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+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+this.EXPORTED_SYMBOLS = ['GlodaCollection', 'GlodaCollectionManager'];
+
+var Cc = Components.classes;
+var Ci = Components.interfaces;
+var Cr = Components.results;
+var Cu = Components.utils;
+
+Cu.import("resource:///modules/gloda/log4moz.js");
+
+var LOG = Log4Moz.repository.getLogger("gloda.collection");
+
+/**
+ * @namespace Central registry and logic for all collections.
+ *
+ * The collection manager is a singleton that has the following tasks:
+ * - Let views of objects (nouns) know when their objects have changed. For
+ * example, an attribute has changed due to user action.
+ * - Let views of objects based on queries know when new objects match their
+ * query, or when their existing objects no longer match due to changes.
+ * - Caching/object-identity maintenance. It is ideal if we only ever have
+ * one instance of an object at a time. (More specifically, only one instance
+ * per database row 'id'.) The collection mechanism lets us find existing
+ * instances to this end. Caching can be directly integrated by being treated
+ * as a special collection.
+ */
+var GlodaCollectionManager = {
+ _collectionsByNoun: {},
+ _cachesByNoun: {},
+
+ /**
+ * Registers the existence of a collection with the collection manager. This
+ * is done using a weak reference so that the collection can go away if it
+ * wants to.
+ */
+ registerCollection: function gloda_colm_registerCollection(aCollection) {
+ let collections;
+ let nounID = aCollection.query._nounDef.id;
+ if (!(nounID in this._collectionsByNoun))
+ collections = this._collectionsByNoun[nounID] = [];
+ else {
+ // purge dead weak references while we're at it
+ collections = this._collectionsByNoun[nounID].filter(function (aRef) {
+ return aRef.get(); });
+ this._collectionsByNoun[nounID] = collections;
+ }
+ collections.push(Cu.getWeakReference(aCollection));
+ },
+
+ getCollectionsForNounID: function gloda_colm_getCollectionsForNounID(aNounID){
+ if (!(aNounID in this._collectionsByNoun))
+ return [];
+
+ // generator would be nice, but I suspect get() is too expensive to use
+ // twice (guard/predicate and value)
+ let weakCollections = this._collectionsByNoun[aNounID];
+ let collections = [];
+ for (let iColl = 0; iColl < weakCollections.length; iColl++) {
+ let collection = weakCollections[iColl].get();
+ if (collection)
+ collections.push(collection);
+ }
+ return collections;
+ },
+
+ defineCache: function gloda_colm_defineCache(aNounDef, aCacheSize) {
+ this._cachesByNoun[aNounDef.id] = new GlodaLRUCacheCollection(aNounDef,
+ aCacheSize);
+ },
+
+ /**
+ * Attempt to locate an instance of the object of the given noun type with the
+ * given id. Counts as a cache hit if found. (And if it was't in a cache,
+ * but rather a collection, it is added to the cache.)
+ */
+ cacheLookupOne: function gloda_colm_cacheLookupOne(aNounID, aID, aDoCache) {
+ let cache = this._cachesByNoun[aNounID];
+
+ if (cache) {
+ if (aID in cache._idMap) {
+ let item = cache._idMap[aID];
+ return cache.hit(item);
+ }
+ }
+
+ if (aDoCache === false)
+ cache = null;
+
+ for (let collection of this.getCollectionsForNounID(aNounID)) {
+ if (aID in collection._idMap) {
+ let item = collection._idMap[aID];
+ if (cache)
+ cache.add([item]);
+ return item;
+ }
+ }
+
+ return null;
+ },
+
+ /**
+ * Lookup multiple nouns by ID from the cache/existing collections.
+ *
+ * @param aNounID The kind of noun identified by its ID.
+ * @param aIDMap A dictionary/map whose keys must be gloda noun ids for the
+ * given noun type and whose values are ignored.
+ * @param aTargetMap An object to hold the noun id's (key) and noun instances
+ * (value) for the noun instances that were found available in memory
+ * because they were cached or in existing query collections.
+ * @param [aDoCache=true] Should we add any items to the cache that we found
+ * in collections that were in memory but not in the cache? You would
+ * likely want to pass false if you are only updating in-memory
+ * representations rather than performing a new query.
+ *
+ * @return [The number that were found, the number that were not found,
+ * a dictionary whose keys are the ids of noun instances that
+ * were not found.]
+ */
+ cacheLookupMany: function gloda_colm_cacheLookupMany(aNounID, aIDMap,
+ aTargetMap, aDoCache) {
+ let foundCount = 0, notFoundCount = 0, notFound = {};
+
+ let cache = this._cachesByNoun[aNounID];
+
+ if (cache) {
+ for (let key in aIDMap) {
+ let cacheValue = cache._idMap[key];
+ if (cacheValue === undefined) {
+ notFoundCount++;
+ notFound[key] = null;
+ }
+ else {
+ foundCount++;
+ aTargetMap[key] = cacheValue;
+ cache.hit(cacheValue);
+ }
+ }
+ }
+
+ if (aDoCache === false)
+ cache = null;
+
+ for (let collection of this.getCollectionsForNounID(aNounID)) {
+ for (let key in notFound) {
+ let collValue = collection._idMap[key];
+ if (collValue !== undefined) {
+ aTargetMap[key] = collValue;
+ delete notFound[key];
+ foundCount++;
+ notFoundCount--;
+ if (cache)
+ cache.add([collValue]);
+ }
+ }
+ }
+
+ return [foundCount, notFoundCount, notFound];
+ },
+
+ /**
+ * Friendlier version of |cacheLookupMany|; takes a list of ids and returns
+ * an object whose keys and values are the gloda id's and instances of the
+ * instances that were found. We don't tell you who we didn't find. The
+ * assumption is this is being used for in-memory updates where we only need
+ * to tweak what is in memory.
+ */
+ cacheLookupManyList: function gloda_colm_cacheLookupManyList(aNounID, aIds) {
+ let checkMap = {}, targetMap = {};
+ for (let id of aIds) {
+ checkMap[id] = null;
+ }
+ // do not promote found items into the cache
+ this.cacheLookupMany(aNounID, checkMap, targetMap, false);
+ return targetMap;
+ },
+
+ /**
+ * Attempt to locate an instance of the object of the given noun type with the
+ * given id. Counts as a cache hit if found. (And if it was't in a cache,
+ * but rather a collection, it is added to the cache.)
+ */
+ cacheLookupOneByUniqueValue:
+ function gloda_colm_cacheLookupOneByUniqueValue(aNounID, aUniqueValue,
+ aDoCache) {
+ let cache = this._cachesByNoun[aNounID];
+
+ if (cache) {
+ if (aUniqueValue in cache._uniqueValueMap) {
+ let item = cache._uniqueValueMap[aUniqueValue];
+ return cache.hit(item);
+ }
+ }
+
+ if (aDoCache === false)
+ cache = null;
+
+ for (let collection of this.getCollectionsForNounID(aNounID)) {
+ if (aUniqueValue in collection._uniqueValueMap) {
+ let item = collection._uniqueValueMap[aUniqueValue];
+ if (cache)
+ cache.add([item]);
+ return item;
+ }
+ }
+
+ return null;
+ },
+
+ /**
+ * Checks whether the provided item with the given id is actually a duplicate
+ * of an instance that already exists in the cache/a collection. If it is,
+ * the pre-existing instance is returned and counts as a cache hit. If it
+ * is not, the passed-in instance is added to the cache and returned.
+ */
+ cacheLoadUnifyOne: function gloda_colm_cacheLoadUnifyOne(aItem) {
+ let items = [aItem];
+ this.cacheLoadUnify(aItem.NOUN_ID, items);
+ return items[0];
+ },
+
+ /**
+ * Given a list of items, check if any of them already have duplicate,
+ * canonical, instances in the cache or collections. Items with pre-existing
+ * instances are replaced by those instances in the provided list, and each
+ * counts as a cache hit. Items without pre-existing instances are added
+ * to the cache and left intact.
+ */
+ cacheLoadUnify: function gloda_colm_cacheLoadUnify(aNounID, aItems,
+ aCacheIfMissing) {
+ let cache = this._cachesByNoun[aNounID];
+ if (aCacheIfMissing === undefined)
+ aCacheIfMissing = true;
+
+ // track the items we haven't yet found in a cache/collection (value) and
+ // their index in aItems (key). We're somewhat abusing the dictionary
+ // metaphor with the intent of storing tuples here. We also do it because
+ // it allows random-access deletion theoretically without cost. (Since
+ // we delete during iteration, that may be wrong, but it sounds like the
+ // semantics still work?)
+ let unresolvedIndexToItem = {};
+ let numUnresolved = 0;
+
+ if (cache) {
+ for (let iItem = 0; iItem < aItems.length; iItem++) {
+ let item = aItems[iItem];
+
+ if (item.id in cache._idMap) {
+ let realItem = cache._idMap[item.id];
+ // update the caller's array with the reference to the 'real' item
+ aItems[iItem] = realItem;
+ cache.hit(realItem);
+ }
+ else {
+ unresolvedIndexToItem[iItem] = item;
+ numUnresolved++;
+ }
+ }
+
+ // we're done if everyone was a hit.
+ if (numUnresolved == 0)
+ return;
+ }
+ else {
+ for (let iItem = 0; iItem < aItems.length; iItem++) {
+ unresolvedIndexToItem[iItem] = aItems[iItem];
+ }
+ numUnresolved = aItems.length;
+ }
+
+ let needToCache = [];
+ // next, let's fall back to our collections
+ for (let collection of this.getCollectionsForNounID(aNounID)) {
+ for (let [iItem, item] in Iterator(unresolvedIndexToItem)) {
+ if (item.id in collection._idMap) {
+ let realItem = collection._idMap[item.id];
+ // update the caller's array to now have the 'real' object
+ aItems[iItem] = realItem;
+ // flag that we need to cache this guy (we use an inclusive cache)
+ needToCache.push(realItem);
+ // we no longer need to resolve this item...
+ delete unresolvedIndexToItem[iItem];
+ // stop checking collections if we got everybody
+ if (--numUnresolved == 0)
+ break;
+ }
+ }
+ }
+
+ // anything left in unresolvedIndexToItem should be added to the cache
+ // unless !aCacheIfMissing. plus, we already have 'needToCache'
+ if (cache && aCacheIfMissing) {
+ cache.add(needToCache.concat(Object.keys(unresolvedIndexToItem).
+ map(key => unresolvedIndexToItem[key])));
+ }
+
+ return aItems;
+ },
+
+ cacheCommitDirty: function glod_colm_cacheCommitDirty() {
+ for (let id in this._cachesByNoun) {
+ let cache = this._cachesByNoun[id];
+ cache.commitDirty();
+ }
+ },
+
+ /**
+ * Notifies the collection manager that an item has been loaded and should
+ * be cached, assuming caching is active.
+ */
+ itemLoaded: function gloda_colm_itemsLoaded(aItem) {
+ let cache = this._cachesByNoun[aItem.NOUN_ID];
+ if (cache) {
+ cache.add([aItem]);
+ }
+ },
+
+ /**
+ * Notifies the collection manager that multiple items has been loaded and
+ * should be cached, assuming caching is active.
+ */
+ itemsLoaded: function gloda_colm_itemsLoaded(aNounID, aItems) {
+ let cache = this._cachesByNoun[aNounID];
+ if (cache) {
+ cache.add(aItems);
+ }
+ },
+
+ /**
+ * This should be called when items are added to the global database. This
+ * should generally mean during indexing by indexers or an attribute
+ * provider.
+ * We walk all existing collections for the given noun type and add the items
+ * to the collection if the item meets the query that defines the collection.
+ */
+ itemsAdded: function gloda_colm_itemsAdded(aNounID, aItems) {
+ let cache = this._cachesByNoun[aNounID];
+ if (cache) {
+ cache.add(aItems);
+ }
+
+ for (let collection of this.getCollectionsForNounID(aNounID)) {
+ let addItems = aItems.filter(item => collection.query.test(item));
+ if (addItems.length)
+ collection._onItemsAdded(addItems);
+ }
+ },
+ /**
+ * This should be called when items in the global database are modified. For
+ * example, as a result of indexing. This should generally only be called
+ * by indexers or by attribute providers.
+ * We walk all existing collections for the given noun type. For items
+ * currently included in each collection but should no longer be (per the
+ * collection's defining query) we generate onItemsRemoved events. For items
+ * not currently included in the collection but should now be, we generate
+ * onItemsAdded events. For items included that still match the query, we
+ * generate onItemsModified events.
+ */
+ itemsModified: function gloda_colm_itemsModified(aNounID, aItems) {
+ for (let collection of this.getCollectionsForNounID(aNounID)) {
+ let added = [], modified = [], removed = [];
+ for (let item of aItems) {
+ if (item.id in collection._idMap) {
+ // currently in... but should it still be there?
+ if (collection.query.test(item))
+ modified.push(item); // yes, keep it
+ // oy, so null queries really don't want any notifications, and they
+ // sorta fit into our existing model, except for the removal bit.
+ // so we need a specialized check for them, and we're using the
+ // frozen attribute to this end.
+ else if (!collection.query.frozen)
+ removed.push(item); // no, bin it
+ }
+ else if (collection.query.test(item)) // not in, should it be?
+ added.push(item); // yep, add it
+ }
+ if (added.length)
+ collection._onItemsAdded(added);
+ if (modified.length)
+ collection._onItemsModified(modified);
+ if (removed.length)
+ collection._onItemsRemoved(removed);
+ }
+ },
+ /**
+ * This should be called when items in the global database are permanently-ish
+ * deleted. (This is distinct from concepts like message deletion which may
+ * involved trash folders or other modified forms of existence. Deleted
+ * means the data is gone and if it were to come back, it would come back
+ * via an itemsAdded event.)
+ * We walk all existing collections for the given noun type. For items
+ * currently in the collection, we generate onItemsRemoved events.
+ *
+ * @param aItemIds A list of item ids that are being deleted.
+ */
+ itemsDeleted: function gloda_colm_itemsDeleted(aNounID, aItemIds) {
+ // cache
+ let cache = this._cachesByNoun[aNounID];
+ if (cache) {
+ for (let itemId of aItemIds) {
+ if (itemId in cache._idMap)
+ cache.deleted(cache._idMap[itemId]);
+ }
+ }
+
+ // collections
+ for (let collection of this.getCollectionsForNounID(aNounID)) {
+ let removeItems = aItemIds.filter(itemId => itemId in collection._idMap).
+ map(itemId => collection._idMap[itemId]);
+ if (removeItems.length)
+ collection._onItemsRemoved(removeItems);
+ }
+ },
+ /**
+ * Like |itemsDeleted| but for the case where the deletion is based on an
+ * attribute that SQLite can more efficiently check than we can and where the
+ * cost of scanning the in-memory items is presumably much cheaper than
+ * trying to figure out what actually got deleted.
+ *
+ * Since we are doing an in-memory walk, this is obviously O(n) where n is the
+ * number of noun instances of a given type in-memory. We are assuming this
+ * is a reasonable number of things and that this type of deletion call is
+ * not going to happen all that frequently. If these assumptions are wrong,
+ * callers are advised to re-think the whole situation.
+ *
+ * @param aNounID Type of noun we are talking about here.
+ * @param aFilter A filter function that returns true when the item should be
+ * thought of as deleted, or false if the item is still good. Screw this
+ * up and you will get some seriously wacky bugs, yo.
+ */
+ itemsDeletedByAttribute: function gloda_colm_itemsDeletedByAttribute(
+ aNounID, aFilter) {
+ // cache
+ let cache = this._cachesByNoun[aNounID];
+ if (cache) {
+ for (let id in cache._idMap) {
+ let item = cache._idMap[id];
+ if (aFilter(item))
+ cache.deleted(item);
+ }
+ }
+
+ // collections
+ for (let collection of this.getCollectionsForNounID(aNounID)) {
+ let removeItems = collection.items.filter(aFilter);
+ if (removeItems.length)
+ collection._onItemsRemoved(removeItems);
+ }
+ },
+};
+
+/**
+ * @class A current view of the set of first-class nouns meeting a given query.
+ * Assuming a listener is present, events are
+ * generated when new objects meet the query, existing objects no longer meet
+ * the query, or existing objects have experienced a change in attributes that
+ * does not affect their ability to be present (but the listener may care about
+ * because it is exposing those attributes).
+ * @constructor
+ */
+function GlodaCollection(aNounDef, aItems, aQuery, aListener,
+ aMasterCollection) {
+ // if aNounDef is null, we are just being invoked for subclassing
+ if (aNounDef === undefined)
+ return;
+
+ this._nounDef = aNounDef;
+ // should we also maintain a unique value mapping...
+ if (this._nounDef.usesUniqueValue)
+ this._uniqueValueMap = {};
+
+ this.pendingItems = [];
+ this._pendingIdMap = {};
+ this.items = [];
+ this._idMap = {};
+
+ // force the listener to null for our call to _onItemsAdded; no events for
+ // the initial load-out.
+ this._listener = null;
+ if (aItems && aItems.length)
+ this._onItemsAdded(aItems);
+
+ this.query = aQuery || null;
+ if (this.query) {
+ this.query.collection = this;
+ if (this.query.options.stashColumns)
+ this.stashedColumns = {};
+ }
+ this._listener = aListener || null;
+
+ this.deferredCount = 0;
+ this.resolvedCount = 0;
+
+ if (aMasterCollection) {
+ this.masterCollection = aMasterCollection.masterCollection;
+ }
+ else {
+ this.masterCollection = this;
+ /** a dictionary of dictionaries. at the top level, the keys are noun IDs.
+ * each of these sub-dictionaries maps the IDs of desired noun instances to
+ * the actual instance, or null if it has not yet been loaded.
+ */
+ this.referencesByNounID = {};
+ /**
+ * a dictionary of dictionaries. at the top level, the keys are noun IDs.
+ * each of the sub-dictionaries maps the IDs of the _recognized parent
+ * noun_ to the list of children, or null if the list has not yet been
+ * populated.
+ *
+ * So if we have a noun definition A with ID 1 who is the recognized parent
+ * noun of noun definition B with ID 2, AND we have an instance A(1) with
+ * two children B(10), B(11), then an example might be: {2: {1: [10, 11]}}.
+ */
+ this.inverseReferencesByNounID = {};
+ this.subCollections = {};
+ }
+}
+
+GlodaCollection.prototype = {
+ get listener() { return this._listener; },
+ set listener(aListener) { this._listener = aListener; },
+
+ /**
+ * If this collection still has a query associated with it, drop the query
+ * and replace it with an 'explicit query'. This means that the Collection
+ * Manager will not attempt to match new items indexed to the system against
+ * our query criteria.
+ * Once you call this method, your collection's listener will no longer
+ * receive onItemsAdded notifications that are not the result of your
+ * initial database query. It will, however, receive onItemsModified
+ * notifications if items in the collection are re-indexed.
+ */
+ becomeExplicit: function gloda_coll_becomeExplicit() {
+ if (!(this.query instanceof this._nounDef.explicitQueryClass)) {
+ this.query = new this._nounDef.explicitQueryClass(this);
+ }
+ },
+
+ /**
+ * Clear the contents of this collection. This only makes sense for explicit
+ * collections or wildcard collections. (Actual query-based collections
+ * should represent the state of the query, so unless we're going to delete
+ * all the items, clearing the collection would violate that constraint.)
+ */
+ clear: function gloda_coll_clear() {
+ this._idMap = {};
+ if (this._uniqueValueMap)
+ this._uniqueValueMap = {};
+ this.items = [];
+ },
+
+ _onItemsAdded: function gloda_coll_onItemsAdded(aItems) {
+ this.items.push.apply(this.items, aItems);
+ if (this._uniqueValueMap) {
+ for (let item of this.items) {
+ this._idMap[item.id] = item;
+ this._uniqueValueMap[item.uniqueValue] = item;
+ }
+ }
+ else {
+ for (let item of this.items) {
+ this._idMap[item.id] = item;
+ }
+ }
+ if (this._listener) {
+ try {
+ this._listener.onItemsAdded(aItems, this);
+ }
+ catch (ex) {
+ LOG.error("caught exception from listener in onItemsAdded: " +
+ ex.fileName + ":" + ex.lineNumber + ": " + ex);
+ }
+ }
+ },
+
+ _onItemsModified: function gloda_coll_onItemsModified(aItems) {
+ if (this._listener) {
+ try {
+ this._listener.onItemsModified(aItems, this);
+ }
+ catch (ex) {
+ LOG.error("caught exception from listener in onItemsModified: " +
+ ex.fileName + ":" + ex.lineNumber + ": " + ex);
+ }
+ }
+ },
+
+ /**
+ * Given a list of items that definitely no longer belong in this collection,
+ * remove them from the collection and notify the listener. The 'tricky'
+ * part is that we need to remove the deleted items from our list of items.
+ */
+ _onItemsRemoved: function gloda_coll_onItemsRemoved(aItems) {
+ // we want to avoid the O(n^2) deletion performance case, and deletion
+ // should be rare enough that the extra cost of building the deletion map
+ // should never be a real problem.
+ let deleteMap = {};
+ // build the delete map while also nuking from our id map/unique value map
+ for (let item of aItems) {
+ deleteMap[item.id] = true;
+ delete this._idMap[item.id];
+ if (this._uniqueValueMap)
+ delete this._uniqueValueMap[item.uniqueValue];
+ }
+ let items = this.items;
+ // in-place filter. probably needless optimization.
+ let iWrite=0;
+ for (let iRead = 0; iRead < items.length; iRead++) {
+ let item = items[iRead];
+ if (!(item.id in deleteMap))
+ items[iWrite++] = item;
+ }
+ items.splice(iWrite);
+
+ if (this._listener) {
+ try {
+ this._listener.onItemsRemoved(aItems, this);
+ }
+ catch (ex) {
+ LOG.error("caught exception from listener in onItemsRemoved: " +
+ ex.fileName + ":" + ex.lineNumber + ": " + ex);
+ }
+ }
+ },
+
+ _onQueryCompleted: function gloda_coll_onQueryCompleted() {
+ this.query.completed = true;
+ if (this._listener && this._listener.onQueryCompleted)
+ this._listener.onQueryCompleted(this);
+ }
+};
+
+/**
+ * Create an LRU cache collection for the given noun with the given size.
+ * @constructor
+ */
+function GlodaLRUCacheCollection(aNounDef, aCacheSize) {
+ GlodaCollection.call(this, aNounDef, null, null, null);
+
+ this._head = null; // aka oldest!
+ this._tail = null; // aka newest!
+ this._size = 0;
+ // let's keep things sane, and simplify our logic a little...
+ if (aCacheSize < 32)
+ aCacheSize = 32;
+ this._maxCacheSize = aCacheSize;
+}
+/**
+ * @class A LRU-discard cache. We use a doubly linked-list for the eviction
+ * tracking. Since we require that there is at most one LRU-discard cache per
+ * noun class, we simplify our lives by adding our own attributes to the
+ * cached objects.
+ * @augments GlodaCollection
+ */
+GlodaLRUCacheCollection.prototype = new GlodaCollection;
+GlodaLRUCacheCollection.prototype.add = function cache_add(aItems) {
+ for (let item of aItems) {
+ if (item.id in this._idMap) {
+ // DEBUGME so, we're dealing with this, but it shouldn't happen. need
+ // trace-debuggage.
+ continue;
+ }
+ this._idMap[item.id] = item;
+ if (this._uniqueValueMap)
+ this._uniqueValueMap[item.uniqueValue] = item;
+
+ item._lruPrev = this._tail;
+ // we do have to make sure that we will set _head the first time we insert
+ // something
+ if (this._tail !== null)
+ this._tail._lruNext = item;
+ else
+ this._head = item;
+ item._lruNext = null;
+ this._tail = item;
+
+ this._size++;
+ }
+
+ while (this._size > this._maxCacheSize) {
+ let item = this._head;
+
+ // we never have to deal with the possibility of needing to make _head/_tail
+ // null.
+ this._head = item._lruNext;
+ this._head._lruPrev = null;
+ // (because we are nice, we will delete the properties...)
+ delete item._lruNext;
+ delete item._lruPrev;
+
+ // nuke from our id map
+ delete this._idMap[item.id];
+ if (this._uniqueValueMap)
+ delete this._uniqueValueMap[item.uniqueValue];
+
+ // flush dirty items to disk (they may not have this attribute, in which
+ // case, this returns false, which is fine.)
+ if (item.dirty) {
+ this._nounDef.objUpdate.call(this._nounDef.datastore, item);
+ delete item.dirty;
+ }
+
+ this._size--;
+ }
+};
+
+GlodaLRUCacheCollection.prototype.hit = function cache_hit(aItem) {
+ // don't do anything in the 0 or 1 items case, or if we're already
+ // the last item
+ if ((this._head === this._tail) || (this._tail === aItem))
+ return aItem;
+
+ // - unlink the item
+ if (aItem._lruPrev !== null)
+ aItem._lruPrev._lruNext = aItem._lruNext;
+ else
+ this._head = aItem._lruNext;
+ // (_lruNext cannot be null)
+ aItem._lruNext._lruPrev = aItem._lruPrev;
+ // - link it in to the end
+ this._tail._lruNext = aItem;
+ aItem._lruPrev = this._tail;
+ aItem._lruNext = null;
+ // update tail tracking
+ this._tail = aItem;
+
+ return aItem;
+};
+
+GlodaLRUCacheCollection.prototype.deleted = function cache_deleted(aItem) {
+ // unlink the item
+ if (aItem._lruPrev !== null)
+ aItem._lruPrev._lruNext = aItem._lruNext;
+ else
+ this._head = aItem._lruNext;
+ if (aItem._lruNext !== null)
+ aItem._lruNext._lruPrev = aItem._lruPrev;
+ else
+ this._tail = aItem._lruPrev;
+
+ // (because we are nice, we will delete the properties...)
+ delete aItem._lruNext;
+ delete aItem._lruPrev;
+
+ // nuke from our id map
+ delete this._idMap[aItem.id];
+ if (this._uniqueValueMap)
+ delete this._uniqueValueMap[aItem.uniqueValue];
+
+ this._size--;
+};
+
+/**
+ * If any of the cached items are dirty, commit them, and make them no longer
+ * dirty.
+ */
+GlodaLRUCacheCollection.prototype.commitDirty = function cache_commitDirty() {
+ // we can only do this if there is an update method available...
+ if (!this._nounDef.objUpdate)
+ return;
+
+ for (let iItem in this._idMap) {
+ let item = this._idMap[iItem];
+ if (item.dirty) {
+ LOG.debug("flushing dirty: " + item);
+ this._nounDef.objUpdate.call(this._nounDef.datastore, item);
+ delete item.dirty;
+ }
+ }
+};