Automap/Subsystems/Snapshot.cs

   1 using System;
   2 using System.Collections.Generic;
   3 using System.Diagnostics;
   4 using System.IO;
   5 using System.Linq;
   6 using System.Threading;
   7 using System.Threading.Tasks;
   8 using Hjg.Pngcs;
   9
  10 namespace Automap
  11 {
  12         public class Snapshotter
  13         {
  14                 public string path;
  15                 public string chunkPath;
  16                 public ColumnsMetadata cols;
  17                 public int chunkSize;
  18                 public int NorthEdge => cols.North_mostChunk;
  19                 public int WestEdge => cols.West_mostChunk;
  20                 public int Width => (cols.East_mostChunk - WestEdge + 1);
  21                 public int Height => (cols.South_mostChunk - NorthEdge + 1);
  22
  23                 public Snapshotter(string path, string chunkPath, ColumnsMetadata cols, int chunkSize)
  24                 {
  25                         this.path = Path.Combine(path, "snapshot.png");
  26                         this.chunkPath = Path.Combine(path, chunkPath);
  27                         this.cols = cols;
  28                         this.chunkSize = chunkSize;
  29                 }
  30
  31                 /// <summary>
  32                 /// takes a snapshot. this should be called from an extra thread.
  33                 /// </summary>
  34                 /// <param name="path">path to the map dir</param>
  35                 /// <param name="chunkPath">name of the chunks dir part thing</param>
  36                 /// <param name="cols"></param>
  37                 /// <param name="chunkSize"></param>
  38                 public async void Take()
  39                 {
  40                         var t = new Stopwatch();
  41                         t.Start();
  42                         Console.WriteLine("snapshot started");
  43
  44                         ImageInfo info = new ImageInfo(Width * chunkSize, Height * chunkSize, 8, false);
  45                         PngWriter snapWriter = FileHelper.CreatePngWriter(path, info, true);
  46                         snapWriter.CompLevel = 5;
  47                         snapWriter.CompressionStrategy = Hjg.Pngcs.Zlib.EDeflateCompressStrategy.Filtered;
  48
  49                         var orderedList =
  50                                 from ch in cols
  51                                 group ch by ch.Location.Y into g
  52                                 orderby g.Key
  53                                 select g;
  54                         // that sorts things in ascending order so we can only create (chunkSize) lines at once
  55                         int row = 0, lastPosY = 0, posY = 0;
  56                         foreach (var chunkGroup in orderedList)
  57                         {
  58                                 // oh god here we go...
  59                                 posY = chunkGroup.Key - NorthEdge;
  60                                 var delta = posY - lastPosY;
  61                                 lastPosY = posY;
  62
  63                                 // if there is more than 1 blank step then the gap needs to be filled.
  64                                 for (int i = 1; i < delta; i++)
  65                                 {
  66                                         byte[] blankLine = new byte[info.BytesPerRow];
  67                                         for (int j = 0; j < chunkSize; j++)
  68                                                 snapWriter.WriteRowByte(blankLine, row++);
  69                                 }
  70
  71                                 var inGroup = (await ReadAllInGroup(chunkGroup)).ToArray();
  72
  73                                 for (int r = 0; r < chunkSize; r++)
  74                                 {
  75                                         var line = new byte[info.BytesPerRow];
  76                                         for (int chunk = 0; chunk < inGroup.Length; chunk++)
  77                                         {
  78                                                 var posX = inGroup[chunk].Key * chunkSize * info.BytesPixel;
  79                                                 inGroup[chunk].Value?[r].CopyTo(line, posX);
  80                                         }
  81                                         snapWriter.WriteRowByte(line, row++);
  82                                 }
  83                         }
  84                         snapWriter.ShouldCloseStream = true;
  85                         try
  86                         {
  87                                 snapWriter.End();
  88                         }
  89                         catch (Exception)
  90                         {
  91                                 Console.WriteLine("Snapshot exception!");
  92                         }
  93                         Console.WriteLine($"snapshot finished in {t.ElapsedMilliseconds}");
  94                 }
  95
  96                 private async Task<Dictionary<int, byte[][]>> ReadAllInGroup(IGrouping<int, ColumnMeta> group)
  97                 {
  98                         var taskGroup = new Dictionary<int, byte[][]>(group.Count());
  99                         foreach (var shardMeta in group)
 100                         {
 101                                 var shardPath = Path.Combine(chunkPath, $"{shardMeta.Location.X}_{shardMeta.Location.Y}.png");
 102                                 taskGroup.Add(shardMeta.Location.X - WestEdge, await ReadNoThrow(shardPath));
 103                         }
 104                         return taskGroup;
 105                 }
 106
 107                 private async Task<byte[][]> ReadNoThrow(string readPath)
 108                 {
 109                         try
 110                         {
 111                                 return await Task.Run(() => FileHelper.CreatePngReader(readPath).ReadRowsByte().ScanlinesB);
 112                         }
 113                         catch (Exception e)
 114                         {
 115                                 Console.WriteLine(e.Message);
 116                                 return null;
 117                         } // do nothing on error
 118                 }
 119         }
 120 }