Keep track of number of queries in the query cache (#776)

* Implement schema versions

* Style fixes

* newlines, copyrights, assumptions

* Fix nullability

* Raw ptr -> shared_ptr

* kVersionTableGlobal -> kVersionGlobalTable

* Drop utils, move into static methods

* Drop extra include

* Add a few more comments

* Move version constant into migrations file

* formatting?

* Fix comment

* Split add and update queryData

* Work on adding targetCount

* More work on count

* Using shared_ptr

* Implement count for query cache

* use quotes

* Add cast

* Styling

* Revert year bump in copyright

* Add adversarial key to migration test

* Add comment

* Fix style

4 files changed, 19 insertions, 1 deletions

diff --git a/Firestore/Protos/FrameworkMaker.xcodeproj/project.pbxproj b/Firestore/Protos/FrameworkMaker.xcodeproj/project.pbxproj
index 51a61b8..2efcb21 100644
--- a/Firestore/Protos/FrameworkMaker.xcodeproj/project.pbxproj
+++ b/Firestore/Protos/FrameworkMaker.xcodeproj/project.pbxproj
@@ -201,7 +201,7 @@
 			);
 			inputPaths = (
 				"${SRCROOT}/Pods/Target Support Files/Pods-FrameworkMaker_iOS/Pods-FrameworkMaker_iOS-resources.sh",
-				"$PODS_CONFIGURATION_BUILD_DIR/gRPC/gRPCCertificates.bundle",
+				"${PODS_CONFIGURATION_BUILD_DIR}/gRPC/gRPCCertificates.bundle",
 			);
 			name = "[CP] Copy Pods Resources";
 			outputPaths = (
diff --git a/Firestore/Protos/objc/firestore/local/Target.pbobjc.h b/Firestore/Protos/objc/firestore/local/Target.pbobjc.h
index d8bf49c..0672a6e 100644
--- a/Firestore/Protos/objc/firestore/local/Target.pbobjc.h
+++ b/Firestore/Protos/objc/firestore/local/Target.pbobjc.h
@@ -160,6 +160,7 @@ typedef GPB_ENUM(FSTPBTargetGlobal_FieldNumber) {
   FSTPBTargetGlobal_FieldNumber_HighestTargetId = 1,
   FSTPBTargetGlobal_FieldNumber_HighestListenSequenceNumber = 2,
   FSTPBTargetGlobal_FieldNumber_LastRemoteSnapshotVersion = 3,
+  FSTPBTargetGlobal_FieldNumber_TargetCount = 4,
 };
 
 /**
@@ -197,6 +198,9 @@ typedef GPB_ENUM(FSTPBTargetGlobal_FieldNumber) {
 /** Test to see if @c lastRemoteSnapshotVersion has been set. */
 @property(nonatomic, readwrite) BOOL hasLastRemoteSnapshotVersion;
 
+/** On platforms that need it, holds the number of targets persisted. */
+@property(nonatomic, readwrite) int32_t targetCount;
+
 @end
 
 NS_ASSUME_NONNULL_END
diff --git a/Firestore/Protos/objc/firestore/local/Target.pbobjc.m b/Firestore/Protos/objc/firestore/local/Target.pbobjc.m
index 6f6ccf2..567c86d 100644
--- a/Firestore/Protos/objc/firestore/local/Target.pbobjc.m
+++ b/Firestore/Protos/objc/firestore/local/Target.pbobjc.m
@@ -183,10 +183,12 @@ void FSTPBTarget_ClearTargetTypeOneOfCase(FSTPBTarget *message) {
 @dynamic highestTargetId;
 @dynamic highestListenSequenceNumber;
 @dynamic hasLastRemoteSnapshotVersion, lastRemoteSnapshotVersion;
+@dynamic targetCount;
 
 typedef struct FSTPBTargetGlobal__storage_ {
   uint32_t _has_storage_[1];
   int32_t highestTargetId;
+  int32_t targetCount;
   GPBTimestamp *lastRemoteSnapshotVersion;
   int64_t highestListenSequenceNumber;
 } FSTPBTargetGlobal__storage_;
@@ -224,6 +226,15 @@ typedef struct FSTPBTargetGlobal__storage_ {
         .flags = GPBFieldOptional,
         .dataType = GPBDataTypeMessage,
       },
+      {
+        .name = "targetCount",
+        .dataTypeSpecific.className = NULL,
+        .number = FSTPBTargetGlobal_FieldNumber_TargetCount,
+        .hasIndex = 3,
+        .offset = (uint32_t)offsetof(FSTPBTargetGlobal__storage_, targetCount),
+        .flags = GPBFieldOptional,
+        .dataType = GPBDataTypeInt32,
+      },
     };
     GPBDescriptor *localDescriptor =
         [GPBDescriptor allocDescriptorForClass:[FSTPBTargetGlobal class]
diff --git a/Firestore/Protos/protos/firestore/local/target.proto b/Firestore/Protos/protos/firestore/local/target.proto
index 7f34515..7f0a886 100644
--- a/Firestore/Protos/protos/firestore/local/target.proto
+++ b/Firestore/Protos/protos/firestore/local/target.proto
@@ -87,4 +87,7 @@ message TargetGlobal {
   // This is updated whenever our we get a TargetChange with a read_time and
   // empty target_ids.
   google.protobuf.Timestamp last_remote_snapshot_version = 3;
+
+  // On platforms that need it, holds the number of targets persisted.
+  int32 target_count = 4;
 }