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_API_ATTACHMENTS_ATTACHMENT_STORE_H_ 6 #define SYNC_API_ATTACHMENTS_ATTACHMENT_STORE_H_ 7 8 #include "base/callback.h" 9 #include "base/memory/ref_counted.h" 10 #include "base/memory/scoped_ptr.h" 11 #include "sync/api/attachments/attachment.h" 12 #include "sync/api/attachments/attachment_id.h" 13 #include "sync/base/sync_export.h" 14 15 namespace base { 16 class RefCountedMemory; 17 } // namespace base 18 19 namespace syncer { 20 21 class Attachment; 22 class AttachmentId; 23 24 // A place to locally store and access Attachments. 25 // 26 // Destroying this object does not necessarily cancel outstanding async 27 // operations. If you need cancel like semantics, use WeakPtr in the callbacks. 28 class SYNC_EXPORT AttachmentStore { 29 public: 30 AttachmentStore(); 31 virtual ~AttachmentStore(); 32 33 // TODO(maniscalco): Consider udpating Read and Write methods to support 34 // resumable transfers (bug 353292). 35 36 enum Result { 37 SUCCESS, // No error, all completed successfully. 38 UNSPECIFIED_ERROR, // An unspecified error occurred for one or more items. 39 }; 40 41 typedef base::Callback<void(const Result&, 42 scoped_ptr<AttachmentMap>, 43 scoped_ptr<AttachmentIdList>)> ReadCallback; 44 typedef base::Callback<void(const Result&)> WriteCallback; 45 typedef base::Callback<void(const Result&)> DropCallback; 46 47 // Asynchronously reads the attachments identified by |ids|. 48 // 49 // |callback| will be invoked when finished. AttachmentStore will attempt to 50 // read all attachments specified in ids. If any of the attachments do not 51 // exist or could not be read, |callback|'s Result will be UNSPECIFIED_ERROR. 52 // Callback's AttachmentMap will contain all attachments that were 53 // successfully read, AttachmentIdList will contain attachment ids of 54 // attachments that are unavailable in attachment store, these need to be 55 // downloaded from server. 56 // 57 // Reads on individual attachments are treated atomically; |callback| will not 58 // read only part of an attachment. 59 virtual void Read(const AttachmentIdList& ids, 60 const ReadCallback& callback) = 0; 61 62 // Asynchronously writes |attachments| to the store. 63 // 64 // Will not overwrite stored attachments. Attempting to overwrite an 65 // attachment that already exists is not an error. 66 // 67 // |callback| will be invoked when finished. If any of the attachments could 68 // not be written |callback|'s Result will be UNSPECIFIED_ERROR. When this 69 // happens, some or none of the attachments may have been written 70 // successfully. 71 virtual void Write(const AttachmentList& attachments, 72 const WriteCallback& callback) = 0; 73 74 // Asynchronously drops |attchments| from this store. 75 // 76 // This does not remove attachments from the server. 77 // 78 // |callback| will be invoked when finished. Attempting to drop an attachment 79 // that does not exist is not an error. If any of the existing attachment 80 // could not be dropped, |callback|'s Result will be UNSPECIFIED_ERROR. When 81 // this happens, some or none of the attachments may have been dropped 82 // successfully. 83 virtual void Drop(const AttachmentIdList& ids, 84 const DropCallback& callback) = 0; 85 }; 86 87 } // namespace syncer 88 89 #endif // SYNC_API_ATTACHMENTS_ATTACHMENT_STORE_H_ 90
