96 lines
2.3 KiB
Go
96 lines
2.3 KiB
Go
package tsm1
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// TimeRange holds a min and max timestamp.
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type TimeRange struct {
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Min, Max int64
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}
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func (t TimeRange) Overlaps(min, max int64) bool {
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return t.Min <= max && t.Max >= min
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}
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// Within returns true if min < t.Min and t.Max < max and therefore the interval [t.Min, t.Max] is
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// contained within [min, max]
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func (t TimeRange) Within(min, max int64) bool {
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return min < t.Min && t.Max < max
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}
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func (t TimeRange) Less(o TimeRange) bool {
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return t.Min < o.Min || (t.Min == o.Min && t.Max < o.Max)
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}
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// timeRangesCoverEntries returns true if the time ranges fully cover the entries.
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func timeRangesCoverEntries(merger timeRangeMerger, entries []IndexEntry) (covers bool) {
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if len(entries) == 0 {
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return true
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}
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mustCover := entries[0].MinTime
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ts, ok := merger.Pop()
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for len(entries) > 0 && ok {
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switch {
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// If the tombstone does not include mustCover, we
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// know we do not fully cover every entry.
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case ts.Min > mustCover:
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return false
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// Otherwise, if the tombstone covers the rest of
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// the entry, consume it and bump mustCover to the
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// start of the next entry.
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case ts.Max >= entries[0].MaxTime:
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entries = entries[1:]
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if len(entries) > 0 {
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mustCover = entries[0].MinTime
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}
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// Otherwise, we're still inside of an entry, and
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// so the tombstone must adjoin the current tombstone.
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default:
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if ts.Max >= mustCover {
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mustCover = ts.Max + 1
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}
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ts, ok = merger.Pop()
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}
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}
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return len(entries) == 0
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}
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// timeRangeMerger is a special purpose data structure to merge three sources of
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// TimeRanges so that we can check if they cover a slice of index entries.
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type timeRangeMerger struct {
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fromMap []TimeRange
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fromPrefix []TimeRange
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single TimeRange
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used bool // if single has been used
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}
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// Pop returns the next TimeRange in sorted order and a boolean indicating that
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// there was a TimeRange to read.
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func (t *timeRangeMerger) Pop() (out TimeRange, ok bool) {
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var where *[]TimeRange
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var what []TimeRange
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if len(t.fromMap) > 0 {
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where, what = &t.fromMap, t.fromMap[1:]
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out, ok = t.fromMap[0], true
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}
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if len(t.fromPrefix) > 0 && (!ok || t.fromPrefix[0].Less(out)) {
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where, what = &t.fromPrefix, t.fromPrefix[1:]
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out, ok = t.fromPrefix[0], true
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}
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if !t.used && (!ok || t.single.Less(out)) {
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t.used = true
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return t.single, true
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}
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if ok {
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*where = what
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}
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return out, ok
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}
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