RedirectData() {}
+
+bool ResourcePrefetchPredictorTables::RedirectData::operator==(
+    const RedirectData& rhs) const {
+  return key_type == rhs.key_type && primary_key == rhs.primary_key &&
+         redirects == rhs.redirects;
+}
+
+// static
+void ResourcePrefetchPredictorTables::RedirectData::FromProto(
+    const RedirectProto& proto,
+    RedirectData* data) {
+  data->last_visit = base::Time::FromInternalValue(proto.last_visit_time());
+  data->redirects.clear();
+  for (const auto& stat : proto.redirects()) {
+    RedirectRow row;
+    RedirectRow::FromProto(stat, &row);
+    data->redirects.push_back(row);
+  }
+}
+
+void ResourcePrefetchPredictorTables::RedirectData::ToProto(
+    RedirectProto* proto) const {
+  proto->set_last_visit_time(last_visit.ToInternalValue());
+  proto->clear_redirects();
+  for (const auto& row : redirects) {
+    RedirectStat* stat = proto->add_redirects();
+    row.ToProto(stat);
+  }
+}
+
 void ResourcePrefetchPredictorTables::GetAllData(
     PrefetchDataMap* url_data_map,
-    PrefetchDataMap* host_data_map) {
+    PrefetchDataMap* host_data_map,
+    RedirectDataMap* url_redirect_data_map,
+    RedirectDataMap* host_redirect_data_map) {
   DCHECK_CURRENTLY_ON(BrowserThread::DB);
   if (CantAccessDatabase())
     return;
 
   DCHECK(url_data_map);
   DCHECK(host_data_map);
+  DCHECK(url_redirect_data_map);
+  DCHECK(host_redirect_data_map);
   url_data_map->clear();
   host_data_map->clear();
+  url_redirect_data_map->clear();
+  host_redirect_data_map->clear();
 
   std::vector<std::string> urls_to_delete, hosts_to_delete;
-  GetAllDataHelper(PREFETCH_KEY_TYPE_URL, url_data_map, &urls_to_delete);
-  GetAllDataHelper(PREFETCH_KEY_TYPE_HOST, host_data_map, &hosts_to_delete);
+  GetAllResourceDataHelper(PREFETCH_KEY_TYPE_URL, url_data_map,
+                           &urls_to_delete);
+  GetAllResourceDataHelper(PREFETCH_KEY_TYPE_HOST, host_data_map,
+                           &hosts_to_delete);
+  GetAllRedirectDataHelper(PREFETCH_KEY_TYPE_URL, url_redirect_data_map);
+  GetAllRedirectDataHelper(PREFETCH_KEY_TYPE_HOST, host_redirect_data_map);
 
   if (!urls_to_delete.empty() || !hosts_to_delete.empty())
-    DeleteData(urls_to_delete, hosts_to_delete);
+    DeleteResourceData(urls_to_delete, hosts_to_delete);
 }
 
 void ResourcePrefetchPredictorTables::UpdateData(
     const PrefetchData& url_data,
-    const PrefetchData& host_data) {
+    const PrefetchData& host_data,
+    const RedirectData& url_redirect_data,
+    const RedirectData& host_redirect_data) {
   DCHECK_CURRENTLY_ON(BrowserThread::DB);
   if (CantAccessDatabase())
     return;
 
   DCHECK(!url_data.is_host() && host_data.is_host());
-  DCHECK(!url_data.primary_key.empty() || !host_data.primary_key.empty());
+  DCHECK(!url_redirect_data.is_host() && host_redirect_data.is_host());
+  DCHECK(!url_data.primary_key.empty() || !host_data.primary_key.empty() ||
+         !url_redirect_data.primary_key.empty() ||
+         !host_redirect_data.primary_key.empty());
 
   DB()->BeginTransaction();
 
-  bool success = (url_data.primary_key.empty() || UpdateDataHelper(url_data)) &&
-      (host_data.primary_key.empty() || UpdateDataHelper(host_data));
+  bool success =
+      (url_data.primary_key.empty() || UpdateResourceDataHelper(url_data)) &&
+      (host_data.primary_key.empty() || UpdateResourceDataHelper(host_data)) &&
+      (url_redirect_data.primary_key.empty() ||
+       UpdateRedirectDataHelper(url_redirect_data)) &&
+      (host_redirect_data.primary_key.empty() ||
+       UpdateRedirectDataHelper(host_redirect_data));
   if (!success)
     DB()->RollbackTransaction();
-
-  DB()->CommitTransaction();
+  else
+    DB()->CommitTransaction();
 }
 
-void ResourcePrefetchPredictorTables::DeleteData(
+void ResourcePrefetchPredictorTables::DeleteResourceData(
     const std::vector<std::string>& urls,
     const std::vector<std::string>& hosts) {
   DCHECK_CURRENTLY_ON(BrowserThread::DB);
+  if (CantAccessDatabase())
+    return;
+
+  DCHECK(!urls.empty() || !hosts.empty());
+
+  if (!urls.empty())
+    DeleteResourceDataHelper(PREFETCH_KEY_TYPE_URL, urls);
+  if (!hosts.empty())
+    DeleteResourceDataHelper(PREFETCH_KEY_TYPE_HOST, hosts);
+}
+
+void ResourcePrefetchPredictorTables::DeleteSingleResourceDataPoint(
+    const std::string& key,
+    PrefetchKeyType key_type) {
+  DCHECK_CURRENTLY_ON(BrowserThread::DB);
+  if (CantAccessDatabase())
+    return;
+
+  DeleteResourceDataHelper(key_type, {key});
+}
+
+void ResourcePrefetchPredictorTables::DeleteRedirectData(
+    const std::vector<std::string>& urls,
+    const std::vector<std::string>& hosts) {
+  DCHECK_CURRENTLY_ON(BrowserThread::DB);
   if (CantAccessDatabase())
     return;
 
   DCHECK(!urls.empty() || !hosts.empty());
 
   if (!urls.empty())
-    DeleteDataHelper(PREFETCH_KEY_TYPE_URL, urls);
+    DeleteRedirectDataHelper(PREFETCH_KEY_TYPE_URL, urls);
   if (!hosts.empty())
-    DeleteDataHelper(PREFETCH_KEY_TYPE_HOST, hosts);
+    DeleteRedirectDataHelper(PREFETCH_KEY_TYPE_HOST, hosts);
 }
 
-void ResourcePrefetchPredictorTables::DeleteSingleDataPoint(
+void ResourcePrefetchPredictorTables::DeleteSingleRedirectDataPoint(
     const std::string& key,
     PrefetchKeyType key_type) {
   DCHECK_CURRENTLY_ON(BrowserThread::DB);
   if (CantAccessDatabase())
     return;
 
-  DeleteDataHelper(key_type, std::vector<std::string>(1, key));
+  DeleteRedirectDataHelper(key_type, {key});
 }
 
 void ResourcePrefetchPredictorTables::DeleteAllData() {
   if (CantAccessDatabase())
     return;
 
   Statement deleter;
   for (const char* table_name :
-       {kUrlResourceTableName, kUrlMetadataTableName, kHostResourceTableName,
-        kHostMetadataTableName}) {
+       {kUrlResourceTableName, kUrlMetadataTableName, kUrlRedirectTableName,
+        kHostResourceTableName, kHostMetadataTableName,
+        kHostRedirectTableName}) {
     deleter.Assign(DB()->GetUniqueStatement(
         base::StringPrintf("DELETE FROM %s", table_name).c_str()));
     deleter.Run();
   }
 }
 
 ResourcePrefetchPredictorTables::ResourcePrefetchPredictorTables()
     : PredictorTableBase() {
 }
 
 ResourcePrefetchPredictorTables::~ResourcePrefetchPredictorTables() {
 }
 
-void ResourcePrefetchPredictorTables::GetAllDataHelper(
+void ResourcePrefetchPredictorTables::GetAllResourceDataHelper(
     PrefetchKeyType key_type,
     PrefetchDataMap* data_map,
     std::vector<std::string>* to_delete) {
   bool is_host = key_type == PREFETCH_KEY_TYPE_HOST;
 
   // Read the resources table and organize it per primary key.
   const char* resource_table_name = is_host ? kHostResourceTableName :
       kUrlResourceTableName;
   Statement resource_reader(DB()->GetUniqueStatement(
       base::StringPrintf("SELECT * FROM %s", resource_table_name).c_str()));
 
   ResourceRow row;
   std::string primary_key;
   while (StepAndInitializeResourceRow(&resource_reader, &row, &primary_key)) {
     PrefetchDataMap::iterator it = data_map->find(primary_key);
     if (it == data_map->end()) {
       it = data_map->insert(std::make_pair(
           primary_key, PrefetchData(key_type, primary_key))).first;
     }
     it->second.resources.push_back(row);
   }
 
   // Sort each of the resource row vectors by score.
   for (auto& kv : *data_map)
     SortResourceRows(&(kv.second.resources));
 
   // Read the metadata and keep track of entries that have metadata, but no
   // resource entries, so they can be deleted.
-  const char* metadata_table_name = is_host ? kHostMetadataTableName :
-      kUrlMetadataTableName;
+  const char* metadata_table_name =
+      is_host ? kHostMetadataTableName : kUrlMetadataTableName;
   Statement metadata_reader(DB()->GetUniqueStatement(
       base::StringPrintf("SELECT * FROM %s", metadata_table_name).c_str()));
 
   while (metadata_reader.Step()) {
     std::string primary_key = metadata_reader.ColumnString(0);
 
     PrefetchDataMap::iterator it = data_map->find(primary_key);
     if (it != data_map->end()) {
       int64_t last_visit = metadata_reader.ColumnInt64(1);
       it->second.last_visit = base::Time::FromInternalValue(last_visit);
     } else {
       to_delete->push_back(primary_key);
     }
   }
 }
 
-bool ResourcePrefetchPredictorTables::UpdateDataHelper(
+void ResourcePrefetchPredictorTables::GetAllRedirectDataHelper(
+    PrefetchKeyType key_type,
+    RedirectDataMap* redirect_map) {
+  bool is_host = key_type == PREFETCH_KEY_TYPE_HOST;
+
+  const char* redirect_table_name =
+      is_host ? kHostRedirectTableName : kUrlRedirectTableName;
+  Statement redirect_reader(DB()->GetUniqueStatement(
+      base::StringPrintf("SELECT * FROM %s", redirect_table_name).c_str()));
+
+  RedirectData data(key_type);
+  std::string primary_key;
+  while (StepAndInitializeRedirectData(&redirect_reader, &data, &primary_key)) {
+    auto result = redirect_map->insert(std::make_pair(primary_key, data));
+    DCHECK(result.second);
+  }
+}
+
+bool ResourcePrefetchPredictorTables::UpdateResourceDataHelper(
     const PrefetchData& data) {
   DCHECK(!data.primary_key.empty());
 
   if (!StringsAreSmallerThanDBLimit(data)) {
     UMA_HISTOGRAM_BOOLEAN("ResourcePrefetchPredictor.DbStringTooLong", true);
     return false;
   }
 
   // Delete the older data from both the tables.
   std::unique_ptr<Statement> deleter(data.is_host()
                                          ? GetHostResourceDeleteStatement()
                                          : GetUrlResourceDeleteStatement());
   deleter->BindString(0, data.primary_key);
   if (!deleter->Run())
     return false;
 
-  deleter.reset(data.is_host() ? GetHostMetadataDeleteStatement() :
-      GetUrlMetadataDeleteStatement());
+  deleter.reset(data.is_host() ? GetHostMetadataDeleteStatement()
+                               : GetUrlMetadataDeleteStatement());
   deleter->BindString(0, data.primary_key);
   if (!deleter->Run())
     return false;
 
   // Add the new data to the tables.
   for (const ResourceRow& resource : data.resources) {
     std::unique_ptr<Statement> resource_inserter(
         data.is_host() ? GetHostResourceUpdateStatement()
                        : GetUrlResourceUpdateStatement());
     BindResourceRowToStatement(resource, data.primary_key,
                                resource_inserter.get());
     if (!resource_inserter->Run())
       return false;
   }
 
   std::unique_ptr<Statement> metadata_inserter(
       data.is_host() ? GetHostMetadataUpdateStatement()
                      : GetUrlMetadataUpdateStatement());
   metadata_inserter->BindString(0, data.primary_key);
   metadata_inserter->BindInt64(1, data.last_visit.ToInternalValue());
   if (!metadata_inserter->Run())
     return false;
 
   return true;
 }
 
-void ResourcePrefetchPredictorTables::DeleteDataHelper(
+bool ResourcePrefetchPredictorTables::UpdateRedirectDataHelper(
+    const RedirectData& data) {
+  DCHECK(!data.primary_key.empty());
+
+  if (!StringsAreSmallerThanDBLimit(data)) {
+    UMA_HISTOGRAM_BOOLEAN("ResourcePrefetchPredictor.DbStringTooLong", true);
+    return false;
+  }
+
+  // Delete the older data from the table.
+  std::unique_ptr<Statement> deleter(data.is_host()
+                                         ? GetHostRedirectDeleteStatement()
+                                         : GetUrlRedirectDeleteStatement());
+  deleter->BindString(0, data.primary_key);
+  if (!deleter->Run())
+    return false;
+
+  // Add the new data to the table.
+  std::unique_ptr<Statement> inserter(data.is_host()
+                                          ? GetHostRedirectUpdateStatement()
+                                          : GetUrlRedirectUpdateStatement());
+  BindRedirectDataToStatement(data, inserter.get());
+  if (!inserter->Run())
+    return false;
+
+  return true;
+}
+
+void ResourcePrefetchPredictorTables::DeleteResourceDataHelper(
     PrefetchKeyType key_type,
     const std::vector<std::string>& keys) {
   bool is_host = key_type == PREFETCH_KEY_TYPE_HOST;
 
   for (const std::string& key : keys) {
     std::unique_ptr<Statement> deleter(is_host
                                            ? GetHostResourceDeleteStatement()
                                            : GetUrlResourceDeleteStatement());
     deleter->BindString(0, key);
     deleter->Run();
 
-    deleter.reset(is_host ? GetHostMetadataDeleteStatement() :
-        GetUrlMetadataDeleteStatement());
+    deleter.reset(is_host ? GetHostMetadataDeleteStatement()
+                          : GetUrlMetadataDeleteStatement());
     deleter->BindString(0, key);
     deleter->Run();
   }
+}
+
+void ResourcePrefetchPredictorTables::DeleteRedirectDataHelper(
+    PrefetchKeyType key_type,
+    const std::vector<std::string>& keys) {
+  bool is_host = key_type == PREFETCH_KEY_TYPE_HOST;
+
+  for (const std::string& key : keys) {
+    std::unique_ptr<Statement> deleter(is_host
+                                           ? GetHostRedirectDeleteStatement()
+                                           : GetUrlRedirectDeleteStatement());
+    deleter->BindString(0, key);
+    deleter->Run();
+  }
 }
 
 // static
 bool ResourcePrefetchPredictorTables::StringsAreSmallerThanDBLimit(
     const PrefetchData& data) {
   if (data.primary_key.length() > kMaxStringLength)
     return false;
 
   for (const ResourceRow& row : data.resources) {
     if (row.resource_url.spec().length() > kMaxStringLength)
       return false;
   }
   return true;
 }
 
 // static
+bool ResourcePrefetchPredictorTables::StringsAreSmallerThanDBLimit(
+    const RedirectData& data) {
+  if (data.primary_key.length() > kMaxStringLength)
+    return false;
+
+  for (const RedirectRow& row : data.redirects) {
+    if (row.url.length() > kMaxStringLength)
+      return false;
+  }
+  return true;
+}
+
+// static
 bool ResourcePrefetchPredictorTables::DropTablesIfOutdated(
     sql::Connection* db) {
   int version = GetDatabaseVersion(db);
   bool success = true;
   // Too new is also a problem.
   bool incompatible_version = version != kDatabaseVersion;
 
   if (incompatible_version) {
     for (const char* table_name :
          {kMetadataTableName, kUrlResourceTableName, kHostResourceTableName,
-          kUrlMetadataTableName, kHostMetadataTableName}) {
+          kUrlRedirectTableName, kHostRedirectTableName, kUrlMetadataTableName,
+          kHostMetadataTableName}) {
       success =
           success &&
           db->Execute(base::StringPrintf("DROP TABLE IF EXISTS %s", table_name)
                           .c_str());
     }
   }
 
   if (incompatible_version) {
     success =
         success &&
@@ skipping 46 matching lines @@
   success =
       success &&
       (db->DoesTableExist(kUrlResourceTableName) ||
        db->Execute(base::StringPrintf(kCreateResourceTableStatementTemplate,
                                       kUrlResourceTableName)
                        .c_str())) &&
       (db->DoesTableExist(kUrlMetadataTableName) ||
        db->Execute(base::StringPrintf(kCreateMetadataTableStatementTemplate,
                                       kUrlMetadataTableName)
                        .c_str())) &&
+      (db->DoesTableExist(kUrlRedirectTableName) ||
+       db->Execute(base::StringPrintf(kCreateRedirectTableStatementTemplate,
+                                      kUrlRedirectTableName)
+                       .c_str())) &&
       (db->DoesTableExist(kHostResourceTableName) ||
        db->Execute(base::StringPrintf(kCreateResourceTableStatementTemplate,
                                       kHostResourceTableName)
                        .c_str())) &&
       (db->DoesTableExist(kHostMetadataTableName) ||
        db->Execute(base::StringPrintf(kCreateMetadataTableStatementTemplate,
                                       kHostMetadataTableName)
+                       .c_str())) &&
+      (db->DoesTableExist(kHostRedirectTableName) ||
+       db->Execute(base::StringPrintf(kCreateRedirectTableStatementTemplate,
+                                      kHostRedirectTableName)
                        .c_str()));
 
   if (success)
     success = transaction.Commit();
   else
     transaction.Rollback();
 
   if (!success)
     ResetDB();
 }
 
 void ResourcePrefetchPredictorTables::LogDatabaseStats()  {
   DCHECK_CURRENTLY_ON(BrowserThread::DB);
   if (CantAccessDatabase())
     return;
 
   Statement statement(DB()->GetUniqueStatement(
       base::StringPrintf("SELECT count(*) FROM %s",
                          kUrlResourceTableName).c_str()));
   if (statement.Step())
     UMA_HISTOGRAM_COUNTS("ResourcePrefetchPredictor.UrlTableRowCount",
                          statement.ColumnInt(0));
 
   statement.Assign(DB()->GetUniqueStatement(
       base::StringPrintf("SELECT count(*) FROM %s",
                          kHostResourceTableName).c_str()));
   if (statement.Step())
     UMA_HISTOGRAM_COUNTS("ResourcePrefetchPredictor.HostTableRowCount",
                          statement.ColumnInt(0));
+
+  statement.Assign(DB()->GetUniqueStatement(
+      base::StringPrintf("SELECT count(*) FROM %s", kUrlRedirectTableName)
+          .c_str()));
+  if (statement.Step())
+    UMA_HISTOGRAM_COUNTS("ResourcePrefetchPredictor.UrlRedirectTableRowCount",
+                         statement.ColumnInt(0));
+
+  statement.Assign(DB()->GetUniqueStatement(
+      base::StringPrintf("SELECT count(*) FROM %s", kHostRedirectTableName)
+          .c_str()));
+  if (statement.Step())
+    UMA_HISTOGRAM_COUNTS("ResourcePrefetchPredictor.HostRedirectTableRowCount",
+                         statement.ColumnInt(0));
 }
 
 Statement*
     ResourcePrefetchPredictorTables::GetUrlResourceDeleteStatement() {
   return new Statement(DB()->GetCachedStatement(
       SQL_FROM_HERE,
       base::StringPrintf(kDeleteStatementTemplate, kUrlResourceTableName)
           .c_str()));
 }
 
 Statement*
     ResourcePrefetchPredictorTables::GetUrlResourceUpdateStatement() {
   return new Statement(DB()->GetCachedStatement(
       SQL_FROM_HERE, base::StringPrintf(kInsertResourceTableStatementTemplate,
                                         kUrlResourceTableName)
                          .c_str()));
 }
 
-Statement*
-    ResourcePrefetchPredictorTables::GetUrlMetadataDeleteStatement() {
+Statement* ResourcePrefetchPredictorTables::GetUrlMetadataDeleteStatement() {
   return new Statement(DB()->GetCachedStatement(
       SQL_FROM_HERE,
       base::StringPrintf(kDeleteStatementTemplate, kUrlMetadataTableName)
           .c_str()));
 }
 
-Statement*
-    ResourcePrefetchPredictorTables::GetUrlMetadataUpdateStatement() {
+Statement* ResourcePrefetchPredictorTables::GetUrlMetadataUpdateStatement() {
   return new Statement(DB()->GetCachedStatement(
       SQL_FROM_HERE, base::StringPrintf(kInsertMetadataTableStatementTemplate,
                                         kUrlMetadataTableName)
                          .c_str()));
 }
 
+Statement* ResourcePrefetchPredictorTables::GetUrlRedirectDeleteStatement() {
+  return new Statement(DB()->GetCachedStatement(
+      SQL_FROM_HERE,
+      base::StringPrintf(kDeleteStatementTemplate, kUrlRedirectTableName)
+          .c_str()));
+}
+
+Statement* ResourcePrefetchPredictorTables::GetUrlRedirectUpdateStatement() {
+  return new Statement(DB()->GetCachedStatement(
+      SQL_FROM_HERE, base::StringPrintf(kInsertRedirectTableStatementTemplate,
+                                        kUrlRedirectTableName)
+                         .c_str()));
+}
+
 Statement*
     ResourcePrefetchPredictorTables::GetHostResourceDeleteStatement() {
   return new Statement(DB()->GetCachedStatement(
       SQL_FROM_HERE,
       base::StringPrintf(kDeleteStatementTemplate, kHostResourceTableName)
           .c_str()));
 }
 
 Statement*
     ResourcePrefetchPredictorTables::GetHostResourceUpdateStatement() {
   return new Statement(DB()->GetCachedStatement(
       SQL_FROM_HERE, base::StringPrintf(kInsertResourceTableStatementTemplate,
                                         kHostResourceTableName)
                          .c_str()));
 }
 
-Statement*
-    ResourcePrefetchPredictorTables::GetHostMetadataDeleteStatement() {
+Statement* ResourcePrefetchPredictorTables::GetHostMetadataDeleteStatement() {
   return new Statement(DB()->GetCachedStatement(
       SQL_FROM_HERE,
       base::StringPrintf(kDeleteStatementTemplate, kHostMetadataTableName)
           .c_str()));
 }
 
 Statement* ResourcePrefetchPredictorTables::GetHostMetadataUpdateStatement() {
   return new Statement(DB()->GetCachedStatement(
       SQL_FROM_HERE, base::StringPrintf(kInsertMetadataTableStatementTemplate,
                                         kHostMetadataTableName)
                          .c_str()));
 }
 
+Statement* ResourcePrefetchPredictorTables::GetHostRedirectDeleteStatement() {
+  return new Statement(DB()->GetCachedStatement(
+      SQL_FROM_HERE,
+      base::StringPrintf(kDeleteStatementTemplate, kHostRedirectTableName)
+          .c_str()));
+}
+
+Statement* ResourcePrefetchPredictorTables::GetHostRedirectUpdateStatement() {
+  return new Statement(DB()->GetCachedStatement(
+      SQL_FROM_HERE, base::StringPrintf(kInsertRedirectTableStatementTemplate,
+                                        kHostRedirectTableName)
+                         .c_str()));
+}
+
 }  // namespace predictors