Merge pull request #66 from crispthinking/feature/buffer-stream

Support non-seekable streams in FromStream method

Author: ShaunWatsonCrisp

src/PdqHash/PdqHasher.cs

@@ -66,7 +66,15 @@ private static void ComputeDCTMatrix(Memory<float> memory)
     public HashResult? FromStream(Stream input, string source)
     {
         var stopwatch = Stopwatch.StartNew();
-        
+
+        using var bufferedStream = input.CanSeek ? null : new MemoryStream();
+        if (bufferedStream != null)
+        {
+            input.CopyTo(bufferedStream);
+            bufferedStream.Position = 0;
+            input = bufferedStream;
+        }
+
         using var codec = SKCodec.Create(input, out var result);
 
         if (codec == null)

test/PdqHash.Tests/Streams/StreamParsingTests.cs

@@ -62,7 +62,11 @@ public async Task EnsureHashingWithNonSeekableStreams()
             return hasher.FromStream(pipe.Reader.AsStream(), "");
         });
 
-        var writeTask = Task.Run(() => pipe.Writer.WriteAsync(bytes));
+        var writeTask = Task.Run(async () =>
+        {
+            await pipe.Writer.WriteAsync(bytes);
+            await pipe.Writer.CompleteAsync();
+        });
 
         await Task.WhenAll(hashTask, writeTask);