Move all Firestore Objective-C to Objective-C++ (#734)

* Move all Firestore files to Objective-C++
* Update project file references
* Don't use module imports from Objective-C++
* Use extern "C" for C-accessible globals
* Work around more stringent type checking in Objective-C++
  * NSMutableDictionary ivars aren't implicitly casted to NSDictionary
  * FSTMaybeDocument callback can't be passed a function that accepts
    FSTDocument
  * NSComparisonResult can't be multiplied by -1 without casting
* Add a #include <inttypes.h> where needed
* Avoid using C++ keywords as variables
* Remove #if __cplusplus guards

1 files changed, 140 insertions, 0 deletions

diff --git a/Firestore/Source/Local/FSTMemoryQueryCache.mm b/Firestore/Source/Local/FSTMemoryQueryCache.mm
new file mode 100644
index 0000000..bcab174
--- /dev/null
+++ b/Firestore/Source/Local/FSTMemoryQueryCache.mm
@@ -0,0 +1,140 @@
+/*
+ * 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 "Firestore/Source/Local/FSTMemoryQueryCache.h"
+
+#import "Firestore/Source/Core/FSTQuery.h"
+#import "Firestore/Source/Core/FSTSnapshotVersion.h"
+#import "Firestore/Source/Local/FSTQueryData.h"
+#import "Firestore/Source/Local/FSTReferenceSet.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FSTMemoryQueryCache ()
+
+/** Maps a query to the data about that query. */
+@property(nonatomic, strong, readonly) NSMutableDictionary<FSTQuery *, FSTQueryData *> *queries;
+
+/** A ordered bidirectional mapping between documents and the remote target IDs. */
+@property(nonatomic, strong, readonly) FSTReferenceSet *references;
+
+/** The highest numbered target ID encountered. */
+@property(nonatomic, assign) FSTTargetID highestTargetID;
+
+@property(nonatomic, assign) FSTListenSequenceNumber highestListenSequenceNumber;
+
+@end
+
+@implementation FSTMemoryQueryCache {
+  /** The last received snapshot version. */
+  FSTSnapshotVersion *_lastRemoteSnapshotVersion;
+}
+
+- (instancetype)init {
+  if (self = [super init]) {
+    _queries = [NSMutableDictionary dictionary];
+    _references = [[FSTReferenceSet alloc] init];
+    _lastRemoteSnapshotVersion = [FSTSnapshotVersion noVersion];
+  }
+  return self;
+}
+
+#pragma mark - FSTQueryCache implementation
+#pragma mark Query tracking
+
+- (void)start {
+  // Nothing to do.
+}
+
+- (void)shutdown {
+  // No resources to release.
+}
+
+- (FSTTargetID)highestTargetID {
+  return _highestTargetID;
+}
+
+- (FSTListenSequenceNumber)highestListenSequenceNumber {
+  return _highestListenSequenceNumber;
+}
+
+- (FSTSnapshotVersion *)lastRemoteSnapshotVersion {
+  return _lastRemoteSnapshotVersion;
+}
+
+- (void)setLastRemoteSnapshotVersion:(FSTSnapshotVersion *)snapshotVersion
+                               group:(FSTWriteGroup *)group {
+  _lastRemoteSnapshotVersion = snapshotVersion;
+}
+
+- (void)addQueryData:(FSTQueryData *)queryData group:(__unused FSTWriteGroup *)group {
+  self.queries[queryData.query] = queryData;
+  if (queryData.targetID > self.highestTargetID) {
+    self.highestTargetID = queryData.targetID;
+  }
+  if (queryData.sequenceNumber > self.highestListenSequenceNumber) {
+    self.highestListenSequenceNumber = queryData.sequenceNumber;
+  }
+}
+
+- (void)removeQueryData:(FSTQueryData *)queryData group:(__unused FSTWriteGroup *)group {
+  [self.queries removeObjectForKey:queryData.query];
+  [self.references removeReferencesForID:queryData.targetID];
+}
+
+- (nullable FSTQueryData *)queryDataForQuery:(FSTQuery *)query {
+  return self.queries[query];
+}
+
+#pragma mark Reference tracking
+
+- (void)addMatchingKeys:(FSTDocumentKeySet *)keys
+            forTargetID:(FSTTargetID)targetID
+                  group:(__unused FSTWriteGroup *)group {
+  [self.references addReferencesToKeys:keys forID:targetID];
+}
+
+- (void)removeMatchingKeys:(FSTDocumentKeySet *)keys
+               forTargetID:(FSTTargetID)targetID
+                     group:(__unused FSTWriteGroup *)group {
+  [self.references removeReferencesToKeys:keys forID:targetID];
+}
+
+- (void)removeMatchingKeysForTargetID:(FSTTargetID)targetID group:(__unused FSTWriteGroup *)group {
+  [self.references removeReferencesForID:targetID];
+}
+
+- (FSTDocumentKeySet *)matchingKeysForTargetID:(FSTTargetID)targetID {
+  return [self.references referencedKeysForID:targetID];
+}
+
+#pragma mark - FSTGarbageSource implementation
+
+- (nullable id<FSTGarbageCollector>)garbageCollector {
+  return self.references.garbageCollector;
+}
+
+- (void)setGarbageCollector:(nullable id<FSTGarbageCollector>)garbageCollector {
+  self.references.garbageCollector = garbageCollector;
+}
+
+- (BOOL)containsKey:(FSTDocumentKey *)key {
+  return [self.references containsKey:key];
+}
+
+@end
+
+NS_ASSUME_NONNULL_END