Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 834 insertions, 0 deletions

diff --git a/comm/mailnews/db/gloda/modules/Collection.jsm b/comm/mailnews/db/gloda/modules/Collection.jsm
new file mode 100644
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--- /dev/null
+++ b/comm/mailnews/db/gloda/modules/Collection.jsm
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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/. */
+
+const EXPORTED_SYMBOLS = ["GlodaCollection", "GlodaCollectionManager"];
+
+var LOG = console.createInstance({
+  prefix: "gloda.collection",
+  maxLogLevel: "Warn",
+  maxLogLevelPref: "gloda.loglevel",
+});
+
+/**
+ * @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(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(aRef => aRef.get());
+      this._collectionsByNoun[nounID] = collections;
+    }
+    collections.push(Cu.getWeakReference(aCollection));
+  },
+
+  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(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 wasn't in a cache,
+   *  but rather a collection, it is added to the cache.)
+   */
+  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;
+      }
+    }
+
+    LOG.debug("cacheLookupOne:\nhit null");
+    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.
+   *
+   * @returns [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(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(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 wasn't in a cache,
+   *  but rather a collection, it is added to the cache.)
+   */
+  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(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(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] of Object.entries(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]
+          )
+        )
+      );
+    }
+  },
+
+  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(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(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(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(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
+          } else if (!collection.query.frozen) {
+            // 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.
+            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(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(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).
+ * @class
+ */
+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() {
+    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() {
+    this._idMap = {};
+    if (this._uniqueValueMap) {
+      this._uniqueValueMap = {};
+    }
+    this.items = [];
+  },
+
+  _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(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(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() {
+    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.
+ *
+ * @class
+ */
+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 (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 (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 (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 () {
+  // 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;
+    }
+  }
+};