Resolve issues around database conversion.

Signal/test/util/OWSDatabaseConverterTest.m

@@ -6,7 +6,9 @@
 #import "OWSDatabaseConverter.h"
 #import <Curve25519Kit/Randomness.h>
 #import <SignalServiceKit/OWSStorage.h>
+#import <SignalServiceKit/YapDatabaseConnection+OWS.h>
 #import <YapDatabase/YapDatabase.h>
+#import <YapDatabase/YapDatabasePrivate.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
@@ -33,37 +35,122 @@ NS_ASSUME_NONNULL_BEGIN
     return [Randomness generateRandomBytes:30];
 }
 
-- (nullable NSString *)createUnconvertedDatabase:(NSData *)passwordData
+- (void)openYapDatabase:(NSString *)databaseFilePath
+       databasePassword:(NSData *)databasePassword
+          databaseBlock:(void (^_Nonnull)(YapDatabase *))databaseBlock
+{
+    OWSAssert(databaseFilePath.length > 0);
+    OWSAssert(databasePassword.length > 0);
+    OWSAssert(databaseBlock);
+
+    DDLogVerbose(@"openYapDatabase: %@", databaseFilePath);
+
+    __weak YapDatabase *_Nullable weakDatabase = nil;
+    dispatch_queue_t snapshotQueue;
+    dispatch_queue_t writeQueue;
+
+    @autoreleasepool {
+        YapDatabaseOptions *options = [[YapDatabaseOptions alloc] init];
+        options.corruptAction = YapDatabaseCorruptAction_Fail;
+        options.cipherKeyBlock = ^{
+            return databasePassword;
+        };
+        options.enableMultiProcessSupport = YES;
+
+        OWSAssert(options.cipherDefaultkdfIterNumber == 0);
+        OWSAssert(options.kdfIterNumber == 0);
+        OWSAssert(options.cipherPageSize == 0);
+        OWSAssert(options.pragmaPageSize == 0);
+        OWSAssert(options.pragmaJournalSizeLimit == 0);
+
+        YapDatabase *database = [[YapDatabase alloc] initWithPath:databaseFilePath
+                                                       serializer:nil
+                                                     deserializer:[OWSStorage logOnFailureDeserializer]
+                                                          options:options];
+        OWSAssert(database);
+
+        weakDatabase = database;
+        snapshotQueue = database->snapshotQueue;
+        writeQueue = database->writeQueue;
+
+        databaseBlock(database);
+
+        // Close the database.
+        database = nil;
+    }
+
+    // Flush the database's queues, which may contain lingering
+    // references to the database.
+    dispatch_sync(snapshotQueue,
+        ^{
+        });
+    dispatch_sync(writeQueue,
+        ^{
+        });
+
+    // Wait for notifications from writes to be fired.
+    {
+        XCTestExpectation *expectation = [self expectationWithDescription:@"Database modified notifications"];
+
+        dispatch_async(dispatch_get_main_queue(), ^{
+            // Database modified notifications are fired on the main queue.
+            // Once this block executes, the main queue has been flushed
+            // and we know that all database modified notifications are
+            // complete.
+            [expectation fulfill];
+        });
+
+        [self waitForExpectationsWithTimeout:5.0
+                                     handler:^(NSError *error) {
+                                         if (error) {
+                                             NSLog(@"Timeout Error: %@", error);
+                                         }
+                                     }];
+    }
+
+    YapDatabase *_Nullable strongDatabase = weakDatabase;
+    OWSAssert(!strongDatabase);
+}
+
+- (nullable NSString *)createUnconvertedDatabase:(NSData *)databasePassword
 {
     NSString *temporaryDirectory = NSTemporaryDirectory();
     NSString *filename = [NSUUID UUID].UUIDString;
     NSString *databaseFilePath = [temporaryDirectory stringByAppendingPathComponent:filename];
 
-    YapDatabaseOptions *options = [[YapDatabaseOptions alloc] init];
+    [self openYapDatabase:databaseFilePath
-    options.corruptAction = YapDatabaseCorruptAction_Fail;
+         databasePassword:databasePassword
-    options.cipherKeyBlock = ^{
+            databaseBlock:^(YapDatabase *database) {
-        return passwordData;
+                YapDatabaseConnection *dbConnection = database.newConnection;
-    };
+                [dbConnection setObject:@(YES) forKey:@"test_key_name" inCollection:@"test_collection_name"];
-    options.enableMultiProcessSupport = YES;
+                [dbConnection flushTransactionsWithCompletionQueue:dispatch_get_main_queue() completionBlock:nil];
-
+            }];
-    OWSAssert(options.cipherDefaultkdfIterNumber == 0);
+
-    OWSAssert(options.kdfIterNumber == 0);
+    OWSAssert([[NSFileManager defaultManager] fileExistsAtPath:databaseFilePath]);
-    OWSAssert(options.cipherPageSize == 0);
+
-    OWSAssert(options.pragmaPageSize == 0);
+    [self openYapDatabase:databaseFilePath
-    OWSAssert(options.pragmaJournalSizeLimit == 0);
+         databasePassword:databasePassword
-
+            databaseBlock:^(YapDatabase *database) {
-    YapDatabase *database = [[YapDatabase alloc] initWithPath:databaseFilePath
+                YapDatabaseConnection *dbConnection = database.newConnection;
-                                                   serializer:nil
+                id _Nullable value = [dbConnection objectForKey:@"test_key_name" inCollection:@"test_collection_name"];
-                                                 deserializer:[OWSStorage logOnFailureDeserializer]
+                OWSAssert([@(YES) isEqual:value]);
-                                                      options:options];
+            }];
-    OWSAssert(database);
+
-    return database ? databaseFilePath : nil;
+    OWSAssert([[NSFileManager defaultManager] fileExistsAtPath:databaseFilePath]);
+
+    NSError *_Nullable error = nil;
+    NSDictionary *fileAttributes =
+        [[NSFileManager defaultManager] attributesOfItemAtPath:databaseFilePath error:&error];
+    OWSAssert(fileAttributes && !error);
+    DDLogVerbose(@"%@ test database file size: %@", self.logTag, fileAttributes[NSFileSize]);
+
+    return databaseFilePath;
 }
 
 - (void)testDoesDatabaseNeedToBeConverted_Unconverted
 {
-    NSData *passwordData = [self randomDatabasePassword];
+    NSData *databasePassword = [self randomDatabasePassword];
-    NSString *_Nullable databaseFilePath = [self createUnconvertedDatabase:passwordData];
+    NSString *_Nullable databaseFilePath = [self createUnconvertedDatabase:databasePassword];
     XCTAssertTrue([OWSDatabaseConverter doesDatabaseNeedToBeConverted:databaseFilePath]);
 }
 
@@ -74,10 +161,15 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (void)testDatabaseConversion
 {
-    NSData *passwordData = [self randomDatabasePassword];
+    NSData *databasePassword = [self randomDatabasePassword];
-    NSString *_Nullable databaseFilePath = [self createUnconvertedDatabase:passwordData];
+    NSString *_Nullable databaseFilePath = [self createUnconvertedDatabase:databasePassword];
     XCTAssertTrue([OWSDatabaseConverter doesDatabaseNeedToBeConverted:databaseFilePath]);
-    [OWSDatabaseConverter convertDatabaseIfNecessary:databaseFilePath];
+    NSError *_Nullable error =
+        [OWSDatabaseConverter convertDatabaseIfNecessary:databaseFilePath databasePassword:databasePassword];
+    if (error) {
+        DDLogError(@"%s error: %@", __PRETTY_FUNCTION__, error);
+    }
+    XCTAssertNil(error);
     XCTAssertFalse([OWSDatabaseConverter doesDatabaseNeedToBeConverted:databaseFilePath]);
 }
 

SignalMessaging/utils/OWSDatabaseConverter.h

@@ -12,8 +12,9 @@ NS_ASSUME_NONNULL_BEGIN
 
 - (instancetype)init NS_UNAVAILABLE;
 
-+ (void)convertDatabaseIfNecessary;
++ (nullable NSError *)convertDatabaseIfNecessary;
-+ (void)convertDatabaseIfNecessary:(NSString *)databaseFilePath;
++ (nullable NSError *)convertDatabaseIfNecessary:(NSString *)databaseFilePath
+                                databasePassword:(NSData *)databasePassword;
 
 @end
 

SignalMessaging/utils/OWSDatabaseConverter.m

@@ -4,42 +4,64 @@
 
 #import "OWSDatabaseConverter.h"
 #import "sqlite3.h"
+#import <SignalServiceKit/NSData+hexString.h>
 #import <SignalServiceKit/OWSError.h>
 #import <SignalServiceKit/OWSFileSystem.h>
 #import <SignalServiceKit/TSStorageManager.h>
 
 NS_ASSUME_NONNULL_BEGIN
 
-const int kSqliteHeaderLength = 32;
+const NSUInteger kSqliteHeaderLength = 32;
+
+@interface OWSStorage (OWSDatabaseConverter)
+
++ (YapDatabaseDeserializer)logOnFailureDeserializer;
+
+@end
+
+#pragma mark -
 
 @implementation OWSDatabaseConverter
 
++ (NSData *)readFirstNBytesOfDatabaseFile:(NSString *)filePath byteCount:(NSUInteger)byteCount
+{
+    OWSAssert(filePath.length > 0);
+
+    @autoreleasepool {
+        NSError *error;
+        // We use NSDataReadingMappedAlways instead of NSDataReadingMappedIfSafe because
+        // we know the database will always exist for the duration of this instance of NSData.
+        NSData *_Nullable data = [NSData dataWithContentsOfURL:[NSURL fileURLWithPath:filePath]
+                                                       options:NSDataReadingMappedAlways
+                                                         error:&error];
+        if (!data || error) {
+            DDLogError(@"%@ Couldn't read database file header.", self.logTag);
+            // TODO: Make a convenience method (on a category of NSException?) that
+            // flushes DDLog before raising a terminal exception.
+            [NSException raise:@"Couldn't read database file header" format:@""];
+        }
+        // Pull this constant out so that we can use it in our YapDatabase fork.
+        NSData *_Nullable headerData = [data subdataWithRange:NSMakeRange(0, byteCount)];
+        if (!headerData || headerData.length != byteCount) {
+            [NSException raise:@"Database file header has unexpected length"
+                        format:@"Database file header has unexpected length: %zd", headerData.length];
+        }
+        return [headerData copy];
+    }
+}
+
 + (BOOL)doesDatabaseNeedToBeConverted:(NSString *)databaseFilePath
 {
     OWSAssert(databaseFilePath.length > 0);
 
     if (![[NSFileManager defaultManager] fileExistsAtPath:databaseFilePath]) {
-        DDLogVerbose(@"%@ Skipping database conversion; no legacy database found.", self.logTag);
+        DDLogVerbose(@"%@ database file not found.", self.logTag);
-        return NO;
+        return nil;
-    }
-    NSError *error;
-    // We use NSDataReadingMappedAlways instead of NSDataReadingMappedIfSafe because
-    // we know the database will always exist for the duration of this instance of NSData.
-    NSData *_Nullable data = [NSData dataWithContentsOfURL:[NSURL fileURLWithPath:databaseFilePath]
-                                                   options:NSDataReadingMappedAlways
-                                                     error:&error];
-    if (!data || error) {
-        DDLogError(@"%@ Couldn't read legacy database file header.", self.logTag);
-        // TODO: Make a convenience method (on a category of NSException?) that
-        // flushes DDLog before raising a terminal exception.
-        [NSException raise:@"Couldn't read legacy database file header" format:@""];
-    }
-    // Pull this constant out so that we can use it in our YapDatabase fork.
-    NSData *_Nullable headerData = [data subdataWithRange:NSMakeRange(0, kSqliteHeaderLength)];
-    if (!headerData || headerData.length != kSqliteHeaderLength) {
-        [NSException raise:@"Database database file header has unexpected length"
-                    format:@"Database database file header has unexpected length: %zd", headerData.length];
     }
+
+    NSData *headerData = [self readFirstNBytesOfDatabaseFile:databaseFilePath byteCount:kSqliteHeaderLength];
+    OWSAssert(headerData);
+
     NSString *kUnencryptedHeader = @"SQLite format 3\0";
     NSData *unencryptedHeaderData = [kUnencryptedHeader dataUsingEncoding:NSUTF8StringEncoding];
     BOOL isUnencrypted = [unencryptedHeaderData
@@ -52,36 +74,46 @@ const int kSqliteHeaderLength = 32;
     return YES;
 }
 
-+ (void)convertDatabaseIfNecessary
++ (nullable NSError *)convertDatabaseIfNecessary
 {
     NSString *databaseFilePath = [TSStorageManager legacyDatabaseFilePath];
-    [self convertDatabaseIfNecessary:databaseFilePath];
+
+    NSError *error;
+    NSData *_Nullable databasePassword = [OWSStorage tryToLoadDatabasePassword:&error];
+    if (!databasePassword || error) {
+        return (error
+                ?: OWSErrorWithCodeDescription(
+                       OWSErrorCodeDatabaseConversionFatalError, @"Failed to load database password"));
+    }
+
+    return [self convertDatabaseIfNecessary:databaseFilePath databasePassword:databasePassword];
 }
 
 // TODO upon failure show user error UI
 // TODO upon failure anything we need to do "back out" partial migration
-+ (void)convertDatabaseIfNecessary:(NSString *)databaseFilePath
++ (nullable NSError *)convertDatabaseIfNecessary:(NSString *)databaseFilePath
+                                databasePassword:(NSData *)databasePassword
 {
     if (![self doesDatabaseNeedToBeConverted:databaseFilePath]) {
-        return;
+        return nil;
     }
 
-    [self convertDatabase:(NSString *)databaseFilePath];
+    return [self convertDatabase:(NSString *)databaseFilePath databasePassword:databasePassword];
 }
 
-+ (nullable NSError *)convertDatabase:(NSString *)databaseFilePath
++ (nullable NSError *)convertDatabase:(NSString *)databaseFilePath databasePassword:(NSData *)databasePassword
 {
     OWSAssert(databaseFilePath.length > 0);
+    OWSAssert(databasePassword.length > 0);
 
-    NSError *error;
+    NSData *headerData = [self readFirstNBytesOfDatabaseFile:databaseFilePath byteCount:kSqliteHeaderLength];
-    NSData *_Nullable databasePassword = [OWSStorage tryToLoadDatabasePassword:&error];
+    OWSAssert(headerData);
-    if (!databasePassword || error) {
+
-        return (error
+    const NSUInteger kSQLCipherSaltLength = 16;
-                ?: OWSErrorWithCodeDescription(
+    OWSAssert(headerData.length >= kSQLCipherSaltLength);
-                       OWSErrorCodeDatabaseConversionFatalError, @"Failed to load database password"));
+    NSData *sqlCipherSaltData = [headerData subdataWithRange:NSMakeRange(0, kSQLCipherSaltLength)];
-    }
 
-    // TODO:
+    // TODO: Write salt to keychain.
 
     //    Hello Matthew,
     //
@@ -181,139 +213,156 @@ const int kSqliteHeaderLength = 32;
         return OWSErrorWithCodeDescription(OWSErrorCodeDatabaseConversionFatalError, @"Failed to set SQLCipher key");
     }
 
-    // TODO set plaintext pragma
-    // TODO modify first page
-    // TODO force checkpoint
-
     // -----------------------------------------------------------
     //
     // This block was derived from [Yapdatabase configureDatabase].
-    //
+    {
-    //    {
+        //
-    //        int status;
+        //    {
-    //
+        //        int status;
-    //        // Set mandatory pragmas
+        //
-    //
+        //        // Set mandatory pragmas
+        //
+
+        // MJK: this isn't relevant since we only migrate existing databses and never set a pageSize option.
+        //        if (isNewDatabaseFile && (options.pragmaPageSize > 0))
+        //        {
+        //            NSString *pragma_page_size =
+        //            [NSString stringWithFormat:@"PRAGMA page_size = %ld;", (long)options.pragmaPageSize];
+        //
+        //            status = sqlite3_exec(db, [pragma_page_size UTF8String], NULL, NULL, NULL);
+        //            if (status != SQLITE_OK)
+        //            {
+        //                YDBLogError(@"Error setting PRAGMA page_size: %d %s", status, sqlite3_errmsg(db));
+        //            }
+        //        }
+
+        //
+        status = sqlite3_exec(db, "PRAGMA journal_mode = WAL;", NULL, NULL, NULL);
+        if (status != SQLITE_OK) {
+            DDLogError(@"Error setting PRAGMA journal_mode: %d %s", status, sqlite3_errmsg(db));
+            return OWSErrorWithCodeDescription(OWSErrorCodeDatabaseConversionFatalError, @"Failed to set WAL mode");
+        }
 
-    // MJK: this isn't relevant since we only migrate existing databses and never set a pageSize option.
+        // MJK: this isn't relevant since we only migrate existing databses
-    //        if (isNewDatabaseFile && (options.pragmaPageSize > 0))
+        //        if (isNewDatabaseFile)
-    //        {
+        //        {
-    //            NSString *pragma_page_size =
+        //            status = sqlite3_exec(db, "PRAGMA auto_vacuum = FULL; VACUUM;", NULL, NULL, NULL);
-    //            [NSString stringWithFormat:@"PRAGMA page_size = %ld;", (long)options.pragmaPageSize];
+        //            if (status != SQLITE_OK)
-    //
+        //            {
-    //            status = sqlite3_exec(db, [pragma_page_size UTF8String], NULL, NULL, NULL);
+        //                YDBLogError(@"Error setting PRAGMA auto_vacuum: %d %s", status, sqlite3_errmsg(db));
-    //            if (status != SQLITE_OK)
+        //            }
-    //            {
+        //        }
-    //                YDBLogError(@"Error setting PRAGMA page_size: %d %s", status, sqlite3_errmsg(db));
+        //
-    //            }
+
-    //        }
+        // TODO verify we need to do this.
+        // Set synchronous to normal for THIS sqlite instance.
+        //
+        // This does NOT affect normal connections.
+        // That is, this does NOT affect YapDatabaseConnection instances.
+        // The sqlite connections of normal YapDatabaseConnection instances will follow the set pragmaSynchronous value.
+        //
+        // The reason we hardcode normal for this sqlite instance is because
+        // it's only used to write the initial snapshot value.
+        // And this doesn't need to be durable, as it is initialized to zero everytime.
+        //
+        // (This sqlite db is also used to perform checkpoints.
+        //  But a normal value won't affect these operations,
+        //  as they will perform sync operations whether the connection is normal or full.)
+        status = sqlite3_exec(db, "PRAGMA synchronous = NORMAL;", NULL, NULL, NULL);
+        if (status != SQLITE_OK) {
+            DDLogError(@"Error setting PRAGMA synchronous: %d %s", status, sqlite3_errmsg(db));
+            // This isn't critical, so we can continue.
+        }
 
-    //
+        // Set journal_size_imit.
-    status = sqlite3_exec(db, "PRAGMA journal_mode = WAL;", NULL, NULL, NULL);
+        //
-    if (status != SQLITE_OK) {
+        // We only need to do set this pragma for THIS connection,
-        DDLogError(@"Error setting PRAGMA journal_mode: %d %s", status, sqlite3_errmsg(db));
+        // because it is the only connection that performs checkpoints.
-        return OWSErrorWithCodeDescription(OWSErrorCodeDatabaseConversionFatalError, @"Failed to set WAL mode");
-    }
 
-    // MJK: this isn't relevant since we only migrate existing databses
+        NSInteger defaultPragmaJournalSizeLimit = 0;
-    //        if (isNewDatabaseFile)
+        NSString *pragma_journal_size_limit =
-    //        {
+            [NSString stringWithFormat:@"PRAGMA journal_size_limit = %ld;", (long)defaultPragmaJournalSizeLimit];
-    //            status = sqlite3_exec(db, "PRAGMA auto_vacuum = FULL; VACUUM;", NULL, NULL, NULL);
-    //            if (status != SQLITE_OK)
-    //            {
-    //                YDBLogError(@"Error setting PRAGMA auto_vacuum: %d %s", status, sqlite3_errmsg(db));
-    //            }
-    //        }
-    //
 
-    // TODO verify we need to do this.
+        status = sqlite3_exec(db, [pragma_journal_size_limit UTF8String], NULL, NULL, NULL);
-    // Set synchronous to normal for THIS sqlite instance.
+        if (status != SQLITE_OK) {
-    //
+            DDLogError(@"Error setting PRAGMA journal_size_limit: %d %s", status, sqlite3_errmsg(db));
-    // This does NOT affect normal connections.
+            // This isn't critical, so we can continue.
-    // That is, this does NOT affect YapDatabaseConnection instances.
+        }
-    // The sqlite connections of normal YapDatabaseConnection instances will follow the set pragmaSynchronous value.
+        //
-    //
+        //        // Set mmap_size (if needed).
-    // The reason we hardcode normal for this sqlite instance is because
+        //        //
-    // it's only used to write the initial snapshot value.
+        //        // This configures memory mapped I/O.
-    // And this doesn't need to be durable, as it is initialized to zero everytime.
+        //        // OWS: we currently don't set options.pragmaMMapSize, so we can ignore this code.
-    //
+        //        if (options.pragmaMMapSize > 0)
-    // (This sqlite db is also used to perform checkpoints.
+        //        {
-    //  But a normal value won't affect these operations,
+        //            NSString *pragma_mmap_size =
-    //  as they will perform sync operations whether the connection is normal or full.)
+        //            [NSString stringWithFormat:@"PRAGMA mmap_size = %ld;", (long)options.pragmaMMapSize];
-    status = sqlite3_exec(db, "PRAGMA synchronous = NORMAL;", NULL, NULL, NULL);
+        //
-    if (status != SQLITE_OK) {
+        //            status = sqlite3_exec(db, [pragma_mmap_size UTF8String], NULL, NULL, NULL);
-        DDLogError(@"Error setting PRAGMA synchronous: %d %s", status, sqlite3_errmsg(db));
+        //            if (status != SQLITE_OK)
-        // This isn't critical, so we can continue.
+        //            {
+        //                YDBLogError(@"Error setting PRAGMA mmap_size: %d %s", status, sqlite3_errmsg(db));
+        //                // This isn't critical, so we can continue.
+        //            }
+        //        }
+        //
+        // Disable autocheckpointing.
+        //
+        // YapDatabase has its own optimized checkpointing algorithm built-in.
+        // It knows the state of every active connection for the database,
+        // so it can invoke the checkpoint methods at the precise time in which a checkpoint can be most effective.
+        sqlite3_wal_autocheckpoint(db, 0);
+
+        // END DB setup copied from YapDatabase
+        // BEGIN SQLCipher migration
     }
 
-    // Set journal_size_imit.
-    //
-    // We only need to do set this pragma for THIS connection,
-    // because it is the only connection that performs checkpoints.
-
-    NSInteger defaultPragmaJournalSizeLimit = 0;
-    NSString *pragma_journal_size_limit =
-        [NSString stringWithFormat:@"PRAGMA journal_size_limit = %ld;", (long)defaultPragmaJournalSizeLimit];
 
-    status = sqlite3_exec(db, [pragma_journal_size_limit UTF8String], NULL, NULL, NULL);
+    // -----------------------------------------------------------
-    if (status != SQLITE_OK) {
-        DDLogError(@"Error setting PRAGMA journal_size_limit: %d %s", status, sqlite3_errmsg(db));
-        // This isn't critical, so we can continue.
-    }
-    //
-    //        // Set mmap_size (if needed).
-    //        //
-    //        // This configures memory mapped I/O.
-    //        // OWS: we currently don't set options.pragmaMMapSize, so we can ignore this code.
-    //        if (options.pragmaMMapSize > 0)
-    //        {
-    //            NSString *pragma_mmap_size =
-    //            [NSString stringWithFormat:@"PRAGMA mmap_size = %ld;", (long)options.pragmaMMapSize];
-    //
-    //            status = sqlite3_exec(db, [pragma_mmap_size UTF8String], NULL, NULL, NULL);
-    //            if (status != SQLITE_OK)
-    //            {
-    //                YDBLogError(@"Error setting PRAGMA mmap_size: %d %s", status, sqlite3_errmsg(db));
-    //                // This isn't critical, so we can continue.
-    //            }
-    //        }
-    //
-    // Disable autocheckpointing.
     //
-    // YapDatabase has its own optimized checkpointing algorithm built-in.
+    // SQLCipher migration
-    // It knows the state of every active connection for the database,
-    // so it can invoke the checkpoint methods at the precise time in which a checkpoint can be most effective.
-    sqlite3_wal_autocheckpoint(db, 0);
-
-    // END DB setup copied from YapDatabase
-    // BEGIN SQLCipher migration
-
-    NSString *setPlainTextHeaderPragma =
-        [NSString stringWithFormat:@"PRAGMA cipher_plaintext_header_size = %d;", kSqliteHeaderLength];
-
-    status = sqlite3_exec(db, [setPlainTextHeaderPragma UTF8String], NULL, NULL, NULL);
-    if (status != SQLITE_OK) {
-        DDLogError(@"Error setting PRAGMA cipher_plaintext_header_size = %d: status: %d, error: %s",
-            kSqliteHeaderLength,
-            status,
-            sqlite3_errmsg(db));
-        return OWSErrorWithCodeDescription(
-            OWSErrorCodeDatabaseConversionFatalError, @"Failed to set PRAGMA cipher_plaintext_header_size");
-    }
 
-    // Modify the first page, so that SQLCipher will overwrite, respecting our new cipher_plaintext_header_size
+    //    if (NO)
-    NSString *tableName = [NSString stringWithFormat:@"signal-migration-%@", [NSUUID new].UUIDString];
+    //    {
-    NSString *modificationSQL =
+    //
-        [NSString stringWithFormat:@"CREATE TABLE %@(int a); INSERT INTO %@(a) VALUES (1);", tableName, tableName];
+    //    NSString *setPlainTextHeaderPragma =
-    status = sqlite3_exec(db, [modificationSQL UTF8String], NULL, NULL, NULL);
+    //    [NSString stringWithFormat:@"PRAGMA cipher_plaintext_header_size = %zd;", kSqliteHeaderLength];
-    if (status != SQLITE_OK) {
+    //
-        DDLogError(@"%@ Error modifying first page: %d, error: %s", self.logTag, status, sqlite3_errmsg(db));
+    //    status = sqlite3_exec(db, [setPlainTextHeaderPragma UTF8String], NULL, NULL, NULL);
-        return OWSErrorWithCodeDescription(OWSErrorCodeDatabaseConversionFatalError, @"Error modifying first page");
+    //    if (status != SQLITE_OK) {
-    }
+    //        DDLogError(@"Error setting PRAGMA cipher_plaintext_header_size = %zd: status: %d, error: %s",
+    //                   kSqliteHeaderLength,
+    //                   status,
+    //                   sqlite3_errmsg(db));
+    //        return OWSErrorWithCodeDescription(
+    //                                           OWSErrorCodeDatabaseConversionFatalError, @"Failed to set PRAGMA
+    //                                           cipher_plaintext_header_size");
+    //    }
+    //
+    //    // Modify the first page, so that SQLCipher will overwrite, respecting our new cipher_plaintext_header_size
+    //    NSString *tableName = [NSString stringWithFormat:@"signal-migration-%@", [NSUUID new].UUIDString];
+    //    NSString *modificationSQL =
+    //    [NSString stringWithFormat:@"CREATE TABLE %@(int a); INSERT INTO %@(a) VALUES (1);", tableName, tableName];
+    //    status = sqlite3_exec(db, [modificationSQL UTF8String], NULL, NULL, NULL);
+    //    if (status != SQLITE_OK) {
+    //        DDLogError(@"%@ Error modifying first page: %d, error: %s", self.logTag, status, sqlite3_errmsg(db));
+    //        return OWSErrorWithCodeDescription(OWSErrorCodeDatabaseConversionFatalError, @"Error modifying first
+    //        page");
+    //    }
+    //
+    //    // Force a checkpoint so that the plaintext is written to the actual DB file, not just living in the WAL.
+    //    // TODO do we need/want the earlier checkpoint if we're checkpointing here?
+    //    sqlite3_wal_autocheckpoint(db, 0);
+    //
+    //
+    //    sqlite3_close(db);
+    //    return nil;
+    //    }
 
-    // Force a checkpoint so that the plaintext is written to the actual DB file, not just living in the WAL.
+    // TODO set plaintext pragma
-    // TODO do we need/want the earlier checkpoint if we're checkpointing here?
+    // TODO modify first page
-    sqlite3_wal_autocheckpoint(db, 0);
+    // TODO force checkpoint
 
     return nil;
 }