From 3ae37c7a195214b0f3e08a4958115f32943830a6 Mon Sep 17 00:00:00 2001 From: morkt Date: Fri, 31 Mar 2017 13:27:51 +0400 Subject: [PATCH] (ArcView): use unsafe pointer to access memory directly. --- GameRes/ArcStream.cs | 199 +++++++++---------------------------------- GameRes/ArcView.cs | 114 ++++++++++--------------- 2 files changed, 86 insertions(+), 227 deletions(-) diff --git a/GameRes/ArcStream.cs b/GameRes/ArcStream.cs index 6be33c13..0f0686bb 100644 --- a/GameRes/ArcStream.cs +++ b/GameRes/ArcStream.cs @@ -28,7 +28,6 @@ using System.Diagnostics; using System.IO; using System.Runtime.InteropServices; using System.Text; -using GameRes.Utility; namespace GameRes { @@ -37,12 +36,7 @@ namespace GameRes private readonly ArcView.Frame m_view; private readonly long m_start; private readonly long m_size; - private long m_position; - private byte[] m_buffer; - private int m_buffer_pos; // read position within buffer - private int m_buffer_len; // length of bytes read in buffer - - private const int DefaultBufferSize = 0x1000; + private long m_position; public string Name { get; set; } public uint Signature { get { return ReadSignature(); } } @@ -54,20 +48,11 @@ namespace GameRes public override long Length { get { return m_size; } } public override long Position { - get { return m_position + (m_buffer_pos - m_buffer_len); } + get { return m_position; } set { if (value < 0) throw new ArgumentOutOfRangeException ("value", "Stream position is out of range."); - var buffer_start = m_position - m_buffer_len; - if (m_buffer_pos != m_buffer_len && value >= buffer_start && value < m_position) - { - m_buffer_pos = (int)(value - buffer_start); - } - else - { - m_position = value; - m_buffer_pos = m_buffer_len = 0; - } + m_position = value; } } @@ -132,61 +117,24 @@ namespace GameRes return new CowArray (m_header, 0, size); } - private void RefillBuffer () - { - if (null == m_buffer) - m_buffer = new byte[DefaultBufferSize]; - uint length = (uint)Math.Min (m_size - m_position, m_buffer.Length); - m_buffer_len = m_view.Read (m_start + m_position, m_buffer, 0, length); - m_position += m_buffer_len; - m_buffer_pos = 0; - } - - private void FlushBuffer () - { - if (m_buffer_len != 0) - { - m_position += m_buffer_pos - m_buffer_len; - m_buffer_pos = m_buffer_len = 0; - } - } - private void EnsureAvailable (int length) { - if (m_buffer_pos + length > m_buffer_len) - { - FlushBuffer(); - if (m_position + length > m_size) - throw new EndOfStreamException(); - RefillBuffer(); - } - } - - private int ReadFromBuffer (byte[] array, int offset, int count) - { - int available = Math.Min (m_buffer_len - m_buffer_pos, count); - if (available > 0) - { - Buffer.BlockCopy (m_buffer, m_buffer_pos, array, offset, available); - m_buffer_pos += available; - } - return available; + if (m_position + length > m_size) + throw new EndOfStreamException(); } public int PeekByte () { - if (m_buffer_pos == m_buffer_len) - RefillBuffer(); - if (m_buffer_pos == m_buffer_len) + if (m_position >= m_size) return -1; - return m_buffer[m_buffer_pos]; + return m_view.ReadByte (m_start+m_position); } public override int ReadByte () { int b = PeekByte(); if (-1 != b) - ++m_buffer_pos; + ++m_position; return b; } @@ -206,8 +154,8 @@ namespace GameRes public short ReadInt16 () { EnsureAvailable (2); - var v = m_buffer.ToInt16 (m_buffer_pos); - m_buffer_pos += 2; + var v = m_view.ReadInt16 (m_start+m_position); + m_position += 2; return v; } @@ -219,16 +167,17 @@ namespace GameRes public int ReadInt24 () { EnsureAvailable (3); - int v = m_buffer.ToInt24 (m_buffer_pos); - m_buffer_pos += 3; + int v = m_view.ReadUInt16 (m_start+m_position); + v |= m_view.ReadByte (m_start+m_position+2) << 16; + m_position += 3; return v; } public int ReadInt32 () { EnsureAvailable (4); - int v = m_buffer.ToInt32 (m_buffer_pos); - m_buffer_pos += 4; + var v = m_view.ReadInt32 (m_start+m_position); + m_position += 4; return v; } @@ -240,8 +189,8 @@ namespace GameRes public long ReadInt64 () { EnsureAvailable (8); - var v = m_buffer.ToInt64 (m_buffer_pos); - m_buffer_pos += 8; + var v = m_view.ReadInt64 (m_start+m_position); + m_position += 8; return v; } @@ -257,39 +206,10 @@ namespace GameRes public string ReadCString (int length, Encoding enc) { - if (m_buffer_pos == m_buffer_len && length <= DefaultBufferSize) - RefillBuffer(); - if (m_buffer_pos + length <= m_buffer_len) - { - // whole string fit into buffer - var str = Binary.GetCString (m_buffer, m_buffer_pos, length, enc); - m_buffer_pos += length; - return str; - } - else if (length > DefaultBufferSize) - { - // requested string length is larger than internal buffer size - var string_buffer = ReadBytes (length); - return Binary.GetCString (string_buffer, 0, string_buffer.Length, enc); - } - else - { - int available = m_buffer_len - m_buffer_pos; - if (available > 0 && m_buffer_pos != 0) - Buffer.BlockCopy (m_buffer, m_buffer_pos, m_buffer, 0, available); - else if (null == m_buffer) - m_buffer = new byte[DefaultBufferSize]; - int count = (int)Math.Min (m_buffer.Length - available, m_size - m_position); - if (count > 0) - { - int read = m_view.Read (m_start + m_position, m_buffer, available, (uint)count); - m_position += read; - available += read; - } - m_buffer_len = available; - m_buffer_pos = Math.Min (length, m_buffer_len); - return Binary.GetCString (m_buffer, 0, m_buffer_pos, enc); - } + uint string_length = (uint)Math.Min (length, m_size-m_position); + var str = m_view.ReadString (m_position, (uint)string_length, enc); + m_position += string_length; + return str; } public string ReadCString () @@ -299,27 +219,12 @@ namespace GameRes public string ReadCString (Encoding enc) { - if (m_buffer_pos == m_buffer_len) - RefillBuffer(); - int available = m_buffer_len - m_buffer_pos; - if (0 == available) - return string.Empty; + // underlying view includes rest of the stream + if (m_view.Offset <= m_position && m_view.Offset + m_view.Reserved >= m_start + m_size) + return ReadCStringUnsafe (enc); - int zero = Array.IndexOf (m_buffer, 0, m_buffer_pos, available); - if (zero != -1) - { - // null byte found within buffer - var str = enc.GetString (m_buffer, m_buffer_pos, zero - m_buffer_pos); - m_buffer_pos = zero+1; - return str; - } - // underlying view includes whole stream - if (m_view.Offset <= m_start && m_view.Offset + m_view.Reserved >= m_start + m_size) - return ReadCStringUnsafe (enc, available); - - var string_buf = new byte[Math.Max (0x20, available * 2)]; - ReadFromBuffer (string_buf, 0, available); - int size = available; + var string_buf = new byte[0x20]; + int size = 0; for (;;) { int b = ReadByte(); @@ -337,7 +242,6 @@ namespace GameRes private unsafe string ReadCStringUnsafe (Encoding enc, int skip_bytes = 0) { Debug.Assert (m_view.Offset + m_view.Reserved >= m_start + m_size); - FlushBuffer(); using (var ptr = m_view.GetPointer()) { byte* s = ptr.Value + (m_start - m_view.Offset + m_position); @@ -350,44 +254,33 @@ namespace GameRes m_position += string_length; if (string_length < view_length) ++m_position; -// return enc.GetString (s, string_length); // .Net v4.6+ only - var string_buf = new byte[string_length]; - Marshal.Copy ((IntPtr)s, string_buf, 0, string_length); - return enc.GetString (string_buf, 0, string_length); + return new string ((sbyte*)s, 0, string_length, enc); } } public byte[] ReadBytes (int count) { - if (m_buffer_pos + count <= m_buffer_len && m_buffer_len != 0) - { - var data = new CowArray (m_buffer, m_buffer_pos, count).ToArray(); - m_buffer_pos += count; - return data; - } - var current_pos = Position; - if (0 == count || current_pos >= m_size) + if (0 == count || m_position >= m_size) return new byte[0]; - var bytes = m_view.ReadBytes (m_start+current_pos, (uint)Math.Min (count, m_size - current_pos)); - Position = current_pos + bytes.Length; + var bytes = m_view.ReadBytes (m_start+m_position, (uint)Math.Min (count, m_size - m_position)); + m_position += bytes.Length; return bytes; } #region System.IO.Stream methods public override void Flush() { - FlushBuffer(); } public override long Seek (long offset, SeekOrigin origin) { switch (origin) { - case SeekOrigin.Begin: Position = offset; break; - case SeekOrigin.Current: Position += offset; break; - case SeekOrigin.End: Position = m_size + offset; break; + case SeekOrigin.Current: offset += m_position; break; + case SeekOrigin.End: offset += m_size; break; } - return Position; + Position = offset; + return m_position; } public override void SetLength (long length) @@ -397,26 +290,12 @@ namespace GameRes public override int Read (byte[] buffer, int offset, int count) { - int read_from_buffer = ReadFromBuffer (buffer, offset, count); - offset += read_from_buffer; - count -= read_from_buffer; if (0 == count || m_position >= m_size) - return read_from_buffer; - if (count < DefaultBufferSize) - { - RefillBuffer(); - count = Math.Min (count, m_buffer_len); - Buffer.BlockCopy (m_buffer, m_buffer_pos, buffer, offset, count); - m_buffer_pos += count; - return read_from_buffer + count; - } - else - { - uint view_count = (uint)Math.Min (count, m_size - m_position); - int read_from_view = m_view.Read (m_start + m_position, buffer, offset, view_count); - m_position += read_from_view; - return read_from_buffer + read_from_view; - } + return 0; + count = (int)Math.Min (count, m_size - m_position); + int read = m_view.Read (m_start + m_position, buffer, offset, (uint)count); + m_position += read; + return read; } public override void Write (byte[] buffer, int offset, int count) diff --git a/GameRes/ArcView.cs b/GameRes/ArcView.cs index 8e0aebe2..c047fc79 100644 --- a/GameRes/ArcView.cs +++ b/GameRes/ArcView.cs @@ -77,27 +77,6 @@ namespace GameRes public static class MappedViewExtension { - static public string ReadString (this MemoryMappedViewAccessor view, long offset, uint size, Encoding enc) - { - if (0 == size) - return string.Empty; - byte[] buffer = new byte[size]; - uint n; - for (n = 0; n < size; ++n) - { - byte b = view.ReadByte (offset+n); - if (0 == b) - break; - buffer[n] = b; - } - return enc.GetString (buffer, 0, (int)n); - } - - static public string ReadString (this MemoryMappedViewAccessor view, long offset, uint size) - { - return ReadString (view, offset, size, Encodings.cp932); - } - unsafe public static byte* GetPointer (this MemoryMappedViewAccessor view, long offset) { var num = offset % info.dwAllocationGranularity; @@ -273,6 +252,7 @@ namespace GameRes private MemoryMappedViewAccessor m_view; private long m_offset; private uint m_size; + private unsafe byte* m_mem; public long Offset { get { return m_offset; } } public uint Reserved { get { return m_size; } } @@ -283,6 +263,7 @@ namespace GameRes m_offset = 0; m_size = (uint)Math.Min (ArcView.PageSize, m_arc.MaxOffset); m_view = m_arc.CreateViewAccessor (m_offset, m_size); + unsafe { m_mem = m_view.GetPointer (m_offset); } } public Frame (Frame other) @@ -291,6 +272,7 @@ namespace GameRes m_offset = 0; m_size = (uint)Math.Min (ArcView.PageSize, m_arc.MaxOffset); m_view = m_arc.CreateViewAccessor (m_offset, m_size); + unsafe { m_mem = m_view.GetPointer (m_offset); } } public Frame (ArcView arc, long offset, uint size) @@ -299,6 +281,7 @@ namespace GameRes m_offset = Math.Min (offset, m_arc.MaxOffset); m_size = (uint)Math.Min (size, m_arc.MaxOffset-m_offset); m_view = m_arc.CreateViewAccessor (m_offset, m_size); + unsafe { m_mem = m_view.GetPointer (m_offset); } } public uint Reserve (long offset, uint size) @@ -313,28 +296,32 @@ namespace GameRes size = (uint)(m_arc.MaxOffset-offset); var old_view = m_view; m_view = m_arc.CreateViewAccessor (offset, size); + old_view.SafeMemoryMappedViewHandle.ReleasePointer(); old_view.Dispose(); m_offset = offset; m_size = size; + unsafe { m_mem = m_view.GetPointer (m_offset); } } return (uint)(m_offset + m_size - offset); } + public void StrictReserve (long offset, uint size) + { + if (Reserve (offset, size) < size) + throw new ArgumentException ("Not enough bytes to read in the memory mapped file view.", "offset"); + } + public bool AsciiEqual (long offset, string data) { if (Reserve (offset, (uint)data.Length) < (uint)data.Length) return false; unsafe { - byte* ptr = m_view.GetPointer (m_offset) + (offset - m_offset); - try { - for (int i = 0; i < data.Length; ++i) - { - if (ptr[i] != data[i]) - return false; - } - } finally { - m_view.SafeMemoryMappedViewHandle.ReleasePointer(); + byte* ptr = m_mem + (offset - m_offset); + for (int i = 0; i < data.Length; ++i) + { + if (ptr[i] != data[i]) + return false; } return true; } @@ -360,12 +347,7 @@ namespace GameRes private unsafe void UnsafeCopy (long offset, byte[] buf, int buf_offset, int count) { - byte* ptr = m_view.GetPointer (m_offset); - try { - Marshal.Copy ((IntPtr)(ptr+(offset-m_offset)), buf, buf_offset, count); - } finally { - m_view.SafeMemoryMappedViewHandle.ReleasePointer(); - } + Marshal.Copy ((IntPtr)(m_mem + (offset-m_offset)), buf, buf_offset, count); } /// @@ -383,77 +365,67 @@ namespace GameRes public byte ReadByte (long offset) { - Reserve (offset, 1); - return m_view.ReadByte (offset-m_offset); + StrictReserve (offset, 1); + unsafe { return m_mem[offset-m_offset]; } } public sbyte ReadSByte (long offset) { - Reserve (offset, 1); - return m_view.ReadSByte (offset-m_offset); + StrictReserve (offset, 1); + unsafe { return (sbyte)m_mem[offset-m_offset]; } } public ushort ReadUInt16 (long offset) { - Reserve (offset, 2); - return m_view.ReadUInt16 (offset-m_offset); + StrictReserve (offset, 2); + unsafe { return *(ushort*)(m_mem+offset-m_offset); } } public short ReadInt16 (long offset) { - Reserve (offset, 2); - return m_view.ReadInt16 (offset-m_offset); + StrictReserve (offset, 2); + unsafe { return *(short*)(m_mem+offset-m_offset); } } public uint ReadUInt32 (long offset) { - Reserve (offset, 4); - return m_view.ReadUInt32 (offset-m_offset); + StrictReserve (offset, 4); + unsafe { return *(uint*)(m_mem+offset-m_offset); } } public int ReadInt32 (long offset) { - Reserve (offset, 4); - return m_view.ReadInt32 (offset-m_offset); + StrictReserve (offset, 4); + unsafe { return *(int*)(m_mem+offset-m_offset); } } public ulong ReadUInt64 (long offset) { - Reserve (offset, 8); - return m_view.ReadUInt64 (offset-m_offset); + StrictReserve (offset, 8); + unsafe { return *(ulong*)(m_mem+offset-m_offset); } } public long ReadInt64 (long offset) { - Reserve (offset, 8); - return m_view.ReadInt64 (offset-m_offset); + StrictReserve (offset, 8); + unsafe { return *(long*)(m_mem+offset-m_offset); } } public string ReadString (long offset, uint size, Encoding enc) { size = Math.Min (size, Reserve (offset, size)); - return m_view.ReadString (offset-m_offset, size, enc); - /* unsafe implementation requires .Net v4.6 if (0 == size) return string.Empty; unsafe { - byte* s = m_view.GetPointer (m_offset) + (offset - m_offset); - try + byte* s = m_mem + (offset - m_offset); + uint string_length = 0; + while (string_length < size && 0 != s[string_length]) { - uint string_length = 0; - while (string_length < size && 0 != s[string_length]) - { - ++string_length; - } - return enc.GetString (s, (int)string_length); // .Net v4.6+ only - } - finally - { - m_view.SafeMemoryMappedViewHandle.ReleasePointer(); + ++string_length; } + return new string ((sbyte*)s, 0, (int)string_length, enc); } - */ } public string ReadString (long offset, uint size) @@ -481,6 +453,14 @@ namespace GameRes { if (disposing) { + unsafe + { + if (m_mem != null) + { + m_view.SafeMemoryMappedViewHandle.ReleasePointer(); + m_mem = null; + } + } m_view.Dispose(); } m_arc = null;