optimization on PrintWriter

instrumentation/servlet/servlet-3.0/javaagent-unit-tests/src/test/java/io/opentelemetry/javaagent/instrumentation/servlet/v3_0/snippet/SnippetServletOutputStreamTest.java

@@ -23,7 +23,7 @@ class SnippetServletOutputStreamTest {
  @Test
  void testInjectionForStringContainHeadTag() throws IOException {
  String snippet = "\n <script type=\"text/javascript\"> Test </script>";
- byte[] html = readFileBytes("beforeSnippetInjection.html", UTF_8);
+ byte[] html = readFileBytes("beforeSnippetInjection.html");
 
  InjectionState obj = createInjectionStateForTesting(snippet, UTF_8);
  InMemoryServletOutputStream out = new InMemoryServletOutputStream();
@@ -33,22 +33,22 @@ void testInjectionForStringContainHeadTag() throws IOException {
  assertThat(obj.getHeadTagBytesSeen()).isEqualTo(-1);
  assertThat(injected).isEqualTo(true);
 
- byte[] expectedHtml = readFileBytes("afterSnippetInjection.html", UTF_8);
+ byte[] expectedHtml = readFileBytes("afterSnippetInjection.html");
  assertThat(out.getBytes()).isEqualTo(expectedHtml);
  }
 
  @Test
  void testInjectionForChinese() throws IOException {
  String snippet = "\n <script type=\"text/javascript\"> Test </script>";
- byte[] html = readFileBytes("beforeSnippetInjectionChinese.html", UTF_8);
+ byte[] html = readFileBytes("beforeSnippetInjectionChinese.html");
 
  InjectionState obj = createInjectionStateForTesting(snippet, UTF_8);
  InMemoryServletOutputStream out = new InMemoryServletOutputStream();
 
  OutputStreamSnippetInjectionHelper helper = new OutputStreamSnippetInjectionHelper(snippet);
  boolean injected = helper.handleWrite(obj, out, html, 0, html.length);
 
- byte[] expectedHtml = readFileBytes("afterSnippetInjectionChinese.html", UTF_8);
+ byte[] expectedHtml = readFileBytes("afterSnippetInjectionChinese.html");
  assertThat(injected).isTrue();
  assertThat(obj.getHeadTagBytesSeen()).isEqualTo(-1);
  assertThat(out.getBytes()).isEqualTo(expectedHtml);
@@ -57,7 +57,7 @@ void testInjectionForChinese() throws IOException {
  @Test
  void testInjectionForStringWithoutHeadTag() throws IOException {
  String snippet = "\n <script type=\"text/javascript\"> Test </script>";
- byte[] html = readFileBytes("htmlWithoutHeadTag.html", UTF_8);
+ byte[] html = readFileBytes("htmlWithoutHeadTag.html");
 
  InjectionState obj = createInjectionStateForTesting(snippet, UTF_8);
  InMemoryServletOutputStream out = new InMemoryServletOutputStream();

instrumentation/servlet/servlet-3.0/javaagent-unit-tests/src/test/java/io/opentelemetry/javaagent/instrumentation/servlet/v3_0/snippet/TestUtil.java

@@ -10,11 +10,10 @@
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.nio.charset.Charset;
 
 public class TestUtil {
 
- public static byte[] readFileBytes(String resourceName, Charset charsetName) throws IOException {
+ public static byte[] readFileBytes(String resourceName) throws IOException {
  InputStream in =
  SnippetPrintWriterTest.class.getClassLoader().getResourceAsStream(resourceName);
  ByteArrayOutputStream result = new ByteArrayOutputStream();
@@ -27,7 +26,7 @@ public static byte[] readFileBytes(String resourceName, Charset charsetName) thr
  }
 
  public static String readFile(String resourceName) throws IOException {
- return new String(readFileBytes(resourceName, UTF_8), UTF_8);
+ return new String(readFileBytes(resourceName), UTF_8);
  }
 
  private TestUtil() {}

instrumentation/servlet/servlet-3.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/servlet/v3_0/snippet/OutputStreamSnippetInjectionHelper.java

@@ -45,7 +45,8 @@ public boolean handleWrite(
  if (!endOfHeadTagFound) {
  return false;
  }
- state.setHeadTagWritten(); // set before write to avoid recursive loop
+ // set before write to avoid recursive loop
+ state.setHeadTagWritten();
  if (state.getWrapper().isNotSafeToInject()) {
  return false;
  }
@@ -71,7 +72,8 @@ public boolean handleWrite(InjectionState state, OutputStream out, int b) throws
  if (!state.processByte(b)) {
  return false;
  }
- state.setHeadTagWritten(); // set before write to avoid recursive loop
+ // set before write to avoid recursive loop
+ state.setHeadTagWritten();
 
  if (state.getWrapper().isNotSafeToInject()) {
  return false;

instrumentation/servlet/servlet-3.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/servlet/v3_0/snippet/SnippetInjectingPrintWriter.java

@@ -20,6 +20,10 @@ public SnippetInjectingPrintWriter(
 
  @Override
  public void write(String s, int off, int len) {
+ if (state.isHeadTagWritten()) {
+ super.write(s, off, len);
+ return;
+ }
  for (int i = off; i < s.length() && i - off < len; i++) {
  write(s.charAt(i));
  }
@@ -35,7 +39,8 @@ public void write(int b) {
  if (!endOfHeadTagFound) {
  return;
  }
- state.setHeadTagWritten(); // set before write to avoid recursive loop
+ // set before write to avoid recursive loop
+ state.setHeadTagWritten();
  if (state.getWrapper().isNotSafeToInject()) {
  return;
  }
@@ -45,6 +50,10 @@ public void write(int b) {
 
  @Override
  public void write(char[] buf, int off, int len) {
+ if (state.isHeadTagWritten()) {
+ super.write(buf, off, len);
+ return;
+ }
  for (int i = off; i < buf.length && i - off < len; i++) {
  write(buf[i]);
  }

instrumentation/servlet/servlet-3.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/servlet/v3_0/snippet/SnippetInjectingResponseWrapper.java

@@ -180,6 +180,6 @@ public boolean isNotSafeToInject() {
  // if content-length was set and response was already committed (headers sent to the client),
  // then it is not safe to inject because the content-length header cannot be updated to account
  // for the snippet length
- return isCommitted() && (contentLength != UNSET);
+ return contentLength != UNSET && isCommitted();
  }
 }