Initial commit

LibDgf/Dat/DatReader.cs

@@ -0,0 +1,89 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace LibDgf.Dat
+{
+    public class DatReader : IDisposable
+    {
+        Stream stream;
+        BinaryReader br;
+        List<DatEntry> entries = new List<DatEntry>();
+        private bool disposedValue;
+
+        public DatReader(Stream stream)
+        {
+            this.stream = stream ?? throw new ArgumentNullException(nameof(stream));
+
+            br = new BinaryReader(stream);
+            if (new string(br.ReadChars(4)) != "DAT\0") throw new InvalidDataException("Not a DAT file.");
+            int numEntries = br.ReadInt32();
+            for (int i = 0; i < numEntries; ++i)
+            {
+                DatEntry entry = new DatEntry();
+                entry.Read(br);
+                entries.Add(entry);
+            }
+        }
+
+        public int EntriesCount
+        {
+            get
+            {
+                CheckDisposed();
+                return entries.Count;
+            }
+        }
+
+        public byte[] GetData(int index)
+        {
+            CheckDisposed();
+            if (index < 0) throw new ArgumentOutOfRangeException(nameof(index), "Index cannot be negative.");
+            if (index >= EntriesCount) throw new ArgumentOutOfRangeException(nameof(index), "Index cannot be greater than or equal to count.");
+
+            var entry = entries[index];
+            stream.Seek(entry.Offset, SeekOrigin.Begin);
+            return br.ReadBytes((int)entry.Length);
+        }
+
+        public DatEntry GetEntry(int index)
+        {
+            CheckDisposed();
+            if (index < 0) throw new ArgumentOutOfRangeException(nameof(index), "Index cannot be negative.");
+            if (index >= EntriesCount) throw new ArgumentOutOfRangeException(nameof(index), "Index cannot be greater than or equal to count.");
+
+            var entry = entries[index];
+            return new DatEntry
+            {
+                Offset = entry.Offset,
+                Length = entry.Length
+            };
+        }
+
+        void CheckDisposed()
+        {
+            if (disposedValue) throw new ObjectDisposedException(GetType().FullName);
+        }
+
+        protected virtual void Dispose(bool disposing)
+        {
+            if (!disposedValue)
+            {
+                if (disposing)
+                {
+                    stream.Dispose();
+                }
+
+                disposedValue = true;
+            }
+        }
+
+        public void Dispose()
+        {
+            // Do not change this code. Put cleanup code in 'Dispose(bool disposing)' method
+            Dispose(disposing: true);
+            GC.SuppressFinalize(this);
+        }
+    }
+}