forked from forgejo/forgejo
Mura Li
Lauris BH
parent
b50dee5a61
commit
9591185c8f
180 changed files with 43400 additions and 41105 deletions
221
vendor/github.com/blevesearch/bleve/geo/geohash.go
generated
vendored
221
vendor/github.com/blevesearch/bleve/geo/geohash.go
generated
vendored
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@ -1,32 +1,21 @@
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// The code here was obtained from:
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// https://github.com/mmcloughlin/geohash
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// The MIT License (MIT)
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// Copyright (c) 2015 Michael McLoughlin
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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// The above copyright notice and this permission notice shall be included in all
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// copies or substantial portions of the Software.
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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// SOFTWARE.
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// Copyright (c) 2019 Couchbase, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// This implementation is inspired from the geohash-js
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// ref: https://github.com/davetroy/geohash-js
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package geo
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import (
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"math"
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)
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// encoding encapsulates an encoding defined by a given base32 alphabet.
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type encoding struct {
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enc string
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@ -47,128 +36,76 @@ func newEncoding(encoder string) *encoding {
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return e
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}
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// Decode string into bits of a 64-bit word. The string s may be at most 12
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// characters.
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func (e *encoding) decode(s string) uint64 {
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x := uint64(0)
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for i := 0; i < len(s); i++ {
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x = (x << 5) | uint64(e.dec[s[i]])
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}
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return x
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}
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// Encode bits of 64-bit word into a string.
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func (e *encoding) encode(x uint64) string {
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b := [12]byte{}
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for i := 0; i < 12; i++ {
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b[11-i] = e.enc[x&0x1f]
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x >>= 5
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}
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return string(b[:])
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}
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// Base32Encoding with the Geohash alphabet.
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// base32encoding with the Geohash alphabet.
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var base32encoding = newEncoding("0123456789bcdefghjkmnpqrstuvwxyz")
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// BoundingBox returns the region encoded by the given string geohash.
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func geoBoundingBox(hash string) geoBox {
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bits := uint(5 * len(hash))
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inthash := base32encoding.decode(hash)
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return geoBoundingBoxIntWithPrecision(inthash, bits)
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}
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var masks = []uint64{16, 8, 4, 2, 1}
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// Box represents a rectangle in latitude/longitude space.
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type geoBox struct {
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minLat float64
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maxLat float64
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minLng float64
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maxLng float64
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}
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// DecodeGeoHash decodes the string geohash faster with
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// higher precision. This api is in experimental phase.
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func DecodeGeoHash(geoHash string) (float64, float64) {
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even := true
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lat := []float64{-90.0, 90.0}
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lon := []float64{-180.0, 180.0}
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// Round returns a point inside the box, making an effort to round to minimal
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// precision.
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func (b geoBox) round() (lat, lng float64) {
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x := maxDecimalPower(b.maxLat - b.minLat)
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lat = math.Ceil(b.minLat/x) * x
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x = maxDecimalPower(b.maxLng - b.minLng)
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lng = math.Ceil(b.minLng/x) * x
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return
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}
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// precalculated for performance
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var exp232 = math.Exp2(32)
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// errorWithPrecision returns the error range in latitude and longitude for in
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// integer geohash with bits of precision.
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func errorWithPrecision(bits uint) (latErr, lngErr float64) {
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b := int(bits)
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latBits := b / 2
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lngBits := b - latBits
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latErr = math.Ldexp(180.0, -latBits)
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lngErr = math.Ldexp(360.0, -lngBits)
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return
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}
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// minDecimalPlaces returns the minimum number of decimal places such that
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// there must exist an number with that many places within any range of width
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// r. This is intended for returning minimal precision coordinates inside a
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// box.
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func maxDecimalPower(r float64) float64 {
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m := int(math.Floor(math.Log10(r)))
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return math.Pow10(m)
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}
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// Encode the position of x within the range -r to +r as a 32-bit integer.
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func encodeRange(x, r float64) uint32 {
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p := (x + r) / (2 * r)
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return uint32(p * exp232)
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}
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// Decode the 32-bit range encoding X back to a value in the range -r to +r.
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func decodeRange(X uint32, r float64) float64 {
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p := float64(X) / exp232
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x := 2*r*p - r
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return x
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}
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// Squash the even bitlevels of X into a 32-bit word. Odd bitlevels of X are
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// ignored, and may take any value.
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func squash(X uint64) uint32 {
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X &= 0x5555555555555555
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X = (X | (X >> 1)) & 0x3333333333333333
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X = (X | (X >> 2)) & 0x0f0f0f0f0f0f0f0f
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X = (X | (X >> 4)) & 0x00ff00ff00ff00ff
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X = (X | (X >> 8)) & 0x0000ffff0000ffff
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X = (X | (X >> 16)) & 0x00000000ffffffff
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return uint32(X)
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}
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// Deinterleave the bits of X into 32-bit words containing the even and odd
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// bitlevels of X, respectively.
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func deinterleave(X uint64) (uint32, uint32) {
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return squash(X), squash(X >> 1)
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}
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// BoundingBoxIntWithPrecision returns the region encoded by the integer
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// geohash with the specified precision.
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func geoBoundingBoxIntWithPrecision(hash uint64, bits uint) geoBox {
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fullHash := hash << (64 - bits)
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latInt, lngInt := deinterleave(fullHash)
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lat := decodeRange(latInt, 90)
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lng := decodeRange(lngInt, 180)
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latErr, lngErr := errorWithPrecision(bits)
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return geoBox{
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minLat: lat,
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maxLat: lat + latErr,
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minLng: lng,
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maxLng: lng + lngErr,
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for i := 0; i < len(geoHash); i++ {
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cd := uint64(base32encoding.dec[geoHash[i]])
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for j := 0; j < 5; j++ {
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if even {
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if cd&masks[j] > 0 {
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lon[0] = (lon[0] + lon[1]) / 2
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} else {
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lon[1] = (lon[0] + lon[1]) / 2
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}
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} else {
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if cd&masks[j] > 0 {
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lat[0] = (lat[0] + lat[1]) / 2
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} else {
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lat[1] = (lat[0] + lat[1]) / 2
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}
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}
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even = !even
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}
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}
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return (lat[0] + lat[1]) / 2, (lon[0] + lon[1]) / 2
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}
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// ----------------------------------------------------------------------
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func EncodeGeoHash(lat, lon float64) string {
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even := true
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lats := []float64{-90.0, 90.0}
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lons := []float64{-180.0, 180.0}
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precision := 12
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var ch, bit uint64
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var geoHash string
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// Decode the string geohash to a (lat, lng) point.
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func GeoHashDecode(hash string) (lat, lng float64) {
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box := geoBoundingBox(hash)
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return box.round()
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for len(geoHash) < precision {
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if even {
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mid := (lons[0] + lons[1]) / 2
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if lon > mid {
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ch |= masks[bit]
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lons[0] = mid
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} else {
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lons[1] = mid
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}
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} else {
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mid := (lats[0] + lats[1]) / 2
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if lat > mid {
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ch |= masks[bit]
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lats[0] = mid
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} else {
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lats[1] = mid
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}
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}
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even = !even
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if bit < 4 {
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bit++
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} else {
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geoHash += string(base32encoding.enc[ch])
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ch = 0
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bit = 0
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}
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}
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return geoHash
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}
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