48 lines
1.1 KiB
Go
48 lines
1.1 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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// Package set contains set types.
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package set
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// Set is a set of T.
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type Set[T comparable] map[T]struct{}
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// Add adds e to the set.
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func (s Set[T]) Add(e T) { s[e] = struct{}{} }
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// Delete removes e from the set.
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func (s Set[T]) Delete(e T) { delete(s, e) }
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// Contains reports whether s contains e.
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func (s Set[T]) Contains(e T) bool {
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_, ok := s[e]
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return ok
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}
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// Len reports the number of items in s.
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func (s Set[T]) Len() int { return len(s) }
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// HandleSet is a set of T.
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//
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// It is not safe for concurrent use.
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type HandleSet[T any] map[Handle]T
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// Handle is a opaque comparable value that's used as the map key
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// in a HandleSet. The only way to get one is to call HandleSet.Add.
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type Handle struct {
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v *byte
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}
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// Add adds the element (map value) e to the set.
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//
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// It returns the handle (map key) with which e can be removed, using a map
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// delete.
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func (s *HandleSet[T]) Add(e T) Handle {
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h := Handle{new(byte)}
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if *s == nil {
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*s = make(HandleSet[T])
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}
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(*s)[h] = e
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return h
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}
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