pylucene 3.5.0-3

[pylucene.git] / lucene-java-3.5.0 / lucene / src / java / org / apache / lucene / util / fst / PositiveIntOutputs.java

diff --git a/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/util/fst/PositiveIntOutputs.java b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/util/fst/PositiveIntOutputs.java
new file mode 100644 (file)
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+++ b/lucene-java-3.5.0/lucene/src/java/org/apache/lucene/util/fst/PositiveIntOutputs.java
@@ -0,0 +1,136 @@
+package org.apache.lucene.util.fst;
+
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import java.io.IOException;
+
+import org.apache.lucene.store.DataInput;
+import org.apache.lucene.store.DataOutput;
+
+/**
+ * Output is a long, for each input term.  NOTE: the
+ * resulting FST is not guaranteed to be minimal!  See
+ * {@link Builder}.  You cannot store 0 output with this
+ * (that's reserved to mean "no output")!
+ *
+ * @lucene.experimental
+ */
+
+public final class PositiveIntOutputs extends Outputs<Long> {
+  
+  private final static Long NO_OUTPUT = new Long(0);
+
+  private final boolean doShare;
+
+  private final static PositiveIntOutputs singletonShare = new PositiveIntOutputs(true);
+  private final static PositiveIntOutputs singletonNoShare = new PositiveIntOutputs(false);
+
+  private PositiveIntOutputs(boolean doShare) {
+    this.doShare = doShare;
+  }
+
+  public static PositiveIntOutputs getSingleton(boolean doShare) {
+    return doShare ? singletonShare : singletonNoShare;
+  }
+
+  public Long get(long v) {
+    if (v == 0) {
+      return NO_OUTPUT;
+    } else {
+      return Long.valueOf(v);
+    }
+  }
+
+  @Override
+  public Long common(Long output1, Long output2) {
+    assert valid(output1);
+    assert valid(output2);
+    if (output1 == NO_OUTPUT || output2 == NO_OUTPUT) {
+      return NO_OUTPUT;
+    } else if (doShare) {
+      assert output1 > 0;
+      assert output2 > 0;
+      return Math.min(output1, output2);
+    } else if (output1.equals(output2)) {
+      return output1;
+    } else {
+      return NO_OUTPUT;
+    }
+  }
+
+  @Override
+  public Long subtract(Long output, Long inc) {
+    assert valid(output);
+    assert valid(inc);
+    assert output >= inc;
+
+    if (inc == NO_OUTPUT) {
+      return output;
+    } else if (output.equals(inc)) {
+      return NO_OUTPUT;
+    } else {
+      return output - inc;
+    }
+  }
+
+  @Override
+  public Long add(Long prefix, Long output) {
+    assert valid(prefix);
+    assert valid(output);
+    if (prefix == NO_OUTPUT) {
+      return output;
+    } else if (output == NO_OUTPUT) {
+      return prefix;
+    } else {
+      return prefix + output;
+    }
+  }
+
+  @Override
+  public void write(Long output, DataOutput out) throws IOException {
+    assert valid(output);
+    out.writeVLong(output);
+  }
+
+  @Override
+  public Long read(DataInput in) throws IOException {
+    long v = in.readVLong();
+    if (v == 0) {
+      return NO_OUTPUT;
+    } else {
+      return v;
+    }
+  }
+
+  private boolean valid(Long o) {
+    assert o != null;
+    assert o instanceof Long;
+    assert o == NO_OUTPUT || o > 0;
+    return true;
+  }
+
+  @Override
+  public Long getNoOutput() {
+    return NO_OUTPUT;
+  }
+
+  @Override
+  public String outputToString(Long output) {
+    return output.toString();
+  }
+}