Add type-aware REQUEST_SYNC sync rounds (#853)

Co-authored-by: jack <jackjackbits@users.noreply.github.com>

bitchat/Models/RequestSyncPacket.swift

@@ -8,6 +8,14 @@ struct RequestSyncPacket {
     let p: Int
     let m: UInt32
     let data: Data
+    let types: SyncTypeFlags?
+
+    init(p: Int, m: UInt32, data: Data, types: SyncTypeFlags? = nil) {
+        self.p = p
+        self.m = m
+        self.data = data
+        self.types = types
+    }
 
     func encode() -> Data {
         var out = Data()
@@ -25,6 +33,9 @@ struct RequestSyncPacket {
         putTLV(0x02, withUnsafeBytes(of: &mBE) { Data($0) })
         // data
         putTLV(0x03, data)
+        if let typesData = types?.toData() {
+            putTLV(0x04, typesData)
+        }
         return out
     }
 
@@ -33,6 +44,7 @@ struct RequestSyncPacket {
         var p: Int? = nil
         var m: UInt32? = nil
         var payload: Data? = nil
+        var types: SyncTypeFlags? = nil
 
         while off + 3 <= data.count {
             let t = Int(data[off]); off += 1
@@ -52,12 +64,16 @@ struct RequestSyncPacket {
             case 0x03:
                 if v.count > maxAcceptBytes { return nil }
                 payload = v
+            case 0x04:
+                if let decoded = SyncTypeFlags.decode(v) {
+                    types = decoded
+                }
             default:
                 break // forward compatible; ignore unknown TLVs
             }
         }
 
         guard let pp = p, let mm = m, let dd = payload, pp >= 1, mm > 0 else { return nil }
-        return RequestSyncPacket(p: pp, m: mm, data: dd)
+        return RequestSyncPacket(p: pp, m: mm, data: dd, types: types)
     }
 }

bitchat/Services/BLE/BLEService.swift

@@ -2803,6 +2803,9 @@ extension BLEService {
                     let isActive = self.collectionsQueue.sync { self.activeTransfers[transferId] != nil }
                     guard isActive else { return }
                 }
+                if fragmentRecipient == nil || fragmentRecipient?.allSatisfy({ $0 == 0xFF }) == true {
+                    self.gossipSyncManager?.onPublicPacketSeen(fragmentPacket)
+                }
                 self.broadcastPacket(fragmentPacket)
                 if let transferId = transferIdentifier {
                     self.markFragmentSent(transferId: transferId)
@@ -2904,6 +2907,14 @@ extension BLEService {
         // Sanity checks - add reasonable upper bound on total to prevent DoS
         guard total > 0 && total <= 10000 && index >= 0 && index < total else { return }
 
+        let isBroadcastFragment: Bool = {
+            guard let recipient = packet.recipientID else { return true }
+            return recipient.count == 8 && recipient.allSatisfy { $0 == 0xFF }
+        }()
+        if isBroadcastFragment {
+            gossipSyncManager?.onPublicPacketSeen(packet)
+        }
+
         // Compute fragment key for this assembly
         let key = FragmentKey(sender: senderU64, id: fragU64)
 

bitchat/Sync/GossipSyncManager.swift

@@ -8,6 +8,55 @@ final class GossipSyncManager {
         func signPacketForBroadcast(_ packet: BitchatPacket) -> BitchatPacket
     }
 
+    private struct PacketStore {
+        private(set) var packets: [String: BitchatPacket] = [:]
+        private(set) var order: [String] = []
+
+        mutating func insert(idHex: String, packet: BitchatPacket, capacity: Int) {
+            guard capacity > 0 else { return }
+            if packets[idHex] != nil {
+                packets[idHex] = packet
+                return
+            }
+            packets[idHex] = packet
+            order.append(idHex)
+            while order.count > capacity {
+                let victim = order.removeFirst()
+                packets.removeValue(forKey: victim)
+            }
+        }
+
+        func allPackets(isFresh: (BitchatPacket) -> Bool) -> [BitchatPacket] {
+            order.compactMap { key in
+                guard let packet = packets[key], isFresh(packet) else { return nil }
+                return packet
+            }
+        }
+
+        mutating func remove(where shouldRemove: (BitchatPacket) -> Bool) {
+            var nextOrder: [String] = []
+            for key in order {
+                guard let packet = packets[key] else { continue }
+                if shouldRemove(packet) {
+                    packets.removeValue(forKey: key)
+                } else {
+                    nextOrder.append(key)
+                }
+            }
+            order = nextOrder
+        }
+
+        mutating func removeExpired(isFresh: (BitchatPacket) -> Bool) {
+            remove { !isFresh($0) }
+        }
+    }
+
+    private struct SyncSchedule {
+        let types: SyncTypeFlags
+        let interval: TimeInterval
+        var lastSent: Date
+    }
+
     struct Config {
         var seenCapacity: Int = 1000          // max packets per sync (cap across types)
         var gcsMaxBytes: Int = 400           // filter size budget (128..1024)
@@ -16,25 +65,43 @@ final class GossipSyncManager {
         var maintenanceIntervalSeconds: TimeInterval = 30.0
         var stalePeerCleanupIntervalSeconds: TimeInterval = 60.0
         var stalePeerTimeoutSeconds: TimeInterval = 60.0
+        var fragmentCapacity: Int = 600
+        var fileTransferCapacity: Int = 200
+        var fragmentSyncIntervalSeconds: TimeInterval = 30.0
+        var fileTransferSyncIntervalSeconds: TimeInterval = 60.0
+        var messageSyncIntervalSeconds: TimeInterval = 15.0
     }
 
     private let myPeerID: PeerID
     private let config: Config
     weak var delegate: Delegate?
 
-    // Storage: broadcast messages (ordered by insert), and latest announce per sender
-    private var messages: [String: BitchatPacket] = [:] // idHex -> packet
-    private var messageOrder: [String] = []
+    // Storage: broadcast packets by type, and latest announce per sender
+    private var messages = PacketStore()
+    private var fragments = PacketStore()
+    private var fileTransfers = PacketStore()
     private var latestAnnouncementByPeer: [PeerID: (id: String, packet: BitchatPacket)] = [:]
 
     // Timer
     private var periodicTimer: DispatchSourceTimer?
     private let queue = DispatchQueue(label: "mesh.sync", qos: .utility)
     private var lastStalePeerCleanup: Date = .distantPast
+    private var syncSchedules: [SyncSchedule] = []
 
     init(myPeerID: PeerID, config: Config = Config()) {
         self.myPeerID = myPeerID
         self.config = config
+        var schedules: [SyncSchedule] = []
+        if config.seenCapacity > 0 && config.messageSyncIntervalSeconds > 0 {
+            schedules.append(SyncSchedule(types: .publicMessages, interval: config.messageSyncIntervalSeconds, lastSent: .distantPast))
+        }
+        if config.fragmentCapacity > 0 && config.fragmentSyncIntervalSeconds > 0 {
+            schedules.append(SyncSchedule(types: .fragment, interval: config.fragmentSyncIntervalSeconds, lastSent: .distantPast))
+        }
+        if config.fileTransferCapacity > 0 && config.fileTransferSyncIntervalSeconds > 0 {
+            schedules.append(SyncSchedule(types: .fileTransfer, interval: config.fileTransferSyncIntervalSeconds, lastSent: .distantPast))
+        }
+        syncSchedules = schedules
     }
 
     func start() {
@@ -55,7 +122,18 @@ final class GossipSyncManager {
 
     func scheduleInitialSyncToPeer(_ peerID: PeerID, delaySeconds: TimeInterval = 5.0) {
         queue.asyncAfter(deadline: .now() + delaySeconds) { [weak self] in
-            self?.sendRequestSync(to: peerID)
+            guard let self = self else { return }
+            self.sendRequestSync(to: peerID, types: .publicMessages)
+            if self.config.fragmentCapacity > 0 && self.config.fragmentSyncIntervalSeconds > 0 {
+                self.queue.asyncAfter(deadline: .now() + 0.5) { [weak self] in
+                    self?.sendRequestSync(to: peerID, types: .fragment)
+                }
+            }
+            if self.config.fileTransferCapacity > 0 && self.config.fileTransferSyncIntervalSeconds > 0 {
+                self.queue.asyncAfter(deadline: .now() + 1.0) { [weak self] in
+                    self?.sendRequestSync(to: peerID, types: .fileTransfer)
+                }
+            }
         }
     }
 
@@ -87,47 +165,45 @@ final class GossipSyncManager {
     }
 
     private func _onPublicPacketSeen(_ packet: BitchatPacket) {
-        let mt = MessageType(rawValue: packet.type)
+        guard let messageType = MessageType(rawValue: packet.type) else { return }
         let isBroadcastRecipient: Bool = {
             guard let r = packet.recipientID else { return true }
             return r.count == 8 && r.allSatisfy { $0 == 0xFF }
         }()
-        let isBroadcastMessage = (mt == .message && isBroadcastRecipient)
-        let isAnnounce = (mt == .announce)
-        guard isBroadcastMessage || isAnnounce else { return }
 
-        // Reject expired packets to prevent ghost peers and old messages
-        guard isPacketFresh(packet) else { return }
-
-        if isAnnounce {
+        switch messageType {
+        case .announce:
+            guard isPacketFresh(packet) else { return }
             guard isAnnouncementFresh(packet) else {
                 let sender = PeerID(hexData: packet.senderID)
                 removeState(for: sender)
                 return
             }
-        }
-
-        let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
-
-        if isBroadcastMessage {
-            if messages[idHex] == nil {
-                messages[idHex] = packet
-                messageOrder.append(idHex)
-                // Enforce capacity
-                let cap = max(1, config.seenCapacity)
-                while messageOrder.count > cap {
-                    let victim = messageOrder.removeFirst()
-                    messages.removeValue(forKey: victim)
-                }
-            }
-        } else if isAnnounce {
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
             let sender = PeerID(hexData: packet.senderID)
             latestAnnouncementByPeer[sender] = (id: idHex, packet: packet)
+        case .message:
+            guard isBroadcastRecipient else { return }
+            guard isPacketFresh(packet) else { return }
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
+            messages.insert(idHex: idHex, packet: packet, capacity: max(1, config.seenCapacity))
+        case .fragment:
+            guard isBroadcastRecipient else { return }
+            guard isPacketFresh(packet) else { return }
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
+            fragments.insert(idHex: idHex, packet: packet, capacity: max(1, config.fragmentCapacity))
+        case .fileTransfer:
+            guard isBroadcastRecipient else { return }
+            guard isPacketFresh(packet) else { return }
+            let idHex = PacketIdUtil.computeId(packet).hexEncodedString()
+            fileTransfers.insert(idHex: idHex, packet: packet, capacity: max(1, config.fileTransferCapacity))
+        default:
+            break
         }
     }
 
-    private func sendRequestSync() {
-        let payload = buildGcsPayload()
+    private func sendRequestSync(for types: SyncTypeFlags) {
+        let payload = buildGcsPayload(for: types)
         let pkt = BitchatPacket(
             type: MessageType.requestSync.rawValue,
             senderID: Data(hexString: myPeerID.id) ?? Data(),
@@ -141,8 +217,8 @@ final class GossipSyncManager {
         delegate?.sendPacket(signed)
     }
 
-    private func sendRequestSync(to peerID: PeerID) {
-        let payload = buildGcsPayload()
+    private func sendRequestSync(to peerID: PeerID, types: SyncTypeFlags) {
+        let payload = buildGcsPayload(for: types)
         var recipient = Data()
         var temp = peerID.id
         while temp.count >= 2 && recipient.count < 8 {
@@ -170,6 +246,7 @@ final class GossipSyncManager {
     }
 
     private func _handleRequestSync(from peerID: PeerID, request: RequestSyncPacket) {
+        let requestedTypes = (request.types ?? .publicMessages)
         // Decode GCS into sorted set and prepare membership checker
         let sorted = GCSFilter.decodeToSortedSet(p: request.p, m: request.m, data: request.data)
         func mightContain(_ id: Data) -> Bool {
@@ -177,60 +254,100 @@ final class GossipSyncManager {
             return GCSFilter.contains(sortedValues: sorted, candidate: bucket)
         }
 
-        // 1) Announcements: send latest per peer if requester lacks them (and not expired)
-        for (_, pair) in latestAnnouncementByPeer {
-            let (idHex, pkt) = pair
-            guard isPacketFresh(pkt) else { continue }
-            let idBytes = Data(hexString: idHex) ?? Data()
-            if !mightContain(idBytes) {
-                var toSend = pkt
-                toSend.ttl = 0
-                delegate?.sendPacket(to: peerID, packet: toSend)
+        if requestedTypes.contains(.announce) {
+            for (_, pair) in latestAnnouncementByPeer {
+                let (idHex, pkt) = pair
+                guard isPacketFresh(pkt) else { continue }
+                let idBytes = Data(hexString: idHex) ?? Data()
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
             }
         }
 
-        // 2) Broadcast messages: send all missing (and not expired)
-        let toSendMsgs = messageOrder.compactMap { messages[$0] }
-        for pkt in toSendMsgs {
-            guard isPacketFresh(pkt) else { continue }
-            let idBytes = PacketIdUtil.computeId(pkt)
-            if !mightContain(idBytes) {
-                var toSend = pkt
-                toSend.ttl = 0
-                delegate?.sendPacket(to: peerID, packet: toSend)
+        if requestedTypes.contains(.message) {
+            let toSendMsgs = messages.allPackets(isFresh: isPacketFresh)
+            for pkt in toSendMsgs {
+                let idBytes = PacketIdUtil.computeId(pkt)
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
+            }
+        }
+
+        if requestedTypes.contains(.fragment) {
+            let frags = fragments.allPackets(isFresh: isPacketFresh)
+            for pkt in frags {
+                let idBytes = PacketIdUtil.computeId(pkt)
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
+            }
+        }
+
+        if requestedTypes.contains(.fileTransfer) {
+            let files = fileTransfers.allPackets(isFresh: isPacketFresh)
+            for pkt in files {
+                let idBytes = PacketIdUtil.computeId(pkt)
+                if !mightContain(idBytes) {
+                    var toSend = pkt
+                    toSend.ttl = 0
+                    delegate?.sendPacket(to: peerID, packet: toSend)
+                }
             }
         }
     }
 
     // Build REQUEST_SYNC payload using current candidates and GCS params
-    private func buildGcsPayload() -> Data {
-        // Collect candidates: latest announce per peer + broadcast messages (only fresh)
+    private func buildGcsPayload(for types: SyncTypeFlags) -> Data {
         var candidates: [BitchatPacket] = []
-        candidates.reserveCapacity(latestAnnouncementByPeer.count + messageOrder.count)
-        for (_, pair) in latestAnnouncementByPeer {
-            if isPacketFresh(pair.packet) {
+        if types.contains(.announce) {
+            for (_, pair) in latestAnnouncementByPeer where isPacketFresh(pair.packet) {
                 candidates.append(pair.packet)
             }
         }
-        for id in messageOrder {
-            if let p = messages[id], isPacketFresh(p) {
-                candidates.append(p)
-            }
+        if types.contains(.message) {
+            candidates.append(contentsOf: messages.allPackets(isFresh: isPacketFresh))
         }
+        if types.contains(.fragment) {
+            candidates.append(contentsOf: fragments.allPackets(isFresh: isPacketFresh))
+        }
+        if types.contains(.fileTransfer) {
+            candidates.append(contentsOf: fileTransfers.allPackets(isFresh: isPacketFresh))
+        }
+        if candidates.isEmpty {
+            let p = GCSFilter.deriveP(targetFpr: config.gcsTargetFpr)
+            let req = RequestSyncPacket(p: p, m: 1, data: Data(), types: types)
+            return req.encode()
+        }
+
         // Sort by timestamp desc
         candidates.sort { $0.timestamp > $1.timestamp }
 
         let p = GCSFilter.deriveP(targetFpr: config.gcsTargetFpr)
         let nMax = GCSFilter.estimateMaxElements(sizeBytes: config.gcsMaxBytes, p: p)
-        let cap = max(1, config.seenCapacity)
+        let cap: Int
+        if types == .fragment {
+            cap = max(1, config.fragmentCapacity)
+        } else if types == .fileTransfer {
+            cap = max(1, config.fileTransferCapacity)
+        } else {
+            cap = max(1, config.seenCapacity)
+        }
         let takeN = min(candidates.count, min(nMax, cap))
         if takeN <= 0 {
-            let req = RequestSyncPacket(p: p, m: 1, data: Data())
+            let req = RequestSyncPacket(p: p, m: 1, data: Data(), types: types)
             return req.encode()
         }
         let ids: [Data] = candidates.prefix(takeN).map { PacketIdUtil.computeId($0) }
         let params = GCSFilter.buildFilter(ids: ids, maxBytes: config.gcsMaxBytes, targetFpr: config.gcsTargetFpr)
-        let req = RequestSyncPacket(p: params.p, m: params.m, data: params.data)
+        let req = RequestSyncPacket(p: params.p, m: params.m, data: params.data, types: types)
         return req.encode()
     }
 
@@ -241,20 +358,21 @@ final class GossipSyncManager {
             isPacketFresh(pair.packet)
         }
 
-        // Remove expired messages
-        let expiredMessageIds = messages.compactMap { id, pkt in
-            isPacketFresh(pkt) ? nil : id
-        }
-        for id in expiredMessageIds {
-            messages.removeValue(forKey: id)
-            messageOrder.removeAll { $0 == id }
-        }
+        messages.removeExpired(isFresh: isPacketFresh)
+        fragments.removeExpired(isFresh: isPacketFresh)
+        fileTransfers.removeExpired(isFresh: isPacketFresh)
     }
 
     private func performPeriodicMaintenance(now: Date = Date()) {
         cleanupExpiredMessages()
         cleanupStaleAnnouncementsIfNeeded(now: now)
-        sendRequestSync()
+        for index in syncSchedules.indices {
+            guard syncSchedules[index].interval > 0 else { continue }
+            if syncSchedules[index].lastSent == .distantPast || now.timeIntervalSince(syncSchedules[index].lastSent) >= syncSchedules[index].interval {
+                syncSchedules[index].lastSent = now
+                sendRequestSync(for: syncSchedules[index].types)
+            }
+        }
     }
 
     private func cleanupStaleAnnouncementsIfNeeded(now: Date) {
@@ -288,17 +406,9 @@ final class GossipSyncManager {
 
     private func removeState(for peerID: PeerID) {
         _ = latestAnnouncementByPeer.removeValue(forKey: peerID)
-        // Remove messages from this peer
-        // Collect IDs to remove first to avoid concurrent modification
-        let messageIdsToRemove = messages.compactMap { (id, message) -> String? in
-            PeerID(hexData: message.senderID) == peerID ? id : nil
-        }
-        
-        // Remove messages and update messageOrder
-        for id in messageIdsToRemove {
-            messages.removeValue(forKey: id)
-            messageOrder.removeAll { $0 == id }
-        }
+        messages.remove { PeerID(hexData: $0.senderID) == peerID }
+        fragments.remove { PeerID(hexData: $0.senderID) == peerID }
+        fileTransfers.remove { PeerID(hexData: $0.senderID) == peerID }
     }
 }
 
@@ -318,7 +428,7 @@ extension GossipSyncManager {
 
     func _messageCount(for peerID: PeerID) -> Int {
         queue.sync {
-            messages.values.filter { PeerID(hexData: $0.senderID) == peerID }.count
+            messages.allPackets { _ in true }.filter { PeerID(hexData: $0.senderID) == peerID }.count
         }
     }
 }

bitchat/Sync/SyncTypeFlags.swift

@@ -0,0 +1,104 @@
+import Foundation
+
+/// Bitfield describing which message types are covered by a REQUEST_SYNC round.
+/// Matches the Android mapping (bit index -> message type).
+struct SyncTypeFlags: OptionSet {
+    let rawValue: UInt64
+
+    init(rawValue: UInt64) {
+        self.rawValue = rawValue & 0x00FF_FFFF_FFFF_FFFF // Trim to max 8 bytes
+    }
+
+    private static func bitIndex(for type: MessageType) -> Int? {
+        switch type {
+        case .announce: return 0
+        case .message: return 1
+        case .leave: return 2
+        case .noiseHandshake: return 3
+        case .noiseEncrypted: return 4
+        case .fragment: return 5
+        case .requestSync: return 6
+        case .fileTransfer: return 7
+        }
+    }
+
+    private static func type(forBit index: Int) -> MessageType? {
+        switch index {
+        case 0: return .announce
+        case 1: return .message
+        case 2: return .leave
+        case 3: return .noiseHandshake
+        case 4: return .noiseEncrypted
+        case 5: return .fragment
+        case 6: return .requestSync
+        case 7: return .fileTransfer
+        default:
+            return nil
+        }
+    }
+
+    static let announce = SyncTypeFlags(messageTypes: [.announce])
+    static let message = SyncTypeFlags(messageTypes: [.message])
+    static let fragment = SyncTypeFlags(messageTypes: [.fragment])
+    static let fileTransfer = SyncTypeFlags(messageTypes: [.fileTransfer])
+
+    static let publicMessages = SyncTypeFlags(messageTypes: [.announce, .message])
+
+    init(messageTypes: [MessageType]) {
+        var raw: UInt64 = 0
+        for type in messageTypes {
+            guard let bit = SyncTypeFlags.bitIndex(for: type) else { continue }
+            raw |= (1 << UInt64(bit))
+        }
+        self.init(rawValue: raw)
+    }
+
+    func contains(_ type: MessageType) -> Bool {
+        guard let bit = SyncTypeFlags.bitIndex(for: type) else { return false }
+        return contains(SyncTypeFlags(rawValue: 1 << UInt64(bit)))
+    }
+
+    func union(_ other: SyncTypeFlags) -> SyncTypeFlags {
+        SyncTypeFlags(rawValue: rawValue | other.rawValue)
+    }
+
+    func intersection(_ other: SyncTypeFlags) -> SyncTypeFlags {
+        SyncTypeFlags(rawValue: rawValue & other.rawValue)
+    }
+
+    func toMessageTypes() -> [MessageType] {
+        guard rawValue != 0 else { return [] }
+        var types: [MessageType] = []
+        for bit in 0..<64 {
+            guard (rawValue & (1 << UInt64(bit))) != 0 else { continue }
+            if let type = SyncTypeFlags.type(forBit: bit) {
+                types.append(type)
+            }
+        }
+        return types
+    }
+
+    func toData() -> Data? {
+        guard rawValue != 0 else { return nil }
+        var value = rawValue
+        var bytes: [UInt8] = []
+        while value > 0 && bytes.count < 8 {
+            bytes.append(UInt8(value & 0xFF))
+            value >>= 8
+        }
+        while let last = bytes.last, last == 0 {
+            bytes.removeLast()
+        }
+        guard !bytes.isEmpty, bytes.count <= 8 else { return nil }
+        return Data(bytes)
+    }
+
+    static func decode(_ data: Data) -> SyncTypeFlags? {
+        guard (1...8).contains(data.count) else { return nil }
+        var raw: UInt64 = 0
+        for (index, byte) in data.enumerated() {
+            raw |= UInt64(byte) << UInt64(index * 8)
+        }
+        return SyncTypeFlags(rawValue: raw)
+    }
+}

bitchatTests/GossipSyncManagerTests.swift

@@ -125,16 +125,138 @@ struct GossipSyncManagerTests {
         #expect(manager._hasAnnouncement(for: PeerID(str: peerHex)) == false)
         #expect(manager._messageCount(for: PeerID(str: peerHex)) == 0)
     }
+
+    @Test func maintenanceEmitsTypedSyncRequests() throws {
+        var config = GossipSyncManager.Config()
+        config.seenCapacity = 10
+        config.fragmentCapacity = 5
+        config.fileTransferCapacity = 4
+        config.messageSyncIntervalSeconds = 1
+        config.fragmentSyncIntervalSeconds = 1
+        config.fileTransferSyncIntervalSeconds = 1
+        config.maintenanceIntervalSeconds = 0
+
+        let manager = GossipSyncManager(myPeerID: myPeerID, config: config)
+        let delegate = RecordingDelegate()
+        manager.delegate = delegate
+
+        let sender = try #require(Data(hexString: "1122334455667788"))
+        let now = UInt64(Date().timeIntervalSince1970 * 1000)
+
+        let announcePacket = BitchatPacket(
+            type: MessageType.announce.rawValue,
+            senderID: sender,
+            recipientID: nil,
+            timestamp: now,
+            payload: Data(),
+            signature: nil,
+            ttl: 1
+        )
+        let messagePacket = BitchatPacket(
+            type: MessageType.message.rawValue,
+            senderID: sender,
+            recipientID: nil,
+            timestamp: now,
+            payload: Data([0x01]),
+            signature: nil,
+            ttl: 1
+        )
+        let fragmentPacket = BitchatPacket(
+            type: MessageType.fragment.rawValue,
+            senderID: sender,
+            recipientID: nil,
+            timestamp: now,
+            payload: Data([0xAA]),
+            signature: nil,
+            ttl: 1
+        )
+        let filePacket = BitchatPacket(
+            type: MessageType.fileTransfer.rawValue,
+            senderID: sender,
+            recipientID: nil,
+            timestamp: now,
+            payload: Data([0xBB]),
+            signature: nil,
+            ttl: 1,
+            version: 2
+        )
+
+        manager.onPublicPacketSeen(announcePacket)
+        manager.onPublicPacketSeen(messagePacket)
+        manager.onPublicPacketSeen(fragmentPacket)
+        manager.onPublicPacketSeen(filePacket)
+
+        manager._performMaintenanceSynchronously(now: Date())
+
+        let sentPackets = delegate.packets
+        #expect(sentPackets.count == 3)
+        let decoded = sentPackets.compactMap { RequestSyncPacket.decode(from: $0.payload) }
+        #expect(decoded.count == 3)
+        #expect(decoded[0].types == .publicMessages)
+        #expect(decoded[1].types == .fragment)
+        #expect(decoded[2].types == .fileTransfer)
+    }
+
+    @Test func handleRequestSyncHonorsTypeFilter() async throws {
+        var config = GossipSyncManager.Config()
+        config.seenCapacity = 5
+        config.fragmentCapacity = 5
+        config.fileTransferCapacity = 0
+        config.messageSyncIntervalSeconds = 0
+        config.fragmentSyncIntervalSeconds = 0
+        config.fileTransferSyncIntervalSeconds = 0
+
+        let manager = GossipSyncManager(myPeerID: myPeerID, config: config)
+        let delegate = RecordingDelegate()
+        manager.delegate = delegate
+
+        let sender = try #require(Data(hexString: "aabbccddeeff0011"))
+        let now = UInt64(Date().timeIntervalSince1970 * 1000)
+
+        let messagePacket = BitchatPacket(
+            type: MessageType.message.rawValue,
+            senderID: sender,
+            recipientID: nil,
+            timestamp: now,
+            payload: Data([0x10]),
+            signature: nil,
+            ttl: 1
+        )
+
+        let fragmentPacket = BitchatPacket(
+            type: MessageType.fragment.rawValue,
+            senderID: sender,
+            recipientID: nil,
+            timestamp: now,
+            payload: Data([0x20]),
+            signature: nil,
+            ttl: 1
+        )
+
+        manager.onPublicPacketSeen(messagePacket)
+        manager.onPublicPacketSeen(fragmentPacket)
+
+        let peer = PeerID(str: "FFFFFFFFFFFFFFFF")
+        let request = RequestSyncPacket(p: 4, m: 1, data: Data(), types: .fragment)
+        manager.handleRequestSync(from: peer, request: request)
+
+        try await sleep(0.01)
+        let sentPackets = delegate.packets
+        #expect(sentPackets.count == 1)
+        #expect(sentPackets[0].type == MessageType.fragment.rawValue)
+    }
 }
 
 private final class RecordingDelegate: GossipSyncManager.Delegate {
     var onSend: (() -> Void)?
     private(set) var lastPacket: BitchatPacket?
+    private(set) var packets: [BitchatPacket] = []
     private let lock = NSLock()
 
     func sendPacket(_ packet: BitchatPacket) {
         lock.lock()
         lastPacket = packet
+        packets.append(packet)
         lock.unlock()
         onSend?()
     }