Update bleve dependency to latest master revision (#6100)

* update bleve to master b17287a86f6cac923a5d886e10618df994eeb54b6724eac2e3b8dde89cfbe3a2

* remove unused pkg from dep file

* change bleve from master to recent revision

vendor/github.com/blevesearch/bleve/geo/geohash.go

@@ -0,0 +1,174 @@
+// The code here was obtained from:
+//   https://github.com/mmcloughlin/geohash
+
+// The MIT License (MIT)
+// Copyright (c) 2015 Michael McLoughlin
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package geo
+
+import (
+	"math"
+)
+
+// encoding encapsulates an encoding defined by a given base32 alphabet.
+type encoding struct {
+	enc string
+	dec [256]byte
+}
+
+// newEncoding constructs a new encoding defined by the given alphabet,
+// which must be a 32-byte string.
+func newEncoding(encoder string) *encoding {
+	e := new(encoding)
+	e.enc = encoder
+	for i := 0; i < len(e.dec); i++ {
+		e.dec[i] = 0xff
+	}
+	for i := 0; i < len(encoder); i++ {
+		e.dec[encoder[i]] = byte(i)
+	}
+	return e
+}
+
+// Decode string into bits of a 64-bit word. The string s may be at most 12
+// characters.
+func (e *encoding) decode(s string) uint64 {
+	x := uint64(0)
+	for i := 0; i < len(s); i++ {
+		x = (x << 5) | uint64(e.dec[s[i]])
+	}
+	return x
+}
+
+// Encode bits of 64-bit word into a string.
+func (e *encoding) encode(x uint64) string {
+	b := [12]byte{}
+	for i := 0; i < 12; i++ {
+		b[11-i] = e.enc[x&0x1f]
+		x >>= 5
+	}
+	return string(b[:])
+}
+
+// Base32Encoding with the Geohash alphabet.
+var base32encoding = newEncoding("0123456789bcdefghjkmnpqrstuvwxyz")
+
+// BoundingBox returns the region encoded by the given string geohash.
+func geoBoundingBox(hash string) geoBox {
+	bits := uint(5 * len(hash))
+	inthash := base32encoding.decode(hash)
+	return geoBoundingBoxIntWithPrecision(inthash, bits)
+}
+
+// Box represents a rectangle in latitude/longitude space.
+type geoBox struct {
+	minLat float64
+	maxLat float64
+	minLng float64
+	maxLng float64
+}
+
+// Round returns a point inside the box, making an effort to round to minimal
+// precision.
+func (b geoBox) round() (lat, lng float64) {
+	x := maxDecimalPower(b.maxLat - b.minLat)
+	lat = math.Ceil(b.minLat/x) * x
+	x = maxDecimalPower(b.maxLng - b.minLng)
+	lng = math.Ceil(b.minLng/x) * x
+	return
+}
+
+// precalculated for performance
+var exp232 = math.Exp2(32)
+
+// errorWithPrecision returns the error range in latitude and longitude for in
+// integer geohash with bits of precision.
+func errorWithPrecision(bits uint) (latErr, lngErr float64) {
+	b := int(bits)
+	latBits := b / 2
+	lngBits := b - latBits
+	latErr = math.Ldexp(180.0, -latBits)
+	lngErr = math.Ldexp(360.0, -lngBits)
+	return
+}
+
+// minDecimalPlaces returns the minimum number of decimal places such that
+// there must exist an number with that many places within any range of width
+// r. This is intended for returning minimal precision coordinates inside a
+// box.
+func maxDecimalPower(r float64) float64 {
+	m := int(math.Floor(math.Log10(r)))
+	return math.Pow10(m)
+}
+
+// Encode the position of x within the range -r to +r as a 32-bit integer.
+func encodeRange(x, r float64) uint32 {
+	p := (x + r) / (2 * r)
+	return uint32(p * exp232)
+}
+
+// Decode the 32-bit range encoding X back to a value in the range -r to +r.
+func decodeRange(X uint32, r float64) float64 {
+	p := float64(X) / exp232
+	x := 2*r*p - r
+	return x
+}
+
+// Squash the even bitlevels of X into a 32-bit word. Odd bitlevels of X are
+// ignored, and may take any value.
+func squash(X uint64) uint32 {
+	X &= 0x5555555555555555
+	X = (X | (X >> 1)) & 0x3333333333333333
+	X = (X | (X >> 2)) & 0x0f0f0f0f0f0f0f0f
+	X = (X | (X >> 4)) & 0x00ff00ff00ff00ff
+	X = (X | (X >> 8)) & 0x0000ffff0000ffff
+	X = (X | (X >> 16)) & 0x00000000ffffffff
+	return uint32(X)
+}
+
+// Deinterleave the bits of X into 32-bit words containing the even and odd
+// bitlevels of X, respectively.
+func deinterleave(X uint64) (uint32, uint32) {
+	return squash(X), squash(X >> 1)
+}
+
+// BoundingBoxIntWithPrecision returns the region encoded by the integer
+// geohash with the specified precision.
+func geoBoundingBoxIntWithPrecision(hash uint64, bits uint) geoBox {
+	fullHash := hash << (64 - bits)
+	latInt, lngInt := deinterleave(fullHash)
+	lat := decodeRange(latInt, 90)
+	lng := decodeRange(lngInt, 180)
+	latErr, lngErr := errorWithPrecision(bits)
+	return geoBox{
+		minLat: lat,
+		maxLat: lat + latErr,
+		minLng: lng,
+		maxLng: lng + lngErr,
+	}
+}
+
+// ----------------------------------------------------------------------
+
+// Decode the string geohash to a (lat, lng) point.
+func GeoHashDecode(hash string) (lat, lng float64) {
+	box := geoBoundingBox(hash)
+	return box.round()
+}