Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.lz4 / src / net / jpountz / lz4 / LZ4FastDecompressor.java

diff --git a/bundles/org.simantics.lz4/src/net/jpountz/lz4/LZ4FastDecompressor.java b/bundles/org.simantics.lz4/src/net/jpountz/lz4/LZ4FastDecompressor.java
new file mode 100644 (file)
index 0000000..8427cc6
--- /dev/null
+++ b/bundles/org.simantics.lz4/src/net/jpountz/lz4/LZ4FastDecompressor.java
@@ -0,0 +1,106 @@
+package net.jpountz.lz4;
+
+import java.nio.ByteBuffer;
+
+/*
+ * 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.
+ */
+
+/**
+ * LZ4 decompressor that requires the size of the original input to be known.
+ * Use {@link LZ4SafeDecompressor} if you only know the size of the
+ * compressed stream.
+ * <p>
+ * Instances of this class are thread-safe.
+ */
+public abstract class LZ4FastDecompressor implements LZ4Decompressor {
+
+  /** Decompress <code>src[srcOff:]</code> into <code>dest[destOff:destOff+destLen]</code>
+   * and return the number of bytes read from <code>src</code>.
+   * <code>destLen</code> must be exactly the size of the decompressed data.
+   *
+   * @param destLen the <b>exact</b> size of the original input
+   * @return the number of bytes read to restore the original input
+   */
+  public abstract int decompress(byte[] src, int srcOff, byte[] dest, int destOff, int destLen);
+
+  /** Decompress <code>src[srcOff:]</code> into <code>dest[destOff:destOff+destLen]</code>
+   * and return the number of bytes read from <code>src</code>.
+   * <code>destLen</code> must be exactly the size of the decompressed data.
+   * The positions and limits of the {@link ByteBuffer}s remain unchanged.
+   *
+   * @param destLen the <b>exact</b> size of the original input
+   * @return the number of bytes read to restore the original input
+   */
+  public abstract int decompress(ByteBuffer src, int srcOff, ByteBuffer dest, int destOff, int destLen);
+
+  /**
+   * Convenience method, equivalent to calling
+   * {@link #decompress(byte[], int, byte[], int, int) decompress(src, 0, dest, 0, destLen)}.
+   */
+  public final int decompress(byte[] src, byte[] dest, int destLen) {
+    return decompress(src, 0, dest, 0, destLen);
+  }
+
+  /**
+   * Convenience method, equivalent to calling
+   * {@link #decompress(byte[], byte[], int) decompress(src, dest, dest.length)}.
+   */
+  public final int decompress(byte[] src, byte[] dest) {
+    return decompress(src, dest, dest.length);
+  }
+
+  /**
+   * Convenience method which returns <code>src[srcOff:?]</code>
+   * decompressed.
+   * <p><b><span style="color:red">Warning</span></b>: this method has an
+   * important overhead due to the fact that it needs to allocate a buffer to
+   * decompress into.</p>
+   * <p>Here is how this method is implemented:</p>
+   * <pre>
+   * final byte[] decompressed = new byte[destLen];
+   * decompress(src, srcOff, decompressed, 0, destLen);
+   * return decompressed;
+   * </pre>
+   */
+  public final byte[] decompress(byte[] src, int srcOff, int destLen) {
+    final byte[] decompressed = new byte[destLen];
+    decompress(src, srcOff, decompressed, 0, destLen);
+    return decompressed;
+  }
+
+  /**
+   * Convenience method, equivalent to calling
+   * {@link #decompress(byte[], int, int) decompress(src, 0, destLen)}.
+   */
+  public final byte[] decompress(byte[] src, int destLen) {
+    return decompress(src, 0, destLen);
+  }
+
+  /**
+   * Decompress <code>src</code> into <code>dest</code>. <code>dest</code>'s
+   * {@link ByteBuffer#remaining()} must be exactly the size of the decompressed
+   * data. This method moves the positions of the buffers.
+   */
+  public final void decompress(ByteBuffer src, ByteBuffer dest) {
+    final int read = decompress(src, src.position(), dest, dest.position(), dest.remaining());
+    dest.position(dest.limit());
+    src.position(src.position() + read);
+  }
+
+  @Override
+  public String toString() {
+    return getClass().getSimpleName();
+  }
+
+}