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

2 files changed, 6 insertions, 2 deletions

diff --git a/Firestore/core/src/firebase/firestore/local/leveldb_transaction.cc b/Firestore/core/src/firebase/firestore/local/leveldb_transaction.cc
index f034b19..d84d441 100644
--- a/Firestore/core/src/firebase/firestore/local/leveldb_transaction.cc
+++ b/Firestore/core/src/firebase/firestore/local/leveldb_transaction.cc
@@ -143,6 +143,7 @@ bool LevelDbTransaction::Iterator::Valid() {
 }
 
 LevelDbTransaction::LevelDbTransaction(DB* db,
+                                       absl::string_view label,
                                        const ReadOptions& read_options,
                                        const WriteOptions& write_options)
     : db_(db),
@@ -150,7 +151,8 @@ LevelDbTransaction::LevelDbTransaction(DB* db,
       deletions_(),
       read_options_(read_options),
       write_options_(write_options),
-      version_(0) {
+      version_(0),
+      label_(std::string{label}) {
 }
 
 const ReadOptions& LevelDbTransaction::DefaultReadOptions() {
@@ -225,7 +227,7 @@ void LevelDbTransaction::Commit() {
 }
 
 std::string LevelDbTransaction::ToString() {
-  std::string dest("<LevelDbTransaction: ");
+  std::string dest("<LevelDbTransaction " + label_ + ": ");
   int64_t changes = deletions_.size() + mutations_.size();
   int64_t bytes = 0;  // accumulator for size of individual mutations.
   dest += std::to_string(changes) + " changes ";
diff --git a/Firestore/core/src/firebase/firestore/local/leveldb_transaction.h b/Firestore/core/src/firebase/firestore/local/leveldb_transaction.h
index bcc7c91..56a9a77 100644
--- a/Firestore/core/src/firebase/firestore/local/leveldb_transaction.h
+++ b/Firestore/core/src/firebase/firestore/local/leveldb_transaction.h
@@ -126,6 +126,7 @@ class LevelDbTransaction {
 
   explicit LevelDbTransaction(
       leveldb::DB* db,
+      absl::string_view label,
       const leveldb::ReadOptions& read_options = DefaultReadOptions(),
       const leveldb::WriteOptions& write_options = DefaultWriteOptions());
 
@@ -197,6 +198,7 @@ class LevelDbTransaction {
   leveldb::ReadOptions read_options_;
   leveldb::WriteOptions write_options_;
   int32_t version_;
+  std::string label_;
 };
 
 }  // namespace local