Add zlib decompressor

Author: electrum

src/main/java/io/airlift/compress/zlib/InflateDecompressor.java

@@ -0,0 +1,111 @@
+/*
+ * 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 io.airlift.compress.zlib;
+
+import io.airlift.compress.Decompressor;
+import io.airlift.compress.MalformedInputException;
+
+import java.nio.Buffer;
+import java.nio.ByteBuffer;
+
+import static io.airlift.compress.zlib.UnsafeUtil.getAddress;
+import static java.lang.String.format;
+import static java.util.Objects.requireNonNull;
+import static sun.misc.Unsafe.ARRAY_BYTE_BASE_OFFSET;
+
+public class InflateDecompressor
+        implements Decompressor
+{
+    @Override
+    public int decompress(byte[] input, int inputOffset, int inputLength, byte[] output, int outputOffset, int maxOutputLength)
+            throws MalformedInputException
+    {
+        verifyRange(input, inputOffset, inputLength);
+        verifyRange(output, outputOffset, maxOutputLength);
+
+        long inputAddress = ARRAY_BYTE_BASE_OFFSET + inputOffset;
+        long inputLimit = inputAddress + inputLength;
+        long outputAddress = ARRAY_BYTE_BASE_OFFSET + outputOffset;
+        long outputLimit = outputAddress + maxOutputLength;
+
+        return InflateRawDecompressor.decompress(input, inputAddress, inputLimit, output, outputAddress, outputLimit);
+    }
+
+    @Override
+    public void decompress(ByteBuffer inputBuffer, ByteBuffer outputBuffer)
+            throws MalformedInputException
+    {
+        // Java 9+ added an overload of various methods in ByteBuffer. When compiling with Java 11+ and targeting Java 8 bytecode
+        // the resulting signatures are invalid for JDK 8, so accesses below result in NoSuchMethodError. Accessing the
+        // methods through the interface class works around the problem
+        // Sidenote: we can't target "javac --release 8" because Unsafe is not available in the signature data for that profile
+        Buffer input = inputBuffer;
+        Buffer output = outputBuffer;
+
+        Object inputBase;
+        long inputAddress;
+        long inputLimit;
+        if (input.isDirect()) {
+            inputBase = null;
+            long address = getAddress(input);
+            inputAddress = address + input.position();
+            inputLimit = address + input.limit();
+        }
+        else if (input.hasArray()) {
+            inputBase = input.array();
+            inputAddress = ARRAY_BYTE_BASE_OFFSET + input.arrayOffset() + input.position();
+            inputLimit = ARRAY_BYTE_BASE_OFFSET + input.arrayOffset() + input.limit();
+        }
+        else {
+            throw new IllegalArgumentException("Unsupported input ByteBuffer implementation " + input.getClass().getName());
+        }
+
+        Object outputBase;
+        long outputAddress;
+        long outputLimit;
+        if (output.isDirect()) {
+            outputBase = null;
+            long address = getAddress(output);
+            outputAddress = address + output.position();
+            outputLimit = address + output.limit();
+        }
+        else if (output.hasArray()) {
+            outputBase = output.array();
+            outputAddress = ARRAY_BYTE_BASE_OFFSET + output.arrayOffset() + output.position();
+            outputLimit = ARRAY_BYTE_BASE_OFFSET + output.arrayOffset() + output.limit();
+        }
+        else {
+            throw new IllegalArgumentException("Unsupported output ByteBuffer implementation " + output.getClass().getName());
+        }
+
+        // HACK: Assure JVM does not collect Slice wrappers while decompressing, since the
+        // collection may trigger freeing of the underlying memory resulting in a segfault
+        // There is no other known way to signal to the JVM that an object should not be
+        // collected in a block, and technically, the JVM is allowed to eliminate these locks.
+        synchronized (input) {
+            synchronized (output) {
+                int written = InflateRawDecompressor.decompress(inputBase, inputAddress, inputLimit, outputBase, outputAddress, outputLimit);
+                output.position(output.position() + written);
+            }
+        }
+    }
+
+    private static void verifyRange(byte[] data, int offset, int length)
+    {
+        requireNonNull(data, "data is null");
+        if (offset < 0 || length < 0 || offset + length > data.length) {
+            throw new IllegalArgumentException(format("Invalid offset or length (%s, %s) in array of length %s", offset, length, data.length));
+        }
+    }
+}