Local salient image storage for enhanced bookmark experiment.

components/bookmarks_enhanced/persistent_image_store.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/bookmarks_enhanced/persistent_image_store.h"
+
+#include "components/bookmarks_enhanced/image_store_util.h"
+#include "sql/statement.h"
+#include "sql/transaction.h"
+#include "ui/gfx/geometry/size.h"
+#include "url/gurl.h"
+
+namespace {
+
+bool InitTables(sql::Connection& db) {
+  const char kTableSql[] =
+      "CREATE TABLE IF NOT EXISTS images_by_url ("
+      "  page_url LONGVARCHAR NOT NULL,"
+      "  image_url LONGVARCHAR NOT NULL,"
+      "  image_data BLOB,"
+      "  width INTEGER,"
+      "  height INTEGER"
+      ")";
+  if (!db.Execute(kTableSql))
+    return false;
+  return true;
+}
+
+bool InitIndices(sql::Connection& db) {
+  const char kIndexSql[] =
+      "CREATE INDEX IF NOT EXISTS images_by_url_idx ON images_by_url(page_url)";
+  if (!db.Execute(kIndexSql))
+    return false;
+  return true;
+}
+
+sql::InitStatus OpenDatabaseImpl(sql::Connection& db,
+                                 const base::FilePath& db_path) {
+  DCHECK(!db.is_open());
+
+  db.set_histogram_tag("BookmarkImages");
+  // TODO(noyau): Set page and cache sizes?
+  // TODO(noyau): Set error callback?
+
+  // Run the database in exclusive mode. Nobody else should be accessing the
+  // database while we're running, and this will give somewhat improved perf.
+  db.set_exclusive_locking();
+
+  if (!db.Open(db_path))
+    return sql::INIT_FAILURE;
+
+  // Scope initialization in a transaction so we can't be partially initialized.
+  sql::Transaction transaction(&db);
+  if (!transaction.Begin())
+    return sql::INIT_FAILURE;
+
+  // Create the tables.
+  if (!InitTables(db) ||
+      !InitIndices(db)) {
+    return sql::INIT_FAILURE;
+  }
+
+  // Initialization is complete.
+  if (!transaction.Commit())
+    return sql::INIT_FAILURE;
+
+  return sql::INIT_OK;
+}
+
+}  // namespace
+
+PersistentImageStore::PersistentImageStore(const base::FilePath& path)
+    : ImageStore(), path_(path.Append("BookmarkImageAndUrlStore.db")) {}
+
+bool PersistentImageStore::HasKey(const GURL& page_url) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  OpenDatabase();
+  sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
+      "SELECT COUNT(*) FROM images_by_url WHERE page_url = ?"));
+  statement.BindString(0, page_url.possibly_invalid_spec());
+
+  int count = statement.Step() ? statement.ColumnInt(0) : 0;
+
+  return !!count;
+}
+
+void PersistentImageStore::Insert(const GURL& page_url,
+                                  const GURL& image_url,
+                                  const gfx::Image& image) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  Erase(page_url);  // Remove previous image for this url, if any.
+  sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
+      "INSERT INTO images_by_url "
+      "    (page_url, image_url, image_data, width, height)"
+      "    VALUES (?, ?, ?, ?, ?)"));
+
+  statement.BindString(0, page_url.possibly_invalid_spec());
+  statement.BindString(1, image_url.possibly_invalid_spec());
+
+  scoped_refptr<base::RefCountedMemory> image_bytes =
+        bookmarks_enhanced::BytesForImage(image);
+
+  // Insert an empty image in case encoding fails.
+  if (!image_bytes.get())
+    image_bytes = bookmarks_enhanced::BytesForImage(gfx::Image());
+
+  CHECK(image_bytes.get());
+
+  statement.BindBlob(2, image_bytes->front(), image_bytes->size());
+
+  statement.BindInt(3, image.Size().width());
+  statement.BindInt(4, image.Size().height());
+  statement.Run();
+}
+
+void PersistentImageStore::Erase(const GURL& page_url) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  OpenDatabase();
+  sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
+      "DELETE FROM images_by_url WHERE page_url = ?"));
+  statement.BindString(0, page_url.possibly_invalid_spec());
+  statement.Run();
+}
+
+std::pair<gfx::Image, GURL> PersistentImageStore::Get(const GURL& page_url) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  OpenDatabase();
+  sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
+      "SELECT image_data, image_url FROM images_by_url WHERE page_url = ?"));
+
+  statement.BindString(0, page_url.possibly_invalid_spec());
+
+  while (statement.Step()) {
+    if (statement.ColumnByteLength(0) > 0) {
+      scoped_refptr<base::RefCountedBytes> data(new base::RefCountedBytes());
+      statement.ColumnBlobAsVector(0, &data->data());
+
+      return std::make_pair(bookmarks_enhanced::ImageForBytes(data),
+                            GURL(statement.ColumnString(1)));
+    }
+  }
+
+  return std::make_pair(gfx::Image(), GURL());
+}
+
+gfx::Size PersistentImageStore::GetSize(const GURL& page_url) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  OpenDatabase();
+  sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
+      "SELECT width, height FROM images_by_url WHERE page_url = ?"));
+
+  statement.BindString(0, page_url.possibly_invalid_spec());
+
+  while (statement.Step()) {
+    if (statement.ColumnByteLength(0) > 0) {
+      int width = statement.ColumnInt(0);
+      int height = statement.ColumnInt(1);
+      return gfx::Size(width, height);
+    }
+  }
+  return gfx::Size();
+}
+
+void PersistentImageStore::GetAllPageUrls(std::set<GURL>* urls) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  DCHECK(urls->empty());
+
+  OpenDatabase();
+  sql::Statement statement(db_.GetCachedStatement(SQL_FROM_HERE,
+      "SELECT page_url FROM images_by_url"));
+  while (statement.Step())
+    urls->insert(GURL(statement.ColumnString(0)));
+}
+
+PersistentImageStore::~PersistentImageStore() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+}
+
+void PersistentImageStore::OpenDatabase() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (db_.is_open())
+    return;
+
+  const size_t kAttempts = 2;
+
+  sql::InitStatus status = sql::INIT_FAILURE;
+  for (size_t i = 0; i < kAttempts; ++i) {
+    status = OpenDatabaseImpl(db_, path_);
+    if (status == sql::INIT_OK)
+      return;
+
+    // Can't open, raze().
+    if (db_.is_open())
+      db_.Raze();
+    db_.Close();
+  }
+  CHECK(false) << "Can't open image DB";
+}