8346239: Improve memory efficiency of JimageDiffGenerator

jerboaa · jerboaa · commit f696d9c521fa · 2025-01-08T10:39:13.000Z
Reviewed-by: mbaesken
diff --git a/src/jdk.jlink/share/classes/jdk/tools/jlink/internal/runtimelink/JimageDiffGenerator.java b/src/jdk.jlink/share/classes/jdk/tools/jlink/internal/runtimelink/JimageDiffGenerator.java
@@ -24,6 +24,9 @@
  */
 package jdk.tools.jlink.internal.runtimelink;
 
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashSet;
@@ -49,6 +52,7 @@ public class JimageDiffGenerator {
     public interface ImageResource extends AutoCloseable {
         public List<String> getEntries();
         public byte[] getResourceBytes(String name);
+        public InputStream getResource(String name);
     }
 
     /**
@@ -71,7 +75,6 @@ public List<ResourceDiff> generateDiff(ImageResource base, ImageResource image)
             resources.addAll(image.getEntries());
             baseResources = base.getEntries();
             for (String item: baseResources) {
-                byte[] baseBytes = base.getResourceBytes(item);
                 // First check that every item in the base image exist in
                 // the optimized image as well. If it does not, it's a removed
                 // item in the optimized image.
@@ -82,19 +85,18 @@ public List<ResourceDiff> generateDiff(ImageResource base, ImageResource image)
                     ResourceDiff.Builder builder = new ResourceDiff.Builder();
                     ResourceDiff diff = builder.setKind(ResourceDiff.Kind.REMOVED)
                            .setName(item)
-                           .setResourceBytes(baseBytes)
+                           .setResourceBytes(base.getResourceBytes(item))
                            .build();
                     diffs.add(diff);
                     continue;
                 }
                 // Verify resource bytes are equal if present in both images
-                boolean contentEquals = Arrays.equals(baseBytes, image.getResourceBytes(item));
-                if (!contentEquals) {
+                if (!compareStreams(base.getResource(item), image.getResource(item))) {
                     // keep track of original bytes (non-optimized)
                     ResourceDiff.Builder builder = new ResourceDiff.Builder();
                     ResourceDiff diff = builder.setKind(ResourceDiff.Kind.MODIFIED)
                         .setName(item)
-                        .setResourceBytes(baseBytes)
+                        .setResourceBytes(base.getResourceBytes(item))
                         .build();
                     diffs.add(diff);
                 }
@@ -112,4 +114,51 @@ public List<ResourceDiff> generateDiff(ImageResource base, ImageResource image)
         return diffs;
     }
 
+    /**
+     * Compare the contents of the two input streams (byte-by-byte).
+     *
+     * @param is1 The first input stream
+     * @param is2 The second input stream
+     * @return {@code true} iff the two streams contain the same number of
+     *         bytes and each byte of the streams are equal. {@code false}
+     *         otherwise.
+     */
+    private boolean compareStreams(InputStream is1, InputStream is2) {
+        byte[] buf1 = new byte[1024];
+        byte[] buf2 = new byte[1024];
+        int bytesRead1, bytesRead2 = 0;
+        try {
+            try (is1; is2) {
+                while ((bytesRead1 = is1.read(buf1)) != -1 &&
+                       (bytesRead2 = is2.read(buf2)) != -1) {
+                    if (bytesRead1 != bytesRead2) {
+                        return false;
+                    }
+                    if (bytesRead1 == buf1.length) {
+                        if (!Arrays.equals(buf1, buf2)) {
+                            return false;
+                        }
+                    } else {
+                        for (int i = 0; i < bytesRead1; i++) {
+                            if (buf1[i] != buf2[i]) {
+                                return false;
+                            }
+                        }
+                    }
+                }
+                // ensure we read both to the end
+                if (bytesRead1 == -1) {
+                    bytesRead2 = is2.read(buf2);
+                    if (bytesRead2 != -1) {
+                        return false;
+                    }
+                    return true;
+                }
+            }
+        } catch (IOException e) {
+            throw new UncheckedIOException("IO exception when comparing bytes", e);
+        }
+        return false;
+    }
+
 }
diff --git a/src/jdk.jlink/share/classes/jdk/tools/jlink/internal/runtimelink/ResourcePoolReader.java b/src/jdk.jlink/share/classes/jdk/tools/jlink/internal/runtimelink/ResourcePoolReader.java
@@ -25,6 +25,7 @@
 
 package jdk.tools.jlink.internal.runtimelink;
 
+import java.io.InputStream;
 import java.util.List;
 import java.util.Objects;
 
@@ -56,4 +57,9 @@ public byte[] getResourceBytes(String name) {
         return pool.findEntry(name).orElseThrow().contentBytes();
     }
 
+    @Override
+    public InputStream getResource(String name) {
+        return pool.findEntry(name).orElseThrow().content();
+    }
+
 }
diff --git a/test/jdk/tools/jlink/runtimeImage/AddOptionsTest.java b/test/jdk/tools/jlink/runtimeImage/AddOptionsTest.java
@@ -40,7 +40,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m AddOptionsTest
+ * @run main/othervm -Xmx1g AddOptionsTest
  */
 public class AddOptionsTest extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/BasicJlinkMissingJavaBase.java b/test/jdk/tools/jlink/runtimeImage/BasicJlinkMissingJavaBase.java
@@ -41,7 +41,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m BasicJlinkMissingJavaBase
+ * @run main/othervm -Xmx1g BasicJlinkMissingJavaBase
  */
 public class BasicJlinkMissingJavaBase extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/BasicJlinkTest.java b/test/jdk/tools/jlink/runtimeImage/BasicJlinkTest.java
@@ -39,7 +39,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m BasicJlinkTest false
+ * @run main/othervm -Xmx1g BasicJlinkTest false
  */
 public class BasicJlinkTest extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/CustomModuleJlinkTest.java b/test/jdk/tools/jlink/runtimeImage/CustomModuleJlinkTest.java
@@ -39,7 +39,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m CustomModuleJlinkTest
+ * @run main/othervm -Xmx1g CustomModuleJlinkTest
  */
 public class CustomModuleJlinkTest extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/GenerateJLIClassesTest.java b/test/jdk/tools/jlink/runtimeImage/GenerateJLIClassesTest.java
@@ -39,7 +39,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m GenerateJLIClassesTest
+ * @run main/othervm -Xmx1g GenerateJLIClassesTest
  */
 public class GenerateJLIClassesTest extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/JavaSEReproducibleTest.java b/test/jdk/tools/jlink/runtimeImage/JavaSEReproducibleTest.java
@@ -40,7 +40,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m JavaSEReproducibleTest
+ * @run main/othervm -Xmx1g JavaSEReproducibleTest
  */
 public class JavaSEReproducibleTest extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/KeepPackagedModulesFailTest.java b/test/jdk/tools/jlink/runtimeImage/KeepPackagedModulesFailTest.java
@@ -41,7 +41,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m KeepPackagedModulesFailTest
+ * @run main/othervm -Xmx1g KeepPackagedModulesFailTest
  */
 public class KeepPackagedModulesFailTest extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/ModifiedFilesExitTest.java b/test/jdk/tools/jlink/runtimeImage/ModifiedFilesExitTest.java
@@ -40,7 +40,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m ModifiedFilesExitTest
+ * @run main/othervm -Xmx1g ModifiedFilesExitTest
  */
 public class ModifiedFilesExitTest extends ModifiedFilesTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/ModifiedFilesWarningTest.java b/test/jdk/tools/jlink/runtimeImage/ModifiedFilesWarningTest.java
@@ -39,7 +39,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m ModifiedFilesWarningTest
+ * @run main/othervm -Xmx1g ModifiedFilesWarningTest
  */
 public class ModifiedFilesWarningTest extends ModifiedFilesTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/MultiHopTest.java b/test/jdk/tools/jlink/runtimeImage/MultiHopTest.java
@@ -40,7 +40,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m MultiHopTest
+ * @run main/othervm -Xmx1g MultiHopTest
  */
 public class MultiHopTest extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/PackagedModulesVsRuntimeImageLinkTest.java b/test/jdk/tools/jlink/runtimeImage/PackagedModulesVsRuntimeImageLinkTest.java
@@ -49,7 +49,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm/timeout=1200 -Xmx1400m PackagedModulesVsRuntimeImageLinkTest
+ * @run main/othervm/timeout=1200 -Xmx1g PackagedModulesVsRuntimeImageLinkTest
  */
 public class PackagedModulesVsRuntimeImageLinkTest extends AbstractLinkableRuntimeTest {
 
@@ -76,7 +76,6 @@ void runTest(Helper helper, boolean isLinkableRuntime) throws Exception {
                 .output(helper.createNewImageDir("java-se-jmodfull"))
                 .addMods("java.se").call().assertSuccess();
 
-        System.out.println("Now comparing jmod-less and jmod-full) images");
         compareRecursively(javaSEruntimeLink, javaSEJmodFull);
     }
 
diff --git a/test/jdk/tools/jlink/runtimeImage/PatchedJDKModuleJlinkTest.java b/test/jdk/tools/jlink/runtimeImage/PatchedJDKModuleJlinkTest.java
@@ -42,7 +42,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m PatchedJDKModuleJlinkTest
+ * @run main/othervm -Xmx1g PatchedJDKModuleJlinkTest
  */
 public class PatchedJDKModuleJlinkTest extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/SystemModulesTest.java b/test/jdk/tools/jlink/runtimeImage/SystemModulesTest.java
@@ -41,7 +41,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m SystemModulesTest
+ * @run main/othervm -Xmx1g SystemModulesTest
  */
 public class SystemModulesTest extends AbstractLinkableRuntimeTest {
 
diff --git a/test/jdk/tools/jlink/runtimeImage/SystemModulesTest2.java b/test/jdk/tools/jlink/runtimeImage/SystemModulesTest2.java
@@ -42,7 +42,7 @@
  *          jdk.jlink/jdk.tools.jimage
  * @build tests.* jdk.test.lib.process.OutputAnalyzer
  *        jdk.test.lib.process.ProcessTools
- * @run main/othervm -Xmx1400m SystemModulesTest2
+ * @run main/othervm -Xmx1g SystemModulesTest2
  */
 public class SystemModulesTest2 extends AbstractLinkableRuntimeTest {
 

Original file line number	Diff line number	Diff line change
`@@ -25,6 +25,7 @@`
`25`	`25`
`26`	`26`	`package jdk.tools.jlink.internal.runtimelink;`
`27`	`27`
	`28`	`+import java.io.InputStream;`
`28`	`29`	`import java.util.List;`
`29`	`30`	`import java.util.Objects;`
`30`	`31`
`@@ -56,4 +57,9 @@ public byte[] getResourceBytes(String name) {`
`56`	`57`	`return pool.findEntry(name).orElseThrow().contentBytes();`
`57`	`58`	`}`
`58`	`59`
	`60`	`+ @Override`
	`61`	`+ public InputStream getResource(String name) {`
	`62`	`+ return pool.findEntry(name).orElseThrow().content();`
	`63`	`+ }`
	`64`	`+`
`59`	`65`	`}`