using Communicator; using log4net; using Parser.BinaryParser.Util; using System; using System.Collections; using System.Collections.Generic; using System.Linq; using System.Text; using System.Threading.Tasks; namespace WayneChina_IcCardReader_SinoChem { public class StateMachineMessageCutter : IMessageCutter { public byte[] Message { get; private set; } public event EventHandler OnMessageCut; static ILog innerLogger = log4net.LogManager.GetLogger("StateMachineMessageCutter"); private string loggerAppendix = "WayneChina_IcCardReader_SinoChem msgCutter "; private readonly SizableWindow window; private State nextState = State.Uninitialized; /// /// if the 0xFA count is odd, will use round up for count/2. /// e.g.: 0xFA appeared 2 times, return 1. /// 0xFA appeared 3 times, return 2, this is considered as window is not big enough to include further 0xFA since they're always even. /// /// private int Get0xFAPairCountInWindow(IList target) { return (int)Math.Round(((double)(target.Count(w => w == 0xFA)) / 2), MidpointRounding.AwayFromZero); } /// /// found all pair(one besides one) of 0xFA in a list, and reduce the pair to a single 0xFA. /// /// private int Reduce0xFAPair(IList target, int from) { var faAppearedPositions = new List(); for (int i = from; i < target.Count; i++) { if (target[i] == 0xFA) { faAppearedPositions.Add(i); i++; } } for (int i = 0; i < faAppearedPositions.Count; i++) { target.RemoveAt(faAppearedPositions[i] - i); } return faAppearedPositions.Count; } /// /// /// public StateMachineMessageCutter() { //通讯数据包格式为:数据包头(0xFA)+源地址(1byte)+有效数据长度(2 bytes)+有效数据+数据校验(2 bytes) this.window = new SizableWindow(); this.window.OnWindowFull += (data) => { switch (nextState) { case State.Uninitialized: if (data.First() == 0xFA) { // extend to 2 to see if exists extra 0xFA this.window.NewSize = 2; this.nextState = State.PrefixReady; innerLogger.Debug(this.loggerAppendix + " state is State.Uninitialized and next is 0xFF, switch to LengthReady"); } else this.window.Clear(); break; case State.PrefixReady: if (this.window.Count(h => h == 0xFA) == 1) { innerLogger.Debug(this.loggerAppendix + " 1 time of 0xFA in header window, valid starter, switch to LengthReady"); this.nextState = State.LengthReady; this.window.NewSize = 4; } else { innerLogger.Debug(this.loggerAppendix + " 2 times of 0xFA in potential header window, drop all and wait..."); // double 0xFA, not a starter. this.nextState = State.Uninitialized; this.window.Clear(); } break; case State.LengthReady: //this.DumpWindowToQueue(); try { this.window.NewSize += this.window.Skip(2).Take(2).GetBCD(); this.nextState = State.BodyReady; innerLogger.Debug(this.loggerAppendix + " MsgBodyLen caculated with: " + this.window.NewSize); } catch (Exception ex) { innerLogger.Debug($"LengthReady: Exception in parsing message length bytes : {ex.ToString()}"); this.nextState = State.Uninitialized; this.window.Clear(); } break; case State.BodyReady: //innerLogger.Debug(this.loggerAppendix + " Fire OnMessageConstructed with innerQueue: " + this.buffer.ToHexLogString()); if (this.window.All(w => w != 0xFA)) { innerLogger.Debug(this.loggerAppendix + " MsgBody have NO 0xFA, fastly switch to CrcReady"); /* window size exactly match with MsgBodyLen, indicats there's no 0xFA in body.*/ this.window.NewSize += 2; this.nextState = State.CrcReady; } else { try { /* window size not match with MsgBodyLen, indicates there's one or more 0xFA in body.*/ var __msgBodyLen = this.window.Skip(2).Take(2).GetBCD(); var faPairCount = Get0xFAPairCountInWindow(this.window.Skip(1).ToList()); if ((this.window.Count - 4) == (__msgBodyLen + faPairCount)) { //innerLogger.Debug(this.loggerAppendix + " Reduce0xFAPair from raw window: " + this.window.ToHexLogString()); var reducedCount = this.Reduce0xFAPair(this.window, 1); this.window.NewSize += (2 - reducedCount); this.nextState = State.CrcReady; } else { /*extend the window based on 0xFA count in `current` window. NOTE, every extend may include new 0xFA pair.*/ this.window.NewSize += 1; //innerLogger.Debug(this.loggerAppendix + " Re-extend window size to: " + this.windowSize); } } catch (Exception ex) { innerLogger.Debug($"BodyReady: Exception in parsing message length bytes : {ex.ToString()}"); this.nextState = State.Uninitialized; this.window.Clear(); } } break; case State.CrcReady: try { var _msgBodyLen = this.window.Skip(2).Take(2).GetBCD(); var crcPart = this.window.Skip(4 + _msgBodyLen).ToList(); if (crcPart.Count == 2 && crcPart[0] == 0xFA) { innerLogger.Debug(this.loggerAppendix + " Crc[0] is 0xFA, extend windowSize to 3"); this.window.NewSize += 1; return; } if (crcPart.Count == 3 && crcPart[2] == 0xFA) { innerLogger.Debug(this.loggerAppendix + " Crc[2] is 0xFA, extend windowSize to 4"); this.window.NewSize += 1; return; } Enumerable.Repeat("_", (int)Math.Round(((double)(crcPart.Count(w => w == 0xFA)) / 2))).ToList().ForEach( s => { innerLogger.Debug(this.loggerAppendix + " Removing one 0xFA from Crc part."); crcPart.Remove(0xFA); }); this.Message = this.window.Take(4 + _msgBodyLen).ToList().Concat(crcPart).ToArray(); var safe = this.OnMessageCut; safe?.Invoke(this, null); this.nextState = State.Uninitialized; this.window.Clear(); //this.window.NewSize = this.initWindowSize; } catch (Exception ex) { innerLogger.Debug($"CrcReady: BodyReady: Exception in parsing message length bytes : {ex.ToString()}"); this.nextState = State.Uninitialized; this.window.Clear(); } break; default: throw new ArgumentOutOfRangeException(); } }; } private enum State { Uninitialized, // single 0xFA PrefixReady, // 0xFA + 1 byte source address HeaderReady, // 0xFA + 1 byte source address + 2 bytes real length LengthReady, // 0xFA + 1 byte source address + 2 bytes real length + real data BodyReady, // 0xFA + 1 byte source address + 2 bytes real length + real data + 2 bytes CRC CrcReady, } public void Feed(byte[] next) { //innerLogger.Debug(this.loggerAppendix + " " + next.ToHexLogString() + " is feed in Window in state: " + nextState); for (int i = 0; i < next.Length; i++) this.window.Add(next[i]); } } }