Bug 482670 - WBORecord should implement a .deleted property

Expose a .deleted property that engines can set to true to store an even thinner deleted payload (empty string "" instead of "[null]") on the server. Handle deserializing of deleted records by setting the property. Note: Engines must set their payloads to something JSON-able if it's not a delete record.

services/sync/modules/base_records/crypto.js

@@ -84,8 +84,8 @@ CryptoWrapper.prototype = {
   _encrypt: function CryptoWrap__encrypt(passphrase) {
     let self = yield;
 
-    // Don't encrypt empty payloads
-    if (!this.payload) {
+    // No need to encrypt deleted records
+    if (this.deleted) {
       self.done();
       return;
     }
@@ -109,8 +109,8 @@ CryptoWrapper.prototype = {
   _decrypt: function CryptoWrap__decrypt(passphrase) {
     let self = yield;
 
-    // Empty payloads aren't encrypted
-    if (!this.payload) {
+    // Deleted records aren't encrypted
+    if (this.deleted) {
       self.done();
       return;
     }
@@ -132,13 +132,13 @@ CryptoWrapper.prototype = {
     this._decrypt.async(this, onComplete, passphrase);
   },
 
-  toString: function WBORec_toString() {
-    return "{ id: " + this.id + "\n" +
-      "  parent: " + this.parentid + "\n" +
-      "  depth: " + this.depth + ", index: " + this.sortindex + "\n" +
-      "  modified: " + this.modified + "\n" +
-      "  payload: " + JSON.stringify(this.cleartext) + " }";
-  }
+  toString: function CryptoWrap_toString() "{ " + [
+      "id: " + this.id,
+      "parent: " + this.parentid,
+      "depth: " + this.depth + ", index: " + this.sortindex,
+      "modified: " + this.modified,
+      "payload: " + (this.deleted ? "DELETED" : JSON.stringify(this.cleartext))
+    ].join("\n  ") + " }",
 };
 
 function CryptoMeta(uri) {

services/sync/modules/base_records/wbo.js

@@ -52,8 +52,16 @@ function WBORecord(uri) {
   this._WBORec_init(uri);
 }
 WBORecord.prototype = {
+  //////////////////////////////////////////////////////////////////////////////
+  // WBORecord Attributes
+
+  deleted: false,
+
   _logName: "Record.WBO",
 
+  //////////////////////////////////////////////////////////////////////////////
+  // WBORecord Methods
+
   _WBORec_init: function WBORec_init(uri) {
     this.data = {
       payload: {}
@@ -115,27 +123,36 @@ WBORecord.prototype = {
     this.data.payload = value;
   },
 
-  // payload is encoded twice in serialized form, because the
-  // server expects a string
   serialize: function WBORec_serialize() {
-    this.payload = JSON.stringify([this.payload]);
+    // Convert the payload into a string because the server expects that
+    let payload = this.payload;
+    this.payload = this.deleted ? "" : JSON.stringify(payload);
+
     let ret = JSON.stringify(this.data);
-    this.payload = JSON.parse(this.payload)[0];
+
+    // Restore the original payload
+    this.payload = payload;
+
     return ret;
   },
 
   deserialize: function WBORec_deserialize(json) {
     this.data = JSON.parse(json);
-    this.payload = JSON.parse(this.payload)[0];
+
+    // Empty string payloads are deleted records
+    if (this.payload === "")
+      this.deleted = true;
+    else
+      this.payload = JSON.parse(this.payload);
   },
 
-  toString: function WBORec_toString() {
-    return "{ id: " + this.id + "\n" +
-      "  parent: " + this.parentid + "\n" +
-      "  depth: " + this.depth + ", index: " + this.sortindex + "\n" +
-      "  modified: " + this.modified + "\n" +
-      "  payload: " + JSON.stringify(this.payload) + " }";
-  }
+  toString: function WBORec_toString() "{ " + [
+      "id: " + this.id,
+      "parent: " + this.parentid,
+      "depth: " + this.depth + ", index: " + this.sortindex,
+      "modified: " + this.modified,
+      "payload: " + (this.deleted ? "DELETED" : JSON.stringify(this.payload))
+    ].join("\n  ") + " }",
 };
 
 Utils.lazy(this, 'Records', RecordManager);

services/sync/modules/engines.js

@@ -246,7 +246,7 @@ SyncEngine.prototype = {
     if (a.depth != b.depth)
       return false;
     // note: sortindex ignored
-    if (a.payload == null || b.payload == null) // deleted items
+    if (a.deleted || b.deleted)
       return false;
     return Utils.deepEquals(a.cleartext, b.cleartext);
   },
@@ -396,7 +396,7 @@ SyncEngine.prototype = {
 
     // If the incoming item has been deleted, skip step 3
     this._log.trace("Reconcile step 2.5");
-    if (item.payload === null) {
+    if (item.deleted) {
       self.done(true);
       return;
     }
@@ -451,7 +451,7 @@ SyncEngine.prototype = {
       for (let id in this._tracker.changedIDs) {
         let out = this._createRecord(id);
         this._log.trace("Outgoing:\n" + out);
-        if (out.payload) // skip deleted records
+        if (!out.deleted)
           this._store.createMetaRecords(out.id, meta);
         yield out.encrypt(self.cb, ID.get('WeaveCryptoID').password);
         up.pushData(JSON.parse(out.serialize())); // FIXME: inefficient

services/sync/modules/engines/bookmarks.js

@@ -487,7 +487,7 @@ BookmarksStore.prototype = {
     if (placeId <= 0) { // deleted item
       record = new PlacesItem();
       record.id = guid;
-      record.payload = null;
+      record.deleted = true;
       this.cache.put(guid, record);
       return record;
     }

services/sync/modules/engines/history.js

@@ -89,7 +89,7 @@ HistoryEngine.prototype = {
     }
 
     // Step 2: Check if the item is deleted - we don't support that (yet?)
-    if (item.cleartext == null) {
+    if (item.deleted) {
       self.done(false);
       return;
     }
@@ -455,9 +455,9 @@ HistoryStore.prototype = {
       record.title = foo.title;
       record.visits = this._getVisits(record.histUri);
       record.encryption = cryptoMetaURL;
-    } else {
-      record.payload = null; // deleted item
     }
+    else
+      record.deleted = true;
     this.cache.put(guid, record);
     return record;
   },

services/sync/modules/engines/passwords.js

@@ -180,10 +180,9 @@ PasswordStore.prototype = {
       record.password = login.password;
       record.usernameField = login.usernameField;
       record.passwordField = login.passwordField;
-    } else {
-      /* Deleted item */
-      record.payload = null;
     }
+    else
+      record.deleted = true;
     return record;
   },
 

services/sync/modules/stores.js

@@ -77,7 +77,7 @@ Store.prototype = {
   applyIncoming: function Store_applyIncoming(onComplete, record) {
     let fn = function(rec) {
       let self = yield;
-      if (rec.payload == null)
+      if (rec.deleted)
         this.remove(rec);
       else if (!this.itemExists(rec.id))
         this.create(rec);