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, 84 insertions, 0 deletions

diff --git a/Firestore/Source/Local/FSTMemoryRemoteDocumentCache.mm b/Firestore/Source/Local/FSTMemoryRemoteDocumentCache.mm
new file mode 100644
index 0000000..9bbc047
--- /dev/null
+++ b/Firestore/Source/Local/FSTMemoryRemoteDocumentCache.mm
@@ -0,0 +1,84 @@
+/*
+ * 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/FSTMemoryRemoteDocumentCache.h"
+
+#import "Firestore/Source/Core/FSTQuery.h"
+#import "Firestore/Source/Model/FSTDocument.h"
+#import "Firestore/Source/Model/FSTDocumentDictionary.h"
+#import "Firestore/Source/Model/FSTDocumentKey.h"
+#import "Firestore/Source/Model/FSTPath.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface FSTMemoryRemoteDocumentCache ()
+
+/** Underlying cache of documents. */
+@property(nonatomic, strong) FSTMaybeDocumentDictionary *docs;
+
+@end
+
+@implementation FSTMemoryRemoteDocumentCache
+
+- (instancetype)init {
+  if (self = [super init]) {
+    _docs = [FSTMaybeDocumentDictionary maybeDocumentDictionary];
+  }
+  return self;
+}
+
+- (void)shutdown {
+}
+
+- (void)addEntry:(FSTMaybeDocument *)document group:(FSTWriteGroup *)group {
+  self.docs = [self.docs dictionaryBySettingObject:document forKey:document.key];
+}
+
+- (void)removeEntryForKey:(FSTDocumentKey *)key group:(FSTWriteGroup *)group {
+  self.docs = [self.docs dictionaryByRemovingObjectForKey:key];
+}
+
+- (nullable FSTMaybeDocument *)entryForKey:(FSTDocumentKey *)key {
+  return self.docs[key];
+}
+
+- (FSTDocumentDictionary *)documentsMatchingQuery:(FSTQuery *)query {
+  FSTDocumentDictionary *result = [FSTDocumentDictionary documentDictionary];
+
+  // Documents are ordered by key, so we can use a prefix scan to narrow down the documents
+  // we need to match the query against.
+  FSTDocumentKey *prefix = [FSTDocumentKey keyWithPath:[query.path pathByAppendingSegment:@""]];
+  NSEnumerator<FSTDocumentKey *> *enumerator = [self.docs keyEnumeratorFrom:prefix];
+  for (FSTDocumentKey *key in enumerator) {
+    if (![query.path isPrefixOfPath:key.path]) {
+      break;
+    }
+    FSTMaybeDocument *maybeDoc = self.docs[key];
+    if (![maybeDoc isKindOfClass:[FSTDocument class]]) {
+      continue;
+    }
+    FSTDocument *doc = (FSTDocument *)maybeDoc;
+    if ([query matchesDocument:doc]) {
+      result = [result dictionaryBySettingObject:doc forKey:doc.key];
+    }
+  }
+
+  return result;
+}
+
+@end
+
+NS_ASSUME_NONNULL_END