size_t TempSpace::allocateBatch(size_t count, size_t minSize, size_t maxSize, Segments& segments)
{
// adjust passed chunk size to amount of free memory we have and number
// of runs still not allocated.
offset_t freeMem = 0;
for (bool found = freeSegments.getFirst(); found; found = freeSegments.getNext())
freeMem += freeSegments.current().size;
freeMem = MIN(freeMem / count, maxSize);
freeMem = MAX(freeMem, minSize);
freeMem = MIN(freeMem, minBlockSize);
freeMem &= ~(FB_ALIGNMENT - 1);
bool is_positioned = freeSegments.getFirst();
while (segments.getCount() < count && is_positioned)
{
Segment* freeSpace = &freeSegments.current();
offset_t freeSeek = freeSpace->position;
const offset_t freeEnd = freeSpace->position + freeSpace->size;
UCHAR* const mem = findMemory(freeSeek, freeEnd, freeMem);
if (mem)
{
fb_assert(freeSeek + freeMem <= freeEnd);
#ifdef DEV_BUILD
offset_t seek1 = freeSeek;
UCHAR* const p = findMemory(seek1, freeEnd, freeMem);
fb_assert(p == mem);
fb_assert(seek1 == freeSeek);
#endif
if (freeSeek != freeSpace->position)
{
const offset_t skip_size = freeSeek - freeSpace->position;
const Segment skip_space(freeSpace->position, skip_size);
freeSpace->position += skip_size;
freeSpace->size -= skip_size;
fb_assert(freeSpace->size != 0);
if (!freeSegments.add(skip_space))
fb_assert(false);
if (!freeSegments.locate(skip_space.position + skip_size))
fb_assert(false);
freeSpace = &freeSegments.current();
}
SegmentInMemory seg;
seg.memory = mem;
seg.position = freeSeek;
seg.size = freeMem;
segments.add(seg);
freeSpace->position += freeMem;
freeSpace->size -= freeMem;
if (!freeSpace->size)
{
is_positioned = freeSegments.fastRemove();
}
}
else
{
is_positioned = freeSegments.getNext();
}
}
return segments.getCount();
}
