/// <summary>
/// 附近的人,最多返回100个
/// </summary>
/// <param name="lat">维度</param>
/// <param name="lng">经度</param>
/// <param name="radius">半径,单位为米,当radius为零时表示使用默认初始范围，并自动扩大范围, 每次扩大20km,最大到500km</param>
private IEnumerable <GeoRadiusResult> NearbyUsers(double lat, double lng, double radius, ref PageViewModel page,
Func <int[], int[]> filterUser = null, string key = RedisConfigureDbModel.GEODbModel)
{
var needExt = radius == 0; //是否需要自动扩展
Stopwatch watch = new Stopwatch();
watch.Start();
var extStep = 100000;
var extMax = 20000000;
if (radius == 0)
{
radius = extStep;
}
page = page ?? PageViewModel.Default();
var db = getRedis().GetDatabase((int)RedisDbIndex.GEO);
var pos = new GeoPosition(lng, lat);
GeoRadius geoRadius;
List <GeoRadiusResult> finalResult = new List <GeoRadiusResult>();
var extTimes = 0;
var preCount = 0;//记录上次查询到的数量，, 再过滤时跳过
while (extTimes == 0 || (needExt && !page.CurrentPageIsFull && radius < extMax))
{
geoRadius = new GeoRadius(
key,
pos, radius, 20000000,
GeoUnit.Meters,
DTO.GeoRadiusOptions.WithCoordinates | DTO.GeoRadiusOptions.WithDistance
);
var result = db.GeoRadius(key, geoRadius.GeoPosition.Longitude, geoRadius.GeoPosition.Latitude, radius);
if (result.Count() > preCount) //有新id拿到才需要过滤
{
var newResult = result.Skip(preCount).ToArray();
var newUserIds = newResult.Select(e => Int32.Parse(e.Member)).ToArray();
//找出新查询到的UserId,
if (filterUser != null)//Remove excluded
{
newUserIds = filterUser(newUserIds).ToArray();
}
finalResult.AddRange(newResult.Where(e => newUserIds.Contains(Int32.Parse(e.Member))));
}
preCount = result.Count();
extTimes++;
radius += extStep;
page.RecordCount = finalResult.Count();
}
//处理最后页一条正好满的情况. 再增加一页
if (page.CurrentPageIsFull && page.PageNo == page.PageCount)
{
page.RecordCount += 1;
}
watch.Stop();
return(finalResult.Skip(page.Skip).Take(page.PageSize));
}
