mirror of https://github.com/FOME-Tech/fome-fw.git
48 lines
1.3 KiB
C++
48 lines
1.3 KiB
C++
/*
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* FragmentEntry.cpp
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*
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* Created on: Jan 5, 2022
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* @author Andrey Belomutskiy, (c) 2012-2022
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*/
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#include "pch.h"
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#include "FragmentEntry.h"
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/**
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* copy dataLength of fragmented outputs starting at dataOffset into destination starting at zero
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*/
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void copyRange(uint8_t *destination,
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FragmentEntry *fragments, int fragmentsCount,
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size_t dataOffset, size_t dataLength) {
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int fragmentIndex = 0;
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// scroll to starting fragment
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while (dataOffset > fragments[fragmentIndex].size && fragmentIndex <= fragmentsCount) {
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dataOffset -= fragments[fragmentIndex].size;
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fragmentIndex ++;
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}
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int destinationIndex = 0;
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while (dataLength > 0) {
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if (fragmentIndex > fragmentsCount) {
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// somehow we are past the end of fragments - fill with zeros
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memset(destination + destinationIndex, 0, dataLength);
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return;
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}
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int copyNowSize = minI(dataLength, fragments[fragmentIndex].size - dataOffset);
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const uint8_t *fromBase = fragments[fragmentIndex].data;
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if (fromBase == nullptr) {
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// we have no buffer for this fragment - fill with zeroes
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memset(destination + destinationIndex, 0, copyNowSize);
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} else {
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memcpy(destination + destinationIndex, fromBase + dataOffset, copyNowSize);
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}
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destinationIndex += copyNowSize;
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dataOffset = 0;
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dataLength -= copyNowSize;
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fragmentIndex++;
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}
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}
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