Add CharBufferReader benchmark

Author: schlosna

src/main/java/com/fasterxml/jackson/perf/json/JsonArbitraryFieldNameBenchmark.java

@@ -25,6 +25,10 @@
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStreamReader;
+import java.io.Reader;
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.Map;
 import java.util.concurrent.ThreadLocalRandom;
@@ -80,6 +84,15 @@ JsonParser create(JsonFactory factory, Supplier<byte[]> bytesSupplier) throws IO
                         StandardCharsets.UTF_8));
             }
         },
+        CHAR_READER() {
+            @Override
+            JsonParser create(JsonFactory factory, Supplier<byte[]> jsonSupplier) throws IOException {
+                ByteBuffer byteBuffer = ByteBuffer.wrap(jsonSupplier.get());
+                CharBuffer charBuffer = Charset.forName("UTF-8").decode(byteBuffer);
+                CharBufferReader charBufferReader = new CharBufferReader(charBuffer);
+                return factory.createParser(charBufferReader);
+            }
+        },
         ;
 
         abstract JsonParser create(JsonFactory factory, Supplier<byte[]> jsonSupplier) throws IOException;
@@ -154,6 +167,68 @@ public static final class SimpleClass {
         public String stringThree;
     }
 
+    public static class CharBufferReader extends Reader {
+        private final CharBuffer charBuffer;
+
+        public CharBufferReader(CharBuffer buffer) {
+            this.charBuffer = buffer.duplicate();
+        }
+
+        @Override
+        public int read(char[] chars, int off, int len) {
+            int remaining = this.charBuffer.remaining();
+            if (remaining <= 0) {
+                return -1;
+            }
+            int length = Math.min(len, remaining);
+            this.charBuffer.get(chars, off, length);
+            return length;
+        }
+
+        @Override
+        public int read() {
+            if (this.charBuffer.hasRemaining()) {
+                return this.charBuffer.get();
+            }
+            return -1;
+        }
+
+        @Override
+        public long skip(long n) {
+            if (n < 0L) {
+                throw new IllegalArgumentException("number of characters to skip cannot be negative");
+            }
+            int skipped = Math.min((int) n, this.charBuffer.remaining());
+            this.charBuffer.position(this.charBuffer.position() + skipped);
+            return skipped;
+        }
+
+        @Override
+        public boolean ready() {
+            return true;
+        }
+
+        @Override
+        public boolean markSupported() {
+            return true;
+        }
+
+        @Override
+        public void mark(int readAheadLimit) {
+            this.charBuffer.mark();
+        }
+
+        @Override
+        public void reset() {
+            this.charBuffer.reset();
+        }
+
+        @Override
+        public void close() {
+            this.charBuffer.position(this.charBuffer.limit());
+        }
+    }
+
     public static void main(String[] _args) throws Exception {
         new Runner(new OptionsBuilder()
                 .include(JsonArbitraryFieldNameBenchmark.class.getName())