func TestZeroThreshhold(t *testing.T) {
var pages [4]btreepq.Page
queue := btreepq.New(
uint(len(pages)),
0,
10,
func() btreepq.Page {
return &pageForTesting{}
})
for i := range pages {
pages[i] = queue.NextPage()
}
assertNextValues(t, queue, pages[:], 0)
}
func TestRemovePages(t *testing.T) {
var pages [8]btreepq.Page
queue := btreepq.New(
uint(len(pages)),
2,
10,
func() btreepq.Page {
return &pageForTesting{}
})
// Get all pages in queue. We will always revisit these pages in the same
// order unless pages are marked high priority for reclaiming.
for i := range pages {
pages[i] = queue.NextPage()
}
verifyPagesAreUnique(t, pages[:])
// The next pages off the queue
assertNextValues(t, queue, pages[:], 0, 1, 2, 3, 4, 5, 6, 7, 0, 1)
removed, ok := queue.RemovePage()
assertValueEquals(t, pages[2], removed)
assertValueEquals(t, true, ok)
removed, ok = queue.RemovePage()
assertValueEquals(t, pages[3], removed)
assertValueEquals(t, true, ok)
removed, ok = queue.RemovePage()
assertValueEquals(t, pages[4], removed)
assertValueEquals(t, true, ok)
// The next pages off the queue
assertNextValues(t, queue, pages[:], 5, 6, 7, 0, 1, 5, 6, 7, 0)
// We can successfully remove 4 out of 5 pages
for i := 0; i < 4; i++ {
_, ok := queue.RemovePage()
assertValueEquals(t, true, ok)
}
// Removing last page fails.
_, ok = queue.RemovePage()
assertValueEquals(t, false, ok)
}
func newPageQueueType(
bytesPerPage uint,
pageCount uint,
inactiveThreshhold float64,
degree uint) *pageQueueType {
if inactiveThreshhold < 0.0 {
panic("inactiveThreshhold cannot be negative")
}
pages := btreepq.New(
pageCount,
uint(float64(pageCount)*inactiveThreshhold),
degree,
func() btreepq.Page {
return newPageWithMetaDataType(bytesPerPage)
})
return &pageQueueType{
valueCountPerPage: bytesPerPage / kTsAndValueSize,
inactiveThreshhold: inactiveThreshhold,
degree: degree,
bytesPerPage: bytesPerPage,
pq: pages}
}
func TestAPI(t *testing.T) {
var pages [8]btreepq.Page
queue := btreepq.New(
uint(len(pages)),
2,
10,
func() btreepq.Page {
return &pageForTesting{}
})
// Get all pages in queue. We will always revisit these pages in the same
// order unless pages are marked high priority for reclaiming.
for i := range pages {
pages[i] = queue.NextPage()
}
verifyPagesAreUnique(t, pages[:])
// Mark page 4 high priority for reclaiming
queue.ReclaimHigh(pages[4])
// Next page off the queue should be page 0 as we haven't reached the
// threshhold for pulling high priority pages
assertValueEquals(t, pages[0], queue.NextPage())
// Mark page 5 high priority. Now high priority queue is {4, 5}
queue.ReclaimHigh(pages[5])
// Next page will be page 4, not page 1 as the high priority queue has
// reached its threshhold of 2.
assertValueEquals(t, pages[4], queue.NextPage())
// Once again high priority queue has fallen below its threshhold so
// next page is page 1, not page 5
assertValueEquals(t, pages[1], queue.NextPage())
// Mark pages 6 and 7 as high priority. High priority queue is now {5, 6, 7}
queue.ReclaimHigh(pages[6])
queue.ReclaimHigh(pages[7])
// The next pages off the queue
assertNextValues(t, queue, pages[:], 5, 6, 2, 3, 7)
// Now the high priority queue has nothing and the normal queue is now
// {0, 4, 1, 5, 6, 2, 3, 7}
// We now mark pages as high priority and then mark the same pages as
// low priority to show that ReclaimLow works
queue.ReclaimHigh(pages[7])
queue.ReclaimHigh(pages[2])
queue.ReclaimHigh(pages[3])
queue.ReclaimHigh(pages[1])
queue.ReclaimLow(pages[7])
queue.ReclaimLow(pages[2])
queue.ReclaimLow(pages[3])
queue.ReclaimLow(pages[1])
// Since all pages are low priority, we should visit the pages in the
// same order as before.
assertNextValues(t, queue, pages[:], 0, 4, 1, 5, 6, 2, 3, 7)
}