github/qBittorrent
1
0
Fork 0
mirror of https://github.com/qbittorrent/qBittorrent synced 2025-08-14 02:27:09 -07:00
Code Issues Projects Releases Packages Wiki Activity Actions 3

Allocate memory on stack whenever feasible

Browse source 
The fast path gives another 20% speed up than the slower path.
This commit is contained in:
Chocobo1 2022-01-26 12:20:21 +08:00
commit aafee60033
No known key found for this signature in database
GPG key ID: 210D9C873253A68C
1 changed files with 13 additions and 0 deletions
Download patch file Download diff file Expand all files Collapse all files

13
src/base/bittorrent/ltqbitarray.cpp
View file

@ -47,9 +47,22 @@ namespace BitTorrent::LT
{
QBitArray toQBitArray(const lt::bitfield &bits)
{
const int STACK_ALLOC_SIZE = 10 * 1024;
const char *bitsData = bits.data();
const int dataLength = (bits.size() + 7) / 8;
if (dataLength <= STACK_ALLOC_SIZE)
{
// fast path for small bitfields
char tmp[STACK_ALLOC_SIZE]; // uninitialized for faster allocation
for (int i = 0; i < dataLength; ++i)
tmp[i] = reverseByte(bitsData[i]);
return QBitArray::fromBits(tmp, bits.size());
}
// slow path for big bitfields
auto tmp = std::make_unique<char []>(dataLength);
for (int i = 0; i < dataLength; ++i)
tmp[i] = reverseByte(bitsData[i]);