180 lines
7.2 KiB
Swift
180 lines
7.2 KiB
Swift
import Foundation
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/// 通过 RTCDataChannel 传输的控制指令。
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/// 与 control_message.proto (proto3) 二进制格式完全兼容（手写极简 protobuf 编解码，
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/// 免去 SwiftProtobuf 依赖与代码生成）。
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/// 坐标 x/y/x1/y1/x2/y2 均为相对屏幕的百分比，取值范围 0.0 ~ 1.0。
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struct ControlMessage {
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enum Action: Int {
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case unknown = 0
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case touch = 1
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case swipe = 2
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case key = 3
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case longPress = 4
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case motionEvent = 5
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case setResolution = 6 // 控制端请求被控端切换屏幕采集分辨率
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case reportResolution = 7 // 被控端上报当前实际采集分辨率
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case setStreamMode = 8 // 控制端请求被控端切换屏幕串流模式
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case reportStreamMode = 9 // 被控端上报当前生效的串流模式
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}
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var action: Action = .unknown // field 1, varint
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var x: Double = 0 // field 2, fixed64
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var y: Double = 0 // field 3, fixed64
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var x1: Double = 0 // field 4, fixed64
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var y1: Double = 0 // field 5, fixed64
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var x2: Double = 0 // field 6, fixed64
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var y2: Double = 0 // field 7, fixed64
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var duration: Int64 = 0 // field 8, varint
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var keyCode: Int32 = 0 // field 9, varint
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var keyAction: Int32 = 0 // field 10, varint (0=按下 1=抬起)
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var motionAction: Int32 = 0 // field 11, varint (0=DOWN 1=UP 2=MOVE 3=CANCEL)
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var width: Int32 = 0 // field 12, varint
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var height: Int32 = 0 // field 13, varint
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var fps: Int32 = 0 // field 14, varint
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var streamMode: Int32 = 0 // field 15, varint (0=WebRTC 1=自编码)
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// MARK: - Encode
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func serializedData() -> Data {
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var w = ProtoWriter()
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w.writeVarintField(1, UInt64(action.rawValue))
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w.writeDoubleField(2, x)
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w.writeDoubleField(3, y)
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w.writeDoubleField(4, x1)
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w.writeDoubleField(5, y1)
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w.writeDoubleField(6, x2)
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w.writeDoubleField(7, y2)
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w.writeVarintField(8, UInt64(bitPattern: duration))
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w.writeVarintField(9, UInt64(bitPattern: Int64(keyCode)))
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w.writeVarintField(10, UInt64(bitPattern: Int64(keyAction)))
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w.writeVarintField(11, UInt64(bitPattern: Int64(motionAction)))
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w.writeVarintField(12, UInt64(bitPattern: Int64(width)))
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w.writeVarintField(13, UInt64(bitPattern: Int64(height)))
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w.writeVarintField(14, UInt64(bitPattern: Int64(fps)))
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w.writeVarintField(15, UInt64(bitPattern: Int64(streamMode)))
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return w.data
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}
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// MARK: - Decode
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static func parse(from data: Data) -> ControlMessage? {
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var msg = ControlMessage()
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var r = ProtoReader(data: data)
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while let (field, wire) = r.readTag() {
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switch (field, wire) {
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case (1, 0):
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guard let v = r.readVarint() else { return nil }
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msg.action = Action(rawValue: Int(v)) ?? .unknown
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case (2, 1): guard let v = r.readDouble() else { return nil }; msg.x = v
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case (3, 1): guard let v = r.readDouble() else { return nil }; msg.y = v
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case (4, 1): guard let v = r.readDouble() else { return nil }; msg.x1 = v
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case (5, 1): guard let v = r.readDouble() else { return nil }; msg.y1 = v
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case (6, 1): guard let v = r.readDouble() else { return nil }; msg.x2 = v
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case (7, 1): guard let v = r.readDouble() else { return nil }; msg.y2 = v
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case (8, 0): guard let v = r.readVarint() else { return nil }; msg.duration = Int64(bitPattern: v)
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case (9, 0): guard let v = r.readVarint() else { return nil }; msg.keyCode = Int32(truncatingIfNeeded: Int64(bitPattern: v))
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case (10, 0): guard let v = r.readVarint() else { return nil }; msg.keyAction = Int32(truncatingIfNeeded: Int64(bitPattern: v))
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case (11, 0): guard let v = r.readVarint() else { return nil }; msg.motionAction = Int32(truncatingIfNeeded: Int64(bitPattern: v))
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case (12, 0): guard let v = r.readVarint() else { return nil }; msg.width = Int32(truncatingIfNeeded: Int64(bitPattern: v))
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case (13, 0): guard let v = r.readVarint() else { return nil }; msg.height = Int32(truncatingIfNeeded: Int64(bitPattern: v))
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case (14, 0): guard let v = r.readVarint() else { return nil }; msg.fps = Int32(truncatingIfNeeded: Int64(bitPattern: v))
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case (15, 0): guard let v = r.readVarint() else { return nil }; msg.streamMode = Int32(truncatingIfNeeded: Int64(bitPattern: v))
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default:
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// 未知字段按 wire type 跳过
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if !r.skip(wireType: wire) { return nil }
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}
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}
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return msg
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}
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}
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// MARK: - 极简 protobuf 读写器
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private struct ProtoWriter {
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var data = Data()
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mutating func writeVarint(_ value: UInt64) {
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var v = value
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while v >= 0x80 {
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data.append(UInt8((v & 0x7F) | 0x80))
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v >>= 7
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}
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data.append(UInt8(v))
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}
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/// proto3：默认值(0)不编码
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mutating func writeVarintField(_ field: Int, _ value: UInt64) {
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guard value != 0 else { return }
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writeVarint(UInt64(field << 3 | 0))
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writeVarint(value)
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}
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mutating func writeDoubleField(_ field: Int, _ value: Double) {
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guard value != 0 else { return }
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writeVarint(UInt64(field << 3 | 1))
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var bits = value.bitPattern.littleEndian
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withUnsafeBytes(of: &bits) { data.append(contentsOf: $0) }
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}
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}
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private struct ProtoReader {
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let data: Data
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var offset: Int
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init(data: Data) {
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self.data = data
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self.offset = data.startIndex
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}
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mutating func readTag() -> (Int, Int)? {
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guard offset < data.endIndex, let key = readVarint() else { return nil }
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return (Int(key >> 3), Int(key & 0x7))
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}
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mutating func readVarint() -> UInt64? {
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var result: UInt64 = 0
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var shift: UInt64 = 0
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while offset < data.endIndex {
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let byte = data[offset]
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offset += 1
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result |= UInt64(byte & 0x7F) << shift
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if byte & 0x80 == 0 { return result }
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shift += 7
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if shift >= 64 { return nil }
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}
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return nil
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}
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mutating func readDouble() -> Double? {
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guard offset + 8 <= data.endIndex else { return nil }
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var bits: UInt64 = 0
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for i in (0..<8).reversed() {
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bits = (bits << 8) | UInt64(data[offset + i])
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}
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offset += 8
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return Double(bitPattern: bits)
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}
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mutating func skip(wireType: Int) -> Bool {
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switch wireType {
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case 0: return readVarint() != nil
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case 1:
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guard offset + 8 <= data.endIndex else { return false }
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offset += 8
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return true
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case 2:
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guard let len = readVarint(), offset + Int(len) <= data.endIndex else { return false }
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offset += Int(len)
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return true
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case 5:
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guard offset + 4 <= data.endIndex else { return false }
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offset += 4
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return true
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default:
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return false
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}
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}
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}
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