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

#region Copyright notice and license

// Copyright 2015, Google Inc.
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// 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.
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// 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
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#endregion

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

namespace Grpc.Core.Internal
{
    /// <summary>
    /// Not owned version of 
    /// grpcsharp_batch_context
    /// </summary>
    internal class BatchContextSafeHandle : SafeHandleZeroIsInvalid
    {
        [DllImport("grpc_csharp_ext.dll")]
        static extern BatchContextSafeHandle grpcsharp_batch_context_create();

        [DllImport("grpc_csharp_ext.dll")]
        static extern IntPtr grpcsharp_batch_context_recv_message_length(BatchContextSafeHandle ctx);

        [DllImport("grpc_csharp_ext.dll")]
        static extern void grpcsharp_batch_context_recv_message_to_buffer(BatchContextSafeHandle ctx, byte[] buffer, UIntPtr bufferLen);

        [DllImport("grpc_csharp_ext.dll")]
        static extern StatusCode grpcsharp_batch_context_recv_status_on_client_status(BatchContextSafeHandle ctx);

        [DllImport("grpc_csharp_ext.dll")]
        static extern IntPtr grpcsharp_batch_context_recv_status_on_client_details(BatchContextSafeHandle ctx);  // returns const char*

        [DllImport("grpc_csharp_ext.dll")]
        static extern CallSafeHandle grpcsharp_batch_context_server_rpc_new_call(BatchContextSafeHandle ctx);

        [DllImport("grpc_csharp_ext.dll")]
        static extern IntPtr grpcsharp_batch_context_server_rpc_new_method(BatchContextSafeHandle ctx);  // returns const char*

        [DllImport("grpc_csharp_ext.dll")]
        static extern int grpcsharp_batch_context_recv_close_on_server_cancelled(BatchContextSafeHandle ctx);

        [DllImport("grpc_csharp_ext.dll")]
        static extern void grpcsharp_batch_context_destroy(IntPtr ctx);

        private BatchContextSafeHandle()
        {
        }

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

        public IntPtr Handle
        {
            get
            {
                return handle;
            }
        }

        public Status GetReceivedStatus()
        {
            // TODO: can the native method return string directly?
            string details = Marshal.PtrToStringAnsi(grpcsharp_batch_context_recv_status_on_client_details(this));
            return new Status(grpcsharp_batch_context_recv_status_on_client_status(this), details);
        }

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

        public CallSafeHandle GetServerRpcNewCall()
        {
            return grpcsharp_batch_context_server_rpc_new_call(this);
        }

        public string GetServerRpcNewMethod()
        {
            return Marshal.PtrToStringAnsi(grpcsharp_batch_context_server_rpc_new_method(this));
        }

        public bool GetReceivedCloseOnServerCancelled()
        {
            return grpcsharp_batch_context_recv_close_on_server_cancelled(this) != 0;
        }
            
        protected override bool ReleaseHandle()
        {
            grpcsharp_batch_context_destroy(handle);
            return true;
        }
    }
}