Add log processors to the builder so LogSinkSdkProvider is immutable (#3751)

* Add log processors to the builder so LogSinkSdkProvider is immutable

* Add api diff

sdk/logs/src/main/java/io/opentelemetry/sdk/logs/LogSinkSdkProvider.java

@@ -10,11 +10,10 @@ import io.opentelemetry.sdk.logs.data.LogRecord;
 import java.util.ArrayList;
 import java.util.Collection;
 import java.util.List;
-import java.util.Objects;
 
 public final class LogSinkSdkProvider {
   private final LogSink logSink = new SdkLogSink();
-  private final List<LogProcessor> processors = new ArrayList<>();
+  private final List<LogProcessor> processors;
 
   /**
    * Returns a new {@link LogSinkSdkProviderBuilder} for this class.
@@ -25,17 +24,15 @@ public final class LogSinkSdkProvider {
     return new LogSinkSdkProviderBuilder();
   }
 
-  LogSinkSdkProvider() {}
+  LogSinkSdkProvider(List<LogProcessor> processors) {
+    this.processors = processors;
+  }
 
   public LogSink get(String instrumentationName, String instrumentationVersion) {
     // Currently there is no differentiation by instrumentation library
     return logSink;
   }
 
-  public void addLogProcessor(LogProcessor processor) {
-    processors.add(Objects.requireNonNull(processor, "Processor can not be null"));
-  }
-
   /**
    * Flushes all attached processors.
    *

sdk/logs/src/main/java/io/opentelemetry/sdk/logs/LogSinkSdkProviderBuilder.java

@@ -5,10 +5,32 @@
 
 package io.opentelemetry.sdk.logs;
 
+import static java.util.Objects.requireNonNull;
+
+import io.opentelemetry.sdk.logs.data.LogRecord;
+import java.util.ArrayList;
+import java.util.List;
+
 public final class LogSinkSdkProviderBuilder {
+
+  private final List<LogProcessor> logProcessors = new ArrayList<>();
+
   LogSinkSdkProviderBuilder() {}
 
+  /**
+   * Add a LogProcessor to the log pipeline that will be built. {@link LogProcessor} will be called
+   * each time a {@link LogRecord} is offered to a {@link LogSink}.
+   *
+   * @param processor the processor to be added to the processing pipeline.
+   * @return this
+   */
+  public LogSinkSdkProviderBuilder addLogProcessor(LogProcessor processor) {
+    requireNonNull(processor, "processor can not be null");
+    logProcessors.add(processor);
+    return this;
+  }
+
   public LogSinkSdkProvider build() {
-    return new LogSinkSdkProvider();
+    return new LogSinkSdkProvider(logProcessors);
   }
 }

sdk/logs/src/test/java/io/opentelemetry/sdk/logs/LogSinkSdkProviderTest.java

@@ -28,8 +28,7 @@ class LogSinkSdkProviderTest {
   void testLogSinkSdkProvider() {
     TestLogExporter exporter = new TestLogExporter();
     LogProcessor processor = BatchLogProcessor.builder(exporter).build();
-    LogSinkSdkProvider provider = LogSinkSdkProvider.builder().build();
-    provider.addLogProcessor(processor);
+    LogSinkSdkProvider provider = LogSinkSdkProvider.builder().addLogProcessor(processor).build();
     LogSink sink = provider.get("test", "0.1a");
     LogRecord log = createLog(Severity.ERROR, "test");
     sink.offer(log);
@@ -48,8 +47,7 @@ class LogSinkSdkProviderTest {
             .setMaxExportBatchSize(5)
             .setMaxQueueSize(10)
             .build();
-    LogSinkSdkProvider provider = LogSinkSdkProvider.builder().build();
-    provider.addLogProcessor(processor);
+    LogSinkSdkProvider provider = LogSinkSdkProvider.builder().addLogProcessor(processor).build();
     LogSink sink = provider.get("test", "0.1a");
 
     for (int i = 0; i < 7; i++) {
@@ -80,8 +78,7 @@ class LogSinkSdkProviderTest {
             .setMaxExportBatchSize(5)
             .setMaxQueueSize(10)
             .build();
-    LogSinkSdkProvider provider = LogSinkSdkProvider.builder().build();
-    provider.addLogProcessor(processor);
+    LogSinkSdkProvider provider = LogSinkSdkProvider.builder().addLogProcessor(processor).build();
     LogSink sink = provider.get("test", "0.1a");
 
     long start = System.currentTimeMillis();
@@ -99,9 +96,11 @@ class LogSinkSdkProviderTest {
   void testMultipleProcessors() {
     TestLogProcessor processorOne = new TestLogProcessor();
     TestLogProcessor processorTwo = new TestLogProcessor();
-    LogSinkSdkProvider provider = LogSinkSdkProvider.builder().build();
-    provider.addLogProcessor(processorOne);
-    provider.addLogProcessor(processorTwo);
+    LogSinkSdkProvider provider =
+        LogSinkSdkProvider.builder()
+            .addLogProcessor(processorOne)
+            .addLogProcessor(processorTwo)
+            .build();
     LogSink sink = provider.get("test", "0.1");
     LogRecord record = createLog(Severity.INFO, "test");
     sink.offer(record);