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session-ios/SessionMessagingKit/Sending & Receiving/Pollers/SwarmPoller.swift

387 lines
21 KiB
Swift

// Copyright © 2024 Rangeproof Pty Ltd. All rights reserved.
import Foundation
import Combine
import GRDB
import SessionSnodeKit
import SessionUtilitiesKit
// MARK: - SwarmPollerType
public protocol SwarmPollerType {
typealias PollResponse = [ProcessedMessage]
var receivedPollResponse: AnyPublisher<PollResponse, Never> { get }
func startIfNeeded()
func stop()
}
// MARK: - SwarmPoller
public class SwarmPoller: SwarmPollerType & PollerType {
public let dependencies: Dependencies
public let pollerQueue: DispatchQueue
public let pollerName: String
public let pollerDestination: PollerDestination
public let pollerDrainBehaviour: Atomic<SwarmDrainBehaviour>
public let logStartAndStopCalls: Bool
public var receivedPollResponse: AnyPublisher<PollResponse, Never> {
receivedPollResponseSubject.eraseToAnyPublisher()
}
public var isPolling: Bool = false
public var pollCount: Int = 0
public var failureCount: Int
public var lastPollStart: TimeInterval = 0
public var cancellable: AnyCancellable?
private let namespaces: [SnodeAPI.Namespace]
private let customAuthMethod: AuthenticationMethod?
private let shouldStoreMessages: Bool
private let receivedPollResponseSubject: PassthroughSubject<PollResponse, Never> = PassthroughSubject()
// MARK: - Initialization
required public init(
pollerName: String,
pollerQueue: DispatchQueue,
pollerDestination: PollerDestination,
pollerDrainBehaviour: SwarmDrainBehaviour,
namespaces: [SnodeAPI.Namespace],
failureCount: Int = 0,
shouldStoreMessages: Bool,
logStartAndStopCalls: Bool,
customAuthMethod: AuthenticationMethod? = nil,
using dependencies: Dependencies
) {
self.dependencies = dependencies
self.pollerName = pollerName
self.pollerQueue = pollerQueue
self.pollerDestination = pollerDestination
self.pollerDrainBehaviour = Atomic(pollerDrainBehaviour)
self.namespaces = namespaces
self.failureCount = failureCount
self.customAuthMethod = customAuthMethod
self.shouldStoreMessages = shouldStoreMessages
self.logStartAndStopCalls = logStartAndStopCalls
}
// MARK: - Abstract Methods
/// Calculate the delay which should occur before the next poll
public func nextPollDelay() -> TimeInterval {
preconditionFailure("abstract class - override in subclass")
}
/// Perform and logic which should occur when the poll errors, will stop polling if `false` is returned
public func handlePollError(_ error: Error, _ lastError: Error?) -> PollerErrorResponse {
preconditionFailure("abstract class - override in subclass")
}
// MARK: - Private API
/// Polls based on it's configuration and processes any messages, returning an array of messages that were
/// successfully processed
///
/// **Note:** The returned messages will have already been processed by the `Poller`, they are only returned
/// for cases where we need explicit/custom behaviours to occur (eg. Onboarding)
public func poll(forceSynchronousProcessing: Bool) -> AnyPublisher<PollResult, Error> {
let pollerQueue: DispatchQueue = self.pollerQueue
let configHashes: [String] = dependencies.mutate(cache: .libSession) { $0.configHashes(for: pollerDestination.target) }
/// Fetch the messages
return dependencies[singleton: .network]
.getSwarm(for: pollerDestination.target)
.tryFlatMapWithRandomSnode(drainBehaviour: pollerDrainBehaviour, using: dependencies) { [pollerDestination, customAuthMethod, namespaces, dependencies] snode -> AnyPublisher<Network.PreparedRequest<SnodeAPI.PollResponse>, Error> in
dependencies[singleton: .storage].readPublisher { db -> Network.PreparedRequest<SnodeAPI.PollResponse> in
let authMethod: AuthenticationMethod = try (customAuthMethod ?? Authentication.with(
db,
swarmPublicKey: pollerDestination.target,
using: dependencies
))
return try SnodeAPI.preparedPoll(
db,
namespaces: namespaces,
refreshingConfigHashes: configHashes,
from: snode,
authMethod: authMethod,
using: dependencies
)
}
}
.flatMap { [dependencies] request in request.send(using: dependencies) }
.flatMap { [pollerDestination, shouldStoreMessages, dependencies] (_: ResponseInfoType, namespacedResults: SnodeAPI.PollResponse) -> AnyPublisher<(configMessageJobs: [Job], standardMessageJobs: [Job], pollResult: PollResult), Error> in
// Get all of the messages and sort them by their required 'processingOrder'
let sortedMessages: [(namespace: SnodeAPI.Namespace, messages: [SnodeReceivedMessage])] = namespacedResults
.compactMap { namespace, result in (result.data?.messages).map { (namespace, $0) } }
.sorted { lhs, rhs in lhs.namespace.processingOrder < rhs.namespace.processingOrder }
let rawMessageCount: Int = sortedMessages.map { $0.messages.count }.reduce(0, +)
// No need to do anything if there are no messages
guard rawMessageCount > 0 else {
return Just(([], [], ([], 0, 0, false)))
.setFailureType(to: Error.self)
.eraseToAnyPublisher()
}
// Otherwise process the messages and add them to the queue for handling
let lastHashes: [String] = namespacedResults
.compactMap { $0.value.data?.lastHash }
let otherKnownHashes: [String] = namespacedResults
.filter { $0.key.shouldFetchSinceLastHash }
.compactMap { $0.value.data?.messages.map { $0.info.hash } }
.reduce([], +)
var messageCount: Int = 0
var processedMessages: [ProcessedMessage] = []
var hadValidHashUpdate: Bool = false
return dependencies[singleton: .storage].writePublisher { db -> (configMessageJobs: [Job], standardMessageJobs: [Job], pollResult: PollResult) in
let allProcessedMessages: [ProcessedMessage] = sortedMessages
.compactMap { namespace, messages -> [ProcessedMessage]? in
let processedMessages: [ProcessedMessage] = messages
.compactMap { message -> ProcessedMessage? in
do {
return try Message.processRawReceivedMessage(
db,
rawMessage: message,
swarmPublicKey: pollerDestination.target,
shouldStoreMessages: shouldStoreMessages,
using: dependencies
)
}
catch {
switch error {
/// Ignore duplicate & selfSend message errors (and don't bother logging them as there
/// will be a lot since we each service node duplicates messages)
case DatabaseError.SQLITE_CONSTRAINT_UNIQUE,
DatabaseError.SQLITE_CONSTRAINT, /// Sometimes thrown for UNIQUE
MessageReceiverError.duplicateMessage,
MessageReceiverError.duplicateControlMessage,
MessageReceiverError.selfSend:
break
case MessageReceiverError.duplicateMessageNewSnode:
hadValidHashUpdate = true
break
case DatabaseError.SQLITE_ABORT:
Log.warn(.poller, "Failed to the database being suspended (running in background with no background task).")
default: Log.error(.poller, "Failed to deserialize envelope due to error: \(error).")
}
return nil
}
}
/// If this message should be handled by this poller and should be handled synchronously then do so here before
/// processing the next namespace
guard shouldStoreMessages && namespace.shouldHandleSynchronously else {
return processedMessages
}
if namespace.isConfigNamespace {
do {
/// Process config messages all at once in case they are multi-part messages
try dependencies.mutate(cache: .libSession) {
try $0.handleConfigMessages(
db,
swarmPublicKey: pollerDestination.target,
messages: ConfigMessageReceiveJob
.Details(messages: processedMessages)
.messages
)
}
}
catch { Log.error(.poller, "Failed to handle processed config message due to error: \(error).") }
}
else {
/// Individually process non-config messages
processedMessages.forEach { processedMessage in
guard case .standard(let threadId, let threadVariant, let proto, let messageInfo) = processedMessage else {
return
}
do {
try MessageReceiver.handle(
db,
threadId: threadId,
threadVariant: threadVariant,
message: messageInfo.message,
serverExpirationTimestamp: messageInfo.serverExpirationTimestamp,
associatedWithProto: proto,
using: dependencies
)
}
catch { Log.error(.poller, "Failed to handle processed message due to error: \(error).") }
}
}
return nil
}
.flatMap { $0 }
// If we don't want to store the messages then no need to continue (don't want
// to create message receive jobs or mess with cached hashes)
guard shouldStoreMessages else {
messageCount += allProcessedMessages.count
processedMessages += allProcessedMessages
return ([], [], (processedMessages, rawMessageCount, messageCount, hadValidHashUpdate))
}
// Add a job to process the config messages first
let configMessageJobs: [Job] = allProcessedMessages
.filter { $0.isConfigMessage && !$0.namespace.shouldHandleSynchronously }
.grouped { $0.threadId }
.compactMap { threadId, threadMessages in
messageCount += threadMessages.count
processedMessages += threadMessages
let job: Job? = Job(
variant: .configMessageReceive,
behaviour: .runOnce,
threadId: threadId,
details: ConfigMessageReceiveJob.Details(messages: threadMessages)
)
// If we are force-polling then add to the JobRunner so they are
// persistent and will retry on the next app run if they fail but
// don't let them auto-start
return dependencies[singleton: .jobRunner].add(
db,
job: job,
canStartJob: (
!forceSynchronousProcessing &&
!dependencies[singleton: .appContext].isInBackground
)
)
}
let configJobIds: [Int64] = configMessageJobs.compactMap { $0.id }
// Add jobs for processing non-config messages which are dependant on the config message
// processing jobs
let standardMessageJobs: [Job] = allProcessedMessages
.filter { !$0.isConfigMessage && !$0.namespace.shouldHandleSynchronously }
.grouped { $0.threadId }
.compactMap { threadId, threadMessages in
messageCount += threadMessages.count
processedMessages += threadMessages
let job: Job? = Job(
variant: .messageReceive,
behaviour: .runOnce,
threadId: threadId,
details: MessageReceiveJob.Details(messages: threadMessages)
)
// If we are force-polling then add to the JobRunner so they are
// persistent and will retry on the next app run if they fail but
// don't let them auto-start
let updatedJob: Job? = dependencies[singleton: .jobRunner].add(
db,
job: job,
canStartJob: (
!forceSynchronousProcessing &&
!dependencies[singleton: .appContext].isInBackground
)
)
// Create the dependency between the jobs (config processing should happen before
// standard message processing)
if let updatedJobId: Int64 = updatedJob?.id {
do {
try configJobIds.forEach { configJobId in
try JobDependencies(
jobId: updatedJobId,
dependantId: configJobId
)
.insert(db)
}
}
catch {
Log.warn(.poller, "Failed to add dependency between config processing and non-config processing messageReceive jobs.")
}
}
return updatedJob
}
// Clean up message hashes and add some logs about the poll results
if sortedMessages.isEmpty && !hadValidHashUpdate {
// Update the cached validity of the messages
try SnodeReceivedMessageInfo.handlePotentialDeletedOrInvalidHash(
db,
potentiallyInvalidHashes: lastHashes,
otherKnownValidHashes: otherKnownHashes
)
}
return (configMessageJobs, standardMessageJobs, (processedMessages, rawMessageCount, messageCount, hadValidHashUpdate))
}
}
.flatMap { [dependencies] (configMessageJobs: [Job], standardMessageJobs: [Job], pollResult: PollResult) -> AnyPublisher<PollResult, Error> in
// If we don't want to forcible process the response synchronously then just finish immediately
guard forceSynchronousProcessing else {
return Just(pollResult)
.setFailureType(to: Error.self)
.eraseToAnyPublisher()
}
// We want to try to handle the receive jobs immediately in the background
return Publishers
.MergeMany(
configMessageJobs.map { job -> AnyPublisher<Void, Error> in
Deferred {
Future<Void, Error> { resolver in
// Note: In the background we just want jobs to fail silently
ConfigMessageReceiveJob.run(
job,
queue: pollerQueue,
success: { _, _ in resolver(Result.success(())) },
failure: { _, _, _ in resolver(Result.success(())) },
deferred: { _ in resolver(Result.success(())) },
using: dependencies
)
}
}
.eraseToAnyPublisher()
}
)
.collect()
.flatMap { _ in
Publishers
.MergeMany(
standardMessageJobs.map { job -> AnyPublisher<Void, Error> in
Deferred {
Future<Void, Error> { resolver in
// Note: In the background we just want jobs to fail silently
MessageReceiveJob.run(
job,
queue: pollerQueue,
success: { _, _ in resolver(Result.success(())) },
failure: { _, _, _ in resolver(Result.success(())) },
deferred: { _ in resolver(Result.success(())) },
using: dependencies
)
}
}
.eraseToAnyPublisher()
}
)
.collect()
}
.map { _ in pollResult }
.eraseToAnyPublisher()
}
.handleEvents(
receiveOutput: { [weak self] (pollResult: PollResult) in
/// Notify any observers that we got a result
self?.receivedPollResponseSubject.send(pollResult.response)
}
)
.eraseToAnyPublisher()
}
}