X-Git-Url: https://git.mdrn.pl/pylucene.git/blobdiff_plain/a2e61f0c04805cfcb8706176758d1283c7e3a55c..aaeed5504b982cf3545252ab528713250aa33eed:/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/util/encoding/EightFlagsIntDecoder.java?ds=inline
diff --git a/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/util/encoding/EightFlagsIntDecoder.java b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/util/encoding/EightFlagsIntDecoder.java
new file mode 100644
index 0000000..5f8e22b
--- /dev/null
+++ b/lucene-java-3.5.0/lucene/contrib/facet/src/java/org/apache/lucene/util/encoding/EightFlagsIntDecoder.java
@@ -0,0 +1,91 @@
+package org.apache.lucene.util.encoding;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * 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.
+ */
+
+/**
+ * Decodes data which was encoded by {@link EightFlagsIntEncoder}. Scans
+ * the indicator
, one flag (1-bits) at a time, and decodes extra
+ * data using {@link VInt8IntDecoder}.
+ *
+ * @see EightFlagsIntEncoder
+ * @lucene.experimental
+ */
+public class EightFlagsIntDecoder extends IntDecoder {
+
+ /**
+ * Holds all combinations of indicator for fast decoding (saves time
+ * on real-time bit manipulation)
+ */
+ private static final byte[][] decodeTable = new byte[256][8];
+
+ /** Generating all combinations of indicator into separate flags. */
+ static {
+ for (int i = 256; i != 0;) {
+ --i;
+ for (int j = 8; j != 0;) {
+ --j;
+ decodeTable[i][j] = (byte) ((i >>> j) & 0x1);
+ }
+ }
+ }
+
+ private final IntDecoder decoder = new VInt8IntDecoder();
+
+ /** The indicator for decoding a chunk of 8 integers. */
+ private int indicator;
+
+ /** Used as an ordinal of 0 - 7, as the decoder decodes chunks of 8 integers. */
+ private int ordinal = 0;
+
+ @Override
+ public long decode() throws IOException {
+ // If we've decoded 8 integers, read the next indicator.
+ if ((ordinal & 0x7) == 0) {
+ indicator = in.read();
+ if (indicator < 0) {
+ return EOS;
+ }
+ ordinal = 0;
+ }
+
+ if (decodeTable[indicator][ordinal++] == 0) {
+ // decode the value from the stream.
+ long decode = decoder.decode();
+ return decode == EOS ? EOS : decode + 2;
+ }
+
+ return 1;
+ }
+
+ @Override
+ public void reInit(InputStream in) {
+ super.reInit(in);
+ decoder.reInit(in);
+ ordinal = 0;
+ indicator = 0;
+ }
+
+ @Override
+ public String toString() {
+ return "EightFlags (VInt8)";
+ }
+
+}