dev-npgsql/npgsql: Npgsql is the .NET data provider for PostgreSQL.

src/Npgsql.NetTopologySuite/Internal/NetTopologySuiteHandler.cs
168 строк7 KB
Shay Rojansky
Fix thread safety of NetTopologySuiteHandler (#4767)
17 ноя 2022, 11:33
17 ноя 2022, 11:33b17850a
using System;
using System.IO;
using System.Threading;
using System.Threading.Tasks;
using NetTopologySuite.Geometries;
using NetTopologySuite.IO;
using Npgsql.BackendMessages;
using Npgsql.Internal;
using Npgsql.Internal.TypeHandling;
using Npgsql.PostgresTypes;

namespace Npgsql.NetTopologySuite.Internal;

partial class NetTopologySuiteHandler : NpgsqlTypeHandler<Geometry>,
    INpgsqlTypeHandler<Point>,
    INpgsqlTypeHandler<LineString>,
    INpgsqlTypeHandler<Polygon>,
    INpgsqlTypeHandler<MultiPoint>,
    INpgsqlTypeHandler<MultiLineString>,
    INpgsqlTypeHandler<MultiPolygon>,
    INpgsqlTypeHandler<GeometryCollection>
{
    readonly PostGisReader _reader;
    readonly PostGisWriter _writer;

    internal NetTopologySuiteHandler(PostgresType postgresType, PostGisReader reader, PostGisWriter writer)
        : base(postgresType)
    {
        _reader = reader;
        _writer = writer;
    }

    #region Read

    public override ValueTask<Geometry> Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription? fieldDescription = null)
        => ReadCore<Geometry>(buf, len);

    ValueTask<Point> INpgsqlTypeHandler<Point>.Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription? fieldDescription)
        => ReadCore<Point>(buf, len);

    ValueTask<LineString> INpgsqlTypeHandler<LineString>.Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription? fieldDescription)
        => ReadCore<LineString>(buf, len);

    ValueTask<Polygon> INpgsqlTypeHandler<Polygon>.Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription? fieldDescription)
        => ReadCore<Polygon>(buf, len);

    ValueTask<MultiPoint> INpgsqlTypeHandler<MultiPoint>.Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription? fieldDescription)
        => ReadCore<MultiPoint>(buf, len);

    ValueTask<MultiLineString> INpgsqlTypeHandler<MultiLineString>.Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription? fieldDescription)
        => ReadCore<MultiLineString>(buf, len);

    ValueTask<MultiPolygon> INpgsqlTypeHandler<MultiPolygon>.Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription? fieldDescription)
        => ReadCore<MultiPolygon>(buf, len);

    ValueTask<GeometryCollection> INpgsqlTypeHandler<GeometryCollection>.Read(NpgsqlReadBuffer buf, int len, bool async, FieldDescription? fieldDescription)
        => ReadCore<GeometryCollection>(buf, len);

    ValueTask<T> ReadCore<T>(NpgsqlReadBuffer buf, int len)
        where T : Geometry
        => new((T)_reader.Read(buf.GetStream(len, false)));

    #endregion

    #region ValidateAndGetLength

    public override int ValidateAndGetLength(Geometry value, ref NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter)
        => ValidateAndGetLengthCore(value);

    int INpgsqlTypeHandler<Point>.ValidateAndGetLength(Point value, ref NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter)
        => ValidateAndGetLength(value, ref lengthCache, parameter);

    int INpgsqlTypeHandler<LineString>.ValidateAndGetLength(LineString value, ref NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter)
        => ValidateAndGetLength(value, ref lengthCache, parameter);

    int INpgsqlTypeHandler<Polygon>.ValidateAndGetLength(Polygon value, ref NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter)
        => ValidateAndGetLength(value, ref lengthCache, parameter);

    int INpgsqlTypeHandler<MultiPoint>.ValidateAndGetLength(MultiPoint value, ref NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter)
        => ValidateAndGetLength(value, ref lengthCache, parameter);

    int INpgsqlTypeHandler<MultiLineString>.ValidateAndGetLength(MultiLineString value, ref NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter)
        => ValidateAndGetLength(value, ref lengthCache, parameter);

    int INpgsqlTypeHandler<MultiPolygon>.ValidateAndGetLength(MultiPolygon value, ref NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter)
        => ValidateAndGetLength(value, ref lengthCache, parameter);

    int INpgsqlTypeHandler<GeometryCollection>.ValidateAndGetLength(GeometryCollection value, ref NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter)
        => ValidateAndGetLength(value, ref lengthCache, parameter);

    int ValidateAndGetLengthCore(Geometry value)
    {
        var lengthStream = new LengthStream();
        lengthStream.SetLength(0);
        _writer.Write(value, lengthStream);
        return (int)lengthStream.Length;
    }

    sealed class LengthStream : Stream
    {
        long _length;

        public override bool CanRead => false;

        public override bool CanSeek => false;

        public override bool CanWrite => true;

        public override long Length => _length;

        public override long Position
        {
            get => _length;
            set => throw new NotSupportedException();
        }

        public override void Flush()
        { }

        public override int Read(byte[] buffer, int offset, int count)
            => throw new NotSupportedException();

        public override long Seek(long offset, SeekOrigin origin)
            => throw new NotSupportedException();

        public override void SetLength(long value)
            => _length = value;

        public override void Write(byte[] buffer, int offset, int count)
            => _length += count;
    }

    #endregion

    #region Write

    public override Task Write(Geometry value, NpgsqlWriteBuffer buf, NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter, bool async, CancellationToken cancellationToken = default)
        => WriteCore(value, buf);

    Task INpgsqlTypeHandler<Point>.Write(Point value, NpgsqlWriteBuffer buf, NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter, bool async, CancellationToken cancellationToken)
        => WriteCore(value, buf);

    Task INpgsqlTypeHandler<LineString>.Write(LineString value, NpgsqlWriteBuffer buf, NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter, bool async, CancellationToken cancellationToken)
        => WriteCore(value, buf);

    Task INpgsqlTypeHandler<Polygon>.Write(Polygon value, NpgsqlWriteBuffer buf, NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter, bool async, CancellationToken cancellationToken)
        => WriteCore(value, buf);

    Task INpgsqlTypeHandler<MultiPoint>.Write(MultiPoint value, NpgsqlWriteBuffer buf, NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter, bool async, CancellationToken cancellationToke)
        => WriteCore(value, buf);

    Task INpgsqlTypeHandler<MultiLineString>.Write(MultiLineString value, NpgsqlWriteBuffer buf, NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter, bool async, CancellationToken cancellationToken)
        => WriteCore(value, buf);

    Task INpgsqlTypeHandler<MultiPolygon>.Write(MultiPolygon value, NpgsqlWriteBuffer buf, NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter, bool async, CancellationToken cancellationToken)
        => WriteCore(value, buf);

    Task INpgsqlTypeHandler<GeometryCollection>.Write(GeometryCollection value, NpgsqlWriteBuffer buf, NpgsqlLengthCache? lengthCache, NpgsqlParameter? parameter, bool async, CancellationToken cancellationToken)
        => WriteCore(value, buf);

    Task WriteCore(Geometry value, NpgsqlWriteBuffer buf)
    {
        _writer.Write(value, buf.GetStream());
        return Task.CompletedTask;
    }

    #endregion
}