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author | k-m_schindler <k-m_schindler@b956fd51-792f-4845-bead-9b4dfca2ff2c> | 2008-08-27 14:59:38 +0000 |
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committer | k-m_schindler <k-m_schindler@b956fd51-792f-4845-bead-9b4dfca2ff2c> | 2008-08-27 14:59:38 +0000 |
commit | 16a6e6801fde495b2782e2e04a0cf055ce1e1516 (patch) | |
tree | 0dcfda2e6848b6157bfb51bb3037d52b595a22ae /src/Classes/URingBuffer.pas | |
parent | 873f177f08dc7c4fe2d7e50bbe7709df98e238d3 (diff) | |
download | usdx-16a6e6801fde495b2782e2e04a0cf055ce1e1516.tar.gz usdx-16a6e6801fde495b2782e2e04a0cf055ce1e1516.tar.xz usdx-16a6e6801fde495b2782e2e04a0cf055ce1e1516.zip |
rename Classes part1
git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@1307 b956fd51-792f-4845-bead-9b4dfca2ff2c
Diffstat (limited to 'src/Classes/URingBuffer.pas')
-rw-r--r-- | src/Classes/URingBuffer.pas | 128 |
1 files changed, 0 insertions, 128 deletions
diff --git a/src/Classes/URingBuffer.pas b/src/Classes/URingBuffer.pas deleted file mode 100644 index ce51e209..00000000 --- a/src/Classes/URingBuffer.pas +++ /dev/null @@ -1,128 +0,0 @@ -unit URingBuffer; - -interface - -{$IFDEF FPC} - {$MODE Delphi} -{$ENDIF} - -{$I switches.inc} - -uses - SysUtils; - -type - TRingBuffer = class - private - RingBuffer: PChar; - BufferCount: integer; - BufferSize: integer; - WritePos: integer; - ReadPos: integer; - public - constructor Create(Size: integer); - destructor Destroy; override; - function Read(Buffer: PChar; Count: integer): integer; - function Write(Buffer: PChar; Count: integer): integer; - procedure Flush(); - end; - -implementation - -uses - Math; - -constructor TRingBuffer.Create(Size: integer); -begin - BufferSize := Size; - - GetMem(RingBuffer, Size); - if (RingBuffer = nil) then - raise Exception.Create('No memory'); -end; - -destructor TRingBuffer.Destroy; -begin - FreeMem(RingBuffer); -end; - -function TRingBuffer.Read(Buffer: PChar; Count: integer): integer; -var - PartCount: integer; -begin - // adjust output count - if (Count > BufferCount) then - begin - //DebugWriteln('Read too much: ' + inttostr(count) +',count:'+ inttostr(BufferCount) + '/size:' + inttostr(BufferSize)); - Count := BufferCount; - end; - - // check if there is something to do - if (Count <= 0) then - begin - Result := Count; - Exit; - end; - - // copy data to output buffer - - // first step: copy from the area between the read-position and the end of the buffer - PartCount := Min(Count, BufferSize - ReadPos); - Move(RingBuffer[ReadPos], Buffer[0], PartCount); - - // second step: if we need more data, copy from the beginning of the buffer - if (PartCount < Count) then - Move(RingBuffer[0], Buffer[0], Count-PartCount); - - // mark the copied part of the buffer as free - BufferCount := BufferCount - Count; - ReadPos := (ReadPos + Count) mod BufferSize; - - Result := Count; -end; - -function TRingBuffer.Write(Buffer: PChar; Count: integer): integer; -var - PartCount: integer; -begin - // check for a reasonable request - if (Count <= 0) then - begin - Result := Count; - Exit; - end; - - // skip input data if the input buffer is bigger than the ring-buffer - if (Count > BufferSize) then - begin - //DebugWriteln('Write skip data:' + inttostr(count) +',count:'+ inttostr(BufferCount) + '/size:' + inttostr(BufferSize)); - Buffer := @Buffer[Count - BufferSize]; - Count := BufferSize; - end; - - // first step: copy to the area between the write-position and the end of the buffer - PartCount := Min(Count, BufferSize - WritePos); - Move(Buffer[0], RingBuffer[WritePos], PartCount); - - // second step: copy data to front of buffer - if (PartCount < Count) then - Move(Buffer[PartCount], RingBuffer[0], Count-PartCount); - - // update info - BufferCount := Min(BufferCount + Count, BufferSize); - WritePos := (WritePos + Count) mod BufferSize; - // if the buffer is full, we have to reposition the read-position - if (BufferCount = BufferSize) then - ReadPos := WritePos; - - Result := Count; -end; - -procedure TRingBuffer.Flush(); -begin - ReadPos := 0; - WritePos := 0; - BufferCount := 0; -end; - -end.
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