diff options
Diffstat (limited to 'vendor/github.com/mattermost/rsc/regexp/regmerge/sort.go')
-rw-r--r-- | vendor/github.com/mattermost/rsc/regexp/regmerge/sort.go | 199 |
1 files changed, 0 insertions, 199 deletions
diff --git a/vendor/github.com/mattermost/rsc/regexp/regmerge/sort.go b/vendor/github.com/mattermost/rsc/regexp/regmerge/sort.go deleted file mode 100644 index e40f87714..000000000 --- a/vendor/github.com/mattermost/rsc/regexp/regmerge/sort.go +++ /dev/null @@ -1,199 +0,0 @@ -// Copyright 2012 The Go Authors. All rights reserved. -// Use of this source code is governed by a BSD-style -// license that can be found in the LICENSE file. - -// Copy of go/src/pkg/sort/sort.go, specialized for []int -// and to remove some array indexing. - -package main - -func min(a, b int) int { - if a < b { - return a - } - return b -} - -// Insertion sort -func insertionSort(data []int, a, b int) { - for i := a + 1; i < b; i++ { - for j := i; j > a && data[j] < data[j-1]; j-- { - data[j], data[j-1] = data[j-1], data[j] - } - } -} - -// siftDown implements the heap property on data[lo, hi). -// first is an offset into the array where the root of the heap lies. -func siftDown(data []int, lo, hi, first int) { - root := lo - for { - child := 2*root + 1 - if child >= hi { - break - } - if child+1 < hi && data[first+child] < data[first+child+1] { - child++ - } - if !(data[first+root] < data[first+child]) { - return - } - data[first+root], data[first+child] = data[first+child], data[first+root] - root = child - } -} - -func heapSort(data []int, a, b int) { - first := a - lo := 0 - hi := b - a - - // Build heap with greatest element at top. - for i := (hi - 1) / 2; i >= 0; i-- { - siftDown(data, i, hi, first) - } - - // Pop elements, largest first, into end of data. - for i := hi - 1; i >= 0; i-- { - data[first], data[first+i] = data[first+i], data[first] - siftDown(data, lo, i, first) - } -} - -// Quicksort, following Bentley and McIlroy, -// ``Engineering a Sort Function,'' SP&E November 1993. - -// medianOfThree moves the median of the three values data[a], data[b], data[c] into data[a]. -func medianOfThree(data []int, a, b, c int) { - m0 := b - m1 := a - m2 := c - // bubble sort on 3 elements - if data[m1] < data[m0] { - data[m1], data[m0] = data[m0], data[m1] - } - if data[m2] < data[m1] { - data[m2], data[m1] = data[m1], data[m2] - } - if data[m1] < data[m0] { - data[m1], data[m0] = data[m0], data[m1] - } - // now data[m0] <= data[m1] <= data[m2] -} - -func swapRange(data []int, a, b, n int) { - for i := 0; i < n; i++ { - data[a+i], data[b+i] = data[b+i], data[a+i] - } -} - -func doPivot(data []int, lo, hi int) (midlo, midhi int) { - m := lo + (hi-lo)/2 // Written like this to avoid integer overflow. - if hi-lo > 40 { - // Tukey's ``Ninther,'' median of three medians of three. - s := (hi - lo) / 8 - medianOfThree(data, lo, lo+s, lo+2*s) - medianOfThree(data, m, m-s, m+s) - medianOfThree(data, hi-1, hi-1-s, hi-1-2*s) - } - medianOfThree(data, lo, m, hi-1) - - // Invariants are: - // data[lo] = pivot (set up by ChoosePivot) - // data[lo <= i < a] = pivot - // data[a <= i < b] < pivot - // data[b <= i < c] is unexamined - // data[c <= i < d] > pivot - // data[d <= i < hi] = pivot - // - // Once b meets c, can swap the "= pivot" sections - // into the middle of the slice. - pivot := lo - a, b, c, d := lo+1, lo+1, hi, hi - dpivot := data[pivot] - db, dc1 := data[b], data[c-1] - for b < c { - if db < dpivot { // data[b] < pivot - b++ - if b < c { - db = data[b] - } - continue - } - if !(dpivot < db) { // data[b] = pivot - data[a], data[b] = db, data[a] - a++ - b++ - if b < c { - db = data[b] - } - continue - } - if dpivot < dc1 { // data[c-1] > pivot - c-- - if c > 0 { - dc1 = data[c-1] - } - continue - } - if !(dc1 < dpivot) { // data[c-1] = pivot - data[c-1], data[d-1] = data[d-1], dc1 - c-- - d-- - if c > 0 { - dc1 = data[c-1] - } - continue - } - // data[b] > pivot; data[c-1] < pivot - data[b], data[c-1] = dc1, db - b++ - c-- - if b < c { - db = data[b] - dc1 = data[c-1] - } - } - - n := min(b-a, a-lo) - swapRange(data, lo, b-n, n) - - n = min(hi-d, d-c) - swapRange(data, c, hi-n, n) - - return lo + b - a, hi - (d - c) -} - -func quickSort(data []int, a, b, maxDepth int) { - for b-a > 7 { - if maxDepth == 0 { - heapSort(data, a, b) - return - } - maxDepth-- - mlo, mhi := doPivot(data, a, b) - // Avoiding recursion on the larger subproblem guarantees - // a stack depth of at most lg(b-a). - if mlo-a < b-mhi { - quickSort(data, a, mlo, maxDepth) - a = mhi // i.e., quickSort(data, mhi, b) - } else { - quickSort(data, mhi, b, maxDepth) - b = mlo // i.e., quickSort(data, a, mlo) - } - } - if b-a > 1 { - insertionSort(data, a, b) - } -} - -func sortInts(data []int) { - // Switch to heapsort if depth of 2*ceil(lg(n)) is reached. - n := len(data) - maxDepth := 0 - for 1<<uint(maxDepth) < n { - maxDepth++ - } - maxDepth *= 2 - quickSort(data, 0, n, maxDepth) -} |