mirror of
https://codeberg.org/superseriousbusiness/gotosocial.git
synced 2024-12-25 10:28:18 +03:00
98263a7de6
* start fixing up tests * fix up tests + automate with drone * fiddle with linting * messing about with drone.yml * some more fiddling * hmmm * add cache * add vendor directory * verbose * ci updates * update some little things * update sig
93 lines
2.6 KiB
Go
93 lines
2.6 KiB
Go
// Copyright 2020 Google Inc. All rights reserved.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
|
|
package s2
|
|
|
|
import "container/heap"
|
|
|
|
// A queryQueueEntry stores CellIDs and distance from a target. It is used by the
|
|
// different S2 Query types to efficiently build their internal priority queue
|
|
// in the optimized algorithm implementations.
|
|
type queryQueueEntry struct {
|
|
// A lower bound on the distance from the target to ID. This is the key
|
|
// of the priority queue.
|
|
distance distance
|
|
|
|
// The cell being queued.
|
|
id CellID
|
|
|
|
// If the CellID belongs to a ShapeIndex, this field stores the
|
|
// corresponding ShapeIndexCell. Otherwise ID is a proper ancestor of
|
|
// one or more ShapeIndexCells and this field stores is nil.
|
|
indexCell *ShapeIndexCell
|
|
}
|
|
|
|
// queryQueue is used by the optimized algorithm to maintain a priority queue of
|
|
// unprocessed CellIDs, sorted in increasing order of distance from the target.
|
|
type queryQueue struct {
|
|
queue queryPQ
|
|
}
|
|
|
|
// newQueryQueue returns a new initialized queryQueue.
|
|
func newQueryQueue() *queryQueue {
|
|
q := &queryQueue{
|
|
queue: make(queryPQ, 0),
|
|
}
|
|
heap.Init(&q.queue)
|
|
return q
|
|
}
|
|
|
|
// push adds the given entry to the top of this queue.
|
|
func (q *queryQueue) push(e *queryQueueEntry) {
|
|
heap.Push(&q.queue, e)
|
|
}
|
|
|
|
// pop returns the top element of this queue.
|
|
func (q *queryQueue) pop() *queryQueueEntry {
|
|
return heap.Pop(&q.queue).(*queryQueueEntry)
|
|
}
|
|
|
|
func (q *queryQueue) size() int {
|
|
return q.queue.Len()
|
|
}
|
|
|
|
func (q *queryQueue) reset() {
|
|
q.queue = q.queue[:0]
|
|
}
|
|
|
|
// queryPQ is a priority queue that implements the heap interface.
|
|
type queryPQ []*queryQueueEntry
|
|
|
|
func (q queryPQ) Len() int { return len(q) }
|
|
func (q queryPQ) Less(i, j int) bool {
|
|
return q[i].distance.less(q[j].distance)
|
|
}
|
|
|
|
// Swap swaps the two entries.
|
|
func (q queryPQ) Swap(i, j int) {
|
|
q[i], q[j] = q[j], q[i]
|
|
}
|
|
|
|
// Push adds the given entry to the queue.
|
|
func (q *queryPQ) Push(x interface{}) {
|
|
item := x.(*queryQueueEntry)
|
|
*q = append(*q, item)
|
|
}
|
|
|
|
// Pop returns the top element of the queue.
|
|
func (q *queryPQ) Pop() interface{} {
|
|
item := (*q)[len(*q)-1]
|
|
*q = (*q)[:len(*q)-1]
|
|
return item
|
|
}
|