From c42dbdf94001e2447dc1becde977d47cad644ec2 Mon Sep 17 00:00:00 2001
From: vnugent <public@vaughnnugent.com>
Date: Mon, 23 Oct 2023 21:10:58 -0400
Subject: Native compressor api span support

---
 .../VNLib.Net.Compression/CompressionExtensions.cs | 52 +++++++++++++++++++++-
 .../VNLib.Net.Compression/INativeCompressor.cs     | 14 ++++++
 .../VNLib.Net.Compression/NativeCompressionLib.cs  | 19 +++++++-
 3 files changed, 83 insertions(+), 2 deletions(-)

(limited to 'lib/Net.Compression/VNLib.Net.Compression')

diff --git a/lib/Net.Compression/VNLib.Net.Compression/CompressionExtensions.cs b/lib/Net.Compression/VNLib.Net.Compression/CompressionExtensions.cs
index ab451d9..4509b67 100644
--- a/lib/Net.Compression/VNLib.Net.Compression/CompressionExtensions.cs
+++ b/lib/Net.Compression/VNLib.Net.Compression/CompressionExtensions.cs
@@ -24,6 +24,7 @@
 
 using System;
 using System.Buffers;
+using System.Runtime.InteropServices;
 
 using VNLib.Net.Http;
 
@@ -79,5 +80,54 @@ namespace VNLib.Net.Compression
                 BytesWritten = (int)op->bytesWritten
             };
         }
+
+        /// <summary>
+        /// Compresses a block using the compressor context pointer provided
+        /// </summary>
+        /// <param name="nativeLib"></param>
+        /// <param name="comp">A pointer to the compressor context</param>
+        /// <param name="output">A buffer to write the result to</param>
+        /// <param name="input">The input block of memory to compress</param>
+        /// <param name="finalBlock">A value that indicates if a flush is requested</param>
+        /// <returns>The results of the compression operation</returns>
+        public static unsafe CompressionResult CompressBlock(this LibraryWrapper nativeLib, IntPtr comp, Span<byte> output, ReadOnlySpan<byte> 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
+                };
+            }
+        }
     }
-}
\ No newline at end of file
+}
diff --git a/lib/Net.Compression/VNLib.Net.Compression/INativeCompressor.cs b/lib/Net.Compression/VNLib.Net.Compression/INativeCompressor.cs
index c522860..ceaa87f 100644
--- a/lib/Net.Compression/VNLib.Net.Compression/INativeCompressor.cs
+++ b/lib/Net.Compression/VNLib.Net.Compression/INativeCompressor.cs
@@ -53,6 +53,13 @@ namespace VNLib.Net.Compression
         /// <returns>The number of bytes written to the output buffer</returns>
         int Flush(Memory<byte> buffer);
 
+        /// <summary>
+        /// Flushes all remaining data in the compressor to the output buffer
+        /// </summary>
+        /// <param name="buffer">The output buffer to write flushed compressor data to</param>
+        /// <returns>The number of bytes written to the output buffer</returns>
+        int Flush(Span<byte> buffer);
+
         /// <summary>
         /// Compresses the input block and writes the compressed data to the output block
         /// </summary>
@@ -60,6 +67,13 @@ namespace VNLib.Net.Compression
         /// <param name="output">The output buffer to write compressed data to</param>
         CompressionResult Compress(ReadOnlyMemory<byte> input, Memory<byte> output);
 
+        /// <summary>
+        /// Compresses the input block and writes the compressed data to the output block
+        /// </summary>
+        /// <param name="input">The input buffer to compress</param>
+        /// <param name="output">The output buffer to write compressed data to</param>
+        CompressionResult Compress(ReadOnlySpan<byte> input, Span<byte> output);
+
         /// <summary>
         /// Gets the compressor block size if configured
         /// </summary>
diff --git a/lib/Net.Compression/VNLib.Net.Compression/NativeCompressionLib.cs b/lib/Net.Compression/VNLib.Net.Compression/NativeCompressionLib.cs
index 10bad84..438f777 100644
--- a/lib/Net.Compression/VNLib.Net.Compression/NativeCompressionLib.cs
+++ b/lib/Net.Compression/VNLib.Net.Compression/NativeCompressionLib.cs
@@ -98,6 +98,14 @@ namespace VNLib.Net.Compression
                 return LibComp.CompressBlock(compressor, output, input, false);
             }
 
+            ///<inheritdoc/>
+            public CompressionResult Compress(ReadOnlySpan<byte> input, Span<byte> output)
+            {
+                CompressorHandle.ThrowIfClosed();
+                IntPtr compressor = CompressorHandle.DangerousGetHandle();
+                return LibComp.CompressBlock(compressor, output, input, false);
+            }
+
             ///<inheritdoc/>
             public void Dispose() => CompressorHandle.Dispose();
 
@@ -106,7 +114,16 @@ namespace VNLib.Net.Compression
             {
                 CompressorHandle.ThrowIfClosed();
                 IntPtr compressor = CompressorHandle.DangerousGetHandle();
-                CompressionResult result = LibComp.CompressBlock(compressor, buffer, ReadOnlyMemory<byte>.Empty, true);
+                CompressionResult result = LibComp.CompressBlock(compressor, buffer, default, true);
+                return result.BytesWritten;
+            }
+
+            ///<inheritdoc/>
+            public int Flush(Span<byte> buffer)
+            {
+                CompressorHandle.ThrowIfClosed();
+                IntPtr compressor = CompressorHandle.DangerousGetHandle();
+                CompressionResult result = LibComp.CompressBlock(compressor, buffer, default, true);
                 return result.BytesWritten;
             }
 
-- 
cgit