Release 4.3.0 (#327)

Initial release of Firestore at 0.8.0
Bump FirebaseCommunity to 0.1.3

1 files changed, 95 insertions, 0 deletions

diff --git a/Firestore/Source/Local/FSTGarbageCollector.h b/Firestore/Source/Local/FSTGarbageCollector.h
new file mode 100644
index 0000000..c999f66
--- /dev/null
+++ b/Firestore/Source/Local/FSTGarbageCollector.h
@@ -0,0 +1,95 @@
+/*
+ * Copyright 2017 Google
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+
+#import "FSTTypes.h"
+
+@class FSTDocumentKey;
+@class FSTDocumentReference;
+@protocol FSTGarbageCollector;
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+ * A pseudo-collection that maintains references to documents. FSTGarbageSource collections
+ * notify the FSTGarbageCollector when references to documents change through the
+ * -addPotentialGarbageKey: message.
+ */
+@protocol FSTGarbageSource
+
+/**
+ * The garbage collector to which this collection should send -addPotentialGarbageKey: messages.
+ */
+@property(nonatomic, weak, readwrite, nullable) id<FSTGarbageCollector> garbageCollector;
+
+/**
+ * Checks to see if there are any references to a document with the given key. This can be used by
+ * garbage collectors to double-check if a key exists in this collection when it was released
+ * elsewhere.
+ */
+- (BOOL)containsKey:(FSTDocumentKey *)key;
+
+@end
+
+/**
+ * Tracks different kinds of references to a document, for all the different ways the client
+ * needs to retain a document.
+ *
+ * Usually the local store this means tracking of three different types of references to a
+ * document:
+ * 1. RemoteTarget reference identified by a target ID.
+ * 2. LocalView reference identified also by a target ID.
+ * 3. Local mutation reference identified by a batch ID.
+ *
+ * The idea is that we want to keep a document around at least as long as any remote target or
+ * local (latency compensated) view is referencing it, or there's an outstanding local mutation to
+ * that document.
+ */
+@protocol FSTGarbageCollector
+
+/**
+ * A property that describes whether or not the collector wants to eagerly collect keys.
+ *
+ * TODO(b/33384523) Delegate deleting released queries to the GC.
+ * This flag is a temporary workaround for dealing with a persistent query cache. The collector
+ * really should have an API for releasing queries that does the right thing for its policy.
+ */
+@property(nonatomic, assign, readonly, getter=isEager) BOOL eager;
+
+/** Adds a garbage source to the collector. */
+- (void)addGarbageSource:(id<FSTGarbageSource>)garbageSource;
+
+/** Removes a garbage source from the collector. */
+- (void)removeGarbageSource:(id<FSTGarbageSource>)garbageSource;
+
+/**
+ * Notifies the garbage collector that a document with the given key may have become garbage.
+ *
+ * This is useful in both when a document has definitely been released (for example when removed
+ * from a garbage source) but also when a document has been updated. Documents should be marked in
+ * this way because the client accepts updates for documents even after the document no longer
+ * matches any active targets. This behavior allows the client to avoid re-showing an old document
+ * in the next latency-compensated view.
+ */
+- (void)addPotentialGarbageKey:(FSTDocumentKey *)key;
+
+/** Returns the contents of the garbage bin and clears it. */
+- (NSSet<FSTDocumentKey *> *)collectGarbage;
+
+@end
+
+NS_ASSUME_NONNULL_END