1 files changed, 113 insertions, 0 deletions
diff --git a/java/org/brotli/integration/BundleHelper.java b/java/org/brotli/integration/BundleHelper.java
new file mode 100755
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+++ b/java/org/brotli/integration/BundleHelper.java
@@ -0,0 +1,113 @@
+/* Copyright 2016 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+package org.brotli.integration;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+/**
+ * Utilities to work test files bundles in zip archive.
+ */
+public class BundleHelper {
+  private BundleHelper() { }
+
+  public static List<String> listEntries(InputStream input) throws IOException {
+    List<String> result = new ArrayList<String>();
+    ZipInputStream zis = new ZipInputStream(input);
+    ZipEntry entry;
+    try {
+      while ((entry = zis.getNextEntry()) != null) {
+        if (!entry.isDirectory()) {
+          result.add(entry.getName());
+        }
+        zis.closeEntry();
+      }
+    } finally {
+      zis.close();
+    }
+    return result;
+  }
+
+  public static byte[] readStream(InputStream input) throws IOException {
+    ByteArrayOutputStream result = new ByteArrayOutputStream();
+    byte[] buffer = new byte[65536];
+    int bytesRead;
+    while ((bytesRead = input.read(buffer)) != -1) {
+      result.write(buffer, 0, bytesRead);
+    }
+    return result.toByteArray();
+  }
+
+  public static byte[] readEntry(InputStream input, String entryName) throws IOException {
+    ZipInputStream zis = new ZipInputStream(input);
+    ZipEntry entry;
+    try {
+      while ((entry = zis.getNextEntry()) != null) {
+        if (entry.getName().equals(entryName)) {
+          byte[] result = readStream(zis);
+          zis.closeEntry();
+          return result;
+        }
+        zis.closeEntry();
+      }
+    } finally {
+      zis.close();
+    }
+    /* entry not found */
+    return null;
+  }
+
+  /** ECMA CRC64 polynomial. */
+  private static final long CRC_64_POLY =
+      new BigInteger("C96C5795D7870F42", 16).longValue();
+
+  /**
+   * Rolls CRC64 calculation.
+   *
+   * <p> {@code CRC64(data) = -1 ^ updateCrc64((... updateCrc64(-1, firstBlock), ...), lastBlock);}
+   * <p> This simple and reliable checksum is chosen to make is easy to calculate the same value
+   * across the variety of languages (C++, Java, Go, ...).
+   */
+  public static long updateCrc64(long crc, byte[] data, int offset, int length) {
+    for (int i = offset; i < offset + length; ++i) {
+      long c = (crc ^ (long) (data[i] & 0xFF)) & 0xFF;
+      for (int k = 0; k < 8; k++) {
+        c = ((c & 1) == 1) ? CRC_64_POLY ^ (c >>> 1) : c >>> 1;
+      }
+      crc = c ^ (crc >>> 8);
+    }
+    return crc;
+  }
+
+  /**
+   * Calculates CRC64 of stream contents.
+   */
+  public static long fingerprintStream(InputStream input) throws IOException {
+    byte[] buffer = new byte[65536];
+    long crc = -1;
+    while (true) {
+      int len = input.read(buffer);
+      if (len <= 0) {
+        break;
+      }
+      crc = updateCrc64(crc, buffer, 0, len);
+    }
+    return ~crc;
+  }
+
+  public static long getExpectedFingerprint(String entryName) {
+    int dotIndex = entryName.indexOf('.');
+    String entryCrcString = (dotIndex == -1) ? entryName : entryName.substring(0, dotIndex);
+    return new BigInteger(entryCrcString, 16).longValue();
+  }
+}