Extract InputStream impl to BoundedDataReader

Author: Glavo

src/main/java/org/glavo/nbt/internal/input/BoundedDataReader.java

@@ -15,7 +15,12 @@
  */
 package org.glavo.nbt.internal.input;
 
+import org.jetbrains.annotations.Nullable;
+
+import java.io.EOFException;
 import java.io.IOException;
+import java.io.InputStream;
+import java.util.Objects;
 
 public abstract non-sealed class BoundedDataReader extends DataReader {
     private final RawDataReader rawReader;
@@ -51,4 +56,49 @@ public void close() throws IOException {
 
         getRawReader().skip(endPosition - currentPosition);
     }
+
+    protected final InputStream asInputStream() {
+        return new InputStream() {
+            private byte @Nullable [] singleByte;
+
+            @Override
+            public int read() throws IOException {
+                if (singleByte == null) {
+                    singleByte = new byte[1];
+                }
+
+                if (read(singleByte) < 1) {
+                    return -1;
+                } else {
+                    return Byte.toUnsignedInt(singleByte[0]);
+                }
+            }
+
+            @Override
+            public int read(byte[] b, int off, int len) throws IOException {
+                Objects.checkFromIndexSize(off, len, b.length);
+                if (len == 0) {
+                    return 0;
+                }
+
+                long rawRemaining = endPosition - rawReader.position();
+                if (rawRemaining <= 0) {
+                    return -1;
+                }
+
+                if (rawReader.getBuffer().remaining() == 0) {
+                    try {
+                        rawReader.ensureBufferRemaining(1);
+                    } catch (EOFException e) {
+                        return -1;
+                    }
+                }
+
+                int n = (int) Math.min(Math.min(len, rawReader.getBuffer().remaining()), rawRemaining);
+                rawReader.getBuffer().getBytes(b, off, n);
+                return n;
+            }
+
+        };
+    }
 }

src/main/java/org/glavo/nbt/internal/input/LZ4DataReader.java

@@ -31,48 +31,7 @@ public final class LZ4DataReader extends BoundedDataReader {
 
     public LZ4DataReader(RawDataReader rawReader, long limit) {
         super(rawReader, rawReader.getDecompressBuffer(), limit);
-        this.lz4Stream = LZ4BlockInputStream.newBuilder().build(new InputStream() {
-            private byte @Nullable [] singleByte;
-
-            @Override
-            public int read() throws IOException {
-                if (singleByte == null) {
-                    singleByte = new byte[1];
-                }
-
-                if (read(singleByte) < 1) {
-                    return -1;
-                } else {
-                    return Byte.toUnsignedInt(singleByte[0]);
-                }
-            }
-
-            @Override
-            public int read(byte[] b, int off, int len) throws IOException {
-                Objects.checkFromIndexSize(off, len, b.length);
-                if (len == 0) {
-                    return 0;
-                }
-
-                long rawRemaining = endPosition - rawReader.position();
-                if (rawRemaining <= 0) {
-                    return -1;
-                }
-
-                if (rawReader.getBuffer().remaining() == 0) {
-                    try {
-                        rawReader.ensureBufferRemaining(1);
-                    } catch (EOFException e) {
-                        return -1;
-                    }
-                }
-
-                int n = (int) Math.min(Math.min(len, rawReader.getBuffer().remaining()), rawRemaining);
-                rawReader.getBuffer().getBytes(b, off, n);
-                return n;
-            }
-
-        });
+        this.lz4Stream = LZ4BlockInputStream.newBuilder().build(asInputStream());
 
         assert getBuffer().getByteBuffer().hasArray();
     }