In the above specification, a tracestate entry is sometimes called member. The key of the
+ * entry is most often called vendor name, but it is more about a tracing system vs something vendor
+ * specific. We choose to not use the term vendor as this is open source code. Instead, we use term
+ * entry (key/value).
+ */
+final class TracestateFormat implements EntrySplitter.Handler See https://www.w3.org/TR/trace-context-1/#key
+ */
+ // Logic to narrow error messages is intentionally deferred.
+ // Performance matters as this could be called up to 32 times per header.
+ boolean validateKey(CharSequence buffer, int beginKey, int endKey) {
+ int length = endKey - beginKey;
+ if (length == 0) return logOrThrow("Invalid key: empty", shouldThrow);
+ if (length > 256) return logOrThrow("Invalid key: too large", shouldThrow);
+ char first = buffer.charAt(beginKey);
+ if (!isLetterOrNumber(first)) {
+ return logOrThrow("Invalid key: must start with a-z 0-9", shouldThrow);
+ }
+
+ for (int i = beginKey + 1; i < endKey; i++) {
+ char c = buffer.charAt(i);
+
+ if (c > LAST_VALID_KEY_CHAR || !VALID_KEY_CHARS[c]) {
+ return logOrThrow("Invalid key: valid characters are: a-z 0-9 _ - * / @", shouldThrow);
+ }
+ }
+ return true;
+ }
+
+ boolean validateValue(CharSequence buffer, int beginValue, int endValue) {
+ // TODO: empty and whitespace-only allowed Ex. 'foo=' or 'foo= '
+ // There are likely other rules, so figure out what they are and implement.
+ return true;
+ }
+
+ static boolean logOrThrow(String msg, boolean shouldThrow) {
+ if (shouldThrow) throw new IllegalArgumentException(msg);
+ Platform.get().log(msg, null);
+ return false;
+ }
+}
diff --git a/propagation/w3c/src/test/java/brave/propagation/w3c/TraceContextPropagationClassLoaderTest.java b/propagation/w3c/src/test/java/brave/propagation/w3c/TraceContextPropagationClassLoaderTest.java
new file mode 100644
index 0000000000..565cd0dee5
--- /dev/null
+++ b/propagation/w3c/src/test/java/brave/propagation/w3c/TraceContextPropagationClassLoaderTest.java
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2013-2020 The OpenZipkin Authors
+ *
+ * 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 brave.propagation.w3c;
+
+import brave.propagation.Propagation;
+import brave.propagation.TraceContext;
+import brave.propagation.TraceContext.Extractor;
+import brave.propagation.TraceContext.Injector;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import org.junit.Test;
+
+import static brave.test.util.ClassLoaders.assertRunIsUnloadable;
+
+public class TraceContextPropagationClassLoaderTest {
+ @Test public void unloadable_afterBasicUsage() {
+ assertRunIsUnloadable(BasicUsage.class, getClass().getClassLoader());
+ }
+
+ static class BasicUsage implements Runnable {
+ @Override public void run() {
+ Propagation.Factory propagation = TraceContextPropagation.create();
+ Injector