Add the readonly version

sources/OpenMcdf/DirectoryEntry.cs

@@ -43,10 +43,10 @@ public int SID
  }
 
  internal static Int32 NOSTREAM
- = unchecked((int)0xFFFFFFFF);
+ => unchecked((int)0xFFFFFFFF);
 
  internal static Int32 ZERO
- = 0;
+ => 0;
 
  private DirectoryEntry(String name, StgType stgType, IList<IDirectoryEntry> dirRepository)
  {
@@ -71,13 +71,13 @@ private DirectoryEntry(String name, StgType stgType, IList<IDirectoryEntry> dirR
  }
  }
 
- private byte[] entryName = new byte[64];
+ private byte[] entryName;//= new byte[64];
 
  public byte[] EntryName
  {
  get
  {
- return entryName;
+ return entryName ?? new byte[64];
  }
  //set
  //{
@@ -214,27 +214,27 @@ public Int32 StateBits
  set { stateBits = value; }
  }
 
- private byte[] creationDate = new byte[8] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+ private byte[] creationDate;//= new byte[8] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 
  public byte[] CreationDate
  {
  get
  {
- return creationDate;
+ return creationDate ?? new byte[8];
  }
  set
  {
  creationDate = value;
  }
  }
 
- private byte[] modifyDate = new byte[8] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+ private byte[] modifyDate;//= new byte[8] { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
 
  public byte[] ModifyDate
  {
  get
  {
- return modifyDate;
+ return modifyDate ?? new byte[8];
  }
  set
  {
@@ -331,14 +331,14 @@ private static ulong fnv_hash(byte[] buffer)
 
  public override int GetHashCode()
  {
- return (int)fnv_hash(this.entryName);
+ return (int)fnv_hash(this.EntryName);
  }
 
  public void Write(Stream stream)
  {
  StreamRW rw = new StreamRW(stream);
 
- rw.Write(entryName);
+ rw.Write(EntryName);
  rw.Write(nameLength);
  rw.Write((byte)stgType);
  rw.Write((byte)stgColor);
@@ -347,8 +347,8 @@ public void Write(Stream stream)
  rw.Write(child);
  rw.Write(storageCLSID.ToByteArray());
  rw.Write(stateBits);
- rw.Write(creationDate);
- rw.Write(modifyDate);
+ rw.Write(CreationDate);
+ rw.Write(ModifyDate);
  rw.Write(startSetc);
  rw.Write(size);
 
@@ -384,7 +384,7 @@ public void Write(Stream stream)
 
  public void Read(Stream stream, CFSVersion ver = CFSVersion.Ver_3)
  {
- StreamRW rw = new StreamRW(stream);
+ IStreamReader rw = stream.ToStreamReader();
 
  entryName = rw.ReadBytes(64);
  nameLength = rw.ReadUInt16();
@@ -405,8 +405,8 @@ public void Read(Stream stream, CFSVersion ver = CFSVersion.Ver_3)
 
  storageCLSID = new Guid(rw.ReadBytes(16));
  stateBits = rw.ReadInt32();
- creationDate = rw.ReadBytes(8);
- modifyDate = rw.ReadBytes(8);
+ CreationDate = rw.ReadBytes(8);
+ ModifyDate = rw.ReadBytes(8);
  startSetc = rw.ReadInt32();
 
  if (ver == CFSVersion.Ver_3)
@@ -415,7 +415,7 @@ public void Read(Stream stream, CFSVersion ver = CFSVersion.Ver_3)
  // where most significant bits are not initialized to zero
 
  size = rw.ReadInt32();
- rw.ReadBytes(4); //discard most significant 4 (possibly) dirty bytes
+ rw.ReadInt32(); //rw.ReadBytes(4); //discard most significant 4 (possibly) dirty bytes
  }
  else
  {

sources/OpenMcdf/Header.cs

@@ -13,13 +13,17 @@ namespace OpenMcdf
 {
  internal class Header
  {
+ /// <summary>
+ /// Number of DIFAT entries in the header
+ /// </summary>
+ private const int HEADER_DIFAT_ENTRIES_COUNT = 109;
+
  //0 8 Compound document file identifier: D0H CFH 11H E0H A1H B1H 1AH E1H
- private byte[] headerSignature
- = new byte[] { 0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1 };
 
  public byte[] HeaderSignature
  {
- get { return headerSignature; }
+ get => _headerSignature ??= new byte[] { 0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1 };
+ private set => _headerSignature = value;
  }
 
  //8 16 Unique identifier (UID) of this file (not of interest in the following, may be all 0)
@@ -63,7 +67,7 @@ public ushort ByteOrder
  public ushort SectorShift
  {
  get { return sectorShift; }
- 
+
  }
 
  //32 2 Size of a short-sector in the short-stream container stream (➜6.1) in power-of-two (sssz),
@@ -171,7 +175,8 @@ public uint DIFATSectorsNumber
  }
 
  //76 436 First part of the master sector allocation table (➜5.1) containing 109 SecIDs
- private int[] difat = new int[109];
+ private int[] difat = new int[HEADER_DIFAT_ENTRIES_COUNT];
+ private byte[] _headerSignature;
 
  public int[] DIFAT
  {
@@ -207,19 +212,17 @@ public Header(ushort version)
 
  }
 
- for (int i = 0; i < 109; i++)
+ for (int i = 0; i < HEADER_DIFAT_ENTRIES_COUNT; i++)
  {
  difat[i] = Sector.FREESECT;
  }
-
-
  }
 
  public void Write(Stream stream)
  {
  StreamRW rw = new StreamRW(stream);
 
- rw.Write(headerSignature);
+ rw.Write(HeaderSignature);
  rw.Write(clsid);
  rw.Write(minorVersion);
  rw.Write(majorVersion);
@@ -253,10 +256,12 @@ public void Write(Stream stream)
 
  public void Read(Stream stream)
  {
- StreamRW rw = new StreamRW(stream);
+ var rw = stream.ToStreamReader();
+
+ var headerSignature = rw.ReadBytes(8);
+ CheckSignature(headerSignature);
+ HeaderSignature = headerSignature;
 
- headerSignature = rw.ReadBytes(8);
- CheckSignature();
  clsid = rw.ReadBytes(16);
  minorVersion = rw.ReadUInt16();
  majorVersion = rw.ReadUInt16();
@@ -275,32 +280,35 @@ public void Read(Stream stream)
  firstDIFATSectorID = rw.ReadInt32();
  difatSectorsNumber = rw.ReadUInt32();
 
- for (int i = 0; i < 109; i++)
+ for (int i = 0; i < HEADER_DIFAT_ENTRIES_COUNT; i++)
  {
  this.DIFAT[i] = rw.ReadInt32();
  }
-
- rw.Close();
  }
 
-
  private void CheckVersion()
  {
  if (this.majorVersion != 3 && this.majorVersion != 4)
  throw new CFFileFormatException("Unsupported Binary File Format version: OpenMcdf only supports Compound Files with major version equal to 3 or 4 ");
  }
 
- /// <summary>
- /// Structured Storage signature
- /// </summary>
- private byte[] OLE_CFS_SIGNATURE = new byte[] { 0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1 };
-
- private void CheckSignature()
+ private static void CheckSignature(byte[] headerSignature)
  {
- for (int i = 0; i < headerSignature.Length; i++)
+ var success = headerSignature.Length == 8;
+ success = success
+ //var oleCfsSignature = new byte[] { 0xD0, 0xCF, 0x11, 0xE0, 0xA1, 0xB1, 0x1A, 0xE1 };
+ && headerSignature[0] == 0xD0
+ && headerSignature[1] == 0xCF
+ && headerSignature[2] == 0x11
+ && headerSignature[3] == 0xE0
+ && headerSignature[4] == 0xA1
+ && headerSignature[5] == 0xB1
+ && headerSignature[6] == 0x1A
+ && headerSignature[7] == 0xE1;
+
+ if (!success)
  {
- if (headerSignature[i] != OLE_CFS_SIGNATURE[i])
- throw new CFFileFormatException("Invalid OLE structured storage file");
+ throw new CFFileFormatException("Invalid OLE structured storage file");
  }
  }
  }

sources/OpenMcdf/OpenMcdf.csproj

@@ -18,6 +18,7 @@
  <GenerateAssemblyCopyrightAttribute>false</GenerateAssemblyCopyrightAttribute>
  <GenerateAssemblyVersionAttribute>false</GenerateAssemblyVersionAttribute>
  <GenerateAssemblyConfigurationAttribute>false</GenerateAssemblyConfigurationAttribute>
+ <LangVersion>latest</LangVersion>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
  <DebugSymbols>true</DebugSymbols>
@@ -90,9 +91,8 @@
  <PropertyGroup Condition="'$(TF_BUILD)' == 'true'">
  <ContinuousIntegrationBuild>true</ContinuousIntegrationBuild>
  </PropertyGroup>
- <ItemGroup />
  <ItemGroup>
- <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All"/>
+ <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.0.0" PrivateAssets="All" />
  </ItemGroup>
  <ItemGroup>
  <None Include="OpenMcdf.snk" />

sources/OpenMcdf/Readonly/ByteArrayPool.cs

@@ -0,0 +1,42 @@
+namespace OpenMcdf
+{
+ class ByteArrayPool : IByteArrayPool
+ {
+ public byte[] Rent(int minimumLength)
+ {
+ for (var i = 0; i < _bufferList.Length; i++)
+ {
+ var buffer = _bufferList[i];
+
+ if (buffer != null && buffer.Length >= minimumLength)
+ {
+ _bufferList[i] = null;
+ return buffer;
+ }
+ }
+
+ return new byte[minimumLength];
+ }
+
+ public void Return(byte[] byteList)
+ {
+ if (byteList == null || byteList.Length >= MaxBufferLength)
+ {
+ return;
+ }
+
+ for (var i = 0; i < _bufferList.Length; i++)
+ {
+ var buffer = _bufferList[i];
+ if (buffer is null || byteList.Length > buffer.Length)
+ {
+ buffer = byteList;
+ _bufferList[i] = buffer;
+ }
+ }
+ }
+
+ private readonly byte[][] _bufferList = new byte[4][];
+ private const int MaxBufferLength = 8 * 1024;
+ }
+}

sources/OpenMcdf/Readonly/IByteArrayPool.cs

@@ -0,0 +1,8 @@
+namespace OpenMcdf
+{
+ public interface IByteArrayPool
+ {
+ byte[] Rent(int minimumLength);
+ void Return(byte[] byteList);
+ }
+}

sources/OpenMcdf/Readonly/IStreamReader.cs

@@ -0,0 +1,16 @@
+namespace OpenMcdf
+{
+ internal interface IStreamReader
+ {
+ long Seek(long offset);
+ byte ReadByte();
+ ushort ReadUInt16();
+ int ReadInt32();
+ uint ReadUInt32();
+ long ReadInt64();
+ ulong ReadUInt64();
+ byte[] ReadBytes(int count);
+ byte[] ReadBytes(int count, out int readCount);
+ void Close();
+ }
+}