58 lines
1.1 KiB
Go
58 lines
1.1 KiB
Go
package gg
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// The structure to store objects
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// with O(1) add, remove and search operations.
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type Objects struct {
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// The place to store all the objects.
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store []Object
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// Find index by Object.
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searchMap map[Object] int
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// Available nil values in the store.
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freeIndexes []int
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}
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func NewObjects() *Objects {
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ret := &Objects{}
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ret.searchMap = map[Object] int {}
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return ret
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}
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func (objects *Objects) has(object Object) bool {
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_, ok := objects.searchMap[object]
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return ok
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}
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func (objects *Objects) add(object Object) bool {
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if objects.has(object) {
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return false
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}
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if len(objects.freeIndexes) > 0 {
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freeIndex := objects.freeIndexes[0]
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objects.freeIndexes = objects.freeIndexes[1:]
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objects.store[freeIndex] = object
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objects.searchMap[object] = freeIndex
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} else {
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objects.store = append(objects.store, object)
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objects.searchMap[object] = len(objects.store)-1
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}
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return true
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}
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func (objects *Objects) remove(object Object) bool {
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objectIndex, ok := objects.searchMap[object]
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if !ok {
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return false
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}
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objects.store[objectIndex] = nil
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objects.freeIndexes = append(
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objects.freeIndexes,
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objectIndex,
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)
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return true
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}
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