PumpStream

PumpStream is a handy C# static method for moving (or "pumping") all the bytes from one stream to another.

It's helpful when you want to move data from a FileStream into a DeflateStream, for example. Another good use is streaming data from a MemoryStream or FileStream to a client via ASP.NET's Response.OutputStream property.

Since PumpStream uses a configurable size intermediate buffer, you're never going to run out of memory no matter how much data you're pumping.

Download
Download PumpStream.zip (~1KB)
Code
  1 // Copyright 2003-2007 Josh Christie
  2 // http://www.joshchristie.com
  3
  4 using System;
  5 using System.Collections;
  6 using System.IO;
  7
  8 namespace JC.Utility {
  9     public static class IOHelper {
 10         /// <summary>
 11         /// Pumps all data from the input stream to the output stream using an intermediate buffer.
 12         /// </summary>
 13         /// <remarks>
 14         /// The input stream is closed by this method.
 15         /// </remarks>
 16         /// <param name="input">Stream to read from.</param>
 17         /// <param name="output">Stream to write to.</param>
 18         /// <returns>Number of bytes pumped from input stream to output stream.</returns>
 19         public static int PumpStream(Stream input, Stream output) {
 20             return PumpStream(input, output, 8192);
 21         }
 22
 23         /// <summary>
 24         /// Pumps all data from the input stream to the output stream using an intermediate buffer of specified size.
 25         /// </summary>
 26         /// <remarks>
 27         /// The input stream is closed by this method.
 28         /// </remarks>
 29         /// <param name="input">Stream to read from.</param>
 30         /// <param name="output">Stream to write to.</param>
 31         /// <param name="pumpBufferSize">Size in bytes of the intermediate buffer.</param>
 32         /// <returns>Number of bytes pumped from input stream to output stream.</returns>
 33         public static int PumpStream(Stream input, Stream output, int pumpBufferSize) {
 34             if (input == null) {
 35                 throw new ArgumentNullException("input", "Input stream cannot be null.");
 36             }
 37
 38             if (output == null) {
 39                 throw new ArgumentNullException("output", "Output stream cannot be null.");
 40             }
 41
 42             if (pumpBufferSize < 1) {
 43                 throw new ArgumentOutOfRangeException("pumpBufferSize", pumpBufferSize, "PumpBufferSize cannot be less than 1 byte.");
 44             }
 45
 46             byte[] bytes = new byte[pumpBufferSize];
 47             int numBytesRead;
 48             int totalBytesRead = 0;
 49             try {
 50                 while ((numBytesRead = input.Read(bytes, 0, pumpBufferSize)) > 0) {
 51                     totalBytesRead += numBytesRead;
 52                     output.Write(bytes, 0, numBytesRead);
 53                 }
 54                 output.Flush();
 55             } finally {
 56                 input.Close();
 57             }
 58
 59             return totalBytesRead;
 60         }
 61     }
 62 }