From 059879e14301660c9fce1e5e59bdfaef89fc4aaf Mon Sep 17 00:00:00 2001 From: Reapor-Yurnero Date: Wed, 20 May 2020 22:48:41 -0700 Subject: Implement gap tracking in the segment set. This change was derived from a change by: Reapor-Yurnero And has been modified by: Adin Scannell (The original change author is preserved for the commit.) This change implements gap tracking in the segment set by adding additional information in each node, and using that information to speed up gap finding from a linear scan to a O(log(n)) walk of the tree. This gap tracking is optional, and will default to off except for segment instances that set gapTracking equal to 1 in their const lists. PiperOrigin-RevId: 312621607 --- pkg/segment/test/set_functions.go | 32 ++++++++++++++++++++++---------- 1 file changed, 22 insertions(+), 10 deletions(-) (limited to 'pkg/segment/test/set_functions.go') diff --git a/pkg/segment/test/set_functions.go b/pkg/segment/test/set_functions.go index bcddb39bb..7cd895cc7 100644 --- a/pkg/segment/test/set_functions.go +++ b/pkg/segment/test/set_functions.go @@ -14,21 +14,16 @@ package segment -// Basic numeric constants that we define because the math package doesn't. -// TODO(nlacasse): These should be Math.MaxInt64/MinInt64? -const ( - maxInt = int(^uint(0) >> 1) - minInt = -maxInt - 1 -) - type setFunctions struct{} -func (setFunctions) MinKey() int { - return minInt +// MinKey returns the minimum key for the set. +func (s setFunctions) MinKey() int { + return -s.MaxKey() - 1 } +// MaxKey returns the maximum key for the set. func (setFunctions) MaxKey() int { - return maxInt + return int(^uint(0) >> 1) } func (setFunctions) ClearValue(*int) {} @@ -40,3 +35,20 @@ func (setFunctions) Merge(_ Range, val1 int, _ Range, _ int) (int, bool) { func (setFunctions) Split(_ Range, val int, _ int) (int, int) { return val, val } + +type gapSetFunctions struct { + setFunctions +} + +// MinKey is adjusted to make sure no add overflow would happen in test cases. +// e.g. A gap with range {MinInt32, 2} would cause overflow in Range().Length(). +// +// Normally Keys should be unsigned to avoid these issues. +func (s gapSetFunctions) MinKey() int { + return s.setFunctions.MinKey() / 2 +} + +// MaxKey returns the maximum key for the set. +func (s gapSetFunctions) MaxKey() int { + return s.setFunctions.MaxKey() / 2 +} -- cgit v1.2.3