Java Code Examples for org.apache.lucene.store.ChecksumIndexInput#length()

public static void checkFooter(ChecksumIndexInput input) throws IOException {
  BytesRefBuilder scratch = new BytesRefBuilder();
  String expectedChecksum = String.format(Locale.ROOT, "%020d", input.getChecksum());
  readLine(input, scratch);
  if (StringHelper.startsWith(scratch.get(), CHECKSUM) == false) {
    throw new CorruptIndexException("SimpleText failure: expected checksum line but got " + scratch.get().utf8ToString(), input);
  }
  String actualChecksum = new BytesRef(scratch.bytes(), CHECKSUM.length, scratch.length() - CHECKSUM.length).utf8ToString();
  if (!expectedChecksum.equals(actualChecksum)) {
    throw new CorruptIndexException("SimpleText checksum failure: " + actualChecksum + " != " + expectedChecksum, input);
  }
  if (input.length() != input.getFilePointer()) {
    throw new CorruptIndexException("Unexpected stuff at the end of file, please be careful with your text editor!", input);
  }
}
 

/** 
 * Validates the codec footer previously written by {@link #writeFooter}, optionally
 * passing an unexpected exception that has already occurred.
 * <p>
 * When a {@code priorException} is provided, this method will add a suppressed exception 
 * indicating whether the checksum for the stream passes, fails, or cannot be computed, and 
 * rethrow it. Otherwise it behaves the same as {@link #checkFooter(ChecksumIndexInput)}.
 * <p>
 * Example usage:
 * <pre class="prettyprint">
 * try (ChecksumIndexInput input = ...) {
 *   Throwable priorE = null;
 *   try {
 *     // ... read a bunch of stuff ... 
 *   } catch (Throwable exception) {
 *     priorE = exception;
 *   } finally {
 *     CodecUtil.checkFooter(input, priorE);
 *   }
 * }
 * </pre>
 */
public static void checkFooter(ChecksumIndexInput in, Throwable priorException) throws IOException {
  if (priorException == null) {
    checkFooter(in);
  } else {
    try {
      // If we have evidence of corruption then we return the corruption as the
      // main exception and the prior exception gets suppressed. Otherwise we
      // return the prior exception with a suppressed exception that notifies
      // the user that checksums matched.
      long remaining = in.length() - in.getFilePointer();
      if (remaining < footerLength()) {
        // corruption caused us to read into the checksum footer already: we can't proceed
        throw new CorruptIndexException("checksum status indeterminate: remaining=" + remaining +
                                        "; please run checkindex for more details", in);
      } else {
        // otherwise, skip any unread bytes.
        in.skipBytes(remaining - footerLength());
        
        // now check the footer
        long checksum = checkFooter(in);
        priorException.addSuppressed(new CorruptIndexException("checksum passed (" + Long.toHexString(checksum) +
                                                               "). possibly transient resource issue, or a Lucene or JVM bug", in));
      }
    } catch (CorruptIndexException corruptException) {
      corruptException.addSuppressed(priorException);
      throw corruptException;
    } catch (Throwable t) {
      // catch-all for things that shouldn't go wrong (e.g. OOM during readInt) but could...
      priorException.addSuppressed(new CorruptIndexException("checksum status indeterminate: unexpected exception", in, t));
    }
    throw IOUtils.rethrowAlways(priorException);
  }
}
 

/** Constructs a ByteSequencesReader from the provided IndexInput */
public ByteSequencesReader(ChecksumIndexInput in, String name) {
  this.in = in;
  this.name = name;
  end = in.length() - CodecUtil.footerLength();
}