Add DroppedAttributeCount field to Otel/STEF schema (#22)

Resolves #8

Otel/STEF schema changes:

- Added "DroppedAttributeCount" field in the "Resource", "Scope", "Span", etc structs.

Also updated testdata files (because the schema is now different) and renamed
the incorrect ".tefz" to ".stefz" extension.

benchmarks/benchmarks_test.go

@@ -23,7 +23,7 @@ import (
 
 var testEncodings = []encodings.MetricEncoding{
 	&otlp.OTLPEncoding{},
-	&stef.STEFEncoding{},
+	&stef.STEFEncoding{Opts: pkg.WriterOptions{Compression: pkg.CompressionNone}},
 	//&stef.STEFSEncoding{},
 	//&stef.STEFUEncoding{},
 	&otelarrow.OtelArrowEncoding{},

benchmarks/readwrite_test.go

@@ -16,10 +16,10 @@ import (
 
 func TestCopy(t *testing.T) {
 	files := []string{
-		"oteldemo-with-histogram.tefz",
-		"hipstershop.tefz",
-		"hostandcollectormetrics.tefz",
-		"astronomyshop.tefz",
+		"oteldemo-with-histogram.stefz",
+		"hipstershop.stefz",
+		"hostandcollectormetrics.stefz",
+		"astronomyshop.stefz",
 	}
 
 	fmt.Printf(
@@ -78,7 +78,7 @@ func TestCopy(t *testing.T) {
 }
 
 func BenchmarkReadSTEF(b *testing.B) {
-	tefBytes, err := os.ReadFile("testdata/hipstershop.tefz")
+	tefBytes, err := os.ReadFile("testdata/hipstershop.stefz")
 	require.NoError(b, err)
 
 	tefSrc, err := oteltef.NewMetricsReader(bytes.NewBuffer(tefBytes))
@@ -136,7 +136,7 @@ func BenchmarkReadSTEF(b *testing.B) {
 }
 
 func BenchmarkReadSTEFZ(b *testing.B) {
-	tefBytes, err := os.ReadFile("testdata/hipstershop.tefz")
+	tefBytes, err := os.ReadFile("testdata/hipstershop.stefz")
 	require.NoError(b, err)
 
 	recCount := 0
@@ -164,7 +164,7 @@ func BenchmarkReadSTEFZ(b *testing.B) {
 }
 
 func BenchmarkReadSTEFZWriteSTEF(b *testing.B) {
-	tefBytes, err := os.ReadFile("testdata/hipstershop.tefz")
+	tefBytes, err := os.ReadFile("testdata/hipstershop.stefz")
 	require.NoError(b, err)
 
 	recCount := 0

benchmarks/size_test.go

@@ -5,6 +5,8 @@ import (
 	"fmt"
 	"io"
 	"log"
+	"os"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -89,6 +91,14 @@ func TestTracesMultipart(t *testing.T) {
 	}
 }
 
+func replaceExt(fname string, ext string) string {
+	idx := strings.Index(fname, ".")
+	if idx > 0 {
+		return fname[:idx] + ext
+	}
+	return fname
+}
+
 func TestMetricsSize(t *testing.T) {
 
 	dataVariations := []struct {
@@ -184,10 +194,14 @@ func TestMetricsSize(t *testing.T) {
 				log.Fatal(err)
 			}
 
-			//if enc, ok := encoding.(*stef.STEFEncoding); ok {
-			//	fname := "testdata/" + dataVariation.generator.GetName() + "." + strings.ToLower(enc.Name())
-			//	os.WriteFile(fname, bodyBytes, 0644)
-			//}
+			if enc, ok := encoding.(*stef.STEFEncoding); ok {
+				// Write STEF file if it does not exist
+				fname := "testdata/" + replaceExt(dataVariation.generator.GetName(), "."+strings.ToLower(enc.Name()))
+				_, err = os.Stat(fname)
+				if err != nil {
+					os.WriteFile(fname, bodyBytes, 0644)
+				}
+			}
 
 			zstdedBytes := testutils.CompressZstd(bodyBytes)
 

go/otel/oteltef.wire.json

@@ -246,6 +246,10 @@
         {
           "multimap": "Attributes",
           "name": "Attributes"
+        },
+        {
+          "name": "DroppedAttributesCount",
+          "primitive": 1
         }
       ]
     },
@@ -271,6 +275,10 @@
         {
           "multimap": "Attributes",
           "name": "Attributes"
+        },
+        {
+          "name": "DroppedAttributesCount",
+          "primitive": 1
         }
       ]
     },
@@ -319,6 +327,10 @@
           "multimap": "Attributes",
           "name": "Attributes"
         },
+        {
+          "name": "DroppedAttributesCount",
+          "primitive": 1
+        },
         {
           "array": {
             "struct": "Event"
@@ -360,6 +372,10 @@
         {
           "multimap": "Attributes",
           "name": "Attributes"
+        },
+        {
+          "name": "DroppedAttributesCount",
+          "primitive": 1
         }
       ]
     },
@@ -379,6 +395,10 @@
         {
           "multimap": "Attributes",
           "name": "Attributes"
+        },
+        {
+          "name": "DroppedAttributesCount",
+          "primitive": 1
         }
       ]
     },