ceph/src/rocksdb/include/rocksdb/utilities/geo_db.h

   1 //  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
   2 //  This source code is licensed under both the GPLv2 (found in the
   3 //  COPYING file in the root directory) and Apache 2.0 License
   4 //  (found in the LICENSE.Apache file in the root directory).
   5 //
   6
   7 #ifndef ROCKSDB_LITE
   8 #pragma once
   9 #include <string>
  10 #include <vector>
  11
  12 #include "rocksdb/utilities/stackable_db.h"
  13 #include "rocksdb/status.h"
  14
  15 namespace rocksdb {
  16
  17 //
  18 // Configurable options needed for setting up a Geo database
  19 //
  20 struct GeoDBOptions {
  21   // Backup info and error messages will be written to info_log
  22   // if non-nullptr.
  23   // Default: nullptr
  24   Logger* info_log;
  25
  26   explicit GeoDBOptions(Logger* _info_log = nullptr):info_log(_info_log) { }
  27 };
  28
  29 //
  30 // A position in the earth's geoid
  31 //
  32 class GeoPosition {
  33  public:
  34   double latitude;
  35   double longitude;
  36
  37   explicit GeoPosition(double la = 0, double lo = 0) :
  38     latitude(la), longitude(lo) {
  39   }
  40 };
  41
  42 //
  43 // Description of an object on the Geoid. It is located by a GPS location,
  44 // and is identified by the id. The value associated with this object is
  45 // an opaque string 'value'. Different objects identified by unique id's
  46 // can have the same gps-location associated with them.
  47 //
  48 class GeoObject {
  49  public:
  50   GeoPosition position;
  51   std::string id;
  52   std::string value;
  53
  54   GeoObject() {}
  55
  56   GeoObject(const GeoPosition& pos, const std::string& i,
  57             const std::string& val) :
  58     position(pos), id(i), value(val) {
  59   }
  60 };
  61
  62 class GeoIterator {
  63  public:
  64   GeoIterator() = default;
  65   virtual ~GeoIterator() {}
  66   virtual void Next() = 0;
  67   virtual bool Valid() const = 0;
  68   virtual const GeoObject& geo_object() = 0;
  69   virtual Status status() const = 0;
  70 };
  71
  72 //
  73 // Stack your DB with GeoDB to be able to get geo-spatial support
  74 //
  75 class GeoDB : public StackableDB {
  76  public:
  77   // GeoDBOptions have to be the same as the ones used in a previous
  78   // incarnation of the DB
  79   //
  80   // GeoDB owns the pointer `DB* db` now. You should not delete it or
  81   // use it after the invocation of GeoDB
  82   // GeoDB(DB* db, const GeoDBOptions& options) : StackableDB(db) {}
  83   GeoDB(DB* db, const GeoDBOptions& /*options*/) : StackableDB(db) {}
  84   virtual ~GeoDB() {}
  85
  86   // Insert a new object into the location database. The object is
  87   // uniquely identified by the id. If an object with the same id already
  88   // exists in the db, then the old one is overwritten by the new
  89   // object being inserted here.
  90   virtual Status Insert(const GeoObject& object) = 0;
  91
  92   // Retrieve the value of the object located at the specified GPS
  93   // location and is identified by the 'id'.
  94   virtual Status GetByPosition(const GeoPosition& pos,
  95                                const Slice& id, std::string* value) = 0;
  96
  97   // Retrieve the value of the object identified by the 'id'. This method
  98   // could be potentially slower than GetByPosition
  99   virtual Status GetById(const Slice& id, GeoObject*  object) = 0;
 100
 101   // Delete the specified object
 102   virtual Status Remove(const Slice& id) = 0;
 103
 104   // Returns an iterator for the items within a circular radius from the
 105   // specified gps location. If 'number_of_values' is specified,
 106   // then the iterator is capped to that number of objects.
 107   // The radius is specified in 'meters'.
 108   virtual GeoIterator* SearchRadial(const GeoPosition& pos,
 109                                     double radius,
 110                                     int number_of_values = INT_MAX) = 0;
 111 };
 112
 113 }  // namespace rocksdb
 114 #endif  // ROCKSDB_LITE