Migrated source code from Simantics SVN

[simantics/platform.git] / bundles / org.simantics.lz4 / src / net / jpountz / lz4 / LZ4JNIFastDecompressor.java

diff --git a/bundles/org.simantics.lz4/src/net/jpountz/lz4/LZ4JNIFastDecompressor.java b/bundles/org.simantics.lz4/src/net/jpountz/lz4/LZ4JNIFastDecompressor.java
new file mode 100644 (file)
index 0000000..5c355d8
--- /dev/null
+++ b/bundles/org.simantics.lz4/src/net/jpountz/lz4/LZ4JNIFastDecompressor.java
@@ -0,0 +1,82 @@
+package net.jpountz.lz4;
+
+/*
+ * 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.
+ */
+
+
+import java.nio.ByteBuffer;
+
+import net.jpountz.util.ByteBufferUtils;
+import net.jpountz.util.SafeUtils;
+
+
+/**
+ * {@link LZ4FastDecompressor} implemented with JNI bindings to the original C
+ * implementation of LZ4.
+ */
+final class LZ4JNIFastDecompressor extends LZ4FastDecompressor {
+
+  public static final LZ4JNIFastDecompressor INSTANCE = new LZ4JNIFastDecompressor();
+  private static LZ4FastDecompressor SAFE_INSTANCE;
+
+  @Override
+  public final int decompress(byte[] src, int srcOff, byte[] dest, int destOff, int destLen) {
+    SafeUtils.checkRange(src, srcOff);
+    SafeUtils.checkRange(dest, destOff, destLen);
+    final int result = LZ4JNI.LZ4_decompress_fast(src, null, srcOff, dest, null, destOff, destLen);
+    if (result < 0) {
+      throw new LZ4Exception("Error decoding offset " + (srcOff - result) + " of input buffer");
+    }
+    return result;
+  }
+
+  @Override
+  public int decompress(ByteBuffer src, int srcOff, ByteBuffer dest, int destOff, int destLen) {
+    ByteBufferUtils.checkNotReadOnly(dest);
+    ByteBufferUtils.checkRange(src, srcOff);
+    ByteBufferUtils.checkRange(dest, destOff, destLen);
+
+    if ((src.hasArray() || src.isDirect()) && (dest.hasArray() || dest.isDirect())) {
+      byte[] srcArr = null, destArr = null;
+      ByteBuffer srcBuf = null, destBuf = null;
+      if (src.hasArray()) {
+        srcArr = src.array();
+        srcOff += src.arrayOffset();
+      } else {
+        assert src.isDirect();
+        srcBuf = src;
+      }
+      if (dest.hasArray()) {
+        destArr = dest.array();
+        destOff += dest.arrayOffset();
+      } else {
+        assert dest.isDirect();
+        destBuf = dest;
+      }
+
+      final int result = LZ4JNI.LZ4_decompress_fast(srcArr, srcBuf, srcOff, destArr, destBuf, destOff, destLen);
+      if (result < 0) {
+        throw new LZ4Exception("Error decoding offset " + (srcOff - result) + " of input buffer");
+      }
+      return result;
+    } else {
+      LZ4FastDecompressor safeInstance = SAFE_INSTANCE;
+      if (safeInstance == null) {
+        safeInstance = SAFE_INSTANCE = LZ4Factory.safeInstance().fastDecompressor();
+      }
+      return safeInstance.decompress(src, srcOff, dest, destOff, destLen);
+    }
+  }
+
+}