initial commit

2024-12-28 09:02:28 +08:00
commit d76f5b46b5
374 changed files with 49432 additions and 0 deletions
--- a/src/main/java/com/google/code/yanf4j/util/ShiftAndByteBufferMatcher.java
+++ b/src/main/java/com/google/code/yanf4j/util/ShiftAndByteBufferMatcher.java
@@ -0,0 +1,94 @@
+/**
+ * Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)] Licensed 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
+ */
+/**
+ * Copyright [2009-2010] [dennis zhuang(killme2008@gmail.com)] Licensed 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
+ */
+package com.google.code.yanf4j.util;
+
+import java.util.ArrayList;
+import java.util.List;
+import com.google.code.yanf4j.buffer.IoBuffer;
+
+/**
+ * ByteBuffer matcher based on shift-and algorithm
+ * 
+ * @author dennis
+ * 
+ */
+public class ShiftAndByteBufferMatcher implements ByteBufferMatcher {
+
+  private int[] b;
+  private int mask;
+
+  private int patternLimit;
+  private int patternPos;
+  private int patternLen;
+
+  public ShiftAndByteBufferMatcher(IoBuffer pat) {
+    if (pat == null || pat.remaining() == 0) {
+      throw new IllegalArgumentException("blank buffer");
+    }
+    this.patternLimit = pat.limit();
+    this.patternPos = pat.position();
+    this.patternLen = pat.remaining();
+    preprocess(pat);
+    this.mask = 1 << (this.patternLen - 1);
+  }
+
+  /**
+   * Ԥ<><D4A4><EFBFBD><EFBFBD>
+   * 
+   * @param pat
+   */
+  private void preprocess(IoBuffer pat) {
+    this.b = new int[256];
+    for (int i = this.patternPos; i < this.patternLimit; i++) {
+      int p = ByteBufferUtils.uByte(pat.get(i));
+      this.b[p] = this.b[p] | (1 << i);
+    }
+  }
+
+  public final List<Integer> matchAll(IoBuffer buffer) {
+    List<Integer> matches = new ArrayList<Integer>();
+    int bufferLimit = buffer.limit();
+    int d = 0;
+    for (int pos = buffer.position(); pos < bufferLimit; pos++) {
+      d <<= 1;
+      d |= 1;
+      d &= this.b[ByteBufferUtils.uByte(buffer.get(pos))];
+      if ((d & this.mask) != 0) {
+        matches.add(pos - this.patternLen + 1);
+      }
+    }
+    return matches;
+  }
+
+  public final int matchFirst(IoBuffer buffer) {
+    if (buffer == null) {
+      return -1;
+    }
+    int bufferLimit = buffer.limit();
+    int d = 0;
+    for (int pos = buffer.position(); pos < bufferLimit; pos++) {
+      d <<= 1;
+      d |= 1;
+      d &= this.b[buffer.get(pos) & 0XFF];
+      if ((d & this.mask) != 0) {
+        return pos - this.patternLen + 1;
+      }
+    }
+    return -1;
+  }
+
+}