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Unified Diff: chrome/browser/image_decoder.h

Issue 931993002: Make image_decoder a Leaky LazyInstance (Closed) Base URL: https://chromium.googlesource.com/chromium/src.git@master
Patch Set: git cl format Created 5 years, 9 months ago
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Index: chrome/browser/image_decoder.h
diff --git a/chrome/browser/image_decoder.h b/chrome/browser/image_decoder.h
index 2206dd9f454ebcbfc3a29674cf41e1d42eb594ee..0de36ead1f4a3dedb6ae9509c6366599df9a495e 100644
--- a/chrome/browser/image_decoder.h
+++ b/chrome/browser/image_decoder.h
@@ -5,33 +5,50 @@
#ifndef CHROME_BROWSER_IMAGE_DECODER_H_
#define CHROME_BROWSER_IMAGE_DECODER_H_
+#include <map>
#include <string>
#include <vector>
#include "base/compiler_specific.h"
+#include "base/lazy_instance.h"
#include "base/memory/ref_counted.h"
+#include "base/synchronization/lock.h"
#include "base/threading/sequenced_worker_pool.h"
+#include "base/timer/timer.h"
+#include "content/public/browser/utility_process_host.h"
#include "content/public/browser/utility_process_host_client.h"
class SkBitmap;
-// Decodes an image in a sandboxed process.
-class ImageDecoder : public content::UtilityProcessHostClient {
+// This is a helper class for decoding images safely in a utility process. To
+// use this, call ImageDecoder::Start(...) on any thread.
+//
+// Internally, all of the work happens on the IO thread, and then
+// the result (ImageRequest::OnImageDecoded or
+// ImageRequest::OnDecodeImageFailed) is posted back to the task runner
+// specified when Start(...) was called.
+class ImageDecoder {
public:
- class Delegate {
+ class ImageRequest {
public:
// Called when image is decoded.
- // |decoder| is used to identify the image in case of decoding several
- // images simultaneously.
- virtual void OnImageDecoded(const ImageDecoder* decoder,
- const SkBitmap& decoded_image) = 0;
+ virtual void OnImageDecoded(const SkBitmap& decoded_image) = 0;
- // Called when decoding image failed. Delegate can do some cleanup in
+ // Called when decoding image failed. ImageRequest can do some cleanup in
// this handler.
- virtual void OnDecodeImageFailed(const ImageDecoder* decoder) {}
+ virtual void OnDecodeImageFailed() {}
+
+ base::SequencedTaskRunner* task_runner() const {
+ return task_runner_.get();
+ }
protected:
- virtual ~Delegate() {}
+ explicit ImageRequest(
+ const scoped_refptr<base::SequencedTaskRunner>& task_runner);
+ virtual ~ImageRequest();
+
+ private:
+ const scoped_refptr<base::SequencedTaskRunner> task_runner_;
};
enum ImageCodec {
@@ -39,44 +56,75 @@ class ImageDecoder : public content::UtilityProcessHostClient {
ROBUST_JPEG_CODEC, // Restrict decoding to robust jpeg codec.
};
- ImageDecoder(Delegate* delegate,
- const std::string& image_data,
- ImageCodec image_codec);
-
- ImageDecoder(Delegate* delegate,
- const std::vector<char>& image_data,
- ImageCodec image_codec);
-
// Starts asynchronous image decoding. Once finished, the callback will be
// posted back to |task_runner|.
- void Start(scoped_refptr<base::SequencedTaskRunner> task_runner);
-
- const std::vector<unsigned char>& get_image_data() const {
- return image_data_;
- }
+ static void Start(ImageRequest* image_request,
+ const std::string& image_data,
+ ImageCodec image_codec,
+ bool shrink_to_fit);
- void set_delegate(Delegate* delegate) { delegate_ = delegate; }
- void set_shrink_to_fit(bool shrink_to_fit) { shrink_to_fit_ = shrink_to_fit; }
+ // Removes all instances of image_request from image_request_id_map_,
+ // ensuring callbacks are not made to the image_request after it is destroyed.
+ static void Cancel(ImageRequest* image_request);
private:
- // It's a reference counted object, so destructor is private.
- ~ImageDecoder() override;
+ friend struct base::DefaultLazyInstanceTraits<ImageDecoder>;
+ static ImageDecoder* GetInstance();
+ ImageDecoder();
+ ~ImageDecoder();
+
+ class ImageDecoderImpl : public content::UtilityProcessHostClient {
+ public:
+ ImageDecoderImpl();
+
+ // Sends a request to the sandboxed process to decode the image. Starts
+ // batch mode if necessary.
+ void DecodeImageInSandbox(ImageRequest* image_request,
+ const std::vector<unsigned char>& image_data,
+ ImageCodec image_codec,
+ bool shrink_to_fit);
+
+ void Cancel(ImageRequest* image_request);
+
+ private:
+ using RequestMap = std::map<int, ImageRequest*>;
- // Overidden from UtilityProcessHostClient:
- bool OnMessageReceived(const IPC::Message& message) override;
+ // It's a reference counted object, so destructor is private.
+ ~ImageDecoderImpl() override;
- // IPC message handlers.
- void OnDecodeImageSucceeded(const SkBitmap& decoded_image);
- void OnDecodeImageFailed();
+ // Starts UtilityProcessHost in batch mode and starts batch_mode_timer_.
+ void StartBatchMode();
- // Launches sandboxed process that will decode the image.
- void DecodeImageInSandbox(const std::vector<unsigned char>& image_data);
+ // Stops batch mode if no requests have come in since kBatchModeTimeout.
+ void StopBatchMode();
+
+ // Overidden from UtilityProcessHostClient.
+ bool OnMessageReceived(const IPC::Message& message) override;
+
+ // IPC message handlers.
+ void OnDecodeImageSucceeded(const SkBitmap& decoded_image, int id);
+ void OnDecodeImageFailed(int id);
+
+ // id to use for the next Start request that comes in.
+ int image_request_id_counter_;
+
+ // Map of request id's to ImageRequests.
+ RequestMap image_request_id_map_;
+
+ // Protects image_request_id_map_ and image_request_id_counter_.
+ base::Lock map_lock_;
+
+ // The UtilityProcessHost requests are sent to.
+ base::WeakPtr<content::UtilityProcessHost> utility_process_host_;
+
+ // Calls StopBatchMode after kBatchModeTimeout has elapsed.
+ base::RepeatingTimer<ImageDecoderImpl> batch_mode_timer_;
+
+ // The time Start was last called.
+ base::TimeTicks last_request_;
+ };
- Delegate* delegate_;
- std::vector<unsigned char> image_data_;
- const ImageCodec image_codec_;
- scoped_refptr<base::SequencedTaskRunner> task_runner_;
- bool shrink_to_fit_; // if needed for IPC msg size limit
+ const scoped_refptr<ImageDecoderImpl> image_decoder_impl_;
DISALLOW_COPY_AND_ASSIGN(ImageDecoder);
};

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