86 lines
1.6 KiB
C++
86 lines
1.6 KiB
C++
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#include "IFIFO.h"
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IFIFO::IFIFO(UInt32 length)
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{
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fifoBuf = new UInt8[length];
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fifoBufSize = length;
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fifoBase = 0;
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fifoDataLength = 0;
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}
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IFIFO::~IFIFO()
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{
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delete fifoBuf;
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}
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bool IFIFO::Push(UInt8 * buf, UInt32 length)
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{
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// would that overflow the buffer?
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if(length > GetBufferRemain())
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return false;
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UInt32 writeOffset = GetWriteOffset();
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// will this cross the end of the buffer?
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if(writeOffset + length > fifoBufSize)
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{
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UInt32 segmentLength = fifoBufSize - writeOffset;
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std::memcpy(&fifoBuf[writeOffset], buf, segmentLength);
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std::memcpy(fifoBuf, &buf[segmentLength], length - segmentLength);
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}
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else
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{
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std::memcpy(&fifoBuf[writeOffset], buf, length);
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}
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// update pointers
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fifoDataLength += length;
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return true;
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}
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bool IFIFO::Pop(UInt8 * buf, UInt32 length)
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{
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bool result = Peek(buf, length);
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// update pointers if we were successful
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if(result)
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{
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fifoDataLength -= length;
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fifoBase = ToRawOffset(fifoBase + length);
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}
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return result;
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}
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bool IFIFO::Peek(UInt8 * buf, UInt32 length)
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{
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// would that underflow the buffer?
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if(length > fifoDataLength)
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return false;
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// will this cross the end of the buffer?
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if(fifoBase + length > fifoBufSize)
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{
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UInt32 segmentLength = fifoBufSize - fifoBase;
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std::memcpy(buf, &fifoBuf[fifoBase], segmentLength);
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std::memcpy(&buf[segmentLength], fifoBuf, length - segmentLength);
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}
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else
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{
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std::memcpy(buf, &fifoBuf[fifoBase], length);
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}
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return true;
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}
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void IFIFO::Clear(void)
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{
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fifoDataLength = 0;
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// this isn't needed, but staying away from the buffer end is always good
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fifoBase = 0;
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}
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