64 lines
1.3 KiB
Go
64 lines
1.3 KiB
Go
package structr
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import (
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"sync"
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"unsafe"
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)
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type indexed_item struct {
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// linked list elem this item
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// is stored in a main list.
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elem list_elem
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// cached data with type.
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data interface{}
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// indexed stores the indices
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// this item is stored under.
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indexed []*index_entry
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}
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var indexed_item_pool sync.Pool
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// new_indexed_item returns a new prepared indexed_item.
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func new_indexed_item() *indexed_item {
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v := indexed_item_pool.Get()
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if v == nil {
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i := new(indexed_item)
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i.elem.data = unsafe.Pointer(i)
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v = i
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}
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item := v.(*indexed_item)
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return item
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}
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// free_indexed_item releases the indexed_item.
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func free_indexed_item(item *indexed_item) {
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if len(item.indexed) > 0 ||
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item.elem.next != nil ||
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item.elem.prev != nil {
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should_not_reach()
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return
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}
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item.data = nil
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indexed_item_pool.Put(item)
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}
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// drop_index will drop the given index entry from item's indexed.
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func (i *indexed_item) drop_index(entry *index_entry) {
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for x := 0; x < len(i.indexed); x++ {
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if i.indexed[x] != entry {
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// Prof. Obiwan:
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// this is not the index
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// we are looking for.
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continue
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}
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// Reslice index entries minus 'x'.
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_ = copy(i.indexed[x:], i.indexed[x+1:])
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i.indexed[len(i.indexed)-1] = nil
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i.indexed = i.indexed[:len(i.indexed)-1]
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break
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}
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}
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