/*
* Copyright (c) 2023 Vaughn Nugent
*
* Library: VNLib
* Package: VNLib.Net.Compression
* File: CompressionExtensions.cs
*
* CompressionExtensions.cs is part of VNLib.Net.Compression which is part of
* the larger VNLib collection of libraries and utilities.
*
* VNLib.Net.Compression is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published
* by the Free Software Foundation, either version 2 of the License,
* or (at your option) any later version.
*
* VNLib.Net.Compression 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
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with VNLib.Net.Compression. If not, see http://www.gnu.org/licenses/.
*/
using System;
using System.Buffers;
using System.Runtime.InteropServices;
using VNLib.Net.Http;
namespace VNLib.Net.Compression
{
internal static class CompressionExtensions
{
///
/// Compresses a block using the compressor context pointer provided
///
///
/// A pointer to the compressor context
/// A buffer to write the result to
/// The input block of memory to compress
/// A value that indicates if a flush is requested
/// The results of the compression operation
public static unsafe CompressionResult CompressBlock(this LibraryWrapper nativeLib, IntPtr comp, Memory output, ReadOnlyMemory input, bool finalBlock)
{
/*
* Since .NET only supports int32 size memory blocks
* we dont need to worry about integer overflow.
*
* Output sizes can never be larger than input
* sizes (read/written)
*/
//get pointers to the input and output buffers
using MemoryHandle inPtr = input.Pin();
using MemoryHandle outPtr = output.Pin();
//Create the operation struct
CompressionOperation operation;
CompressionOperation* op = &operation;
op->flush = finalBlock ? 1 : 0;
op->bytesRead = 0;
op->bytesWritten = 0;
//Configure the input and output buffers
op->inputBuffer = inPtr.Pointer;
op->inputSize = (uint)input.Length;
op->outputBuffer = outPtr.Pointer;
op->outputSize = (uint)output.Length;
//Call the native compress function
nativeLib!.CompressBlock(comp, &operation);
//Return the number of bytes written
return new()
{
BytesRead = (int)op->bytesRead,
BytesWritten = (int)op->bytesWritten
};
}
///
/// Compresses a block using the compressor context pointer provided
///
///
/// A pointer to the compressor context
/// A buffer to write the result to
/// The input block of memory to compress
/// A value that indicates if a flush is requested
/// The results of the compression operation
public static unsafe CompressionResult CompressBlock(this LibraryWrapper nativeLib, IntPtr comp, Span output, ReadOnlySpan input, bool finalBlock)
{
/*
* Since .NET only supports int32 size memory blocks
* we dont need to worry about integer overflow.
*
* Output sizes can never be larger than input
* sizes (read/written)
*/
fixed(byte* inputPtr = &MemoryMarshal.GetReference(input),
outPtr = &MemoryMarshal.GetReference(output))
{
//Create the operation struct
CompressionOperation operation;
CompressionOperation* op = &operation;
op->flush = finalBlock ? 1 : 0;
op->bytesRead = 0;
op->bytesWritten = 0;
//Configure the input and output buffers
op->inputBuffer = inputPtr;
op->inputSize = (uint)input.Length;
op->outputBuffer = outPtr;
op->outputSize = (uint)output.Length;
//Call the native compress function
nativeLib!.CompressBlock(comp, &operation);
//Return the number of bytes written
return new()
{
BytesRead = (int)op->bytesRead,
BytesWritten = (int)op->bytesWritten
};
}
}
}
}