Added MediaGalleryDatabase

content/browser/media_gallery/media_gallery_database.cc

+// 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 "content/browser/media_gallery/media_gallery_database.h"
+
+#include <algorithm>
+
+#include "base/file_path.h"
+#include "base/logging.h"
+#include "sql/diagnostic_error_delegate.h"
+#include "sql/statement.h"
+#include "sql/transaction.h"
+
+#define MEDIA_GALLERY_COLLECTION_ROW_FIELDS \
+    " collections.id, collections.path, collections.last_modified_time, " \
+    "collections.entry_count, collections.all_parsed "
+
+#define COLLECTION_TABLE_NAME "collections"

[vandebo (ex-Chrome), 2012/03/05 23:16:03]

You've hard coded the column creation, what's the idea behind having the table
name as a constant?

[tpayne, 2012/03/06 01:52:37]

Done.

+
+std::ostream& operator<<(std::ostream& out,

[vandebo (ex-Chrome), 2012/03/05 23:16:03]

In anonymous namespace?

[tpayne, 2012/03/06 01:52:37]

Done.

+    const media_gallery::MediaGalleryDatabase::CollectionRow& row) {
+  out << "Collection"
+      << " id " << row.GetId()
+      << " path " << row.GetPath().value()
+      << " last modified time " << row.GetLastModifiedTime().ToInternalValue()
+      << " entry count " << row.GetEntryCount()
+      << " all parsed " << (row.IsAllParsed() ? "true" : "false") << std::endl;
+  return out;
+}
+
+namespace media_gallery {
+
+namespace {
+
+static const int kCurrentVersionNumber = 1;
+static const int kCompatibleVersionNumber = 1;
+static const char kMediaGalleryDatabaseName[] = "media_gallery.db";

[vandebo (ex-Chrome), 2012/03/05 23:16:03]

nit: we might want to use a "hidden" name, i.e. start with a dot.

[tpayne, 2012/03/06 01:52:37]

Done.

+
+class HistogramName {
+ public:
+  static const char* name() {
+    return "Sqlite.MediaGallery.Error";
+  }
+};
+
+}  // namespace
+
+MediaGalleryDatabase::MediaGalleryDatabase() { }
+
+MediaGalleryDatabase::~MediaGalleryDatabase() { }
+
+sql::InitStatus MediaGalleryDatabase::Init(const FilePath& database_dir) {
+  // Set the exceptional sqlite error handler.
+  db_.set_error_delegate(new sql::DiagnosticErrorDelegate<HistogramName>());
+
+  // Set the database page size to something a little larger to give us
+  // better performance (we're typically seek rather than bandwidth limited).
+  // This only has an effect before any tables have been created, otherwise
+  // this is a NOP. Must be a power of 2 and a max of 8192.
+  db_.set_page_size(4096);
+
+  // Increase the cache size. The page size, plus a little extra, times this
+  // value, tells us how much memory the cache will use maximum.
+  // 6000 * 4MB = 24MB

[vandebo (ex-Chrome), 2012/03/05 23:16:03]

are you calling 4MB the page size here?  set_page_size probably takes page size
in bytes.

[tpayne, 2012/03/06 01:52:37]

This is copied verbatim from url_database. Looks like they've got a typo. I'll
fix this version.

+  db_.set_cache_size(6000);
+
+  if (!db_.Open(database_dir.Append(kMediaGalleryDatabaseName)))
+    return sql::INIT_FAILURE;
+
+  return InitInternal(&db_);
+}
+
+sql::InitStatus MediaGalleryDatabase::InitInternal(sql::Connection* db) {
+  // Wrap the rest of init in a tranaction. This will prevent the database from
+  // getting corrupted if we crash in the middle of initialization or migration.
+  sql::Transaction committer(db);
+  if (!committer.Begin())
+    return sql::INIT_FAILURE;
+
+  // Prime the cache.
+  db->Preload();
+
+  // Create the tables and indices.
+  if (!meta_table_.Init(db, GetCurrentVersion(), kCompatibleVersionNumber))
+    return sql::INIT_FAILURE;
+
+  if (!CreateCollectionsTable(db)) {
+    return sql::INIT_FAILURE;
+  }
+
+  // Version check.
+  sql::InitStatus version_status = EnsureCurrentVersion();
+  if (version_status != sql::INIT_OK)
+    return version_status;
+
+  return committer.Commit() ? sql::INIT_OK : sql::INIT_FAILURE;
+}
+
+sql::InitStatus MediaGalleryDatabase::EnsureCurrentVersion() {
+    // We can't read databases newer than we were designed for.
+    if (meta_table_.GetCompatibleVersionNumber() > kCurrentVersionNumber) {
+      LOG(WARNING) << "Media Gallery database is too new.";
+      return sql::INIT_TOO_NEW;
+    }
+    int cur_version = meta_table_.GetVersionNumber();
+    if (cur_version == 0) {
+      LOG(WARNING) << "Initializing the Media Gallery database.";
+
+      ++cur_version;

[vandebo (ex-Chrome), 2012/03/05 23:16:03]

set it to kCurrentVersionNumber.

[tpayne, 2012/03/06 01:52:37]

Once we have migration code, that's not going to be a good idea. The idea is
that we update it as we do each step of the migration. If the migration fails
partway through, we want the current version to match the current state of the
db.

+      meta_table_.SetVersionNumber(cur_version);
+      meta_table_.SetCompatibleVersionNumber(
+          std::min(cur_version, kCompatibleVersionNumber));
+    }
+    return sql::INIT_OK;
+}
+
+// static
+int MediaGalleryDatabase::GetCurrentVersion() {

[vandebo (ex-Chrome), 2012/03/05 23:16:03]

Why a method to return a constant?

[tpayne, 2012/03/06 01:52:37]

I don't know. I cribbed this from url_database.cc. It may not be necessary in
our case.

+  return kCurrentVersionNumber;
+}
+
+COLLECTIONID MediaGalleryDatabase::CreateCollectionRow(
+    CollectionRow* row) {
+  const char* sql = "INSERT INTO " COLLECTION_TABLE_NAME
+      "(path, last_modified_time, entry_count, all_parsed) "
+      "VALUES(?, ?, ?, ?)";
+
+  sql::Statement statement(GetDB().GetCachedStatement(SQL_FROM_HERE, sql));
+  statement.BindString(0, row->GetPath().value().c_str());
+  statement.BindInt64(1, row->GetLastModifiedTime().ToInternalValue());
+  statement.BindInt(2, row->GetEntryCount());
+  statement.BindInt(3, row->IsAllParsed() ? 1 : 0);
+
+  if (!statement.Run()) {
+    VLOG(0) << "Failed to add collection " << row->GetPath().value()
+            << " to table media_gallery.collections";
+    return 0;
+  }
+  return row->id_ = GetDB().GetLastInsertRowId();
+}
+
+bool MediaGalleryDatabase::GetCollectionRow(COLLECTIONID id,
+                                            CollectionRow* row) {
+  sql::Statement statement(GetDB().GetCachedStatement(SQL_FROM_HERE,
+      "SELECT" MEDIA_GALLERY_COLLECTION_ROW_FIELDS
+      "FROM " COLLECTION_TABLE_NAME " WHERE id=?"));
+  statement.BindInt64(0, id);
+
+  if (statement.Step()) {
+    FillCollectionRow(statement, row);
+    return true;
+  }
+  return false;
+}
+
+// Convenience method to fill a row from a statement. Must be in sync with the
+// columns in MEDIA_GALLERY_COLLECTION_ROW_FIELDS
+void MediaGalleryDatabase::FillCollectionRow(const sql::Statement& s,
+                                             CollectionRow* i) {
+  DCHECK(i);
+  i->id_ = s.ColumnInt64(0);
+  i->path_ = FilePath(s.ColumnString(1));
+  i->last_modified_time_ = base::Time::FromInternalValue(s.ColumnInt64(2));
+  i->entry_count_ = s.ColumnInt(3);
+  i->all_parsed_ = s.ColumnInt(4) != 0;
+}
+
+bool MediaGalleryDatabase::CreateCollectionsTable(sql::Connection* db) {
+  const char* name = COLLECTION_TABLE_NAME;
+  if (db->DoesTableExist(name))
+    return true;
+
+  const char *sql = "CREATE TABLE " COLLECTION_TABLE_NAME
+                    " (id INTEGER PRIMARY KEY,"
+                    "path LONGVARCHAR NOT NULL,"
+                    "last_modified_time INTEGER NOT NULL,"
+                    "entry_count INTEGER DEFAULT 0 NOT NULL,"
+                    "all_parsed INTEGER DEFAULT 0 NOT NULL)";
+  return db->Execute(sql);
+}
+
+}  // namespace media_gallery