blob: cf021449706461efa0fdbd97bf6fa325875ac32f [file] [log] [blame]
// 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 <memory>
#include <vector>
#include "base/compiler_specific.h"
#include "base/containers/mru_cache.h"
#include "base/macros.h"
#include "chrome/browser/bitmap_fetcher/bitmap_fetcher_delegate.h"
#include "components/keyed_service/core/keyed_service.h"
#include "net/traffic_annotation/network_traffic_annotation.h"
namespace content {
class BrowserContext;
} // namespace content
class BitmapFetcher;
class BitmapFetcherRequest;
class GURL;
class SkBitmap;
// Service to retrieve images for Answers in Suggest.
class BitmapFetcherService : public KeyedService, public BitmapFetcherDelegate {
typedef int RequestId;
static const RequestId REQUEST_ID_INVALID = 0;
class Observer {
virtual ~Observer() {}
// Called whenever the image changes. Called with an empty image if the
// fetch failed or the request ended for any reason.
// TODO(dschuyler) The comment differs from what the code does, follow-up.
virtual void OnImageChanged(RequestId request_id,
const SkBitmap& answers_image) = 0;
explicit BitmapFetcherService(content::BrowserContext* context);
~BitmapFetcherService() override;
// Cancels a request, if it is still in-flight.
void CancelRequest(RequestId requestId);
// Requests a new image. Will either trigger download or satisfy from cache.
// Takes ownership of |observer|. If there are too many outstanding requests,
// the request will fail and |observer| will be called to signal failure.
// Otherwise, |observer| will be called with either the cached image or the
// downloaded one.
// NOTE: The observer might be called back synchronously from RequestImage if
// the image is already in the cache.
RequestId RequestImage(
const GURL& url,
Observer* observer,
const net::NetworkTrafficAnnotationTag& traffic_annotation);
// Start fetching the image at the given |url|.
void Prefetch(const GURL& url,
const net::NetworkTrafficAnnotationTag& traffic_annotation);
// Create a bitmap fetcher for the given |url| and start it. Virtual method
// so tests can override this for different behavior.
virtual std::unique_ptr<BitmapFetcher> CreateFetcher(
const GURL& url,
const net::NetworkTrafficAnnotationTag& traffic_annotation);
friend class BitmapFetcherServiceTest;
// Gets the existing fetcher for |url| or constructs a new one if it doesn't
// exist.
const BitmapFetcher* EnsureFetcherForUrl(
const GURL& url,
const net::NetworkTrafficAnnotationTag& traffic_annotation);
// Find a fetcher with a given |url|. Return NULL if none is found.
const BitmapFetcher* FindFetcherForUrl(const GURL& url);
// Remove |fetcher| from list of active fetchers. |fetcher| MUST be part of
// the list.
void RemoveFetcher(const BitmapFetcher* fetcher);
// BitmapFetcherDelegate implementation.
void OnFetchComplete(const GURL& url, const SkBitmap* bitmap) override;
// Currently active image fetchers.
std::vector<std::unique_ptr<BitmapFetcher>> active_fetchers_;
// Currently active requests.
std::vector<std::unique_ptr<BitmapFetcherRequest>> requests_;
// Cache of retrieved images.
struct CacheEntry {
std::unique_ptr<const SkBitmap> bitmap;
base::MRUCache<GURL, std::unique_ptr<CacheEntry>> cache_;
// Current request ID to be used.
int current_request_id_;
// Browser context this service is active for.
content::BrowserContext* context_;