Refactoring, moving and renaming the NetworkActionPredictor.

chrome/browser/predictors/predictor_database.cc

Index: chrome/browser/predictors/predictor_database.cc
diff --git a/chrome/browser/predictors/predictor_database.cc b/chrome/browser/predictors/predictor_database.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d0f0653f5311eb96dcdae601d6d8bf5603221321
--- /dev/null
+++ b/chrome/browser/predictors/predictor_database.cc
@@ -0,0 +1,296 @@
+// 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/browser/predictors/predictor_database.h"
+
+#include "base/bind.h"
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/metrics/histogram.h"
+#include "base/stringprintf.h"
+#include "base/utf_string_conversions.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/guid.h"
+#include "content/public/browser/browser_thread.h"
+#include "sql/statement.h"
+
+namespace {
+
+// TODO(shishir): Rename the table for consistency.
+const char kAutocompletePredictorTableName[] = "network_action_predictor";
+const FilePath::CharType kPredictorDatabaseName[] =
+    FILE_PATH_LITERAL("Network Action Predictor");
+
+// The maximum length allowed for strings in the database.
+const size_t kMaxDataLength = 2048;
+
+void LogDatabaseStats(const FilePath& db_path, sql::Connection* db) {
+  int64 db_size;
+  bool success = file_util::GetFileSize(db_path, &db_size);
+  DCHECK(success) << "Failed to get file size for " << db_path.value();
+  UMA_HISTOGRAM_MEMORY_KB("Predictor.DatabaseSizeKB",
+                          static_cast<int>(db_size / 1024));
+
+  sql::Statement count_statement(db->GetUniqueStatement(
+      base::StringPrintf("SELECT count(id) FROM %s",
+                         kAutocompletePredictorTableName).c_str()));
+  if (!count_statement.Step())
+    return;
+  UMA_HISTOGRAM_COUNTS("AutocompleteActionPredictor.DatabaseRowCount",
+                       count_statement.ColumnInt(0));
+}
+
+}  // namespace
+
+namespace predictors {
+
+PredictorTableBase::PredictorTableBase() : db_(NULL) {
+}
+
+PredictorTableBase::~PredictorTableBase() {
+}
+
+void PredictorTableBase::Initialize(sql::Connection* db) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+
+  db_ = db;
+  CreateTableIfNonExistent();
+}
+
+
+AutocompleteActionPredictorTable::Row::Row()
+    : number_of_hits(0),
+      number_of_misses(0) {
+}
+
+AutocompleteActionPredictorTable::Row::Row(const Row::Id& id,
+                                           const string16& user_text,
+                                           const GURL& url,
+                                           int number_of_hits,
+                                           int number_of_misses)
+    : id(id),
+      user_text(user_text),
+      url(url),
+      number_of_hits(number_of_hits),
+      number_of_misses(number_of_misses) {
+}
+
+AutocompleteActionPredictorTable::Row::Row(const Row& row)
+    : id(row.id),
+      user_text(row.user_text),
+      url(row.url),
+      number_of_hits(row.number_of_hits),
+      number_of_misses(row.number_of_misses) {
+}
+
+void AutocompleteActionPredictorTable::GetRow(const Row::Id& id, Row* row) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+  if (cancelled_.IsSet() || !db_)
+    return;
+
+  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE,
+      base::StringPrintf("SELECT * FROM %s WHERE id=?",
+                         kAutocompletePredictorTableName).c_str()));
+  statement.BindString(0, id);
+
+  bool success = StepAndInitializeRow(&statement, row);
+  DCHECK(success) << "Failed to get row " << id << " from "
+                  << kAutocompletePredictorTableName;
+}
+
+void AutocompleteActionPredictorTable::GetAllRows(Rows* row_buffer) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+  if (cancelled_.IsSet() || !db_)
+    return;
+
+  CHECK(row_buffer);
+  row_buffer->clear();
+
+  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE,
+      base::StringPrintf(
+          "SELECT * FROM %s", kAutocompletePredictorTableName).c_str()));
+
+  Row row;
+  while (StepAndInitializeRow(&statement, &row))
+    row_buffer->push_back(row);
+}
+
+void AutocompleteActionPredictorTable::AddRow(
+    const AutocompleteActionPredictorTable::Row& row) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+  if (cancelled_.IsSet() || !db_)
+    return;
+
+  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE,
+      base::StringPrintf(
+          "INSERT INTO %s "
+          "(id, user_text, url, number_of_hits, number_of_misses) "
+          "VALUES (?,?,?,?,?)", kAutocompletePredictorTableName).c_str()));
+  BindRowToStatement(row, &statement);
+
+  bool success = statement.Run();
+  DCHECK(success) << "Failed to insert row " << row.id << " into "
+                  << kAutocompletePredictorTableName;
+}
+
+void AutocompleteActionPredictorTable::UpdateRow(
+    const AutocompleteActionPredictorTable::Row& row) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+  if (cancelled_.IsSet() || !db_)
+    return;
+
+  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE,
+      base::StringPrintf(
+          "UPDATE %s "
+          "SET id=?, user_text=?, url=?, number_of_hits=?, number_of_misses=? "
+          "WHERE id=?1", kAutocompletePredictorTableName).c_str()));
+  BindRowToStatement(row, &statement);
+
+  statement.Run();
+  DCHECK_GT(db_->GetLastChangeCount(), 0);
+}
+
+void AutocompleteActionPredictorTable::AddAndUpdateRows(
+    const Rows& rows_to_add,
+    const Rows& rows_to_update) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+  if (cancelled_.IsSet() || !db_)
+    return;
+
+  db_->BeginTransaction();
+  for (Rows::const_iterator it = rows_to_add.begin();
+       it != rows_to_add.end(); ++it) {
+    AddRow(*it);
+  }
+  for (Rows::const_iterator it = rows_to_update.begin();
+       it != rows_to_update.end(); ++it) {
+    AddRow(*it);
+  }
+  db_->CommitTransaction();
+}
+
+void AutocompleteActionPredictorTable::DeleteRow(const Row::Id& id) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+  if (cancelled_.IsSet() || !db_)
+    return;
+
+  DeleteRows(std::vector<Row::Id>(1, id));
+}
+
+void AutocompleteActionPredictorTable::DeleteRows(
+    const std::vector<Row::Id>& id_list) {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+  if (cancelled_.IsSet() || !db_)
+    return;
+
+  sql::Statement statement(db_->GetUniqueStatement(base::StringPrintf(
+      "DELETE FROM %s WHERE id=?",
+      kAutocompletePredictorTableName).c_str()));
+
+  db_->BeginTransaction();
+  for (std::vector<Row::Id>::const_iterator it = id_list.begin();
+       it != id_list.end(); ++it) {
+    statement.BindString(0, *it);
+    statement.Run();
+    statement.Reset();
+  }
+  db_->CommitTransaction();
+}
+
+void AutocompleteActionPredictorTable::DeleteAllRows() {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+  if (cancelled_.IsSet() || !db_)
+    return;
+
+  sql::Statement statement(db_->GetCachedStatement(SQL_FROM_HERE,
+      base::StringPrintf("DELETE FROM %s",
+                         kAutocompletePredictorTableName).c_str()));
+
+  statement.Run();
+}
+
+AutocompleteActionPredictorTable::AutocompleteActionPredictorTable()
+    : PredictorTableBase() {
+}
+
+AutocompleteActionPredictorTable::~AutocompleteActionPredictorTable() {
+}
+
+void AutocompleteActionPredictorTable::CreateTableIfNonExistent() {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+  if (cancelled_.IsSet() || !db_)
+    return;
+
+  if (db_->DoesTableExist(kAutocompletePredictorTableName))
+    return;
+
+  bool success = db_->Execute(base::StringPrintf(
+      "CREATE TABLE %s ( "
+      "id TEXT PRIMARY KEY, "
+      "user_text TEXT, "
+      "url TEXT, "
+      "number_of_hits INTEGER, "
+      "number_of_misses INTEGER)", kAutocompletePredictorTableName).c_str());
+  DCHECK(success) << "Failed to create " << kAutocompletePredictorTableName
+                  << " table.";
+}
+
+void AutocompleteActionPredictorTable::BindRowToStatement(
+    const Row& row,
+    sql::Statement* statement) {
+  DCHECK(guid::IsValidGUID(row.id));
+  statement->BindString(0, row.id);
+  statement->BindString16(1, row.user_text.substr(0, kMaxDataLength));
+  statement->BindString(2, row.url.spec().substr(0, kMaxDataLength));
+  statement->BindInt(3, row.number_of_hits);
+  statement->BindInt(4, row.number_of_misses);
+}
+
+bool AutocompleteActionPredictorTable::StepAndInitializeRow(
+    sql::Statement* statement,
+    Row* row) {
+  if (!statement->Step())
+    return false;
+
+  row->id = statement->ColumnString(0);
+  row->user_text = statement->ColumnString16(1);
+  row->url = GURL(statement->ColumnString(2));
+  row->number_of_hits = statement->ColumnInt(3);
+  row->number_of_misses = statement->ColumnInt(4);
+  return true;
+}
+
+
+PredictorDatabase::PredictorDatabase(Profile* profile)
+    : db_path_(profile->GetPath().Append(kPredictorDatabaseName)),
+      autocomplete_table_(new AutocompleteActionPredictorTable()) {

[dominich, 2012/03/13 14:55:21]

could the tables be created on the DB thread in the Initialize function instead?
Would that allow them to not be RefCounted?

[Shishir, 2012/03/14 21:14:37]

I need to be able to bind to them in the UI thread so I need the pointers to be
non-null.

+}
+
+PredictorDatabase::~PredictorDatabase() {
+}
+
+void PredictorDatabase::Initialize() {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::DB));
+
+  db_.set_exclusive_locking();

[dominich, 2012/03/13 14:55:21]

Does this add a mutex that blocks concurrent access, or wil attempted access
spin until the db_ is available?

[Shishir, 2012/03/14 21:14:37]

Does it matter? Isnt all access to the db_ on the same thread now?

+  bool success = db_.Open(db_path_);
+
+  if (!success) {
+    LOG(ERROR) << "Could not open predictor database @ "
+               << db_path_.AsUTF8Unsafe();
+    return;
+  }
+
+  autocomplete_table_->Initialize(&db_);
+
+  LogDatabaseStats(db_path_, &db_);
+}
+
+void PredictorDatabase::ShutdownOnUIThread() {
+  CHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
+
+  autocomplete_table_->cancelled_.Set();
+}
+
+}  // namespace predictors