content/browser/fileapi/blob_storage_host.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_BROWSER_FILEAPI_BLOB_STORAGE_HOST_H_
   6 #define CONTENT_BROWSER_FILEAPI_BLOB_STORAGE_HOST_H_
   7
   8 #include <map>
   9 #include <set>
  10 #include <string>
  11
  12 #include "base/compiler_specific.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "content/common/content_export.h"
  15 #include "storage/common/data_element.h"
  16
  17 class GURL;
  18
  19 namespace storage {
  20 class BlobDataHandle;
  21 class BlobStorageHost;
  22 class BlobStorageContext;
  23 }
  24
  25 namespace content {
  26
  27 // This class handles the logistics of blob storage for a single child process.
  28 // There is one instance per child process. When the child process
  29 // terminates all blob references attibutable to that process go away upon
  30 // destruction of the instance. The class is single threaded and should
  31 // only be used on the IO thread.
  32 class CONTENT_EXPORT BlobStorageHost {
  33  public:
  34   explicit BlobStorageHost(storage::BlobStorageContext* context);
  35   ~BlobStorageHost();
  36
  37   // Methods to support the IPC message protocol.
  38   // A false return indicates a problem with the inputs
  39   // like a non-existent or pre-existent uuid or url.
  40   bool StartBuildingBlob(const std::string& uuid) WARN_UNUSED_RESULT;
  41   bool AppendBlobDataItem(const std::string& uuid,
  42                           const storage::DataElement& data_item)
  43       WARN_UNUSED_RESULT;
  44   bool CancelBuildingBlob(const std::string& uuid) WARN_UNUSED_RESULT;
  45   bool FinishBuildingBlob(const std::string& uuid,
  46                           const std::string& type) WARN_UNUSED_RESULT;
  47   bool IncrementBlobRefCount(const std::string& uuid) WARN_UNUSED_RESULT;
  48   bool DecrementBlobRefCount(const std::string& uuid) WARN_UNUSED_RESULT;
  49   bool RegisterPublicBlobURL(const GURL& blob_url,
  50                              const std::string& uuid) WARN_UNUSED_RESULT;
  51   bool RevokePublicBlobURL(const GURL& blob_url) WARN_UNUSED_RESULT;
  52
  53  private:
  54   typedef std::map<std::string, int> BlobReferenceMap;
  55
  56   bool IsInUseInHost(const std::string& uuid);
  57   bool IsBeingBuiltInHost(const std::string& uuid);
  58   bool IsUrlRegisteredInHost(const GURL& blob_url);
  59
  60   // Collection of blob ids and a count of how many usages
  61   // of that id are attributable to this consumer.
  62   BlobReferenceMap blobs_inuse_map_;
  63
  64   // The set of public blob urls coined by this consumer.
  65   std::set<GURL> public_blob_urls_;
  66
  67   base::WeakPtr<storage::BlobStorageContext> context_;
  68
  69   DISALLOW_COPY_AND_ASSIGN(BlobStorageHost);
  70 };
  71
  72 }  // namespace content
  73
  74 #endif  // CONTENT_BROWSER_FILEAPI_BLOB_STORAGE_HOST_H_