Signal-iOS/SignalServiceKit/src/Storage/Database/GRDBDatabaseStorageAdapter.swift
2021-04-06 13:57:06 -03:00

750 lines
25 KiB
Swift

//
// Copyright (c) 2021 Open Whisper Systems. All rights reserved.
//
import Foundation
import GRDB
@objc
public class GRDBDatabaseStorageAdapter: NSObject {
// 256 bit key + 128 bit salt
public static let kSQLCipherKeySpecLength: UInt = 48
@objc
public enum DirectoryMode: Int {
case primary
case hotswap
var folderName: String {
switch self {
case .primary: return "grdb"
case .hotswap: return "grdb-hotswap"
}
}
}
@objc
public static func databaseDirUrl(baseDir: URL, directoryMode: DirectoryMode = .primary) -> URL {
return baseDir.appendingPathComponent(directoryMode.folderName, isDirectory: true)
}
public static func databaseFileUrl(baseDir: URL, directoryMode: DirectoryMode = .primary) -> URL {
let databaseDir = databaseDirUrl(baseDir: baseDir, directoryMode: directoryMode)
OWSFileSystem.ensureDirectoryExists(databaseDir.path)
return databaseDir.appendingPathComponent("signal.sqlite", isDirectory: false)
}
public static func databaseWalUrl(baseDir: URL, directoryMode: DirectoryMode = .primary) -> URL {
let databaseDir = databaseDirUrl(baseDir: baseDir, directoryMode: directoryMode)
OWSFileSystem.ensureDirectoryExists(databaseDir.path)
return databaseDir.appendingPathComponent("signal.sqlite-wal", isDirectory: false)
}
private let databaseUrl: URL
private let storage: GRDBStorage
public var pool: DatabasePool {
return storage.pool
}
init(baseDir: URL, directoryMode: DirectoryMode = .primary) {
databaseUrl = GRDBDatabaseStorageAdapter.databaseFileUrl(baseDir: baseDir, directoryMode: directoryMode)
do {
// Crash if keychain is inaccessible.
try GRDBDatabaseStorageAdapter.ensureDatabaseKeySpecExists(baseDir: baseDir)
} catch {
owsFail("\(error.grdbErrorForLogging)")
}
do {
// Crash if storage can't be initialized.
storage = try GRDBStorage(dbURL: databaseUrl, keyspec: GRDBDatabaseStorageAdapter.keyspec)
} catch {
owsFail("\(error.grdbErrorForLogging)")
}
super.init()
AppReadiness.runNowOrWhenAppWillBecomeReady { [weak self] in
// This adapter may have been discarded after running
// schema migrations.
guard let self = self else { return }
BenchEventStart(title: "GRDB Setup", eventId: "GRDB Setup")
defer { BenchEventComplete(eventId: "GRDB Setup") }
do {
try self.setup()
} catch {
owsFail("unable to setup database: \(error)")
}
}
}
public func add(function: DatabaseFunction) {
pool.add(function: function)
}
static let tables: [SDSTableMetadata] = [
// Models
TSThread.table,
TSInteraction.table,
StickerPack.table,
InstalledSticker.table,
KnownStickerPack.table,
TSAttachment.table,
SSKJobRecord.table,
OWSMessageContentJob.table,
OWSRecipientIdentity.table,
ExperienceUpgrade.table,
OWSDisappearingMessagesConfiguration.table,
SignalRecipient.table,
SignalAccount.table,
OWSUserProfile.table,
OWSDevice.table,
TestModel.table,
OWSReaction.table,
IncomingGroupsV2MessageJob.table,
TSMention.table,
TSPaymentModel.table,
TSPaymentRequestModel.table
// NOTE: We don't include OWSMessageDecryptJob,
// since we should never use it with GRDB.
]
// MARK: - Database Snapshot
private var latestSnapshot: DatabaseSnapshot! {
return uiDatabaseObserver!.latestSnapshot
}
@objc
public private(set) var uiDatabaseObserver: UIDatabaseObserver?
@objc
public func setupUIDatabase() throws {
owsAssertDebug(self.uiDatabaseObserver == nil)
// UIDatabaseObserver is a general purpose observer, whose delegates
// are notified when things change, but are not given any specific details
// about the changes.
let uiDatabaseObserver = try UIDatabaseObserver(pool: pool,
checkpointingQueue: storage.checkpointingQueue)
self.uiDatabaseObserver = uiDatabaseObserver
try pool.write { db in
db.add(transactionObserver: uiDatabaseObserver, extent: Database.TransactionObservationExtent.observerLifetime)
}
}
// NOTE: This should only be used in exceptional circumstances,
// e.g. after reloading the database due to a device transfer.
func forceUpdateSnapshot() {
uiDatabaseObserver?.forceUpdateSnapshot()
}
func testing_tearDownUIDatabase() {
// UIDatabaseObserver is a general purpose observer, whose delegates
// are notified when things change, but are not given any specific details
// about the changes.
self.uiDatabaseObserver = nil
}
func setup() throws {
MediaGalleryManager.setup(storage: self)
try setupUIDatabase()
}
// MARK: -
private static let keyServiceName: String = "GRDBKeyChainService"
private static let keyName: String = "GRDBDatabaseCipherKeySpec"
public static var keyspec: GRDBKeySpecSource {
return GRDBKeySpecSource(keyServiceName: keyServiceName, keyName: keyName)
}
@objc
public static var isKeyAccessible: Bool {
do {
return try keyspec.fetchString().count > 0
} catch {
owsFailDebug("Key not accessible: \(error)")
return false
}
}
/// Fetches the GRDB key data from the keychain.
/// - Note: Will fatally assert if not running in a debug or test build.
/// - Returns: The key data, if available.
@objc
public static var debugOnly_keyData: Data? {
owsAssert(OWSIsTestableBuild())
return try? keyspec.fetchData()
}
@objc
public static func ensureDatabaseKeySpecExists(baseDir: URL) throws {
do {
_ = try keyspec.fetchString()
// Key exists and is valid.
return
} catch {
Logger.warn("Key not accessible: \(error)")
}
// Because we use kSecAttrAccessibleAfterFirstUnlockThisDeviceOnly,
// the keychain will be inaccessible after device restart until
// device is unlocked for the first time. If the app receives
// a push notification, we won't be able to access the keychain to
// process that notification, so we should just terminate by throwing
// an uncaught exception.
var errorDescription = "CipherKeySpec inaccessible. New install, migration or no unlock since device restart?"
if CurrentAppContext().isMainApp {
let applicationState = CurrentAppContext().reportedApplicationState
errorDescription += ", ApplicationState: \(NSStringForUIApplicationState(applicationState))"
}
Logger.error(errorDescription)
Logger.flush()
if CurrentAppContext().isMainApp {
if CurrentAppContext().isInBackground() {
// Rather than crash here, we should have already detected the situation earlier
// and exited gracefully (in the app delegate) using isDatabasePasswordAccessible.
// This is a last ditch effort to avoid blowing away the user's database.
throw OWSAssertionError(errorDescription)
}
} else {
throw OWSAssertionError("CipherKeySpec inaccessible; not main app.")
}
// At this point, either:
//
// * This is a new install so there's no existing password to retrieve.
// * The keychain has become corrupt.
let databaseUrl = GRDBDatabaseStorageAdapter.databaseFileUrl(baseDir: baseDir)
let doesDBExist = FileManager.default.fileExists(atPath: databaseUrl.path)
if doesDBExist {
owsFail("Could not load database metadata")
}
keyspec.generateAndStore()
}
@objc
public static func resetAllStorage(baseDir: URL) {
Logger.info("")
// This might be redundant but in the spirit of thoroughness...
GRDBDatabaseStorageAdapter.removeAllFiles(baseDir: baseDir)
deleteDBKeys()
if CurrentAppContext().isMainApp {
TSAttachmentStream.deleteAttachmentsFromDisk()
}
// TODO: Delete Profiles on Disk?
}
private static func deleteDBKeys() {
do {
try keyspec.clear()
} catch {
owsFailDebug("Could not clear keychain: \(error)")
}
}
static func prepareDatabase(db: Database, keyspec: GRDBKeySpecSource, name: String? = nil) throws {
let prefix: String
if let name = name, !name.isEmpty {
prefix = name + "."
} else {
prefix = ""
}
let keyspec = try keyspec.fetchString()
try db.execute(sql: "PRAGMA \(prefix)key = \"\(keyspec)\"")
try db.execute(sql: "PRAGMA \(prefix)cipher_plaintext_header_size = 32")
}
}
// MARK: -
extension GRDBDatabaseStorageAdapter: SDSDatabaseStorageAdapter {
#if TESTABLE_BUILD
// TODO: We could eventually eliminate all nested transactions.
private static let detectNestedTransactions = false
// In debug builds, we can detect transactions opened within transaction.
// These checks can also be used to detect unexpected "sneaky" transactions.
private static let kCanOpenTransactionKey = "kCanOpenTransactionKey"
public static func setCanOpenTransaction(_ value: Bool) {
Thread.current.threadDictionary[kCanOpenTransactionKey] = NSNumber(value: value)
}
private static var canOpenTransaction: Bool {
guard let value = Thread.current.threadDictionary[kCanOpenTransactionKey] as? NSNumber else {
return true
}
return value.boolValue
}
#endif
// TODO readThrows/writeThrows flavors
public func uiReadThrows(block: (GRDBReadTransaction) throws -> Void) rethrows {
#if TESTABLE_BUILD
owsAssertDebug(Self.canOpenTransaction)
// Check for nested tractions.
if Self.detectNestedTransactions {
// Check for nested tractions.
Self.setCanOpenTransaction(false)
}
defer {
if Self.detectNestedTransactions {
Self.setCanOpenTransaction(true)
}
}
#endif
AssertIsOnMainThread()
try latestSnapshot.read { database in
try autoreleasepool {
try block(GRDBReadTransaction(database: database, isUIRead: true))
}
}
}
@discardableResult
public func read<T>(block: (GRDBReadTransaction) throws -> T) throws -> T {
#if TESTABLE_BUILD
owsAssertDebug(Self.canOpenTransaction)
// Check for nested tractions.
if Self.detectNestedTransactions {
// Check for nested tractions.
Self.setCanOpenTransaction(false)
}
defer {
if Self.detectNestedTransactions {
Self.setCanOpenTransaction(true)
}
}
#endif
return try pool.read { database in
try autoreleasepool {
return try block(GRDBReadTransaction(database: database, isUIRead: false))
}
}
}
@discardableResult
public func write<T>(block: (GRDBWriteTransaction) throws -> T) throws -> T {
var value: T!
var thrown: Error?
try write { (transaction) in
do {
value = try block(transaction)
} catch {
thrown = error
}
}
if let error = thrown {
throw error.grdbErrorForLogging
}
return value
}
@objc
public func uiRead(block: (GRDBReadTransaction) -> Void) throws {
AssertIsOnMainThread()
#if TESTABLE_BUILD
owsAssertDebug(Self.canOpenTransaction)
// Check for nested tractions.
if Self.detectNestedTransactions {
// Check for nested tractions.
Self.setCanOpenTransaction(false)
}
defer {
if Self.detectNestedTransactions {
Self.setCanOpenTransaction(true)
}
}
#endif
guard CurrentAppContext().hasUI else {
// Never do uiReads in the NSE.
return try read(block: block)
}
latestSnapshot.read { database in
autoreleasepool {
block(GRDBReadTransaction(database: database, isUIRead: true))
}
}
}
@objc
public func read(block: (GRDBReadTransaction) -> Void) throws {
#if TESTABLE_BUILD
owsAssertDebug(Self.canOpenTransaction)
if Self.detectNestedTransactions {
// Check for nested tractions.
Self.setCanOpenTransaction(false)
}
defer {
if Self.detectNestedTransactions {
Self.setCanOpenTransaction(true)
}
}
#endif
try pool.read { database in
autoreleasepool {
block(GRDBReadTransaction(database: database, isUIRead: false))
}
}
}
@objc
public func write(block: (GRDBWriteTransaction) -> Void) throws {
#if TESTABLE_BUILD
owsAssertDebug(Self.canOpenTransaction)
// Check for nested tractions.
if Self.detectNestedTransactions {
// Check for nested tractions.
Self.setCanOpenTransaction(false)
}
defer {
if Self.detectNestedTransactions {
Self.setCanOpenTransaction(true)
}
}
#endif
var syncCompletions: [GRDBWriteTransaction.CompletionBlock] = []
var asyncCompletions: [GRDBWriteTransaction.AsyncCompletion] = []
try pool.write { database in
autoreleasepool {
let transaction = GRDBWriteTransaction(database: database)
block(transaction)
transaction.finalizeTransaction()
syncCompletions = transaction.syncCompletions
asyncCompletions = transaction.asyncCompletions
}
}
// Perform all completions _after_ the write transaction completes.
for block in syncCompletions {
block()
}
for asyncCompletion in asyncCompletions {
asyncCompletion.queue.async(execute: asyncCompletion.block)
}
}
}
// MARK: -
func filterForDBQueryLog(_ input: String) -> String {
var result = input
while let matchRange = result.range(of: "x'[0-9a-f\n]*'", options: .regularExpression) {
let charCount = result.distance(from: matchRange.lowerBound, to: matchRange.upperBound)
let byteCount = Int64(charCount) / 2
let formattedByteCount = ByteCountFormatter.string(fromByteCount: byteCount, countStyle: .memory)
result = result.replacingCharacters(in: matchRange, with: "x'<\(formattedByteCount)>'")
}
return result
}
private func dbQueryLog(_ value: String) {
guard SDSDatabaseStorage.shouldLogDBQueries else {
return
}
Logger.info(filterForDBQueryLog(value))
}
// MARK: -
private struct GRDBStorage {
let pool: DatabasePool
let checkpointingQueue: DatabaseQueue?
private let dbURL: URL
private let poolConfiguration: Configuration
private let checkpointingQueueConfiguration: Configuration
fileprivate static let maxBusyTimeoutMs = 50
init(dbURL: URL, keyspec: GRDBKeySpecSource) throws {
self.dbURL = dbURL
poolConfiguration = Self.buildConfiguration(keyspec: keyspec,
isForCheckpointingQueue: false)
checkpointingQueueConfiguration = Self.buildConfiguration(keyspec: keyspec,
isForCheckpointingQueue: true)
pool = try DatabasePool(path: dbURL.path, configuration: poolConfiguration)
Logger.debug("dbURL: \(dbURL)")
let shouldCheckpoint = CurrentAppContext().isMainApp
if shouldCheckpoint {
checkpointingQueue = try DatabaseQueue(path: dbURL.path,
configuration: checkpointingQueueConfiguration)
} else {
checkpointingQueue = nil
}
OWSFileSystem.protectFileOrFolder(atPath: dbURL.path)
}
private static func buildConfiguration(keyspec: GRDBKeySpecSource,
isForCheckpointingQueue: Bool) -> Configuration {
var configuration = Configuration()
configuration.readonly = false
configuration.foreignKeysEnabled = true // Default is already true
configuration.trace = { logString in
dbQueryLog(logString)
}
// Useful when your app opens multiple databases
configuration.label = (isForCheckpointingQueue
? "GRDB Checkpointing"
: "GRDB Storage")
configuration.maximumReaderCount = 10 // The default is 5
configuration.busyMode = .callback({ (retryCount: Int) -> Bool in
// sleep N milliseconds
let millis = 25
usleep(useconds_t(millis * 1000))
Logger.verbose("retryCount: \(retryCount)")
let accumulatedWaitMs = millis * (retryCount + 1)
if accumulatedWaitMs > 0, (accumulatedWaitMs % 250) == 0 {
Logger.warn("Database busy for \(accumulatedWaitMs)ms")
}
if isForCheckpointingQueue {
// The checkpointing queue should time out.
if accumulatedWaitMs > GRDBStorage.maxBusyTimeoutMs {
Logger.warn("Aborting busy retry.")
return false
}
return true
} else {
return true
}
})
configuration.prepareDatabase = { db in
try GRDBDatabaseStorageAdapter.prepareDatabase(db: db, keyspec: keyspec)
}
configuration.defaultTransactionKind = .immediate
configuration.allowsUnsafeTransactions = true
return configuration
}
}
// MARK: -
public struct GRDBKeySpecSource {
private var kSQLCipherKeySpecLength: UInt {
GRDBDatabaseStorageAdapter.kSQLCipherKeySpecLength
}
let keyServiceName: String
let keyName: String
func fetchString() throws -> String {
// Use a raw key spec, where the 96 hexadecimal digits are provided
// (i.e. 64 hex for the 256 bit key, followed by 32 hex for the 128 bit salt)
// using explicit BLOB syntax, e.g.:
//
// x'98483C6EB40B6C31A448C22A66DED3B5E5E8D5119CAC8327B655C8B5C483648101010101010101010101010101010101'
let data = try fetchData()
guard data.count == kSQLCipherKeySpecLength else {
owsFail("unexpected keyspec length")
}
let passphrase = "x'\(data.hexadecimalString)'"
return passphrase
}
public func fetchData() throws -> Data {
return try CurrentAppContext().keychainStorage().data(forService: keyServiceName, key: keyName)
}
func clear() throws {
Logger.info("")
try CurrentAppContext().keychainStorage().remove(service: keyServiceName, key: keyName)
}
func generateAndStore() {
Logger.info("")
do {
let keyData = Randomness.generateRandomBytes(Int32(kSQLCipherKeySpecLength))
try store(data: keyData)
} catch {
owsFail("Could not generate key for GRDB: \(error)")
}
}
public func store(data: Data) throws {
guard data.count == kSQLCipherKeySpecLength else {
owsFail("unexpected keyspec length")
}
try CurrentAppContext().keychainStorage().set(data: data, service: keyServiceName, key: keyName)
}
}
// MARK: -
extension GRDBDatabaseStorageAdapter {
public var databaseFilePath: String {
return databaseUrl.path
}
public var databaseWALFilePath: String {
return databaseUrl.path + "-wal"
}
public var databaseSHMFilePath: String {
return databaseUrl.path + "-shm"
}
static func removeAllFiles(baseDir: URL) {
let databaseUrl = GRDBDatabaseStorageAdapter.databaseFileUrl(baseDir: baseDir)
OWSFileSystem.deleteFileIfExists(databaseUrl.path)
OWSFileSystem.deleteFileIfExists(databaseUrl.path + "-wal")
OWSFileSystem.deleteFileIfExists(databaseUrl.path + "-shm")
}
}
// MARK: - Reporting
extension GRDBDatabaseStorageAdapter {
var databaseFileSize: UInt64 {
guard let fileSize = OWSFileSystem.fileSize(ofPath: databaseFilePath) else {
owsFailDebug("Could not determine file size.")
return 0
}
return fileSize.uint64Value
}
var databaseWALFileSize: UInt64 {
guard let fileSize = OWSFileSystem.fileSize(ofPath: databaseWALFilePath) else {
owsFailDebug("Could not determine file size.")
return 0
}
return fileSize.uint64Value
}
var databaseSHMFileSize: UInt64 {
guard let fileSize = OWSFileSystem.fileSize(ofPath: databaseSHMFilePath) else {
owsFailDebug("Could not determine file size.")
return 0
}
return fileSize.uint64Value
}
}
// MARK: - Checkpoints
public struct GrdbTruncationResult {
let walSizePages: Int32
let pagesCheckpointed: Int32
}
extension GRDBDatabaseStorageAdapter {
@objc
public func syncTruncatingCheckpoint() throws {
guard let checkpointingQueue = storage.checkpointingQueue else {
return
}
Logger.info("running truncating checkpoint.")
SDSDatabaseStorage.shared.logFileSizes()
let result = try GRDBDatabaseStorageAdapter.checkpoint(checkpointingQueue: checkpointingQueue,
mode: .truncate)
Logger.info("walSizePages: \(result.walSizePages), pagesCheckpointed: \(result.pagesCheckpointed)")
SDSDatabaseStorage.shared.logFileSizes()
}
public static func checkpoint(checkpointingQueue: DatabaseQueue,
mode: Database.CheckpointMode) throws -> GrdbTruncationResult {
var walSizePages: Int32 = 0
var pagesCheckpointed: Int32 = 0
try Bench(title: "Slow checkpoint: \(mode)", logIfLongerThan: 0.01, logInProduction: true) {
#if TESTABLE_BUILD
let startTime = CACurrentMediaTime()
#endif
try checkpointingQueue.inDatabase { db in
#if TESTABLE_BUILD
let startElapsedSeconds: TimeInterval = CACurrentMediaTime() - startTime
let slowStartSeconds: TimeInterval = TimeInterval(GRDBStorage.maxBusyTimeoutMs) / 1000
if startElapsedSeconds > slowStartSeconds * 2 {
// maxBusyTimeoutMs isn't a hard limit, but slow starts should be very rare.
let formattedTime = String(format: "%0.2fms", startElapsedSeconds * 1000)
owsFailDebug("Slow checkpoint start: \(formattedTime)")
}
#endif
let code = sqlite3_wal_checkpoint_v2(db.sqliteConnection, nil, mode.rawValue, &walSizePages, &pagesCheckpointed)
switch code {
case SQLITE_OK:
if mode != .passive {
Logger.info("Checkpoint succeeded: \(mode).")
}
break
case SQLITE_BUSY:
// Busy is not an error.
Logger.info("Checkpoint \(mode) failed due to busy.")
break
default:
throw OWSAssertionError("checkpoint sql error with code: \(code)")
}
}
}
return GrdbTruncationResult(walSizePages: walSizePages, pagesCheckpointed: pagesCheckpointed)
}
}
// MARK: -
public extension Error {
var grdbErrorForLogging: Error {
// If not a GRDB error, return unmodified.
guard let grdbError = self as? GRDB.DatabaseError else {
return self
}
// DatabaseError.description includes the arguments.
Logger.verbose("grdbError: \(grdbError))")
// DatabaseError.description does not include the extendedResultCode.
Logger.verbose("resultCode: \(grdbError.resultCode), extendedResultCode: \(grdbError.extendedResultCode), message: \(String(describing: grdbError.message)), sql: \(String(describing: grdbError.sql))")
let error = GRDB.DatabaseError(resultCode: grdbError.extendedResultCode,
message: grdbError.message,
sql: nil,
arguments: nil)
return error
}
}