Fix DownloadedPiecesBar::bitfieldToFloatVector().

This commit is contained in:
Vladimir Golovnev (Glassez) 2015-10-29 14:45:51 +03:00 committed by sledgehammer999
parent 1ecdcfc29c
commit 0fbdc6471c

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@ -59,24 +59,17 @@ std::vector<float> DownloadedPiecesBar::bitfieldToFloatVector(const libtorrent::
// image.x(1) = pieces.x(1.7 >= x < 3.4)
for (int x = 0; x < reqSize; ++x) {
// don't use previously calculated value "ratio" here!!!
// float cannot save irrational number like 7/9, if this number will be rounded up by std::ceil
// give you x2 == pieces.size(), and index out of range: pieces[x2]
// this code is safe, so keep that in mind when you try optimize more.
// tested with size = 3000000ul
// R - real
const float fromR = (x * vecin.size()) / (float)reqSize;
const float toR = ((x + 1) * vecin.size()) / (float)reqSize;
const float fromR = x * ratio;
const float toR = (x + 1) * ratio;
// C - integer
int fromC = fromR;// std::floor not needed
int toC = std::ceil(toR);
if (toC > vecin.size())
--toC;
// position in pieces table
// libtorrent::bitfield::m_size is unsigned int(31 bits), so qlonglong is not needed
// tested with size = 3000000ul
int x2 = fromC;
// little speed up for really big pieces table, 10K+ size
@ -88,7 +81,7 @@ std::vector<float> DownloadedPiecesBar::bitfieldToFloatVector(const libtorrent::
// case when calculated range is (15.2 >= x < 15.7)
if (x2 == toCMinusOne) {
if (vecin[x2]) {
value += toR - fromR;
value += ratio;
}
++x2;
}