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author | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
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committer | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
commit | a031b83a09a8628435317a03f199cdc18b78262f (patch) | |
tree | bc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/tchap/go-patricia/patricia/children.go | |
parent | 2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff) | |
download | podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.gz podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.bz2 podman-a031b83a09a8628435317a03f199cdc18b78262f.zip |
Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/tchap/go-patricia/patricia/children.go')
-rw-r--r-- | vendor/github.com/tchap/go-patricia/patricia/children.go | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/vendor/github.com/tchap/go-patricia/patricia/children.go b/vendor/github.com/tchap/go-patricia/patricia/children.go new file mode 100644 index 000000000..a5677c335 --- /dev/null +++ b/vendor/github.com/tchap/go-patricia/patricia/children.go @@ -0,0 +1,325 @@ +// Copyright (c) 2014 The go-patricia AUTHORS +// +// Use of this source code is governed by The MIT License +// that can be found in the LICENSE file. + +package patricia + +import ( + "fmt" + "io" + "sort" +) + +type childList interface { + length() int + head() *Trie + add(child *Trie) childList + remove(b byte) + replace(b byte, child *Trie) + next(b byte) *Trie + walk(prefix *Prefix, visitor VisitorFunc) error + print(w io.Writer, indent int) + total() int +} + +type tries []*Trie + +func (t tries) Len() int { + return len(t) +} + +func (t tries) Less(i, j int) bool { + strings := sort.StringSlice{string(t[i].prefix), string(t[j].prefix)} + return strings.Less(0, 1) +} + +func (t tries) Swap(i, j int) { + t[i], t[j] = t[j], t[i] +} + +type sparseChildList struct { + children tries +} + +func newSparseChildList(maxChildrenPerSparseNode int) childList { + return &sparseChildList{ + children: make(tries, 0, maxChildrenPerSparseNode), + } +} + +func (list *sparseChildList) length() int { + return len(list.children) +} + +func (list *sparseChildList) head() *Trie { + return list.children[0] +} + +func (list *sparseChildList) add(child *Trie) childList { + // Search for an empty spot and insert the child if possible. + if len(list.children) != cap(list.children) { + list.children = append(list.children, child) + return list + } + + // Otherwise we have to transform to the dense list type. + return newDenseChildList(list, child) +} + +func (list *sparseChildList) remove(b byte) { + for i, node := range list.children { + if node.prefix[0] == b { + list.children[i] = list.children[len(list.children)-1] + list.children[len(list.children)-1] = nil + list.children = list.children[:len(list.children)-1] + return + } + } + + // This is not supposed to be reached. + panic("removing non-existent child") +} + +func (list *sparseChildList) replace(b byte, child *Trie) { + // Make a consistency check. + if p0 := child.prefix[0]; p0 != b { + panic(fmt.Errorf("child prefix mismatch: %v != %v", p0, b)) + } + + // Seek the child and replace it. + for i, node := range list.children { + if node.prefix[0] == b { + list.children[i] = child + return + } + } +} + +func (list *sparseChildList) next(b byte) *Trie { + for _, child := range list.children { + if child.prefix[0] == b { + return child + } + } + return nil +} + +func (list *sparseChildList) walk(prefix *Prefix, visitor VisitorFunc) error { + + sort.Sort(list.children) + + for _, child := range list.children { + *prefix = append(*prefix, child.prefix...) + if child.item != nil { + err := visitor(*prefix, child.item) + if err != nil { + if err == SkipSubtree { + *prefix = (*prefix)[:len(*prefix)-len(child.prefix)] + continue + } + *prefix = (*prefix)[:len(*prefix)-len(child.prefix)] + return err + } + } + + err := child.children.walk(prefix, visitor) + *prefix = (*prefix)[:len(*prefix)-len(child.prefix)] + if err != nil { + return err + } + } + + return nil +} + +func (list *sparseChildList) total() int { + tot := 0 + for _, child := range list.children { + if child != nil { + tot = tot + child.total() + } + } + return tot +} + +func (list *sparseChildList) print(w io.Writer, indent int) { + for _, child := range list.children { + if child != nil { + child.print(w, indent) + } + } +} + +type denseChildList struct { + min int + max int + numChildren int + headIndex int + children []*Trie +} + +func newDenseChildList(list *sparseChildList, child *Trie) childList { + var ( + min int = 255 + max int = 0 + ) + for _, child := range list.children { + b := int(child.prefix[0]) + if b < min { + min = b + } + if b > max { + max = b + } + } + + b := int(child.prefix[0]) + if b < min { + min = b + } + if b > max { + max = b + } + + children := make([]*Trie, max-min+1) + for _, child := range list.children { + children[int(child.prefix[0])-min] = child + } + children[int(child.prefix[0])-min] = child + + return &denseChildList{ + min: min, + max: max, + numChildren: list.length() + 1, + headIndex: 0, + children: children, + } +} + +func (list *denseChildList) length() int { + return list.numChildren +} + +func (list *denseChildList) head() *Trie { + return list.children[list.headIndex] +} + +func (list *denseChildList) add(child *Trie) childList { + b := int(child.prefix[0]) + var i int + + switch { + case list.min <= b && b <= list.max: + if list.children[b-list.min] != nil { + panic("dense child list collision detected") + } + i = b - list.min + list.children[i] = child + + case b < list.min: + children := make([]*Trie, list.max-b+1) + i = 0 + children[i] = child + copy(children[list.min-b:], list.children) + list.children = children + list.min = b + + default: // b > list.max + children := make([]*Trie, b-list.min+1) + i = b - list.min + children[i] = child + copy(children, list.children) + list.children = children + list.max = b + } + + list.numChildren++ + if i < list.headIndex { + list.headIndex = i + } + return list +} + +func (list *denseChildList) remove(b byte) { + i := int(b) - list.min + if list.children[i] == nil { + // This is not supposed to be reached. + panic("removing non-existent child") + } + list.numChildren-- + list.children[i] = nil + + // Update head index. + if i == list.headIndex { + for ; i < len(list.children); i++ { + if list.children[i] != nil { + list.headIndex = i + return + } + } + } +} + +func (list *denseChildList) replace(b byte, child *Trie) { + // Make a consistency check. + if p0 := child.prefix[0]; p0 != b { + panic(fmt.Errorf("child prefix mismatch: %v != %v", p0, b)) + } + + // Replace the child. + list.children[int(b)-list.min] = child +} + +func (list *denseChildList) next(b byte) *Trie { + i := int(b) + if i < list.min || list.max < i { + return nil + } + return list.children[i-list.min] +} + +func (list *denseChildList) walk(prefix *Prefix, visitor VisitorFunc) error { + for _, child := range list.children { + if child == nil { + continue + } + *prefix = append(*prefix, child.prefix...) + if child.item != nil { + if err := visitor(*prefix, child.item); err != nil { + if err == SkipSubtree { + *prefix = (*prefix)[:len(*prefix)-len(child.prefix)] + continue + } + *prefix = (*prefix)[:len(*prefix)-len(child.prefix)] + return err + } + } + + err := child.children.walk(prefix, visitor) + *prefix = (*prefix)[:len(*prefix)-len(child.prefix)] + if err != nil { + return err + } + } + + return nil +} + +func (list *denseChildList) print(w io.Writer, indent int) { + for _, child := range list.children { + if child != nil { + child.print(w, indent) + } + } +} + +func (list *denseChildList) total() int { + tot := 0 + for _, child := range list.children { + if child != nil { + tot = tot + child.total() + } + } + return tot +} |