rocksdb/utilities/spatialdb/utils.h

98 lines
3.6 KiB
C
Raw Normal View History

// Copyright (c) 2011-present, Facebook, Inc. All rights reserved.
// This source code is licensed under the BSD-style license found in the
// LICENSE file in the root directory of this source tree. An additional grant
// of patent rights can be found in the PATENTS file in the same directory.
// This source code is also licensed under the GPLv2 license found in the
// COPYING file in the root directory of this source tree.
#pragma once
#include <string>
#include <algorithm>
#include "rocksdb/utilities/spatial_db.h"
namespace rocksdb {
namespace spatial {
// indexing idea from http://msdn.microsoft.com/en-us/library/bb259689.aspx
inline uint64_t GetTileFromCoord(double x, double start, double end,
uint32_t tile_bits) {
if (x < start) {
return 0;
}
uint64_t tiles = 1ull << tile_bits;
uint64_t r = static_cast<uint64_t>(((x - start) / (end - start)) * tiles);
return std::min(r, tiles - 1);
}
inline uint64_t GetQuadKeyFromTile(uint64_t tile_x, uint64_t tile_y,
uint32_t tile_bits) {
uint64_t quad_key = 0;
for (uint32_t i = 0; i < tile_bits; ++i) {
uint64_t mask = (1ull << i);
quad_key |= (tile_x & mask) << i;
quad_key |= (tile_y & mask) << (i + 1);
}
return quad_key;
}
inline BoundingBox<uint64_t> GetTileBoundingBox(
const SpatialIndexOptions& spatial_index, BoundingBox<double> bbox) {
return BoundingBox<uint64_t>(
GetTileFromCoord(bbox.min_x, spatial_index.bbox.min_x,
spatial_index.bbox.max_x, spatial_index.tile_bits),
GetTileFromCoord(bbox.min_y, spatial_index.bbox.min_y,
spatial_index.bbox.max_y, spatial_index.tile_bits),
GetTileFromCoord(bbox.max_x, spatial_index.bbox.min_x,
spatial_index.bbox.max_x, spatial_index.tile_bits),
GetTileFromCoord(bbox.max_y, spatial_index.bbox.min_y,
spatial_index.bbox.max_y, spatial_index.tile_bits));
}
// big endian can be compared using memcpy
inline void PutFixed64BigEndian(std::string* dst, uint64_t value) {
char buf[sizeof(value)];
buf[0] = (value >> 56) & 0xff;
buf[1] = (value >> 48) & 0xff;
buf[2] = (value >> 40) & 0xff;
buf[3] = (value >> 32) & 0xff;
buf[4] = (value >> 24) & 0xff;
buf[5] = (value >> 16) & 0xff;
buf[6] = (value >> 8) & 0xff;
buf[7] = value & 0xff;
dst->append(buf, sizeof(buf));
}
// big endian can be compared using memcpy
inline bool GetFixed64BigEndian(const Slice& input, uint64_t* value) {
if (input.size() < sizeof(uint64_t)) {
return false;
}
auto ptr = input.data();
*value = (static_cast<uint64_t>(static_cast<unsigned char>(ptr[0])) << 56) |
(static_cast<uint64_t>(static_cast<unsigned char>(ptr[1])) << 48) |
(static_cast<uint64_t>(static_cast<unsigned char>(ptr[2])) << 40) |
(static_cast<uint64_t>(static_cast<unsigned char>(ptr[3])) << 32) |
(static_cast<uint64_t>(static_cast<unsigned char>(ptr[4])) << 24) |
(static_cast<uint64_t>(static_cast<unsigned char>(ptr[5])) << 16) |
(static_cast<uint64_t>(static_cast<unsigned char>(ptr[6])) << 8) |
static_cast<uint64_t>(static_cast<unsigned char>(ptr[7]));
return true;
}
inline void PutDouble(std::string* dst, double d) {
dst->append(reinterpret_cast<char*>(&d), sizeof(double));
}
inline bool GetDouble(Slice* input, double* d) {
if (input->size() < sizeof(double)) {
return false;
}
memcpy(d, input->data(), sizeof(double));
input->remove_prefix(sizeof(double));
return true;
}
} // namespace spatial
} // namespace rocksdb