Extract public timeline helpers and rate limiter (#869)

2026-07-26 02:05:19 +00:00 · 2025-10-27 14:13:57 +01:00
parent 14c4e586fc
commit a91978c10e
5 changed files with 620 additions and 475 deletions
@@ -0,0 +1,124 @@
+//
+// PublicTimelineStore.swift
+// bitchat
+//
+// Maintains mesh and geohash public timelines with simple caps and helpers.
+//
+
+import Foundation
+
+struct PublicTimelineStore {
+    private var meshTimeline: [BitchatMessage] = []
+    private var geohashTimelines: [String: [BitchatMessage]] = [:]
+    private var pendingGeohashSystemMessages: [String] = []
+
+    private let meshCap: Int
+    private let geohashCap: Int
+
+    init(meshCap: Int, geohashCap: Int) {
+        self.meshCap = meshCap
+        self.geohashCap = geohashCap
+    }
+
+    mutating func append(_ message: BitchatMessage, to channel: ChannelID) {
+        switch channel {
+        case .mesh:
+            guard !meshTimeline.contains(where: { $0.id == message.id }) else { return }
+            meshTimeline.append(message)
+            trimMeshTimelineIfNeeded()
+        case .location(let channel):
+            append(message, toGeohash: channel.geohash)
+        }
+    }
+
+    mutating func append(_ message: BitchatMessage, toGeohash geohash: String) {
+        var timeline = geohashTimelines[geohash] ?? []
+        guard !timeline.contains(where: { $0.id == message.id }) else { return }
+        timeline.append(message)
+        trimGeohashTimelineIfNeeded(&timeline)
+        geohashTimelines[geohash] = timeline
+    }
+
+    /// Append message if absent, returning true when stored.
+    mutating func appendIfAbsent(_ message: BitchatMessage, toGeohash geohash: String) -> Bool {
+        var timeline = geohashTimelines[geohash] ?? []
+        guard !timeline.contains(where: { $0.id == message.id }) else { return false }
+        timeline.append(message)
+        trimGeohashTimelineIfNeeded(&timeline)
+        geohashTimelines[geohash] = timeline
+        return true
+    }
+
+    mutating func messages(for channel: ChannelID) -> [BitchatMessage] {
+        switch channel {
+        case .mesh:
+            return meshTimeline
+        case .location(let channel):
+            let cleaned = geohashTimelines[channel.geohash]?.cleanedAndDeduped() ?? []
+            geohashTimelines[channel.geohash] = cleaned
+            return cleaned
+        }
+    }
+
+    mutating func clear(channel: ChannelID) {
+        switch channel {
+        case .mesh:
+            meshTimeline.removeAll()
+        case .location(let channel):
+            geohashTimelines[channel.geohash] = []
+        }
+    }
+
+    @discardableResult
+    mutating func removeMessage(withID id: String) -> BitchatMessage? {
+        if let index = meshTimeline.firstIndex(where: { $0.id == id }) {
+            return meshTimeline.remove(at: index)
+        }
+
+        for key in Array(geohashTimelines.keys) {
+            var timeline = geohashTimelines[key] ?? []
+            if let index = timeline.firstIndex(where: { $0.id == id }) {
+                let removed = timeline.remove(at: index)
+                geohashTimelines[key] = timeline.isEmpty ? nil : timeline
+                return removed
+            }
+        }
+
+        return nil
+    }
+
+    mutating func removeMessages(in geohash: String, where predicate: (BitchatMessage) -> Bool) {
+        var timeline = geohashTimelines[geohash] ?? []
+        timeline.removeAll(where: predicate)
+        geohashTimelines[geohash] = timeline.isEmpty ? nil : timeline
+    }
+
+    mutating func mutateGeohash(_ geohash: String, _ transform: (inout [BitchatMessage]) -> Void) {
+        var timeline = geohashTimelines[geohash] ?? []
+        transform(&timeline)
+        geohashTimelines[geohash] = timeline.isEmpty ? nil : timeline
+    }
+
+    mutating func queueGeohashSystemMessage(_ content: String) {
+        pendingGeohashSystemMessages.append(content)
+    }
+
+    mutating func drainPendingGeohashSystemMessages() -> [String] {
+        defer { pendingGeohashSystemMessages.removeAll(keepingCapacity: false) }
+        return pendingGeohashSystemMessages
+    }
+
+    func geohashKeys() -> [String] {
+        Array(geohashTimelines.keys)
+    }
+
+    private mutating func trimMeshTimelineIfNeeded() {
+        guard meshTimeline.count > meshCap else { return }
+        meshTimeline = Array(meshTimeline.suffix(meshCap))
+    }
+
+    private func trimGeohashTimelineIfNeeded(_ timeline: inout [BitchatMessage]) {
+        guard timeline.count > geohashCap else { return }
+        timeline = Array(timeline.suffix(geohashCap))
+    }
+}