Drop FSTWriteGroup (#986)

* Drop write group from remote document change buffer

* Unwind some group dependendencies in local store

* Write group dropped from local store

* Drop write group from mutation queue tests

* Drop write group usage from query cache tests

* Drop write groups from remote document cache tests

* Drop write groups from remote document change buffer tests

* Drop write groups and the write group tracker

* Style

* Put the action in transaction

* Merge master, fix test

* Fix some compiler warnings but mostly trigger travis

* Responses to feedback

1 files changed, 3 insertions, 20 deletions

diff --git a/Firestore/Source/Local/FSTLevelDB.mm b/Firestore/Source/Local/FSTLevelDB.mm
index 922c5b4..4812228 100644
--- a/Firestore/Source/Local/FSTLevelDB.mm
+++ b/Firestore/Source/Local/FSTLevelDB.mm
@@ -23,8 +23,6 @@
 #import "Firestore/Source/Local/FSTLevelDBMutationQueue.h"
 #import "Firestore/Source/Local/FSTLevelDBQueryCache.h"
 #import "Firestore/Source/Local/FSTLevelDBRemoteDocumentCache.h"
-#import "Firestore/Source/Local/FSTWriteGroup.h"
-#import "Firestore/Source/Local/FSTWriteGroupTracker.h"
 #import "Firestore/Source/Remote/FSTSerializerBeta.h"
 #import "Firestore/Source/Util/FSTAssert.h"
 #import "Firestore/Source/Util/FSTLogger.h"
@@ -55,7 +53,6 @@ using leveldb::WriteOptions;
 @interface FSTLevelDB ()
 
 @property(nonatomic, copy) NSString *directory;
-@property(nonatomic, strong) FSTWriteGroupTracker *writeGroupTracker;
 @property(nonatomic, assign, getter=isStarted) BOOL started;
 @property(nonatomic, strong, readonly) FSTLocalSerializer *serializer;
 
@@ -79,7 +76,6 @@ using leveldb::WriteOptions;
                        serializer:(FSTLocalSerializer *)serializer {
   if (self = [super init]) {
     _directory = [directory copy];
-    _writeGroupTracker = [FSTWriteGroupTracker tracker];
     _serializer = serializer;
     _transactionRunner.SetBackingPersistence(self);
   }
@@ -148,7 +144,7 @@ using leveldb::WriteOptions;
     return NO;
   }
   _ptr.reset(database);
-  LevelDbTransaction transaction(_ptr.get());
+  LevelDbTransaction transaction(_ptr.get(), "Start LevelDB");
   [FSTLevelDBMigrations runMigrationsWithTransaction:&transaction];
   transaction.Commit();
   return YES;
@@ -229,9 +225,9 @@ using leveldb::WriteOptions;
   return [[FSTLevelDBRemoteDocumentCache alloc] initWithDB:self serializer:self.serializer];
 }
 
-- (void)startTransaction {
+- (void)startTransaction:(absl::string_view)label {
   FSTAssert(_transaction == nullptr, @"Starting a transaction while one is already outstanding");
-  _transaction = absl::make_unique<LevelDbTransaction>(_ptr.get());
+  _transaction = absl::make_unique<LevelDbTransaction>(_ptr.get(), label);
 }
 
 - (void)commitTransaction {
@@ -240,19 +236,6 @@ using leveldb::WriteOptions;
   _transaction.reset();
 }
 
-- (FSTWriteGroup *)startGroupWithAction:(NSString *)action {
-  FSTAssert(_transaction == nullptr, @"Starting a transaction while one is already outstanding");
-  _transaction = absl::make_unique<LevelDbTransaction>(_ptr.get());
-  return [self.writeGroupTracker startGroupWithAction:action transaction:_transaction.get()];
-}
-
-- (void)commitGroup:(FSTWriteGroup *)group {
-  FSTAssert(_transaction != nullptr, @"Committing a transaction before one is started");
-  [self.writeGroupTracker endGroup:group];
-  _transaction->Commit();
-  _transaction.reset();
-}
-
 - (void)shutdown {
   FSTAssert(self.isStarted, @"FSTLevelDB shutdown without start!");
   self.started = NO;