SONAR-2291 fix performance issue when computing file hashes

2 files changed, 16 insertions, 5 deletions

diff --git a/sonar-home/src/main/java/org/sonar/home/cache/FileHashes.java b/sonar-home/src/main/java/org/sonar/home/cache/FileHashes.java
index 89a973fd2f4..28066cf5b94 100644
--- a/sonar-home/src/main/java/org/sonar/home/cache/FileHashes.java
+++ b/sonar-home/src/main/java/org/sonar/home/cache/FileHashes.java
@@ -36,6 +36,8 @@ import java.security.MessageDigest;
  */
 public class FileHashes {
 
+  private static final int STREAM_BUFFER_LENGTH = 1024;
+
   public String of(File file) {
     try {
       return of(new FileInputStream(file));
@@ -51,10 +53,7 @@ public class FileHashes {
     DigestInputStream digestInputStream = null;
     try {
       MessageDigest digest = MessageDigest.getInstance("MD5");
-      digestInputStream = new DigestInputStream(input, digest);
-      while (digestInputStream.read() != -1) {
-      }
-      byte[] hash = digest.digest();
+      byte[] hash = digest(input, digest);
       return toHex(hash);
 
     } catch (Exception e) {
@@ -66,6 +65,16 @@ public class FileHashes {
     }
   }
 
+  private byte[] digest(InputStream input, MessageDigest digest) throws IOException {
+    final byte[] buffer = new byte[STREAM_BUFFER_LENGTH];
+    int read = input.read(buffer, 0, STREAM_BUFFER_LENGTH);
+    while (read > -1) {
+      digest.update(buffer, 0, read);
+      read = input.read(buffer, 0, STREAM_BUFFER_LENGTH);
+    }
+    return digest.digest();
+  }
+
   static String toHex(byte[] bytes) {
     BigInteger bi = new BigInteger(1, bytes);
     return String.format("%0" + (bytes.length << 1) + "X", bi);
diff --git a/sonar-home/src/test/java/org/sonar/home/cache/FileHashesTest.java b/sonar-home/src/test/java/org/sonar/home/cache/FileHashesTest.java
index 08f7227f49c..ff6c01c7a3e 100644
--- a/sonar-home/src/test/java/org/sonar/home/cache/FileHashesTest.java
+++ b/sonar-home/src/test/java/org/sonar/home/cache/FileHashesTest.java
@@ -33,6 +33,8 @@ import java.math.BigInteger;
 import java.security.SecureRandom;
 
 import static org.fest.assertions.Assertions.assertThat;
+import static org.mockito.Matchers.any;
+import static org.mockito.Matchers.anyInt;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
@@ -84,7 +86,7 @@ public class FileHashesTest {
     thrown.expectMessage("Fail to compute hash");
 
     InputStream input = mock(InputStream.class);
-    when(input.read()).thenThrow(new IllegalThreadStateException());
+    when(input.read(any(byte[].class), anyInt(), anyInt())).thenThrow(new IllegalThreadStateException());
     new FileHashes().of(input);
   }