Migrate FSTLevelDBMigrations to C++ LevelDbMigrations

Firestore/Example/Tests/Local/FSTLevelDBMigrationsTests.mm

@@ -22,11 +22,11 @@
 
 #import "Firestore/Protos/objc/firestore/local/Target.pbobjc.h"
 #import "Firestore/Source/Local/FSTLevelDB.h"
-#import "Firestore/Source/Local/FSTLevelDBMigrations.h"
 #import "Firestore/Source/Local/FSTLevelDBMutationQueue.h"
 #import "Firestore/Source/Local/FSTLevelDBQueryCache.h"
 
 #include "Firestore/core/src/firebase/firestore/local/leveldb_key.h"
+#include "Firestore/core/src/firebase/firestore/local/leveldb_migrations.h"
 #include "Firestore/core/src/firebase/firestore/util/ordered_code.h"
 #include "Firestore/core/src/firebase/firestore/util/status.h"
 #include "Firestore/core/test/firebase/firestore/testutil/testutil.h"
@@ -39,6 +39,7 @@
 
 using firebase::firestore::FirestoreErrorCode;
 using firebase::firestore::local::LevelDbDocumentTargetKey;
+using firebase::firestore::local::LevelDbMigrations;
 using firebase::firestore::local::LevelDbMutationKey;
 using firebase::firestore::local::LevelDbMutationQueueKey;
 using firebase::firestore::local::LevelDbQueryTargetKey;
@@ -54,6 +55,8 @@
 using leveldb::Options;
 using leveldb::Status;
 
+using SchemaVersion = LevelDbMigrations::SchemaVersion;
+
 @interface FSTLevelDBMigrationsTests : XCTestCase
 @end
 
@@ -80,7 +83,7 @@ - (void)tearDown {
 - (void)testAddsTargetGlobal {
   FSTPBTargetGlobal *metadata = [FSTLevelDBQueryCache readTargetMetadataFromDB:_db.get()];
   XCTAssertNil(metadata, @"Not expecting metadata yet, we should have an empty db");
-  [FSTLevelDBMigrations runMigrationsWithDatabase:_db.get()];
+  LevelDbMigrations::RunMigrations(_db.get());
 
   metadata = [FSTLevelDBQueryCache readTargetMetadataFromDB:_db.get()];
   XCTAssertNotNil(metadata, @"Migrations should have added the metadata");
@@ -89,18 +92,16 @@ - (void)testAddsTargetGlobal {
 - (void)testSetsVersionNumber {
   {
     LevelDbTransaction transaction(_db.get(), "testSetsVersionNumber before");
-    FSTLevelDBSchemaVersion initial =
-        [FSTLevelDBMigrations schemaVersionWithTransaction:&transaction];
+    SchemaVersion initial = LevelDbMigrations::ReadSchemaVersion(&transaction);
     XCTAssertEqual(0, initial, "No version should be equivalent to 0");
   }
 
   {
     // Pick an arbitrary high migration number and migrate to it.
-    [FSTLevelDBMigrations runMigrationsWithDatabase:_db.get()];
+    LevelDbMigrations::RunMigrations(_db.get());
 
     LevelDbTransaction transaction(_db.get(), "testSetsVersionNumber after");
-    FSTLevelDBSchemaVersion actual =
-        [FSTLevelDBMigrations schemaVersionWithTransaction:&transaction];
+    SchemaVersion actual = LevelDbMigrations::ReadSchemaVersion(&transaction);
     XCTAssertGreaterThan(actual, 0, @"Expected to migrate to a schema version > 0");
   }
 }
@@ -143,7 +144,7 @@ - (void)testDropsTheQueryCache {
       LevelDbMutationKey::Key(userID, batchID),
   };
 
-  [FSTLevelDBMigrations runMigrationsWithDatabase:_db.get() upToVersion:2];
+  LevelDbMigrations::RunMigrations(_db.get(), 2);
   {
     // Setup some targets to be counted in the migration.
     LevelDbTransaction transaction(_db.get(), "testDropsTheQueryCache setup");
@@ -156,7 +157,7 @@ - (void)testDropsTheQueryCache {
     transaction.Commit();
   }
 
-  [FSTLevelDBMigrations runMigrationsWithDatabase:_db.get() upToVersion:3];
+  LevelDbMigrations::RunMigrations(_db.get(), 3);
   {
     LevelDbTransaction transaction(_db.get(), "testDropsTheQueryCache");
     for (const std::string &key : targetKeys) {
@@ -173,7 +174,7 @@ - (void)testDropsTheQueryCache {
 }
 
 - (void)testDropsTheQueryCacheWithThousandsOfEntries {
-  [FSTLevelDBMigrations runMigrationsWithDatabase:_db.get() upToVersion:2];
+  LevelDbMigrations::RunMigrations(_db.get(), 2);
   {
     // Setup some targets to be destroyed.
     LevelDbTransaction transaction(_db.get(), "testDropsTheQueryCacheWithThousandsOfEntries setup");
@@ -183,7 +184,7 @@ - (void)testDropsTheQueryCacheWithThousandsOfEntries {
     transaction.Commit();
   }
 
-  [FSTLevelDBMigrations runMigrationsWithDatabase:_db.get() upToVersion:3];
+  LevelDbMigrations::RunMigrations(_db.get(), 3);
   {
     LevelDbTransaction transaction(_db.get(), "Verify");
     std::string prefix = LevelDbTargetKey::KeyPrefix();

Firestore/Source/Local/FSTLevelDB.mm

@@ -22,7 +22,6 @@
 #import "FIRFirestoreErrors.h"
 #import "Firestore/Source/Core/FSTListenSequence.h"
 #import "Firestore/Source/Local/FSTLRUGarbageCollector.h"
-#import "Firestore/Source/Local/FSTLevelDBMigrations.h"
 #import "Firestore/Source/Local/FSTLevelDBMutationQueue.h"
 #import "Firestore/Source/Local/FSTLevelDBQueryCache.h"
 #import "Firestore/Source/Local/FSTLevelDBRemoteDocumentCache.h"
@@ -33,6 +32,7 @@
 #include "Firestore/core/src/firebase/firestore/auth/user.h"
 #include "Firestore/core/src/firebase/firestore/core/database_info.h"
 #include "Firestore/core/src/firebase/firestore/local/leveldb_key.h"
+#include "Firestore/core/src/firebase/firestore/local/leveldb_migrations.h"
 #include "Firestore/core/src/firebase/firestore/local/leveldb_transaction.h"
 #include "Firestore/core/src/firebase/firestore/local/leveldb_util.h"
 #include "Firestore/core/src/firebase/firestore/model/database_id.h"
@@ -58,6 +58,7 @@
 using firebase::firestore::local::ConvertStatus;
 using firebase::firestore::local::LevelDbDocumentMutationKey;
 using firebase::firestore::local::LevelDbDocumentTargetKey;
+using firebase::firestore::local::LevelDbMigrations;
 using firebase::firestore::local::LevelDbMutationKey;
 using firebase::firestore::local::LevelDbTransaction;
 using firebase::firestore::model::DatabaseId;
@@ -352,7 +353,7 @@ - (Status)start {
   }
   _ptr = std::move(database).ValueOrDie();
 
-  [FSTLevelDBMigrations runMigrationsWithDatabase:_ptr.get()];
+  LevelDbMigrations::RunMigrations(_ptr.get());
   LevelDbTransaction transaction(_ptr.get(), "Start LevelDB");
   _users = [FSTLevelDB collectUserSet:&transaction];
   transaction.Commit();

Firestore/core/src/firebase/firestore/local/CMakeLists.txt

@@ -16,16 +16,23 @@ if(HAVE_LEVELDB)
   cc_library(
     firebase_firestore_local_persistence_leveldb
     SOURCES
-      leveldb_key.h
       leveldb_key.cc
-      leveldb_transaction.h
+      leveldb_key.h
+      leveldb_migrations.cc
+      leveldb_migrations.h
       leveldb_transaction.cc
-      leveldb_util.h
+      leveldb_transaction.h
       leveldb_util.cc
+      leveldb_util.h
     DEPENDS
+      # TODO(b/111328563) Force nanopb first to work around ODR violations
+      protobuf-nanopb
+
       LevelDB::LevelDB
       absl_strings
       firebase_firestore_model
+      firebase_firestore_nanopb
+      firebase_firestore_protos_nanopb
       firebase_firestore_util
     EXCLUDE_FROM_ALL
   )

Firestore/Source/Local/FSTLevelDBMigrations.mm → Firestore/core/src/firebase/firestore/local/leveldb_migrations.cc

@@ -14,69 +14,69 @@
  * limitations under the License.
  */
 
-#import "Firestore/Source/Local/FSTLevelDBMigrations.h"
+#include "Firestore/core/src/firebase/firestore/local/leveldb_migrations.h"
 
 #include <string>
+#include <utility>
 
-#import "Firestore/Protos/objc/firestore/local/Target.pbobjc.h"
-#import "Firestore/Source/Local/FSTLevelDBQueryCache.h"
-
+#include "Firestore/Protos/nanopb/firestore/local/target.nanopb.h"
 #include "Firestore/core/src/firebase/firestore/local/leveldb_key.h"
-#include "Firestore/core/src/firebase/firestore/util/hard_assert.h"
-#include "absl/base/macros.h"
-#include "absl/memory/memory.h"
+#include "Firestore/core/src/firebase/firestore/nanopb/writer.h"
 #include "absl/strings/match.h"
-#include "leveldb/write_batch.h"
 
-NS_ASSUME_NONNULL_BEGIN
+namespace firebase {
+namespace firestore {
+namespace local {
+
+using leveldb::Iterator;
+using leveldb::Slice;
+using leveldb::Status;
+using leveldb::WriteOptions;
+using nanopb::Writer;
+
+namespace {
 
 /**
  * Schema version for the iOS client.
  *
- * Note that tables aren't a concept in LevelDB. They exist in our schema as just prefixes on keys.
- * This means tables don't need to be created but they also can't easily be dropped and re-created.
+ * Note that tables aren't a concept in LevelDB. They exist in our schema as
+ * just prefixes on keys. This means tables don't need to be created but they
+ * also can't easily be dropped and re-created.
  *
  * Migrations:
- *   * Migration 1 used to ensure the target_global row existed, without clearing it. No longer
- *     required because migration 3 unconditionally clears it.
- *   * Migration 2 used to ensure that the target_global row had a correct count of targets. No
- *     longer required because migration 3 deletes them all.
- *   * Migration 3 deletes the entire query cache to deal with cache corruption related to
- *     limbo resolution. Addresses https://github.com/firebase/firebase-ios-sdk/issues/1548.
+ *   * Migration 1 used to ensure the target_global row existed, without
+ *     clearing it. No longer required because migration 3 unconditionally
+ *     clears it.
+ *   * Migration 2 used to ensure that the target_global row had a correct count
+ *     of targets. No longer required because migration 3 deletes them all.
+ *   * Migration 3 deletes the entire query cache to deal with cache corruption
+ *     related to limbo resolution. Addresses
+ *     https://github.com/firebase/firebase-ios-sdk/issues/1548.
  */
-static FSTLevelDBSchemaVersion kSchemaVersion = 3;
-
-using firebase::firestore::local::LevelDbDocumentTargetKey;
-using firebase::firestore::local::LevelDbQueryTargetKey;
-using firebase::firestore::local::LevelDbTargetDocumentKey;
-using firebase::firestore::local::LevelDbTargetGlobalKey;
-using firebase::firestore::local::LevelDbTargetKey;
-using firebase::firestore::local::LevelDbTransaction;
-using firebase::firestore::local::LevelDbVersionKey;
-using leveldb::Iterator;
-using leveldb::Status;
-using leveldb::Slice;
-using leveldb::WriteOptions;
+const LevelDbMigrations::SchemaVersion kSchemaVersion = 3;
 
 /**
- * Save the given version number as the current version of the schema of the database.
+ * Save the given version number as the current version of the schema of the
+ * database.
  * @param version The version to save
  * @param transaction The transaction in which to save the new version number
  */
-static void SaveVersion(FSTLevelDBSchemaVersion version, LevelDbTransaction *transaction) {
+void SaveVersion(LevelDbMigrations::SchemaVersion version,
+                 LevelDbTransaction* transaction) {
   std::string key = LevelDbVersionKey::Key();
   std::string version_string = std::to_string(version);
   transaction->Put(key, version_string);
 }
 
-static void DeleteEverythingWithPrefix(const std::string &prefix, leveldb::DB *db) {
+void DeleteEverythingWithPrefix(const std::string& prefix, leveldb::DB* db) {
   bool more_deletes = true;
   while (more_deletes) {
     LevelDbTransaction transaction(db, "Delete everything with prefix");
     auto it = transaction.NewIterator();
 
     more_deletes = false;
-    for (it->Seek(prefix); it->Valid() && absl::StartsWith(it->key(), prefix); it->Next()) {
+    for (it->Seek(prefix); it->Valid() && absl::StartsWith(it->key(), prefix);
+         it->Next()) {
       if (transaction.changed_keys() >= 1000) {
         more_deletes = true;
         break;
@@ -89,7 +89,7 @@ static void DeleteEverythingWithPrefix(const std::string &prefix, leveldb::DB *d
 }
 
 /** Migration 3. */
-static void ClearQueryCache(leveldb::DB *db) {
+void ClearQueryCache(leveldb::DB* db) {
   DeleteEverythingWithPrefix(LevelDbTargetKey::KeyPrefix(), db);
   DeleteEverythingWithPrefix(LevelDbDocumentTargetKey::KeyPrefix(), db);
   DeleteEverythingWithPrefix(LevelDbTargetDocumentKey::KeyPrefix(), db);
@@ -98,16 +98,22 @@ static void ClearQueryCache(leveldb::DB *db) {
   LevelDbTransaction transaction(db, "Drop query cache");
 
   // Reset the target global entry too (to reset the target count).
-  transaction.Put(LevelDbTargetGlobalKey::Key(), [FSTPBTargetGlobal message]);
+  firestore_client_TargetGlobal target_global{};
+
+  std::string bytes;
+  Writer writer = Writer::Wrap(&bytes);
+  writer.WriteNanopbMessage(firestore_client_TargetGlobal_fields,
+                            &target_global);
+  transaction.Put(LevelDbTargetGlobalKey::Key(), std::move(bytes));
 
   SaveVersion(3, &transaction);
   transaction.Commit();
 }
 
-@implementation FSTLevelDBMigrations
+}  // namespace
 
-+ (FSTLevelDBSchemaVersion)schemaVersionWithTransaction:
-    (firebase::firestore::local::LevelDbTransaction *)transaction {
+LevelDbMigrations::SchemaVersion LevelDbMigrations::ReadSchemaVersion(
+    LevelDbTransaction* transaction) {
   std::string key = LevelDbVersionKey::Key();
   std::string version_string;
   Status status = transaction->Get(key, &version_string);
@@ -118,22 +124,23 @@ + (FSTLevelDBSchemaVersion)schemaVersionWithTransaction:
   }
 }
 
-+ (void)runMigrationsWithDatabase:(leveldb::DB *)database {
-  [self runMigrationsWithDatabase:database upToVersion:kSchemaVersion];
+void LevelDbMigrations::RunMigrations(leveldb::DB* db) {
+  RunMigrations(db, kSchemaVersion);
 }
 
-+ (void)runMigrationsWithDatabase:(leveldb::DB *)database
-                      upToVersion:(FSTLevelDBSchemaVersion)toVersion {
-  LevelDbTransaction transaction{database, "Read schema version"};
-  FSTLevelDBSchemaVersion fromVersion = [self schemaVersionWithTransaction:&transaction];
+void LevelDbMigrations::RunMigrations(leveldb::DB* db,
+                                      SchemaVersion to_version) {
+  LevelDbTransaction transaction{db, "Read schema version"};
+  SchemaVersion from_version = ReadSchemaVersion(&transaction);
 
-  // This must run unconditionally because schema migrations were added to iOS after the first
-  // release. There may be clients that have never run any migrations that have existing targets.
-  if (fromVersion < 3 && toVersion >= 3) {
-    ClearQueryCache(database);
+  // This must run unconditionally because schema migrations were added to iOS
+  // after the first release. There may be clients that have never run any
+  // migrations that have existing targets.
+  if (from_version < 3 && to_version >= 3) {
+    ClearQueryCache(db);
   }
 }
 
-@end
-
-NS_ASSUME_NONNULL_END
+}  // namespace local
+}  // namespace firestore
+}  // namespace firebase