mobile/android/base/sync/repositories/StoreTracker.java@fc2d59ddac77 (annotated)
mobile/android/base/sync/repositories/StoreTracker.java
Wed, 31 Dec 2014 07:22:50 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 07:22:50 +0100
- branch
- TOR_BUG_3246
- changeset 4
- fc2d59ddac77
- permissions
- -rw-r--r--
Correct previous dual key logic pending first delivery installment.
| michael@0 | 1 | /* This Source Code Form is subject to the terms of the Mozilla Public |
| michael@0 | 2 | * License, v. 2.0. If a copy of the MPL was not distributed with this |
| michael@0 | 3 | * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ |
| michael@0 | 4 | |
| michael@0 | 5 | package org.mozilla.gecko.sync.repositories; |
| michael@0 | 6 | |
| michael@0 | 7 | import java.util.Iterator; |
| michael@0 | 8 | |
| michael@0 | 9 | /** |
| michael@0 | 10 | * Our hacky version of transactional semantics. The goal is to prevent |
| michael@0 | 11 | * the following situation: |
| michael@0 | 12 | * |
| michael@0 | 13 | * * AAA is not modified locally. |
| michael@0 | 14 | * * A modified AAA is downloaded during the storing phase. Its local |
| michael@0 | 15 | * timestamp is advanced. |
| michael@0 | 16 | * * The direction of syncing changes, and AAA is now uploaded to the server. |
| michael@0 | 17 | * |
| michael@0 | 18 | * The following situation should still be supported: |
| michael@0 | 19 | * |
| michael@0 | 20 | * * AAA is not modified locally. |
| michael@0 | 21 | * * A modified AAA is downloaded and merged with the local AAA. |
| michael@0 | 22 | * * The merged AAA is uploaded to the server. |
| michael@0 | 23 | * |
| michael@0 | 24 | * As should: |
| michael@0 | 25 | * |
| michael@0 | 26 | * * AAA is modified locally. |
| michael@0 | 27 | * * A modified AAA is downloaded, and discarded or merged. |
| michael@0 | 28 | * * The current version of AAA is uploaded to the server. |
| michael@0 | 29 | * |
| michael@0 | 30 | * We achieve this by tracking GUIDs during the storing phase. If we |
| michael@0 | 31 | * apply a record such that the local copy is substantially the same |
| michael@0 | 32 | * as the record we just downloaded, we add it to a list of records |
| michael@0 | 33 | * to avoid uploading. The definition of "substantially the same" |
| michael@0 | 34 | * depends on the particular repository. The only consideration is "do we |
| michael@0 | 35 | * want to upload this record in this sync?". |
| michael@0 | 36 | * |
| michael@0 | 37 | * Note that items are removed from this list when a fetch that |
| michael@0 | 38 | * considers them for upload completes successfully. The entire list |
| michael@0 | 39 | * is discarded when the session is completed. |
| michael@0 | 40 | * |
| michael@0 | 41 | * This interface exposes methods to: |
| michael@0 | 42 | * |
| michael@0 | 43 | * * During a store, recording that a record has been stored, and should |
| michael@0 | 44 | * thus not be returned in subsequent fetches; |
| michael@0 | 45 | * * During a fetch, checking whether a record should be returned. |
| michael@0 | 46 | * |
| michael@0 | 47 | * In the future this might also grow self-persistence. |
| michael@0 | 48 | * |
| michael@0 | 49 | * See also RepositorySession.trackRecord. |
| michael@0 | 50 | * |
| michael@0 | 51 | * @author rnewman |
| michael@0 | 52 | * |
| michael@0 | 53 | */ |
| michael@0 | 54 | public interface StoreTracker { |
| michael@0 | 55 | |
| michael@0 | 56 | /** |
| michael@0 | 57 | * @param guid |
| michael@0 | 58 | * The GUID of the item to track. |
| michael@0 | 59 | * @return |
| michael@0 | 60 | * Whether the GUID was a newly tracked value. |
| michael@0 | 61 | */ |
| michael@0 | 62 | public boolean trackRecordForExclusion(String guid); |
| michael@0 | 63 | |
| michael@0 | 64 | /** |
| michael@0 | 65 | * @param guid |
| michael@0 | 66 | * The GUID of the item to check. |
| michael@0 | 67 | * @return |
| michael@0 | 68 | * true if the item is already tracked. |
| michael@0 | 69 | */ |
| michael@0 | 70 | public boolean isTrackedForExclusion(String guid); |
| michael@0 | 71 | |
| michael@0 | 72 | /** |
| michael@0 | 73 | * |
| michael@0 | 74 | * @param guid |
| michael@0 | 75 | * @return true if the specified GUID was removed from the tracked set. |
| michael@0 | 76 | */ |
| michael@0 | 77 | public boolean untrackStoredForExclusion(String guid); |
| michael@0 | 78 | |
| michael@0 | 79 | public RecordFilter getFilter(); |
| michael@0 | 80 | |
| michael@0 | 81 | public Iterator<String> recordsTrackedForExclusion(); |
| michael@0 | 82 | } |
