/*
* Copyright (c) 2024 Vaughn Nugent
*
* Library: VNLib
* Package: VNLib.Net.Messaging.FBM
* File: FBMMessageHeader.cs
*
* FBMMessageHeader.cs is part of VNLib.Net.Messaging.FBM which is part of the larger
* VNLib collection of libraries and utilities.
*
* VNLib.Net.Messaging.FBM is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* VNLib.Net.Messaging.FBM is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see https://www.gnu.org/licenses/.
*/
using System;
namespace VNLib.Net.Messaging.FBM
{
///
/// Represents a Key-Value pair FBM response message header
///
public readonly struct FBMMessageHeader : IEquatable
{
private readonly IFBMHeaderBuffer _buffer;
/*
* Header values are all stored consecutively inside a single
* buffer, position the value is stored within the buffer
* is designated by it's absolute offset and length within
* the buffer segment
*/
private readonly int _headerOffset;
private readonly int _headerLength;
///
/// The header value or command
///
public readonly HeaderCommand Header { get; }
///
/// The header value, or if default
///
public readonly ReadOnlySpan Value => _buffer != null ? _buffer.GetSpan(_headerOffset, _headerLength) : null;
///
/// Gets the header value as a or null if default instance
///
/// The allocates string of the value
public readonly string? GetValueString() => _buffer != null ? Value.ToString() : null;
///
/// Initializes a new of the sepcified command
/// that utilizes memory from the specified buffer
///
/// The buffer that owns the memory our header is stored in
/// The command this header represents
/// The char offset within the buffer our header begins
/// The character length of our header value
internal FBMMessageHeader(IFBMHeaderBuffer buffer, HeaderCommand command, int offset, int length)
{
Header = command;
_buffer = buffer;
_headerLength = length;
_headerOffset = offset;
}
///
public override bool Equals(object? obj) => obj is FBMMessageHeader other && Equals(other);
///
/// Calculates a hash code from the parameter
/// using original string hashcode computation
///
/// The unique hashcode for the character sequence
public override int GetHashCode() => string.GetHashCode(Value, StringComparison.Ordinal);
///
public static bool operator ==(FBMMessageHeader left, FBMMessageHeader right) => left.Equals(right);
///
public static bool operator !=(FBMMessageHeader left, FBMMessageHeader right) => !(left == right);
///
/// Determines if the other response header is equal to the current header by
/// comparing its command and its value
///
/// The other header to compare
/// True if both headers have the same commad and value sequence
public readonly bool Equals(FBMMessageHeader other) => Header == other.Header && Value.SequenceEqual(other.Value);
///
/// Determines if a string value is equal to the current header value
///
/// Value to test
/// The string comparison type
/// True if the values are equal, false otherwise
public readonly bool ValueEquals(ReadOnlySpan other, StringComparison comparison) => Value.Equals(other, comparison);
///
/// Gets a concatinated string of the current instance for debugging purposes
///
public readonly override string ToString() => $"{Header}:{Value.ToString()}";
}
}