/*
* Try to split the range to multiple ranges based on the hash key.
*
* e.g., for the following range:
*
* min: 123456789
* max: 125678912
*
* when the hash key length is 3, we want to split the range to:
*
* 1
* min: 123456789
* max: 123999999
*
* 2
* min: 124000000
* max: 124999999
*
* 3
* min: 125000000
* max: 125678912
*
* For this range:
*
* min: -125678912
* max: -123456789
*
* we want:
*
* 1
* min: -125678912
* max: -125000000
*
* 2
* min: -124999999
* max: -124000000
*
* 3
* min: -123999999
* max: -123456789
*/
public IReadOnlyList <GeohashRange> TrySplit(int hashKeyLength)
{
var result = new List <GeohashRange>();
var minHashKey = S2Manager.GenerateHashKey(RangeMin, hashKeyLength);
var maxHashKey = S2Manager.GenerateHashKey(RangeMax, hashKeyLength);
var denominator = (ulong)Math.Pow(10, RangeMin.ToString(CultureInfo.InvariantCulture).Length - minHashKey.ToString(CultureInfo.InvariantCulture).Length);
if (minHashKey == maxHashKey)
{
result.Add(this);
}
else
{
for (var l = minHashKey; l <= maxHashKey; l++)
{
if (l > 0)
{
result.Add(new GeohashRange(l == minHashKey ? RangeMin : l * denominator,
l == maxHashKey ? RangeMax : (l + 1) * denominator - 1));
}
else
{
result.Add(new GeohashRange(l == minHashKey ? RangeMin : (l - 1) * denominator + 1,
l == maxHashKey ? RangeMax : l * denominator));
}
}
}
return(result);
}
public async Task <GetPointResult> GetPointAsync(GetPointRequest getPointRequest, CancellationToken cancellationToken = default(CancellationToken))
{
if (getPointRequest == null)
{
throw new ArgumentNullException("getPointRequest");
}
var geohash = S2Manager.GenerateGeohash(getPointRequest.GeoPoint);
var hashKey = S2Manager.GenerateHashKey(geohash, _config.HashKeyLength);
var getItemRequest = getPointRequest.GetItemRequest;
getItemRequest.TableName = _config.TableName;
var hashKeyValue = new AttributeValue
{
N = hashKey.ToString(CultureInfo.InvariantCulture)
};
getItemRequest.Key[_config.HashKeyAttributeName] = hashKeyValue;
getItemRequest.Key[_config.RangeKeyAttributeName] = getPointRequest.RangeKeyValue;
GetItemResponse getItemResult = await _config.DynamoDBClient.GetItemAsync(getItemRequest, cancellationToken).ConfigureAwait(false);
var getPointResult = new GetPointResult(getItemResult);
return(getPointResult);
}
public async Task <UpdatePointResult> UpdatePointAsync(UpdatePointRequest updatePointRequest, CancellationToken cancellationToken = default(CancellationToken))
{
if (updatePointRequest == null)
{
throw new ArgumentNullException("updatePointRequest");
}
var geohash = S2Manager.GenerateGeohash(updatePointRequest.GeoPoint);
var hashKey = S2Manager.GenerateHashKey(geohash, _config.HashKeyLength);
var updateItemRequest = updatePointRequest.UpdateItemRequest;
updateItemRequest.TableName = _config.TableName;
var hashKeyValue = new AttributeValue
{
N = hashKey.ToString(CultureInfo.InvariantCulture)
};
updateItemRequest.Key[_config.HashKeyAttributeName] = hashKeyValue;
updateItemRequest.Key[_config.RangeKeyAttributeName] = updatePointRequest.RangeKeyValue;
// Geohash and geoJson cannot be updated.
updateItemRequest.AttributeUpdates.Remove(_config.GeohashAttributeName);
updateItemRequest.AttributeUpdates.Remove(_config.GeoJsonAttributeName);
UpdateItemResponse updateItemResult = await _config.DynamoDBClient.UpdateItemAsync(updateItemRequest, cancellationToken).ConfigureAwait(false);
var updatePointResult = new UpdatePointResult(updateItemResult);
return(updatePointResult);
}
public async Task <QueryRectangleResult> QueryRectangleAsync(QueryRectangleRequest queryRectangleRequest, CancellationToken cancellationToken = default(CancellationToken))
{
if (queryRectangleRequest == null)
{
throw new ArgumentNullException("queryRectangleRequest");
}
var latLngRect = S2Util.GetBoundingLatLngRect(queryRectangleRequest);
var cellUnion = S2Manager.FindCellIds(latLngRect);
var ranges = MergeCells(cellUnion);
var result = await DispatchQueries(ranges, queryRectangleRequest, cancellationToken).ConfigureAwait(false);
return(new QueryRectangleResult(result));
}
public async Task <PutPointResult> PutPointAsync(PutPointRequest putPointRequest, CancellationToken cancellationToken = default(CancellationToken))
{
if (putPointRequest == null)
{
throw new ArgumentNullException("putPointRequest");
}
var geohash = S2Manager.GenerateGeohash(putPointRequest.FromGeoPoint);
var rangeHash = S2Manager.GenerateGeohash(putPointRequest.ToGeoPoint);
var hashKey = S2Manager.GenerateHashKey(geohash, _config.HashKeyLength);
var geoJson = GeoJsonMapper.StringFromGeoObject(putPointRequest.FromGeoPoint);
var putItemRequest = putPointRequest.PutItemRequest;
putItemRequest.TableName = _config.TableName;
var hashKeyValue = new AttributeValue
{
N = hashKey.ToString(CultureInfo.InvariantCulture)
};
putItemRequest.Item[_config.HashKeyAttributeName] = hashKeyValue;
putItemRequest.Item[_config.RangeKeyAttributeName] = new AttributeValue
{
S = rangeHash.ToString(CultureInfo.InvariantCulture)
};
var geohashValue = new AttributeValue
{
N = geohash.ToString(CultureInfo.InvariantCulture)
};
putItemRequest.Item[_config.GeohashAttributeName] = geohashValue;
var geoJsonValue = new AttributeValue
{
S = geoJson
};
putItemRequest.Item[_config.GeoJsonAttributeName] = geoJsonValue;
PutItemResponse putItemResult = await _config.DynamoDBClient.PutItemAsync(putItemRequest, cancellationToken).ConfigureAwait(false);
var putPointResult = new PutPointResult(putItemResult);
return(putPointResult);
}
/// <summary>
/// <p>
/// Query a circular area constructed by a center point and its radius.
/// </p>
/// <b>Sample usage:</b>
/// <pre>
/// GeoPoint centerPoint = new GeoPoint(47.5, -122.3);
/// QueryRadiusRequest queryRadiusRequest = new QueryRadiusRequest(centerPoint, 100);
/// QueryRadiusResult queryRadiusResult = geoIndexManager.queryRadius(queryRadiusRequest);
/// for (Map<String, AttributeValue> item : queryRadiusResult.getItem()) {
/// System.out.println("item: " + item);
/// }
/// </pre>
/// </summary>
/// <param name="queryRadiusRequest">Container for the necessary parameters to execute radius query request.</param>
/// <returns>Result of radius query request.</returns>
public async Task <QueryRadiusResult> QueryRadiusAsync(QueryRadiusRequest queryRadiusRequest, CancellationToken cancellationToken = default(CancellationToken))
{
if (queryRadiusRequest == null)
{
throw new ArgumentNullException("queryRadiusRequest");
}
if (queryRadiusRequest.RadiusInMeter <= 0 || queryRadiusRequest.RadiusInMeter > S2LatLng.EarthRadiusMeters)
{
throw new ArgumentOutOfRangeException("queryRadiusRequest", "RadiusInMeter needs to be > 0 and <= " + S2LatLng.EarthRadiusMeters);
}
var latLngRect = S2Util.GetBoundingLatLngRect(queryRadiusRequest);
var cellUnion = S2Manager.FindCellIds(latLngRect);
var ranges = MergeCells(cellUnion);
var result = await DispatchQueries(ranges, queryRadiusRequest, cancellationToken).ConfigureAwait(false);
return(new QueryRadiusResult(result));
}
public SubscriptionUpdateRequestBuilder SetLocation(Location location)
{
_removedProperties.Remove("Location");
_removedProperties.Remove("LocationHash");
_updatedProperties.Add(new UpdatedSubscriberProperty
{
Name = "Location",
Type = typeof(string),
Value = $"{location.Latitude},{location.Longitude}"
});
_updatedProperties.Add(new UpdatedSubscriberProperty
{
Name = "LocationHash",
Type = typeof(ulong),
Value = S2Manager.GenerateGeohash(location.Latitude, location.Longitude)
});
return(this);
}
private async Task RunGeoQuery(GeoQueryRequest request, GeoQueryResult geoQueryResult, GeohashRange range, CancellationToken cancellationToken)
{
var queryRequest = request.QueryRequest.CopyQueryRequest();
var hashKey = S2Manager.GenerateHashKey(range.RangeMin, _config.HashKeyLength);
var results = await _dynamoDBManager.QueryGeohashAsync(queryRequest, hashKey, range, cancellationToken).ConfigureAwait(false);
foreach (var queryResult in results)
{
cancellationToken.ThrowIfCancellationRequested();
// This is a concurrent collection
geoQueryResult.QueryResults.Add(queryResult);
var filteredQueryResult = Filter(queryResult.Items, request);
// this is a concurrent collection
foreach (var r in filteredQueryResult)
{
geoQueryResult.Items.Add(r);
}
}
}
public async Task <IEnumerable <int> > GetAsync(double magnitude, double latitude, double longitude, int searchRadius)
{
var result = new List <int>();
var searchRectangle = S2Manager.GetBoundingLatLngRect(latitude, longitude, searchRadius);
Dictionary <string, Condition> conditions = new Dictionary <string, Condition>
{
{
"Magnitude",
new Condition
{
ComparisonOperator = ComparisonOperator.LE,
AttributeValueList = new List <AttributeValue> {
new AttributeValue {
N = magnitude.ToString()
}
}
}
}
};
Dictionary <string, AttributeValue> lastEvaluatedKey = null;
do
{
ScanRequest request = new ScanRequest
{
TableName = _tableName,
ScanFilter = conditions
};
if (lastEvaluatedKey != null && lastEvaluatedKey.ContainsKey("chatid"))
{
request.ExclusiveStartKey["chatid"] = lastEvaluatedKey["chatid"];
}
ScanResponse scanResponse = await _amazonDynamoDB.ScanAsync(request);
foreach (var item in scanResponse.Items)
{
if (item.ContainsKey("chatid") && int.TryParse(item["chatid"].S, out int chatId))
{
if (item.ContainsKey("LocationHash"))
{
if (ulong.TryParse(item["LocationHash"].N, out ulong locationHash) && searchRectangle.Intersects(new S2Cell(new S2CellId(locationHash))))
{
result.Add(chatId);
}
}
else
{
result.Add(chatId);
}
}
}
lastEvaluatedKey = scanResponse.LastEvaluatedKey;
} while (lastEvaluatedKey != null && lastEvaluatedKey.Count > 0);
return(result);
}
