93 lines
1.6 KiB
Go
93 lines
1.6 KiB
Go
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package binding
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// DataTreeRootID const is the value used as ID for the root of any tree binding.
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const DataTreeRootID = ""
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// DataTree is the base interface for all bindable data trees.
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//
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// Since: 2.4
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type DataTree interface {
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DataItem
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GetItem(id string) (DataItem, error)
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ChildIDs(string) []string
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}
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type treeBase struct {
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base
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ids map[string][]string
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items map[string]DataItem
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}
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// GetItem returns the DataItem at the specified id.
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func (t *treeBase) GetItem(id string) (DataItem, error) {
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t.lock.RLock()
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defer t.lock.RUnlock()
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if item, ok := t.items[id]; ok {
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return item, nil
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}
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return nil, errOutOfBounds
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}
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// ChildIDs returns the ordered IDs of items in this data tree that are children of the specified ID.
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func (t *treeBase) ChildIDs(id string) []string {
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t.lock.RLock()
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defer t.lock.RUnlock()
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if ids, ok := t.ids[id]; ok {
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return ids
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}
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return []string{}
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}
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func (t *treeBase) appendItem(i DataItem, id, parent string) {
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t.items[id] = i
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ids, ok := t.ids[parent]
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if !ok {
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ids = make([]string, 0)
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}
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for _, in := range ids {
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if in == id {
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return
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}
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}
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t.ids[parent] = append(ids, id)
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}
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func (t *treeBase) deleteItem(id, parent string) {
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delete(t.items, id)
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ids, ok := t.ids[parent]
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if !ok {
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return
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}
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off := -1
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for i, id2 := range ids {
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if id2 == id {
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off = i
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break
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}
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}
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if off == -1 {
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return
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}
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t.ids[parent] = append(ids[:off], ids[off+1:]...)
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}
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func parentIDFor(id string, ids map[string][]string) string {
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for parent, list := range ids {
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for _, child := range list {
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if child == id {
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return parent
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}
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}
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}
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return ""
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}
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