grpc/src/csharp/Grpc.Core/Internal/BatchContextSafeHandle.cs

#region Copyright notice and license

// Copyright 2015, Google Inc.
// All rights reserved.
// 
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
// 
//     * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//     * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following disclaimer
// in the documentation and/or other materials provided with the
// distribution.
//     * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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#endregion

using System;
using System.Runtime.InteropServices;
using System.Text;
using Grpc.Core;

namespace Grpc.Core.Internal
{
    /// <summary>
    /// grpcsharp_batch_context
    /// </summary>
    internal class BatchContextSafeHandle : SafeHandleZeroIsInvalid
    {
        static readonly Encoding EncodingUTF8 = System.Text.Encoding.UTF8;
        static readonly NativeMethods Native = NativeMethods.Get();

        private BatchContextSafeHandle()
        {
        }

        public static BatchContextSafeHandle Create()
        {
            return Native.grpcsharp_batch_context_create();
        }

        public IntPtr Handle
        {
            get
            {
                return handle;
            }
        }

        // Gets data of recv_initial_metadata completion.
        public Metadata GetReceivedInitialMetadata()
        {
            IntPtr metadataArrayPtr = Native.grpcsharp_batch_context_recv_initial_metadata(this);
            return MetadataArraySafeHandle.ReadMetadataFromPtrUnsafe(metadataArrayPtr);
        }
            
        // Gets data of recv_status_on_client completion.
        public ClientSideStatus GetReceivedStatusOnClient()
        {
            UIntPtr detailsLength;
            IntPtr detailsPtr = Native.grpcsharp_batch_context_recv_status_on_client_details(this, out detailsLength);
            string details = PtrToStringUtf8(detailsPtr, (int) detailsLength.ToUInt32());
            var status = new Status(Native.grpcsharp_batch_context_recv_status_on_client_status(this), details);

            IntPtr metadataArrayPtr = Native.grpcsharp_batch_context_recv_status_on_client_trailing_metadata(this);
            var metadata = MetadataArraySafeHandle.ReadMetadataFromPtrUnsafe(metadataArrayPtr);

            return new ClientSideStatus(status, metadata);
        }

        // Gets data of recv_message completion.
        public byte[] GetReceivedMessage()
        {
            IntPtr len = Native.grpcsharp_batch_context_recv_message_length(this);
            if (len == new IntPtr(-1))
            {
                return null;
            }
            byte[] data = new byte[(int)len];
            Native.grpcsharp_batch_context_recv_message_to_buffer(this, data, new UIntPtr((ulong)data.Length));
            return data;
        }

        // Gets data of receive_close_on_server completion.
        public bool GetReceivedCloseOnServerCancelled()
        {
            return Native.grpcsharp_batch_context_recv_close_on_server_cancelled(this) != 0;
        }
            
        protected override bool ReleaseHandle()
        {
            Native.grpcsharp_batch_context_destroy(handle);
            return true;
        }

        string PtrToStringUtf8(IntPtr ptr, int len)
        {
            var bytes = new byte[len];
            Marshal.Copy(ptr, bytes, 0, len);
            return EncodingUTF8.GetString(bytes);
        }
    }
}