Changeset 291

Timestamp:

Nov 4, 2011, 11:46:15 AM (13 years ago)

Author:

george

Message:

• Modified: Method of StreamHelper for reading string data with defined length.
• Modified: BitStream now use class TPositionMemory from package Common instead of TMemoryStream for storing data. TMemoryStream allocate too huge data (4 kB) even if only few bytes are used.

Location:

CoolStreaming

Files:

• CoolStreaming.lpk (modified) (2 diffs)
• UBitStream.pas (modified) (10 diffs)
• UStreamHelper.pas (modified) (4 diffs)

CoolStreaming/CoolStreaming.lpk

@@ -1 +1 @@
 <?xml version="1.0"?>
 <CONFIG>
-  <Package Version="3">
+  <Package Version="4">
     <PathDelim Value="\"/>
     <Name Value="CoolStreaming"/>
+    <AddToProjectUsesSection Value="True"/>
     <Author Value="Chronos"/>
     <CompilerOptions>
-      <Version Value="9"/>
+      <Version Value="10"/>
       <PathDelim Value="\"/>
       <SearchPaths>
         <UnitOutputDirectory Value="lib\$(TargetCPU)-$(TargetOS)"/>
       </SearchPaths>
+      <Linking>
+        <Debugging>
+          <GenerateDebugInfo Value="True"/>
+          <DebugInfoType Value="dsAuto"/>
+        </Debugging>
+      </Linking>
       <Other>
         <CompilerPath Value="$(CompPath)"/>
@@ -49 +56 @@
     </Files>
     <Type Value="RunAndDesignTime"/>
-    <RequiredPkgs Count="3">
+    <RequiredPkgs Count="4">
       <Item1>
-        <PackageName Value="LCL"/>
+        <PackageName Value="Common"/>
       </Item1>
       <Item2>
-        <PackageName Value="TemplateGenerics"/>
+        <PackageName Value="LCL"/>
       </Item2>
       <Item3>
+        <PackageName Value="TemplateGenerics"/>
+      </Item3>
+      <Item4>
         <PackageName Value="FCL"/>
         <MinVersion Major="1" Valid="True"/>
-      </Item3>
+      </Item4>
     </RequiredPkgs>
     <UsageOptions>

CoolStreaming/UBitStream.pas

@@ -8 +8 @@
 
 uses
-  Classes, SysUtils, RtlConsts, Math;
+  Classes, SysUtils, RtlConsts, Math, UMemory;
 
 type
@@ -47 +47 @@
   TMemoryBitStream = class(TBitStream)
   private
-    FStream: TMemoryStream;
+    FMemory: TPositionMemory;
     FPosition: LongInt;
     FSize: LongInt;
@@ -61 +61 @@
     constructor Create;
     destructor Destroy; override;
-    property Stream: TMemoryStream read FStream;
+    property Memory: TPositionMemory read FMemory;
   end;
 
@@ -175 +175 @@
 function TBitStream.ReadNumber(Count: Byte): QWord;
 begin
+  Result := 0;
   Read(Result, Count);
   Result := Result and ((QWord(1) shl Count) - 1);
@@ -224 +225 @@
 begin
   FSize := AValue;
-  Stream.Size := Ceil(AValue / 8);
+  FMemory.Size := Ceil(AValue / 8);
   if FPosition > FSize then FPosition := FSize;
 end;
@@ -251 +252 @@
     ByteCount := Ceil(Count / 8);
     PosInByte := FPosition mod 8;
-    Stream.Position := Trunc(FPosition / 8);
-    Data := Stream.ReadByte; // Read first byte
+    FMemory.Position := Trunc(FPosition / 8);
+    Data := FMemory.ReadByte; // Read first byte
     for I := 0 to ByteCount - 1 do begin
       TBytes(Buffer)[I] := (Data shr PosInByte) and ((1 shl (8 - PosInByte)) - 1);
-      if (I < ByteCount) and (Stream.Position < Stream.Size) then
-        Data := Stream.ReadByte else Data := 0;
+      if (I < ByteCount) and (FMemory.Position < FMemory.Size) then begin
+        Data := FMemory.ReadByte;
+      end else Data := 0;
       if PosInByte > 0 then
         TBytes(Buffer)[I] := TBytes(Buffer)[I] or
@@ -293 +295 @@
   BitCount := Count;
   ByteCount := Ceil(Count / 8);
-  Stream.Position := Trunc(FPosition / 8);
+  FMemory.Position := Trunc(FPosition / 8);
   BytePos := FPosition mod 8;
   I := 0;
   while (I < ByteCount) or (RestBitCount > 0) do begin
     WriteBitCount := Min(8 - BytePos, BitCount);
-    if (Stream.Position < Stream.Size) and (WriteBitCount < 8) then begin
-      Data := Stream.ReadByte;
-      Stream.Position := Stream.Position - 1;
+    if (FMemory.Position < FMemory.Size) and (WriteBitCount < 8) then begin
+      Data := FMemory.ReadByte;
+      FMemory.Position := FMemory.Position - 1;
     end else Data := 0;
 
@@ -311 +313 @@
     // Write part up to one byte from source to target
     Dec(BitCount, WriteToByte(Data, TBytes(Buffer)[I], BytePos, WriteBitCount));
-    Stream.WriteByte(Data);
+    FMemory.WriteByte(Data);
 
     RestBitCount := Min(8 - WriteBitCount, BitCount);
@@ -334 +336 @@
 constructor TMemoryBitStream.Create;
 begin
-  FStream := TMemoryStream.Create;
+  FMemory := TPositionMemory.Create;
   FPosition := 0;
   FSize := 0;
@@ -341 +343 @@
 destructor TMemoryBitStream.Destroy;
 begin
-  FStream.Free;
+  FMemory.Free;
   inherited Destroy;
 end;

CoolStreaming/UStreamHelper.pas

@@ -39 +39 @@
     function ReadCardinal: Cardinal;
     function ReadInt64: Int64;
-    function ReadString: string;
+    function ReadString(Length: Integer): string;
     function ReadShortString: string;
     function ReadAnsiString: string;
@@ -73 +73 @@
 begin
   FStream.ReadBuffer(StringLength, SizeOf(StringLength));
-  SetLength(Result, StringLength);
-  if StringLength > 0 then begin
-    FStream.ReadBuffer(Result[1], StringLength);
-  end;
+  Result := ReadString(StringLength);
 end;
 
@@ -119 +116 @@
 end;
 
-function TStreamHelper.ReadString:string;
-begin
-  SetLength(Result, FStream.Size - FStream.Position);
-  if (FStream.Size - FStream.Position) > 0 then
-    FStream.Read(Result[1], FStream.Size - FStream.Position)
-    else Result := '';
+function TStreamHelper.ReadString(Length: Integer): string;
+begin
+  if Length > 0 then begin
+    SetLength(Result, Length);
+    FStream.Read(Result[1], Length);
+  end else Result := '';
 end;
 
@@ -132 +129 @@
 begin
   FStream.ReadBuffer(Count, 1);
-  SetLength(Result, Count);
-  FStream.ReadBuffer(Result[1], Count);
+  Result := ReadString(Count);
 end;