1 files changed, 114 insertions, 0 deletions

diff --git a/java/org/brotli/wrapper/enc/UseCompoundDictionaryTest.java b/java/org/brotli/wrapper/enc/UseCompoundDictionaryTest.java
new file mode 100644
index 0000000..cbfd0d9
--- /dev/null
+++ b/java/org/brotli/wrapper/enc/UseCompoundDictionaryTest.java
@@ -0,0 +1,114 @@
+package org.brotli.wrapper.enc;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+import org.brotli.common.SharedDictionaryType;
+import org.brotli.enc.PreparedDictionary;
+import org.brotli.enc.PreparedDictionaryGenerator;
+import org.brotli.integration.BrotliJniTestBase;
+import org.brotli.integration.BundleHelper;
+import org.brotli.wrapper.common.BrotliCommon;
+import org.brotli.wrapper.dec.BrotliInputStream;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.util.List;
+import junit.framework.TestCase;
+import junit.framework.TestSuite;
+import org.junit.runner.RunWith;
+import org.junit.runners.AllTests;
+
+/** Tests for compression / decompression aided with LZ77 dictionary. */
+@RunWith(AllTests.class)
+public class UseCompoundDictionaryTest extends BrotliJniTestBase {
+
+  static InputStream getBundle() throws IOException {
+    return new FileInputStream(System.getProperty("TEST_BUNDLE"));
+  }
+
+  /** Creates a test suite. */
+  public static TestSuite suite() throws IOException {
+    TestSuite suite = new TestSuite();
+    InputStream bundle = getBundle();
+    try {
+      List<String> entries = BundleHelper.listEntries(bundle);
+      for (String entry : entries) {
+        suite.addTest(new UseCompoundDictionaryTestCase(entry));
+      }
+    } finally {
+      bundle.close();
+    }
+    return suite;
+  }
+
+  /** Test case with a unique name. */
+  static class UseCompoundDictionaryTestCase extends TestCase {
+    final String entryName;
+    UseCompoundDictionaryTestCase(String entryName) {
+      super("UseCompoundDictionaryTest." + entryName);
+      this.entryName = entryName;
+    }
+
+    @Override
+    protected void runTest() throws Throwable {
+      UseCompoundDictionaryTest.run(entryName);
+    }
+  }
+
+  private static PreparedDictionary prepareRawDictionary(String entryName, ByteBuffer data) {
+    if (entryName.endsWith("E.coli.txt")) {
+      // Default prepared dictionary parameters doesn't work well for DNA data.
+      // Should work well with 8-byte hash.
+      return PreparedDictionaryGenerator.generate(data, 17, 3, 64, 5);
+    } else {
+       return Encoder.prepareDictionary(data, SharedDictionaryType.RAW);
+    }
+  }
+
+  private static void run(String entryName) throws Throwable {
+    InputStream bundle = getBundle();
+    byte[] original;
+    try {
+      original = BundleHelper.readEntry(bundle, entryName);
+    } finally {
+      bundle.close();
+    }
+
+    if (original == null) {
+      throw new RuntimeException("Can't read bundle entry: " + entryName);
+    }
+
+    ByteBuffer dictionary = BrotliCommon.makeNative(original);
+    PreparedDictionary preparedDictionary = prepareRawDictionary(entryName, dictionary);
+
+    ByteArrayOutputStream dst = new ByteArrayOutputStream();
+    BrotliOutputStream encoder =
+        new BrotliOutputStream(dst, new Encoder.Parameters().setQuality(9).setWindow(23), 1 << 23);
+    encoder.attachDictionary(preparedDictionary);
+    try {
+      encoder.write(original);
+    } finally {
+      encoder.close();
+    }
+
+    byte[] compressed = dst.toByteArray();
+
+    // Just copy self from LZ77 dictionary -> ultimate compression ratio.
+    assertTrue(compressed.length < 80 + original.length / 65536);
+
+    BrotliInputStream decoder =
+        new BrotliInputStream(new ByteArrayInputStream(compressed), 1 << 23);
+    decoder.attachDictionary(dictionary);
+    try {
+      long originalCrc = BundleHelper.fingerprintStream(new ByteArrayInputStream(original));
+      long crc = BundleHelper.fingerprintStream(decoder);
+      assertEquals(originalCrc, crc);
+    } finally {
+      decoder.close();
+    }
+  }
+}
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