Changeset 31 for trunk/UDriveScan.pas

Timestamp:

Apr 30, 2016, 12:16:19 AM (8 years ago)

Author:

chronos

Message:

• Added: TFileStreamEx experimental class to support flags O_DIRECT and O_SYNC under Linux.

File:

• trunk/UDriveScan.pas (modified) (6 diffs)

trunk/UDriveScan.pas

@@ -125 +125 @@
 implementation
 
+uses
+  UFileStreamEx;
+
 resourcestring
   SUnknownRunMode = 'Unknown run mode';
@@ -177 +180 @@
 function TTestStream.Write(const Buffer; Count: Longint): Longint;
 begin
+  Result := 0;
 end;
 
 function TTestStream.Seek(const Offset: Int64; Origin: TSeekOrigin): Int64;
 begin
+  Result := 0;
 end;
 
@@ -293 +298 @@
   F: TStream;
   RealSize: Integer;
-  Buffer: array of Byte;
+  Buffer: Pointer;
+  BufferAligned: Pointer;
   I: Integer;
+  Alignment: Integer;
 begin
   try
@@ -301 +308 @@
     if ConfigTest then F := TTestStream.Create
     else begin
+      //if Mode = rmRead then F := TFileStreamEx.Create(DriveName, fmOpenRead, [ffDirect])
+      //  else if Mode = rmWrite then F := TFileStreamEx.Create(DriveName, fmOpenReadWrite, [ffDirect]);
       if Mode = rmRead then F := TFileStream.Create(DriveName, fmOpenRead)
         else if Mode = rmWrite then F := TFileStream.Create(DriveName, fmOpenReadWrite);
     end;
     try
-      SetLength(Buffer, SectorSize);
+      Alignment := SectorSize;
+      Buffer := GetMem(SectorSize + Alignment);
+      BufferAligned := Pointer(Int64(Buffer) - (Int64(Buffer) and (Alignment - 1)) + Alignment);
       if Mode = rmWrite then begin
         if not WritePatternRandom then
-          FillChar(Buffer[0], Length(Buffer), WritePattern)
-          else for I := 0 to Length(Buffer) - 1 do
-            Buffer[I] := Random(256);
+          FillChar(BufferAligned^, SectorSize, WritePattern)
+          else for I := 0 to SectorSize - 1 do
+            PByte(Int64(BufferAligned) + I)^ := Random(256);
       end;
       while FSectorCurrent < SectorEnd do begin
@@ -317 +328 @@
           DoChange;
           F.Position := FSectorCurrent * SectorSize;
-          if Mode = rmRead then RealSize := F.Read(Buffer[0], SectorSize)
-            else if Mode = rmWrite then RealSize := F.Write(Buffer[0], SectorSize)
+          if Mode = rmRead then RealSize := F.Read(BufferAligned^, SectorSize)
+            else if Mode = rmWrite then RealSize := F.Write(BufferAligned^, SectorSize)
             else raise Exception.Create(SUnknownRunMode);
         finally
@@ -333 +344 @@
         if Terminated then Break;
       end;
+      FreeMem(Buffer);
     finally
       F.Free;