Performance improvement for HttpRequestEncoder. Insert char into the string optimized.

Motivation:

Right now HttpRequestEncoder does insertion of slash for url like http://localhost?pararm=1 before the question mark. It is done not effectively.

Modification:

Code:

new StringBuilder(len + 1)
                .append(uri, 0, index)
                .append(SLASH)
                .append(uri, index, len)
                .toString();
Replaced with:

new StringBuilder(uri)
                .insert(index, SLASH)
                .toString();
Result:

Faster HttpRequestEncoder. Additional small test. Attached benchmark in PR.

Benchmark                                      Mode  Cnt        Score        Error  Units
HttpRequestEncoderInsertBenchmark.newEncoder  thrpt   40  3704843.303 ±  98950.919  ops/s
HttpRequestEncoderInsertBenchmark.oldEncoder  thrpt   40  3284236.960 ± 134433.217  ops/s

codec-http/src/main/java/io/netty/handler/codec/http/HttpRequestEncoder.java

@@ -58,12 +58,7 @@ public class HttpRequestEncoder extends HttpObjectEncoder<HttpRequest> {
                     }
                 } else {
                     if (uri.lastIndexOf(SLASH, index) <= startIndex) {
-                        int len = uri.length();
+                        uri = new StringBuilder(uri).insert(index, SLASH).toString();
-                        StringBuilder sb = new StringBuilder(len + 1);
-                        sb.append(uri, 0, index)
-                          .append(SLASH)
-                          .append(uri, index, len);
-                        uri = sb.toString();
                     }
                 }
             }

codec-http/src/test/java/io/netty/handler/codec/http/HttpRequestEncoderTest.java

@@ -35,6 +35,7 @@ public class HttpRequestEncoderTest {
                 HttpMethod.GET, "http://localhost"));
         String req = buffer.toString(Charset.forName("US-ASCII"));
         assertEquals("GET http://localhost/ HTTP/1.1\r\n", req);
+        buffer.release();
     }
 
     @Test
@@ -45,6 +46,18 @@ public class HttpRequestEncoderTest {
                 "http://localhost:9999?p1=v1"));
         String req = buffer.toString(Charset.forName("US-ASCII"));
         assertEquals("GET http://localhost:9999/?p1=v1 HTTP/1.1\r\n", req);
+        buffer.release();
+    }
+
+    @Test
+    public void testUriWithEmptyPath() throws Exception {
+        HttpRequestEncoder encoder = new HttpRequestEncoder();
+        ByteBuf buffer = Unpooled.buffer(64);
+        encoder.encodeInitialLine(buffer, new DefaultHttpRequest(HttpVersion.HTTP_1_1, HttpMethod.GET,
+                "http://localhost:9999/?p1=v1"));
+        String req = buffer.toString(Charset.forName("US-ASCII"));
+        assertEquals("GET http://localhost:9999/?p1=v1 HTTP/1.1\r\n", req);
+        buffer.release();
     }
 
     @Test
@@ -55,6 +68,7 @@ public class HttpRequestEncoderTest {
                 HttpMethod.GET, "http://localhost/"));
         String req = buffer.toString(Charset.forName("US-ASCII"));
         assertEquals("GET http://localhost/ HTTP/1.1\r\n", req);
+        buffer.release();
     }
 
     @Test
@@ -65,6 +79,7 @@ public class HttpRequestEncoderTest {
                 HttpMethod.GET, "/"));
         String req = buffer.toString(Charset.forName("US-ASCII"));
         assertEquals("GET / HTTP/1.1\r\n", req);
+        buffer.release();
     }
 
     @Test
@@ -75,6 +90,7 @@ public class HttpRequestEncoderTest {
                 HttpMethod.GET, ""));
         String req = buffer.toString(Charset.forName("US-ASCII"));
         assertEquals("GET / HTTP/1.1\r\n", req);
+        buffer.release();
     }
 
     @Test
@@ -85,5 +101,6 @@ public class HttpRequestEncoderTest {
                 HttpMethod.GET, "/?url=http://example.com"));
         String req = buffer.toString(Charset.forName("US-ASCII"));
         assertEquals("GET /?url=http://example.com HTTP/1.1\r\n", req);
+        buffer.release();
     }
 }

microbench/src/main/java/io/netty/handler/codec/http/HttpRequestEncoderInsertBenchmark.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2017 The Netty Project
+ *
+ * The Netty Project licenses this file to you 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.netty.handler.codec.http;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.ByteBufUtil;
+import io.netty.buffer.Unpooled;
+import io.netty.microbench.util.AbstractMicrobenchmark;
+import io.netty.util.AsciiString;
+import io.netty.util.CharsetUtil;
+import org.openjdk.jmh.annotations.Benchmark;
+import org.openjdk.jmh.annotations.Measurement;
+import org.openjdk.jmh.annotations.Scope;
+import org.openjdk.jmh.annotations.State;
+import org.openjdk.jmh.annotations.Warmup;
+
+import static io.netty.handler.codec.http.HttpConstants.SP;
+
+@State(Scope.Benchmark)
+@Warmup(iterations = 10)
+@Measurement(iterations = 20)
+public class HttpRequestEncoderInsertBenchmark extends AbstractMicrobenchmark {
+
+    private String uri = "http://localhost?eventType=CRITICAL&from=0&to=1497437160327&limit=10&offset=0";
+    private OldHttpRequestEncoder encoderOld = new OldHttpRequestEncoder();
+    private HttpRequestEncoder encoderNew = new HttpRequestEncoder();
+
+    @Benchmark
+    public ByteBuf oldEncoder() throws Exception {
+        ByteBuf buffer = Unpooled.buffer(100);
+        try {
+            encoderOld.encodeInitialLine(buffer, new DefaultHttpRequest(HttpVersion.HTTP_1_1,
+                    HttpMethod.GET, uri));
+            return buffer;
+        } finally {
+            buffer.release();
+        }
+    }
+
+    @Benchmark
+    public ByteBuf newEncoder() throws Exception {
+        ByteBuf buffer = Unpooled.buffer(100);
+        try {
+            encoderNew.encodeInitialLine(buffer, new DefaultHttpRequest(HttpVersion.HTTP_1_1,
+                    HttpMethod.GET, uri));
+            return buffer;
+        } finally {
+            buffer.release();
+        }
+    }
+
+    private class OldHttpRequestEncoder extends HttpObjectEncoder<HttpRequest> {
+        private static final char SLASH = '/';
+        private static final char QUESTION_MARK = '?';
+
+        @Override
+        public boolean acceptOutboundMessage(Object msg) throws Exception {
+            return super.acceptOutboundMessage(msg) && !(msg instanceof HttpResponse);
+        }
+
+        @Override
+        protected void encodeInitialLine(ByteBuf buf, HttpRequest request) throws Exception {
+            AsciiString method = request.method().asciiName();
+            ByteBufUtil.copy(method, method.arrayOffset(), buf, method.length());
+            buf.writeByte(SP);
+
+            // Add / as absolute path if no is present.
+            // See http://tools.ietf.org/html/rfc2616#section-5.1.2
+            String uri = request.uri();
+
+            if (uri.isEmpty()) {
+                uri += SLASH;
+            } else {
+                int start = uri.indexOf("://");
+                if (start != -1 && uri.charAt(0) != SLASH) {
+                    int startIndex = start + 3;
+                    // Correctly handle query params.
+                    // See https://github.com/netty/netty/issues/2732
+                    int index = uri.indexOf(QUESTION_MARK, startIndex);
+                    if (index == -1) {
+                        if (uri.lastIndexOf(SLASH) <= startIndex) {
+                            uri += SLASH;
+                        }
+                    } else {
+                        if (uri.lastIndexOf(SLASH, index) <= startIndex) {
+                            int len = uri.length();
+                            StringBuilder sb = new StringBuilder(len + 1);
+                            sb.append(uri, 0, index)
+                                    .append(SLASH)
+                                    .append(uri, index, len);
+                            uri = sb.toString();
+                        }
+                    }
+                }
+            }
+
+            buf.writeBytes(uri.getBytes(CharsetUtil.UTF_8));
+
+            buf.writeByte(SP);
+            request.protocolVersion().encode(buf);
+            buf.writeBytes(CRLF);
+        }
+    }
+}

microbench/src/main/java/io/netty/handler/codec/http/package-info.java

@@ -0,0 +1,19 @@
+/*
+ * Copyright 2017 The Netty Project
+ *
+ * The Netty Project licenses this file to you 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.
+ */
+/**
+ * Benchmarks for {@link io.netty.handler.codec.http}.
+ */
+package io.netty.handler.codec.http;