Remove access of span.attributes

lib/src/api/common/attribute.dart

@@ -1,34 +1,48 @@
+import 'package:opentelemetry/src/sdk/internal/utils.dart';
+
 /// A representation of a single piece of metadata attached to trace span.
 class Attribute {
   final String key;
   final Object value;
 
   /// Create an Attribute from a String value.
-  Attribute.fromString(this.key, String this.value);
+  Attribute.fromString(this.key, String this.value) {
+    Utils.checkArgument(key != null, "key can't be null");
+  }
 
   /// Create an Attribute from a boolean value.
   // ignore: avoid_positional_boolean_parameters
-  Attribute.fromBoolean(this.key, bool this.value);
+  Attribute.fromBoolean(this.key, bool this.value) {
+    Utils.checkArgument(key != null, "key can't be null");
+  }
 
   /// Create an Attribute from a double-precision floating-point value.
-  Attribute.fromDouble(this.key, double this.value);
+  Attribute.fromDouble(this.key, double this.value) {
+    Utils.checkArgument(key != null, "key can't be null");
+  }
 
   /// Create an Attribute from an integer value.
-  Attribute.fromInt(this.key, int this.value);
+  Attribute.fromInt(this.key, int this.value) {
+    Utils.checkArgument(key != null, "key can't be null");
+  }
 
   /// Create an Attribute from a list of String values.
-  Attribute.fromStringList(this.key, List<String> this.value);
+  Attribute.fromStringList(this.key, List<String> this.value) {
+    Utils.checkArgument(key != null, "key can't be null");
+  }
 
   /// Create an Attribute from a list of boolean values.
-  Attribute.fromBooleanList(this.key, List<bool> this.value);
+  Attribute.fromBooleanList(this.key, List<bool> this.value) {
+    Utils.checkArgument(key != null, "key can't be null");
+  }
 
   /// Create an Attribute from a list of double-precision floating-point values.
-  Attribute.fromDoubleList(this.key, List<double> this.value);
+  Attribute.fromDoubleList(this.key, List<double> this.value) {
+    Utils.checkArgument(key != null, "key can't be null");
+  }
 
   /// Create an Attribute from a list of integer values.
-  Attribute.fromIntList(this.key, List<int> this.value);
-
-  ///Create an Attribute from an object.
-  ///Do we need to do a type check of value?
-  Attribute.fromObject(this.key, this.value);
+  Attribute.fromIntList(this.key, List<int> this.value) {
+    Utils.checkArgument(key != null, "key can't be null");
+  }
 }

lib/src/api/common/attributes.dart

@@ -1,45 +1,27 @@
 import 'attribute.dart';
-import 'attribute_util.dart';
 
 /// A representation of a collection of metadata attached to a trace span.
-/// From OpenTelemetry Specification about attributes,
-/// https://opentelemetry.io/docs/reference/specification/common/common/#exempt-entities
-/// Some attributes are exempt from limits, in this case, it is set as -1.
-/// If it is 0, it is considered as not accepting attributes.
 class Attributes {
   Map<String, Object> _attributes = {};
-  int _maxNumAttributes;
-  int _maxNumAttributesLength;
 
   /// Instantiate an empty Attributes.
-  Attributes.empty([int maxNumAttributes, int maxNumAttributesLength]) {
+  Attributes.empty() {
     _attributes = {};
-    _maxNumAttributes = maxNumAttributes ?? -1; // no restrain limits
-    _maxNumAttributesLength = maxNumAttributesLength ?? -1;
   }
 
   /// Retrieve the value associated with the Attribute with key [key].
   Object get(String key) => _attributes[key];
 
+  ///
+  int get length => _attributes.length;
+
   /// Retrieve the keys of all Attributes in this collection.
   Iterable<String> get keys => _attributes.keys;
 
-  ///Retrieve the number of attributes contained in this.
-  int get size => _attributes.length;
-
   /// Add an Attribute [attribute].
   /// If an Attribute with the same key already exists, it will be overwritten.
-  /// If the number of attributes is too many, it will drop it silently.
-  /// If the attribute value length is too long, it will be truncated.
   void add(Attribute attribute) {
-    if (_maxNumAttributes == -1) {
-      _attributes[attribute.key] = attribute.value;
-      return;
-    }
-    if (_attributes.length >= _maxNumAttributes &&
-        !_attributes.containsKey(attribute.key)) return;
-    _attributes[attribute.key] = AttributeUtil.applyAttributeLengthLimit(
-        attribute.value, _maxNumAttributesLength);
+    _attributes[attribute.key] = attribute.value;
   }
 
   /// Add all Attributes in List [attributes].

lib/src/api/trace/nonrecording_span.dart

@@ -16,11 +16,10 @@ class NonRecordingSpan implements api.Span {
 
   NonRecordingSpan(this._spanContext);
 
-  @override
   api.Attributes get attributes => _attributes;
 
   @override
-  set attributes(api.Attributes attributes) {
+  void setAttributes(api.Attributes attributes) {
     return;
   }
 

lib/src/api/trace/span.dart

@@ -45,10 +45,7 @@ abstract class Span {
   api.SpanStatus get status;
 
   /// Set metadata to be included on this span.
-  set attributes(api.Attributes attributes);
-
-  /// Retrieve metadata included on this span.
-  api.Attributes get attributes;
+  void setAttributes(api.Attributes attributes);
 
   /// Retrieve the resource on this span.
   api.Resource get resource;

lib/src/sdk/internal/utils.dart

@@ -2,6 +2,6 @@ class Utils {
   ///Check argument
   // ignore: avoid_positional_boolean_parameters
   static void checkArgument(bool isValid, String errorMessage) {
-    if (!isValid) throw Exception(errorMessage);
+    if (!isValid) throw ArgumentError(errorMessage);
   }
 }

lib/src/sdk/trace/exporters/collector_exporter.dart

@@ -6,6 +6,7 @@ import 'opentelemetry/proto/collector/trace/v1/trace_service.pb.dart'
 import 'opentelemetry/proto/trace/v1/trace.pb.dart' as pb_trace;
 import 'opentelemetry/proto/resource/v1/resource.pb.dart' as pb_resource;
 import 'opentelemetry/proto/common/v1/common.pb.dart' as pb_common;
+import '../span.dart' as spansdk;
 
 class CollectorExporter implements api.SpanExporter {
   Uri uri;
@@ -74,7 +75,7 @@ class CollectorExporter implements api.SpanExporter {
     return rss;
   }
 
-  pb_trace.Span _spanToProtobuf(api.Span span) {
+  pb_trace.Span _spanToProtobuf(spansdk.Span span) {
     pb_trace.Status_StatusCode statusCode;
     switch (span.status.code) {
       case api.StatusCode.unset:

lib/src/sdk/trace/span.dart

@@ -2,6 +2,7 @@ import 'package:fixnum/fixnum.dart';
 import 'package:opentelemetry/src/sdk/trace/span_limits.dart';
 
 import '../../../api.dart' as api;
+import '../../../api.dart';
 
 /// A representation of a single operation within a trace.
 class Span implements api.Span {
@@ -25,14 +26,13 @@ class Span implements api.Span {
   /// Construct a [Span].
   Span(this.name, this._spanContext, this._parentSpanId, this._processors,
       this._resource, this._instrumentationLibrary,
-      {api.Attributes attributes, SpanLimits limits}) {
+      {api.Attributes attributes, SpanLimits spanlimits}) {
     _startTime = Int64(DateTime.now().toUtc().microsecondsSinceEpoch);
 
-    if (limits != null) _spanLimits = limits;
-    _attributes = api.Attributes.empty(
-        _spanLimits.maxNumAttributes, _spanLimits.maxNumAttributeLength);
+    if (spanlimits != null) _spanLimits = spanlimits;
+    _attributes = Attributes.empty();
     if (attributes != null) {
-      _setAttributes(attributes);
+      setAttributes(attributes);
     }
 
     for (var i = 0; i < _processors.length; i++) {
@@ -86,59 +86,82 @@ class Span implements api.Span {
   api.InstrumentationLibrary get instrumentationLibrary =>
       _instrumentationLibrary;
 
-  @override
+  /// Retrieve metadata included on this span.
   api.Attributes get attributes => _attributes;
 
-  ///not sure about this part, if span.attributes = attributes, then we need to
-  ///discard all previous added attributes,create a new one?
   @override
-  set attributes(api.Attributes attributes) {
-    _setAttributes(attributes);
-  }
+  void setAttributes(api.Attributes attributes) {
+    if (_spanLimits.maxNumAttributes == 0) return;
 
-  void _setAttributes(api.Attributes attributes) {
     for (final key in attributes.keys) {
-      final val = attributes.get(key);
-
-      //final reBuild = _reBuildAttribute(key, val);
-      //we also could do this if we add an API in attribute.dart
-      final reBuild = api.Attribute.fromObject(key, val);
+      final obj = _attributes.get(key);
+      //If current attributes.length is equal or greater than maxNumAttributes and
+      //key is not in current map, drop it.
+      if (_attributes.length >= _spanLimits.maxNumAttributes && obj == null) {
+        continue;
+      }
+
+      //otherwise rebuild this attribute, truncate it and put it in
+      final reBuild = _reBuildAttribute(key, attributes.get(key));
       _attributes.add(reBuild);
     }
   }
 
   /// reBuild an attribute, this way it is tightly coupled with the type we supported,
   /// if later we added more types, then we need to change this method.
-  // api.Attribute _reBuildAttribute(String key, dynamic value) {
-  //   if (value is bool) {
-  //     return api.Attribute.fromBoolean(key, value);
-  //   } else if (value is List<bool>) {
-  //     return api.Attribute.fromBooleanList(key, value);
-  //   } else if (value is int) {
-  //     return api.Attribute.fromInt(key, value);
-  //   } else if (value is List<int>) {
-  //     return api.Attribute.fromIntList(key, value);
-  //   } else if (value is double) {
-  //     return api.Attribute.fromDouble(key, value);
-  //   } else if (value is List<double>) {
-  //     return api.Attribute.fromDoubleList(key, value);
-  //   } else if (value is String) {
-  //     return api.Attribute.fromString(key, value);
-  //   } else if (value is List<String>) {
-  //     return api.Attribute.fromStringList(key, value);
-  //   } else {
-  //     throw Exception("No responding type with this attribute's value");
-  //   }
-  // }
+  api.Attribute _reBuildAttribute(String key, dynamic value) {
+    if (value is bool) {
+      return api.Attribute.fromBoolean(key, value);
+    } else if (value is List<bool>) {
+      return api.Attribute.fromBooleanList(key, value);
+    } else if (value is int) {
+      return api.Attribute.fromInt(key, value);
+    } else if (value is List<int>) {
+      return api.Attribute.fromIntList(key, value);
+    } else if (value is double) {
+      return api.Attribute.fromDouble(key, value);
+    } else if (value is List<double>) {
+      return api.Attribute.fromDoubleList(key, value);
+    } else if (value is String) {
+      return api.Attribute.fromString(key,
+          _applyAttributeLengthLimit(value, _spanLimits.maxNumAttributeLength));
+    } else if (value is List<String>) {
+      for (var i = 0; i < value.length; i++) {
+        value[i] = _applyAttributeLengthLimit(
+            value[i], _spanLimits.maxNumAttributeLength);
+      }
+      return api.Attribute.fromStringList(key, value);
+    } else {
+      throw Exception("No responding type with this attribute's value");
+    }
+  }
 
   @override
   void recordException(dynamic exception, {StackTrace stackTrace}) {
+    // ignore: todo
     // TODO: O11Y-1531: Consider integration of Events here.
     setStatus(api.StatusCode.error, description: exception.toString());
-    attributes.addAll([
+    _attributes.addAll([
       api.Attribute.fromBoolean('error', true),
       api.Attribute.fromString('exception', exception.toString()),
       api.Attribute.fromString('stacktrace', stackTrace.toString()),
     ]);
   }
+
+  //Truncate just strings which length is longer than configuration.
+  //Reference: https://github.com/open-telemetry/opentelemetry-java/blob/14ffacd1cdd22f5aa556eeda4a569c7f144eadf2/sdk/common/src/main/java/io/opentelemetry/sdk/internal/AttributeUtil.java#L80
+  static Object _applyAttributeLengthLimit(Object value, int lengthLimit) {
+    if (value is String) {
+      return value.length > lengthLimit
+          ? value.substring(0, lengthLimit)
+          : value;
+    } else if (value is List<String>) {
+      for (var i = 0; i < value.length; i++) {
+        value[i] = value[i].length > lengthLimit
+            ? value[i].substring(0, lengthLimit)
+            : value[i];
+      }
+    }
+    return value;
+  }
 }

lib/src/sdk/trace/span_limits.dart

@@ -1,12 +1,12 @@
 import '../internal/utils.dart';
 
 class SpanLimits {
-  final DEFAULT_MAXNUM_ATTRIBUTES = 200;
-  final DEFAULT_MAXNUM_EVENTS = 128;
-  final DEFAULT_MAXNUM_LINKS = 128;
-  final DEFAULT_MAXNUM_ATTRIBUTE_PER_EVENT = 128;
-  final DEFAULT_MAXNUM_ATTRIBUTES_PER_LINK = 128;
-  final DEFAULT_MAXNUM_ATTRIBUTES_LENGTH = 1000;
+  final _DEFAULT_MAXNUM_ATTRIBUTES = 200;
+  final _DEFAULT_MAXNUM_EVENTS = 128;
+  final _DEFAULT_MAXNUM_LINKS = 128;
+  final _DEFAULT_MAXNUM_ATTRIBUTE_PER_EVENT = 128;
+  final _DEFAULT_MAXNUM_ATTRIBUTES_PER_LINK = 128;
+  final _DEFAULT_MAXNUM_ATTRIBUTES_LENGTH = 1000;
 
   int _maxNumAttributes;
   int _maxNumEvents;
@@ -15,7 +15,7 @@ class SpanLimits {
   int _maxNumAttributesPerLink;
   int _maxNumAttributeLength;
 
-  ///
+  ///setters
   set maxNumAttributes(int maxNumberOfAttributes) {
     Utils.checkArgument(maxNumberOfAttributes >= 0,
         'maxNumberOfAttributes must be greater or equal to zero');
@@ -70,14 +70,14 @@ class SpanLimits {
       int maxNumAttributesPerEvent,
       int maxNumAttributesPerLink,
       int maxNumAttributeLength}) {
-    _maxNumAttributes = maxNumAttributes ?? DEFAULT_MAXNUM_ATTRIBUTES;
-    _maxNumEvents = maxNumEvents ?? DEFAULT_MAXNUM_EVENTS;
-    _maxNumLink = maxNumLink ?? DEFAULT_MAXNUM_LINKS;
+    _maxNumAttributes = maxNumAttributes ?? _DEFAULT_MAXNUM_ATTRIBUTES;
+    _maxNumEvents = maxNumEvents ?? _DEFAULT_MAXNUM_EVENTS;
+    _maxNumLink = maxNumLink ?? _DEFAULT_MAXNUM_LINKS;
     _maxNumAttributesPerEvent =
-        maxNumAttributesPerEvent ?? DEFAULT_MAXNUM_ATTRIBUTE_PER_EVENT;
+        maxNumAttributesPerEvent ?? _DEFAULT_MAXNUM_ATTRIBUTE_PER_EVENT;
     _maxNumAttributesPerLink =
-        maxNumAttributesPerLink ?? DEFAULT_MAXNUM_ATTRIBUTES_PER_LINK;
+        maxNumAttributesPerLink ?? _DEFAULT_MAXNUM_ATTRIBUTES_PER_LINK;
     _maxNumAttributeLength =
-        maxNumAttributeLength ?? DEFAULT_MAXNUM_ATTRIBUTES_LENGTH;
+        maxNumAttributeLength ?? _DEFAULT_MAXNUM_ATTRIBUTES_LENGTH;
   }
 }

lib/src/sdk/trace/tracer.dart

@@ -23,8 +23,7 @@ class Tracer implements api.Tracer {
   api.Span startSpan(String name,
       {api.Context context, api.Attributes attributes}) {
     context ??= api.Context.current;
-    attributes ??= api.Attributes.empty(
-        _spanLimits.maxNumAttributes, _spanLimits.maxNumAttributeLength);
+    attributes ??= api.Attributes.empty();
 
     // If a valid, active Span is present in the context, use it as this Span's
     // parent.  If the Context does not contain an active parent Span, create
@@ -56,7 +55,7 @@ class Tracer implements api.Tracer {
 
     return sdk.Span(name, spanContext, parentSpanId, _processors, _resource,
         _instrumentationLibrary,
-        attributes: attributes, limits: _spanLimits);
+        attributes: attributes, spanlimits: _spanLimits);
   }
 
   /// Records a span of the given [name] for the given function