To remove cross module internal utility usage from trace propagators

api/all/src/main/java/io/opentelemetry/api/internal/TemporaryBuffers.java → api/all/src/main/java/io/opentelemetry/api/impl/TemporaryBuffers.java

@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-package io.opentelemetry.api.internal;
+package io.opentelemetry.api.impl;
 
 /**
  * {@link ThreadLocal} buffers for use when creating new derived objects such as {@link String}s.
@@ -12,8 +12,8 @@
  * should get a temporary buffer, fill it with data, and finish by converting into the derived
  * object within the same method to avoid multiple usages of the same buffer.
  *
- * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
- * at any time.
+ * <p>This class is not intended for use by application developers. Its API is stable and will not
+ * be changed or removed in a backwards-incompatible manner.
  */
 public final class TemporaryBuffers {
 
@@ -24,6 +24,9 @@ public final class TemporaryBuffers {
    * {@code len} as this buffer will remain for the lifetime of the thread. The returned buffer will
    * not be zeroed and may be larger than the requested size, you must make sure to fill the entire
    * content to the desired value and set the length explicitly when converting to a {@link String}.
+   *
+   * @param len the minimum buffer capacity
+   * @return a reusable thread-local character buffer with capacity of at least {@code len}
    */
   public static char[] chars(int len) {
     char[] buffer = CHAR_ARRAY.get();

api/all/src/main/java/io/opentelemetry/api/internal/PercentEscaper.java

@@ -20,6 +20,7 @@
 
 package io.opentelemetry.api.internal;
 
+import io.opentelemetry.api.impl.TemporaryBuffers;
 import javax.annotation.CheckForNull;
 
 /**

api/all/src/main/java/io/opentelemetry/api/trace/SpanId.java

@@ -5,8 +5,8 @@
 
 package io.opentelemetry.api.trace;
 
+import io.opentelemetry.api.impl.TemporaryBuffers;
 import io.opentelemetry.api.internal.OtelEncodingUtils;
-import io.opentelemetry.api.internal.TemporaryBuffers;
 import io.opentelemetry.common.impl.ApiUsageLogger;
 import javax.annotation.concurrent.Immutable;
 

api/all/src/main/java/io/opentelemetry/api/trace/TraceId.java

@@ -5,8 +5,8 @@
 
 package io.opentelemetry.api.trace;
 
+import io.opentelemetry.api.impl.TemporaryBuffers;
 import io.opentelemetry.api.internal.OtelEncodingUtils;
-import io.opentelemetry.api.internal.TemporaryBuffers;
 import io.opentelemetry.common.impl.ApiUsageLogger;
 import javax.annotation.concurrent.Immutable;
 

api/all/src/main/java/io/opentelemetry/api/trace/propagation/W3CTraceContextPropagator.java

@@ -8,8 +8,8 @@
 import static io.opentelemetry.api.trace.propagation.internal.W3CTraceContextEncoding.decodeTraceState;
 import static io.opentelemetry.api.trace.propagation.internal.W3CTraceContextEncoding.encodeTraceState;
 
+import io.opentelemetry.api.impl.TemporaryBuffers;
 import io.opentelemetry.api.internal.OtelEncodingUtils;
-import io.opentelemetry.api.internal.TemporaryBuffers;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanContext;
 import io.opentelemetry.api.trace.SpanId;

api/all/src/test/java/io/opentelemetry/api/internal/TemporaryBuffersTest.java → api/all/src/test/java/io/opentelemetry/api/impl/TemporaryBuffersTest.java

@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: Apache-2.0
  */
 
-package io.opentelemetry.api.internal;
+package io.opentelemetry.api.impl;
 
 import static org.assertj.core.api.Assertions.assertThat;
 

docs/apidiffs/current_vs_latest/opentelemetry-api.txt

@@ -1,2 +1,5 @@
 Comparing source compatibility of opentelemetry-api-1.68.0-SNAPSHOT.jar against opentelemetry-api-1.67.0.jar
-No changes.
++++  NEW CLASS: PUBLIC(+) FINAL(+) io.opentelemetry.api.impl.TemporaryBuffers  (not serializable)
+	+++  CLASS FILE FORMAT VERSION: 52.0 <- n.a.
+	+++  NEW SUPERCLASS: java.lang.Object
+	+++  NEW METHOD: PUBLIC(+) STATIC(+) char[] chars(int)

extensions/trace-propagators/src/main/java/io/opentelemetry/extension/trace/propagation/B3PropagatorExtractorSingleHeader.java

@@ -5,7 +5,6 @@
 
 package io.opentelemetry.extension.trace.propagation;
 
-import io.opentelemetry.api.internal.StringUtils;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.context.Context;
 import io.opentelemetry.context.propagation.TextMapGetter;
@@ -34,7 +33,7 @@ public <C> Optional<Context> extract(
   private static <C> Optional<Context> extractSpanContextFromSingleHeader(
       Context context, @Nullable C carrier, TextMapGetter<C> getter) {
     String value = getter.get(carrier, B3Propagator.COMBINED_HEADER);
-    if (StringUtils.isNullOrEmpty(value)) {
+    if (value == null || value.isEmpty()) {
       return Optional.empty();
     }
 

extensions/trace-propagators/src/main/java/io/opentelemetry/extension/trace/propagation/B3PropagatorInjectorSingleHeader.java

@@ -7,7 +7,7 @@
 
 import static io.opentelemetry.extension.trace.propagation.B3Propagator.COMBINED_HEADER;
 
-import io.opentelemetry.api.internal.TemporaryBuffers;
+import io.opentelemetry.api.impl.TemporaryBuffers;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanContext;
 import io.opentelemetry.api.trace.SpanId;

extensions/trace-propagators/src/main/java/io/opentelemetry/extension/trace/propagation/Common.java

@@ -5,7 +5,6 @@
 
 package io.opentelemetry.extension.trace.propagation;
 
-import io.opentelemetry.api.internal.StringUtils;
 import io.opentelemetry.api.trace.SpanContext;
 import io.opentelemetry.api.trace.SpanId;
 import io.opentelemetry.api.trace.TraceFlags;
@@ -56,12 +55,13 @@ static SpanContext buildSpanContext(
   }
 
   static boolean isTraceIdValid(@Nullable String value) {
-    return !(StringUtils.isNullOrEmpty(value)
-        || (value.length() != MIN_TRACE_ID_LENGTH && value.length() != MAX_TRACE_ID_LENGTH)
-        || !TraceId.isValid(StringUtils.padLeft(value, TraceId.getLength())));
+    return value != null
+        && !value.isEmpty()
+        && (value.length() == MIN_TRACE_ID_LENGTH || value.length() == MAX_TRACE_ID_LENGTH)
+        && TraceId.isValid(StringUtils.padLeft(value, TraceId.getLength()));
   }
 
   static boolean isSpanIdValid(@Nullable String value) {
-    return !StringUtils.isNullOrEmpty(value) && SpanId.isValid(value);
+    return value != null && !value.isEmpty() && SpanId.isValid(value);
   }
 }

extensions/trace-propagators/src/main/java/io/opentelemetry/extension/trace/propagation/JaegerPropagator.java

@@ -7,8 +7,7 @@
 
 import io.opentelemetry.api.baggage.Baggage;
 import io.opentelemetry.api.baggage.BaggageBuilder;
-import io.opentelemetry.api.internal.StringUtils;
-import io.opentelemetry.api.internal.TemporaryBuffers;
+import io.opentelemetry.api.impl.TemporaryBuffers;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanContext;
 import io.opentelemetry.api.trace.SpanId;
@@ -184,7 +183,7 @@ public String toString() {
   private static <C> SpanContext getSpanContextFromHeader(
       @Nullable C carrier, TextMapGetter<C> getter) {
     String value = getter.get(carrier, PROPAGATION_HEADER);
-    if (StringUtils.isNullOrEmpty(value)) {
+    if (value == null || value.isEmpty()) {
       return SpanContext.getInvalid();
     }
 
@@ -419,14 +418,14 @@ private static SpanContext buildSpanContext(String traceId, String spanId, Strin
   }
 
   private static boolean isTraceIdValid(String value) {
-    return !(StringUtils.isNullOrEmpty(value) || value.length() > MAX_TRACE_ID_LENGTH);
+    return !value.isEmpty() && value.length() <= MAX_TRACE_ID_LENGTH;
   }
 
   private static boolean isSpanIdValid(String value) {
-    return !(StringUtils.isNullOrEmpty(value) || value.length() > MAX_SPAN_ID_LENGTH);
+    return !value.isEmpty() && value.length() <= MAX_SPAN_ID_LENGTH;
   }
 
   private static boolean isFlagsValid(String value) {
-    return !(StringUtils.isNullOrEmpty(value) || value.length() > MAX_FLAGS_LENGTH);
+    return !value.isEmpty() && value.length() <= MAX_FLAGS_LENGTH;
   }
 }

extensions/trace-propagators/src/main/java/io/opentelemetry/extension/trace/propagation/OtTracePropagator.java

@@ -10,7 +10,6 @@
 
 import io.opentelemetry.api.baggage.Baggage;
 import io.opentelemetry.api.baggage.BaggageBuilder;
-import io.opentelemetry.api.internal.StringUtils;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanContext;
 import io.opentelemetry.api.trace.SpanId;

extensions/trace-propagators/src/main/java/io/opentelemetry/extension/trace/propagation/StringUtils.java

@@ -0,0 +1,69 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.extension.trace.propagation;
+
+import java.util.Objects;
+import javax.annotation.concurrent.Immutable;
+
+/**
+ * Utilities for working with strings.
+ *
+ * <p>This class is internal and is hence not for public use. Its APIs are unstable and can change
+ * at any time.
+ */
+@Immutable
+final class StringUtils {
+
+  /**
+   * Returns {@code value} left-padded with zeroes to at least {@code minLength} characters.
+   *
+   * <p>If {@code value} is already at least {@code minLength} characters long, it is returned
+   * unchanged.
+   *
+   * @param value the string to pad
+   * @param minLength the minimum length of the returned string
+   * @return the padded string, or {@code value} if it already meets the minimum length
+   */
+  static String padLeft(String value, int minLength) {
+    return padStart(value, minLength, '0');
+  }
+
+  /**
+   * Returns a string, of length at least {@code minLength}, consisting of {@code string} prepended
+   * with as many copies of {@code padChar} as are necessary to reach that length. For example,
+   *
+   * <ul>
+   *   <li>{@code padStart("7", 3, '0')} returns {@code "007"}
+   *   <li>{@code padStart("2010", 3, '0')} returns {@code "2010"}
+   * </ul>
+   *
+   * <p>See {@link java.util.Formatter} for a richer set of formatting capabilities.
+   *
+   * <p>This method was copied almost verbatim from Guava library method
+   * com.google.common.base.Strings#padStart(java.lang.String, int, char).
+   *
+   * @param string the string which should appear at the end of the result
+   * @param minLength the minimum length the resulting string must have. Can be zero or negative, in
+   *     which case the input string is always returned.
+   * @param padChar the character to insert at the beginning of the result until the minimum length
+   *     is reached
+   * @return the padded string
+   */
+  private static String padStart(String string, int minLength, char padChar) {
+    Objects.requireNonNull(string);
+    if (string.length() >= minLength) {
+      return string;
+    }
+    StringBuilder sb = new StringBuilder(minLength);
+    for (int i = string.length(); i < minLength; i++) {
+      sb.append(padChar);
+    }
+    sb.append(string);
+    return sb.toString();
+  }
+
+  private StringUtils() {}
+}

extensions/trace-propagators/src/test/java/io/opentelemetry/extension/trace/propagation/B3PropagatorTest.java

@@ -8,7 +8,6 @@
 import static io.opentelemetry.extension.trace.propagation.B3Propagator.DEBUG_CONTEXT_KEY;
 import static org.assertj.core.api.Assertions.assertThat;
 
-import io.opentelemetry.api.internal.StringUtils;
 import io.opentelemetry.api.trace.Span;
 import io.opentelemetry.api.trace.SpanContext;
 import io.opentelemetry.api.trace.SpanId;
@@ -236,6 +235,15 @@ void extract_InvalidTraceId_NotHex() {
     verifyInvalidBehavior(invalidHeaders);
   }
 
+  @Test
+  void extract_EmptyTraceId() {
+    Map<String, String> invalidHeaders = new LinkedHashMap<>();
+    invalidHeaders.put(B3Propagator.TRACE_ID_HEADER, "");
+    invalidHeaders.put(B3Propagator.SPAN_ID_HEADER, SPAN_ID);
+    invalidHeaders.put(B3Propagator.SAMPLED_HEADER, Common.TRUE_INT);
+    verifyInvalidBehavior(invalidHeaders);
+  }
+
   @Test
   void extract_InvalidTraceId_TooShort() {
     Map<String, String> invalidHeaders = new LinkedHashMap<>();
@@ -272,6 +280,15 @@ void extract_InvalidSpanId_NotHex() {
     verifyInvalidBehavior(invalidHeaders);
   }
 
+  @Test
+  void extract_EmptySpanId() {
+    Map<String, String> invalidHeaders = new LinkedHashMap<>();
+    invalidHeaders.put(B3Propagator.TRACE_ID_HEADER, TRACE_ID);
+    invalidHeaders.put(B3Propagator.SPAN_ID_HEADER, "");
+    invalidHeaders.put(B3Propagator.SAMPLED_HEADER, Common.TRUE_INT);
+    verifyInvalidBehavior(invalidHeaders);
+  }
+
   @Test
   void extract_InvalidSpanId_TooShort() {
     Map<String, String> invalidHeaders = new LinkedHashMap<>();

extensions/trace-propagators/src/test/java/io/opentelemetry/extension/trace/propagation/CommonTest.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.extension.trace.propagation;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import org.junit.jupiter.api.Test;
+
+class CommonTest {
+
+  @Test
+  void isTraceIdValid() {
+    assertThat(Common.isTraceIdValid(null)).isFalse();
+    assertThat(Common.isTraceIdValid("")).isFalse();
+    assertThat(Common.isTraceIdValid("0000000000000001")).isTrue();
+    assertThat(Common.isTraceIdValid("00000000000000000000000000000001")).isTrue();
+    assertThat(Common.isTraceIdValid("000000000000000")).isFalse();
+    assertThat(Common.isTraceIdValid("0000000000000000")).isFalse();
+  }
+
+  @Test
+  void isSpanIdValid() {
+    assertThat(Common.isSpanIdValid(null)).isFalse();
+    assertThat(Common.isSpanIdValid("")).isFalse();
+    assertThat(Common.isSpanIdValid("0000000000000001")).isTrue();
+    assertThat(Common.isSpanIdValid("0000000000000000")).isFalse();
+  }
+}

extensions/trace-propagators/src/test/java/io/opentelemetry/extension/trace/propagation/JaegerPropagatorTest.java

@@ -274,6 +274,15 @@ void extract_InvalidTraceId() {
     verifyInvalidBehavior(invalidHeaders);
   }
 
+  @Test
+  void extract_EmptyTraceId() {
+    Map<String, String> invalidHeaders = new LinkedHashMap<>();
+    invalidHeaders.put(
+        PROPAGATION_HEADER, generateTraceIdHeaderValue("", SPAN_ID, DEPRECATED_PARENT_SPAN, "0"));
+
+    verifyInvalidBehavior(invalidHeaders);
+  }
+
   @Test
   void extract_InvalidTraceId_Size() {
     Map<String, String> invalidHeaders = new LinkedHashMap<>();
@@ -294,6 +303,15 @@ void extract_InvalidSpanId() {
     verifyInvalidBehavior(invalidHeaders);
   }
 
+  @Test
+  void extract_EmptySpanId() {
+    Map<String, String> invalidHeaders = new LinkedHashMap<>();
+    invalidHeaders.put(
+        PROPAGATION_HEADER, generateTraceIdHeaderValue(TRACE_ID, "", DEPRECATED_PARENT_SPAN, "0"));
+
+    verifyInvalidBehavior(invalidHeaders);
+  }
+
   @Test
   void extract_InvalidSpanId_Size() {
     Map<String, String> invalidHeaders = new LinkedHashMap<>();

extensions/trace-propagators/src/test/java/io/opentelemetry/extension/trace/propagation/StringUtilsTest.java

@@ -0,0 +1,32 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+package io.opentelemetry.extension.trace.propagation;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatThrownBy;
+
+import org.junit.jupiter.api.Test;
+
+class StringUtilsTest {
+
+  @Test
+  void padLeft() {
+    assertThat(StringUtils.padLeft("value", 10)).isEqualTo("00000value");
+  }
+
+  @Test
+  void padLeft_length_does_not_exceed_minimum() {
+    assertThat(StringUtils.padLeft("value", 3)).isEqualTo("value");
+    assertThat(StringUtils.padLeft("value", -10)).isEqualTo("value");
+    assertThat(StringUtils.padLeft("value", 0)).isEqualTo("value");
+  }
+
+  @Test
+  void padLeft_throws_for_null_value() {
+    assertThatThrownBy(() -> StringUtils.padLeft(null, 10))
+        .isInstanceOf(NullPointerException.class);
+  }
+}

sdk-extensions/incubator/src/main/java/io/opentelemetry/sdk/extension/incubator/trace/samplers/OtelTraceState.java

@@ -12,8 +12,8 @@
 import static io.opentelemetry.sdk.extension.incubator.trace.samplers.ImmutableSamplingIntent.isValidRandomValue;
 import static io.opentelemetry.sdk.extension.incubator.trace.samplers.ImmutableSamplingIntent.isValidThreshold;
 
+import io.opentelemetry.api.impl.TemporaryBuffers;
 import io.opentelemetry.api.internal.OtelEncodingUtils;
-import io.opentelemetry.api.internal.TemporaryBuffers;
 import io.opentelemetry.api.trace.TraceState;
 import java.util.ArrayList;
 import java.util.Collections;