sync/internal_api/public/attachments/attachment_service.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 SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_SERVICE_H_
   6 #define SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_SERVICE_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/callback.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "sync/api/attachments/attachment.h"
  13 #include "sync/base/sync_export.h"
  14
  15 namespace syncer {
  16
  17 class AttachmentStore;
  18 class SyncData;
  19
  20 // AttachmentService is responsible for managing a model type's attachments.
  21 //
  22 // Outside of sync code, AttachmentService shouldn't be used directly. Instead
  23 // use the functionality provided by SyncData and SyncChangeProcessor.
  24 //
  25 // Destroying this object does not necessarily cancel outstanding async
  26 // operations. If you need cancel like semantics, use WeakPtr in the callbacks.
  27 class SYNC_EXPORT AttachmentService {
  28  public:
  29   // The result of a GetOrDownloadAttachments operation.
  30   enum GetOrDownloadResult {
  31     GET_SUCCESS,            // No error, all attachments returned.
  32     GET_UNSPECIFIED_ERROR,  // An unspecified error occurred.
  33   };
  34
  35   typedef base::Callback<
  36       void(const GetOrDownloadResult&, scoped_ptr<AttachmentMap> attachments)>
  37       GetOrDownloadCallback;
  38
  39   // An interface that embedder code implements to be notified about different
  40   // events that originate from AttachmentService.
  41   // This interface will be called from the same thread AttachmentService was
  42   // created and called.
  43   class Delegate {
  44    public:
  45     virtual ~Delegate() {}
  46
  47     // Attachment is uploaded to server and attachment_id is updated with server
  48     // url.
  49     virtual void OnAttachmentUploaded(const AttachmentId& attachment_id) = 0;
  50   };
  51
  52   AttachmentService();
  53   virtual ~AttachmentService();
  54
  55   // See SyncData::GetOrDownloadAttachments.
  56   virtual void GetOrDownloadAttachments(
  57       const AttachmentIdList& attachment_ids,
  58       const GetOrDownloadCallback& callback) = 0;
  59
  60   // Schedules the attachments identified by |attachment_ids| to be uploaded to
  61   // the server.
  62   //
  63   // Assumes the attachments are already in the attachment store.
  64   //
  65   // A request to upload attachments is persistent in that uploads will be
  66   // automatically retried if transient errors occur.
  67   //
  68   // A request to upload attachments does not persist across restarts of Chrome.
  69   //
  70   // Invokes OnAttachmentUploaded on the Delegate (if provided).
  71   virtual void UploadAttachments(const AttachmentIdList& attachment_ids) = 0;
  72 };
  73
  74 }  // namespace syncer
  75
  76 #endif  // SYNC_INTERNAL_API_PUBLIC_ATTACHMENTS_ATTACHMENT_SERVICE_H_