public void preWALWrite(final RegionInfo info, final WALKey logKey, final WALEdit logEdit)
    throws IOException {
    // Not bypassable.
    if (this.coprocEnvironments.isEmpty()) {
      return;
    }
    execOperation(new WALObserverOperation() {
      @Override
      public void call(WALObserver oserver) throws IOException {
        oserver.preWALWrite(this, info, logKey, logEdit);
      }
    });
  }
Constructor
@param log  the write ahead log
@param conf the configuration
hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/wal/WALCoprocessorHost.java