1 files changed, 106 insertions, 0 deletions
diff --git a/Firebase/Database/FValueIndex.m b/Firebase/Database/FValueIndex.m
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+++ b/Firebase/Database/FValueIndex.m
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+/*
+ * 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 "FValueIndex.h"
+#import "FNamedNode.h"
+#import "FSnapshotUtilities.h"
+#import "FUtilities.h"
+#import "FMaxNode.h"
+
+@implementation FValueIndex
+
+- (NSComparisonResult) compareKey:(NSString *)key1
+                          andNode:(id<FNode>)node1
+                       toOtherKey:(NSString *)key2
+                          andNode:(id<FNode>)node2
+{
+    NSComparisonResult indexCmp = [node1 compare:node2];
+    if (indexCmp == NSOrderedSame) {
+        return [FUtilities compareKey:key1 toKey:key2];
+    } else {
+        return indexCmp;
+    }
+}
+
+- (NSComparisonResult) compareKey:(NSString *)key1
+                          andNode:(id<FNode>)node1
+                       toOtherKey:(NSString *)key2
+                          andNode:(id<FNode>)node2
+                          reverse:(BOOL)reverse
+{
+    if (reverse) {
+        return [self compareKey:key2 andNode:node2 toOtherKey:key1 andNode:node1];
+    } else {
+        return [self compareKey:key1 andNode:node1 toOtherKey:key2 andNode:node2];
+    }
+}
+
+- (NSComparisonResult) compareNamedNode:(FNamedNode *)namedNode1 toNamedNode:(FNamedNode *)namedNode2
+{
+    return [self compareKey:namedNode1.name andNode:namedNode1.node toOtherKey:namedNode2.name andNode:namedNode2.node];
+}
+
+- (BOOL)isDefinedOn:(id<FNode>)node {
+    return YES;
+}
+
+- (BOOL)indexedValueChangedBetween:(id<FNode>)oldNode and:(id<FNode>)newNode {
+    return ![oldNode isEqual:newNode];
+}
+
+- (FNamedNode *)minPost {
+    return FNamedNode.min;
+}
+
+- (FNamedNode *)maxPost {
+    return FNamedNode.max;
+}
+
+- (FNamedNode *)makePost:(id<FNode>)indexValue name:(NSString*)name {
+    return [[FNamedNode alloc] initWithName:name andNode:indexValue];
+}
+
+- (NSString *)queryDefinition {
+    return @".value";
+}
+
+- (NSString *) description {
+    return @"FValueIndex";
+}
+
+- (id)copyWithZone:(NSZone *)zone {
+    return self;
+}
+
+- (BOOL) isEqual:(id)other {
+    // since we're a singleton.
+    return (other == self);
+}
+
+- (NSUInteger) hash {
+    return [@".value" hash];
+}
+
+
++ (id<FIndex>) valueIndex {
+    static id<FIndex> valueIndex;
+    static dispatch_once_t once;
+    dispatch_once(&once, ^{
+        valueIndex = [[FValueIndex alloc] init];
+    });
+    return valueIndex;
+}
+@end