[pkg/ottl] Add log body indexing (open-telemetry#22102)

* Add log body indexing

* Validate that an index was actually passed when trying to index an empty pdata value

* Fix lint

* Address PR feedback

---------

Co-authored-by: Evan Bradley <evan-bradley@users.noreply.github.com>

.chloggen/ottl-log-body-indexing.yaml

@@ -0,0 +1,20 @@
+# Use this changelog template to create an entry for release notes.
+# If your change doesn't affect end users, such as a test fix or a tooling change,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: pkg/ottl
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Allow indexing map and slice log bodies
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [17396, 22068]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:

pkg/ottl/contexts/internal/map.go

@@ -9,7 +9,6 @@ import (
 	"go.opentelemetry.io/collector/pdata/pcommon"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
-	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl/internal/ottlcommon"
 )
 
 func GetMapValue(m pcommon.Map, keys []ottl.Key) (interface{}, error) {
@@ -24,29 +23,7 @@ func GetMapValue(m pcommon.Map, keys []ottl.Key) (interface{}, error) {
 	if !ok {
 		return nil, nil
 	}
-	for i := 1; i < len(keys); i++ {
-		switch val.Type() {
-		case pcommon.ValueTypeMap:
-			if keys[i].String == nil {
-				return nil, fmt.Errorf("map must be indexed by a string")
-			}
-			val, ok = val.Map().Get(*keys[i].String)
-			if !ok {
-				return nil, nil
-			}
-		case pcommon.ValueTypeSlice:
-			if keys[i].Int == nil {
-				return nil, fmt.Errorf("slice must be indexed by an int")
-			}
-			if int(*keys[i].Int) >= val.Slice().Len() || int(*keys[i].Int) < 0 {
-				return nil, fmt.Errorf("index %v out of bounds", *keys[i].Int)
-			}
-			val = val.Slice().At(int(*keys[i].Int))
-		default:
-			return nil, fmt.Errorf("type %v does not support string indexing", val.Type())
-		}
-	}
-	return ottlcommon.GetValue(val), nil
+	return getIndexableValue(val, keys[1:])
 }
 
 func SetMapValue(m pcommon.Map, keys []ottl.Key, val interface{}) error {
@@ -57,57 +34,10 @@ func SetMapValue(m pcommon.Map, keys []ottl.Key, val interface{}) error {
 		return fmt.Errorf("non-string indexing is not supported")
 	}
 
-	var newValue pcommon.Value
-	switch val.(type) {
-	case []string, []bool, []int64, []float64, [][]byte, []any:
-		newValue = pcommon.NewValueSlice()
-	default:
-		newValue = pcommon.NewValueEmpty()
-	}
-	err := SetValue(newValue, val)
-	if err != nil {
-		return err
-	}
-
 	currentValue, ok := m.Get(*keys[0].String)
 	if !ok {
 		currentValue = m.PutEmpty(*keys[0].String)
 	}
 
-	for i := 1; i < len(keys); i++ {
-		switch currentValue.Type() {
-		case pcommon.ValueTypeMap:
-			if keys[i].String == nil {
-				return fmt.Errorf("map must be indexed by a string")
-			}
-			potentialValue, ok := currentValue.Map().Get(*keys[i].String)
-			if !ok {
-				currentValue = currentValue.Map().PutEmpty(*keys[i].String)
-			} else {
-				currentValue = potentialValue
-			}
-		case pcommon.ValueTypeSlice:
-			if keys[i].Int == nil {
-				return fmt.Errorf("slice must be indexed by an int")
-			}
-			if int(*keys[i].Int) >= currentValue.Slice().Len() || int(*keys[i].Int) < 0 {
-				return fmt.Errorf("index %v out of bounds", *keys[i].Int)
-			}
-			currentValue = currentValue.Slice().At(int(*keys[i].Int))
-		case pcommon.ValueTypeEmpty:
-			if keys[i].String != nil {
-				currentValue = currentValue.SetEmptyMap().PutEmpty(*keys[i].String)
-			} else if keys[i].Int != nil {
-				currentValue.SetEmptySlice()
-				for k := 0; k < int(*keys[i].Int); k++ {
-					currentValue.Slice().AppendEmpty()
-				}
-				currentValue = currentValue.Slice().AppendEmpty()
-			}
-		default:
-			return fmt.Errorf("type %v does not support string indexing", currentValue.Type())
-		}
-	}
-	newValue.CopyTo(currentValue)
-	return nil
+	return setIndexableValue(currentValue, val, keys[1:])
 }

pkg/ottl/contexts/internal/slice.go

@@ -0,0 +1,44 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package internal // import "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl/contexts/internal"
+
+import (
+	"fmt"
+
+	"go.opentelemetry.io/collector/pdata/pcommon"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
+)
+
+func GetSliceValue(s pcommon.Slice, keys []ottl.Key) (interface{}, error) {
+	if len(keys) == 0 {
+		return nil, fmt.Errorf("cannot get slice value without key")
+	}
+	if keys[0].Int == nil {
+		return nil, fmt.Errorf("non-integer indexing is not supported")
+	}
+	idx := int(*keys[0].Int)
+
+	if idx < 0 || idx >= s.Len() {
+		return nil, fmt.Errorf("index %d out of bounds", idx)
+	}
+
+	return getIndexableValue(s.At(int(*keys[0].Int)), keys[1:])
+}
+
+func SetSliceValue(s pcommon.Slice, keys []ottl.Key, val interface{}) error {
+	if len(keys) == 0 {
+		return fmt.Errorf("cannot set slice value without key")
+	}
+	if keys[0].Int == nil {
+		return fmt.Errorf("non-integer indexing is not supported")
+	}
+	idx := int(*keys[0].Int)
+
+	if idx < 0 || idx >= s.Len() {
+		return fmt.Errorf("index %d out of bounds", idx)
+	}
+
+	return setIndexableValue(s.At(int(*keys[0].Int)), val, keys[1:])
+}

pkg/ottl/contexts/internal/slice_test.go

@@ -0,0 +1,141 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package internal
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"go.opentelemetry.io/collector/pdata/pcommon"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl/ottltest"
+)
+
+func Test_GetSliceValue_Invalid(t *testing.T) {
+	tests := []struct {
+		name string
+		keys []ottl.Key
+		err  error
+	}{
+		{
+			name: "no keys",
+			keys: []ottl.Key{},
+			err:  fmt.Errorf("cannot get slice value without key"),
+		},
+		{
+			name: "first key not an integer",
+			keys: []ottl.Key{
+				{
+					String: ottltest.Strp("key"),
+				},
+			},
+			err: fmt.Errorf("non-integer indexing is not supported"),
+		},
+		{
+			name: "index too large",
+			keys: []ottl.Key{
+				{
+					Int: ottltest.Intp(1),
+				},
+			},
+			err: fmt.Errorf("index 1 out of bounds"),
+		},
+		{
+			name: "index too small",
+			keys: []ottl.Key{
+				{
+					Int: ottltest.Intp(-1),
+				},
+			},
+			err: fmt.Errorf("index -1 out of bounds"),
+		},
+		{
+			name: "invalid type",
+			keys: []ottl.Key{
+				{
+					Int: ottltest.Intp(0),
+				},
+				{
+					String: ottltest.Strp("string"),
+				},
+			},
+			err: fmt.Errorf("type Str does not support string indexing"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s := pcommon.NewSlice()
+			s.AppendEmpty().SetStr("val")
+
+			_, err := GetSliceValue(s, tt.keys)
+			assert.Equal(t, tt.err, err)
+		})
+	}
+}
+
+func Test_SetSliceValue_Invalid(t *testing.T) {
+	tests := []struct {
+		name string
+		keys []ottl.Key
+		err  error
+	}{
+		{
+			name: "no keys",
+			keys: []ottl.Key{},
+			err:  fmt.Errorf("cannot set slice value without key"),
+		},
+		{
+			name: "first key not an integer",
+			keys: []ottl.Key{
+				{
+					String: ottltest.Strp("key"),
+				},
+			},
+			err: fmt.Errorf("non-integer indexing is not supported"),
+		},
+		{
+			name: "index too large",
+			keys: []ottl.Key{
+				{
+					Int: ottltest.Intp(1),
+				},
+			},
+			err: fmt.Errorf("index 1 out of bounds"),
+		},
+		{
+			name: "index too small",
+			keys: []ottl.Key{
+				{
+					Int: ottltest.Intp(-1),
+				},
+			},
+			err: fmt.Errorf("index -1 out of bounds"),
+		},
+		{
+			name: "invalid type",
+			keys: []ottl.Key{
+				{
+					Int: ottltest.Intp(0),
+				},
+				{
+					String: ottltest.Strp("string"),
+				},
+			},
+			err: fmt.Errorf("type Str does not support string indexing"),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			s := pcommon.NewSlice()
+			s.AppendEmpty().SetStr("val")
+
+			err := SetSliceValue(s, tt.keys, "value")
+			assert.Equal(t, tt.err, err)
+		})
+	}
+}