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#region License
// The PostgreSQL License
//
// Copyright (C) 2015 The Npgsql Development Team
//
// Permission to use, copy, modify, and distribute this software and its
// documentation for any purpose, without fee, and without a written
// agreement is hereby granted, provided that the above copyright notice
// and this paragraph and the following two paragraphs appear in all copies.
//
// IN NO EVENT SHALL THE NPGSQL DEVELOPMENT TEAM BE LIABLE TO ANY PARTY
// FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES,
// INCLUDING LOST PROFITS, ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS
// DOCUMENTATION, EVEN IF THE NPGSQL DEVELOPMENT TEAM HAS BEEN ADVISED OF
// THE POSSIBILITY OF SUCH DAMAGE.
//
// THE NPGSQL DEVELOPMENT TEAM SPECIFICALLY DISCLAIMS ANY WARRANTIES,
// INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
// AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
// ON AN "AS IS" BASIS, AND THE NPGSQL DEVELOPMENT TEAM HAS NO OBLIGATIONS
// TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
#endregion
using System;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics.Contracts;
using System.Globalization;
using System.IO;
using System.Net;
using System.Runtime.CompilerServices;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using AsyncRewriter;
namespace Npgsql
{
// ReSharper disable once InconsistentNaming
internal static class PGUtil
{
internal static readonly UTF8Encoding UTF8Encoding = new UTF8Encoding(false, true);
internal static readonly UTF8Encoding RelaxedUTF8Encoding = new UTF8Encoding(false, false);
/// <summary>
/// This method takes a version string as returned by SELECT VERSION() and returns
/// a valid version string ("7.2.2" for example).
/// This is only needed when running protocol version 2.
/// This does not do any validity checks.
/// </summary>
public static string ExtractServerVersion(string VersionString)
{
Int32 Start = 0, End = 0;
// find the first digit and assume this is the start of the version number
for (; Start < VersionString.Length && !Char.IsDigit(VersionString[Start]); Start++)
{
;
}
End = Start;
// read until hitting whitespace, which should terminate the version number
for (; End < VersionString.Length && !Char.IsWhiteSpace(VersionString[End]); End++)
{
;
}
// Deal with this here so that if there are
// changes in a future backend version, we can handle it here in the
// protocol handler and leave everybody else put of it.
VersionString = VersionString.Substring(Start, End - Start + 1);
for (int idx = 0; idx != VersionString.Length; ++idx)
{
char c = VersionString[idx];
if (!Char.IsDigit(c) && c != '.')
{
VersionString = VersionString.Substring(0, idx);
break;
}
}
return VersionString;
}
public static int RotateShift(int val, int shift)
{
return (val << shift) | (val >> (sizeof (int) - shift));
}
/// <summary>
/// Creates a Task<TResult> that's completed successfully with the specified result.
/// </summary>
/// <remarks>
/// In .NET 4.5 Task provides this. In .NET 4.0 with BCL.Async, TaskEx provides this. This
/// method wraps the two.
/// </remarks>
/// <typeparam name="TResult">The type of the result returned by the task.</typeparam>
/// <param name="result">The result to store into the completed task.</param>
/// <returns>The successfully completed task.</returns>
#if !NET40
[MethodImpl(MethodImplOptions.AggressiveInlining)]
#endif
internal static Task<TResult> TaskFromResult<TResult>(TResult result)
{
#if !NET40
return Task.FromResult(result);
#else
return TaskEx.FromResult(result);
#endif
}
internal static Task CompletedTask = TaskFromResult(0);
internal static StringComparer InvariantCaseIgnoringStringComparer
{
get
{
// Note: not assuming string comparers are threadsafe, although they probably are...
#if DNXCORE50
return CultureInfo.InvariantCulture.CompareInfo.GetStringComparer(CompareOptions.IgnoreCase);
#else
return StringComparer.InvariantCultureIgnoreCase;
#endif
}
}
/// <summary>
/// Throws an exception with the given string and also invokes a contract failure, allowing the static checker
/// to detect scenarios leading up to this error.
///
/// See http://blogs.msdn.com/b/francesco/archive/2014/09/12/how-to-use-cccheck-to-prove-no-case-is-forgotten.aspx
/// </summary>
/// <param name="message">the exception message</param>
/// <returns>an exception to be thrown</returns>
[ContractVerification(false)]
public static Exception ThrowIfReached(string message = null)
{
Contract.Requires(false);
return message == null ? new Exception("An internal Npgsql occured, please open an issue in http://github.com/npgsql/npgsql with this exception's stack trace") : new Exception(message);
}
}
/// <summary>
/// Represent the frontend/backend protocol version.
/// </summary>
public enum ProtocolVersion
{
/// <summary>
/// Protocol version 3 (the current version).
/// </summary>
Version3 = 3
}
internal enum FormatCode : short
{
Text = 0,
Binary = 1
}
internal static class EnumerableExtensions
{
internal static string Join(this IEnumerable<string> values, string separator)
{
return string.Join(separator, values);
}
}
/// <summary>
/// Represents a timeout that will expire at some point.
/// </summary>
internal struct NpgsqlTimeout
{
readonly DateTime _expiration;
internal DateTime Expiration { get { return _expiration; } }
internal static NpgsqlTimeout Infinite = new NpgsqlTimeout(TimeSpan.Zero);
internal NpgsqlTimeout(TimeSpan expiration)
{
_expiration = expiration == TimeSpan.Zero
? DateTime.MaxValue
: DateTime.Now + expiration;
}
internal void Check()
{
if (HasExpired)
throw new TimeoutException();
}
internal bool IsSet
{
get { return _expiration != DateTime.MaxValue; }
}
internal bool HasExpired
{
get { return DateTime.Now >= Expiration; }
}
internal Task AsTask
{
get { return Task.Delay(TimeLeft); }
}
internal TimeSpan TimeLeft { get { return Expiration - DateTime.Now; } }
}
}