Assert that enough bytes are read from stream

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/Sockets.java

@@ -88,12 +88,7 @@ private static int readInt(InputStream in) throws IOException {
   }
 
   private static byte[] read(InputStream in, int length) throws IOException {
-    byte[] buffer = new byte[length];
-    int read = in.read(buffer);
-    if (read < length) {
-      throw new EOFException("failed to read bytes from socket");
-    }
-    return buffer;
+    return StreamReader.read(in, length);
   }
 
 }

scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/repository/hooks/StreamReader.java

@@ -0,0 +1,48 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.hooks;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+
+final class StreamReader {
+
+  private StreamReader() {
+  }
+
+  static byte[] read(InputStream stream, int length) throws IOException {
+    byte[] result = new byte[length];
+    int overallBytesRead = 0;
+    while (overallBytesRead < length) {
+      int bytesRead = stream.read(result, overallBytesRead, length - overallBytesRead);
+      if (bytesRead < 0) {
+        throw new EOFException("failed to read bytes from socket");
+      }
+      overallBytesRead += bytesRead;
+    }
+    return result;
+  }
+}

scm-plugins/scm-hg-plugin/src/test/java/sonia/scm/repository/hooks/StreamReaderTest.java

@@ -0,0 +1,79 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2020-present Cloudogu GmbH and Contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+package sonia.scm.repository.hooks;
+
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayInputStream;
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.Arrays;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+class StreamReaderTest {
+
+  @Test
+  void shouldReadRequiredBytes() throws IOException {
+    byte[] input = createBytes(100);
+    InputStream inputStream = new ByteArrayInputStream(input) {
+      @Override
+      public synchronized int read(byte[] b, int off, int len) {
+        return super.read(b, off, Math.min(8, len));
+      }
+    };
+
+    byte[] read = StreamReader.read(inputStream, 50);
+
+    assertThat(read)
+      .hasSize(50)
+      .containsExactly(Arrays.copyOf(input, 50));
+    assertThat(inputStream.available()).isEqualTo(50);
+  }
+
+  @Test
+  void shouldFailIfNotEnoughBytes() {
+    byte[] input = createBytes(49);
+    InputStream inputStream = new ByteArrayInputStream(input);
+
+    assertThrows(EOFException.class, () -> StreamReader.read(inputStream, 50));
+  }
+
+  private byte[] createBytes(int length) {
+    byte[] input = new byte[length];
+    for (int i = 0; i < input.length; ++i) {
+      input[i] = (byte) i;
+    }
+    return input;
+  }
+
+  private void fill(byte[] bytes) {
+    for (int i = 0; i < bytes.length; ++i) {
+      bytes[i] = (byte) i;
+    }
+  }
+}