implement mutable ReadWriteLogRecord (#1482)

open-telemetry/opentelemetry-specification#3907 implements some new
requirements for logging:
- ReadWriteLogRecord can mutate (eg by processors)
- mutated ReadWriteLogRecord can be seen by later processors

This is a breaking change because LogRecordProcessorInterface onEmit param changes to by-reference

Logs/Exporter/InMemoryExporter.php

@@ -9,6 +9,7 @@
 use OpenTelemetry\SDK\Common\Future\CompletedFuture;
 use OpenTelemetry\SDK\Common\Future\FutureInterface;
 use OpenTelemetry\SDK\Logs\LogRecordExporterInterface;
+use OpenTelemetry\SDK\Logs\ReadableLogRecord;
 
 class InMemoryExporter implements LogRecordExporterInterface
 {
@@ -22,7 +23,7 @@ public function __construct(private readonly ArrayObject $storage = new ArrayObj
     public function export(iterable $batch, ?CancellationInterface $cancellation = null): FutureInterface
     {
         foreach ($batch as $record) {
-            $this->storage->append($record);
+            $this->storage->append($this->convert($record));
         }
 
         return new CompletedFuture(true);
@@ -42,4 +43,19 @@ public function getStorage(): ArrayObject
     {
         return $this->storage;
     }
+
+    private function convert(ReadableLogRecord $record): array
+    {
+        return [
+            'timestamp' => $record->getTimestamp(),
+            'observed_timestamp' => $record->getObservedTimestamp(),
+            'severity_number' => $record->getSeverityNumber(),
+            'severity_text' => $record->getSeverityText(),
+            'body' => $record->getBody(),
+            'attributes' => $record->getAttributes()->toArray(),
+            'trace_id' => $record->getSpanContext()?->getTraceId(),
+            'span_id' => $record->getSpanContext()?->getSpanId(),
+            'trace_flags' => $record->getSpanContext()?->getTraceFlags(),
+        ];
+    }
 }

Logs/LogRecordProcessorInterface.php

@@ -9,7 +9,7 @@
 
 interface LogRecordProcessorInterface
 {
-    public function onEmit(ReadWriteLogRecord $record, ?ContextInterface $context = null): void;
+    public function onEmit(ReadWriteLogRecord &$record, ?ContextInterface $context = null): void;
     public function shutdown(?CancellationInterface $cancellation = null): bool;
     public function forceFlush(?CancellationInterface $cancellation = null): bool;
 }

Logs/Processor/BatchLogRecordProcessor.php

@@ -134,7 +134,7 @@ public function __construct(
             });
     }
 
-    public function onEmit(ReadWriteLogRecord $record, ?ContextInterface $context = null): void
+    public function onEmit(ReadWriteLogRecord &$record, ?ContextInterface $context = null): void
     {
         if ($this->closed) {
             return;

Logs/Processor/MultiLogRecordProcessor.php

@@ -22,7 +22,7 @@ public function __construct(array $processors)
         }
     }
 
-    public function onEmit(ReadWriteLogRecord $record, ?ContextInterface $context = null): void
+    public function onEmit(ReadWriteLogRecord &$record, ?ContextInterface $context = null): void
     {
         foreach ($this->processors as $processor) {
             $processor->onEmit($record, $context);

Logs/Processor/NoopLogRecordProcessor.php

@@ -21,7 +21,7 @@ public static function getInstance(): self
     /**
      * @codeCoverageIgnore
      */
-    public function onEmit(ReadWriteLogRecord $record, ?ContextInterface $context = null): void
+    public function onEmit(ReadWriteLogRecord &$record, ?ContextInterface $context = null): void
     {
     }
 

Logs/Processor/SimpleLogRecordProcessor.php

@@ -19,7 +19,7 @@ public function __construct(private readonly LogRecordExporterInterface $exporte
     /**
      * @see https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/logs/sdk.md#onemit
      */
-    public function onEmit(ReadWriteLogRecord $record, ?ContextInterface $context = null): void
+    public function onEmit(ReadWriteLogRecord &$record, ?ContextInterface $context = null): void
     {
         $this->exporter->export([$record]);
     }

Logs/ReadWriteLogRecord.php

@@ -6,4 +6,17 @@
 
 class ReadWriteLogRecord extends ReadableLogRecord
 {
+    public function setAttribute(string $name, mixed $value): self
+    {
+        $this->attributesBuilder->offsetSet($name, $value);
+
+        return $this;
+    }
+
+    public function removeAttribute(string $key): self
+    {
+        $this->attributesBuilder->offsetUnset($key);
+
+        return $this;
+    }
 }

Logs/ReadableLogRecord.php

@@ -9,6 +9,7 @@
 use OpenTelemetry\API\Trace\SpanContextInterface;
 use OpenTelemetry\Context\Context;
 use OpenTelemetry\Context\ContextInterface;
+use OpenTelemetry\SDK\Common\Attribute\AttributesBuilderInterface;
 use OpenTelemetry\SDK\Common\Attribute\AttributesInterface;
 use OpenTelemetry\SDK\Common\Attribute\LogRecordAttributeValidator;
 use OpenTelemetry\SDK\Common\Instrumentation\InstrumentationScopeInterface;
@@ -20,7 +21,7 @@
  */
 class ReadableLogRecord extends LogRecord
 {
-    protected AttributesInterface $convertedAttributes;
+    protected AttributesBuilderInterface $attributesBuilder;
     protected SpanContextInterface $spanContext;
 
     public function __construct(
@@ -38,12 +39,10 @@ public function __construct(
         $this->severityNumber = $logRecord->severityNumber;
         $this->severityText = $logRecord->severityText;
 
-        //convert attributes now so that excess data is not sent to processors
-        $this->convertedAttributes = $this->loggerSharedState
+        $this->attributesBuilder = $this->loggerSharedState
             ->getLogRecordLimits()
             ->getAttributeFactory()
-            ->builder($logRecord->attributes, new LogRecordAttributeValidator())
-            ->build();
+            ->builder($logRecord->attributes, new LogRecordAttributeValidator());
     }
 
     public function getInstrumentationScope(): InstrumentationScopeInterface
@@ -96,6 +95,6 @@ public function getBody()
 
     public function getAttributes(): AttributesInterface
     {
-        return $this->convertedAttributes;
+        return $this->attributesBuilder->build();
     }
 }