Add OTTL delete function

.chloggen/add-ottl-delete-elemelt-function.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# 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. receiver/filelog)
+component: pkg/ottl
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Introducing `delete` function for deleting items from an existing array"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [43098]
+
+# (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:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

pkg/ottl/e2e/e2e_test.go

@@ -63,6 +63,7 @@ func Test_e2e_editors(t *testing.T) {
 				tCtx.GetLogRecord().Attributes().Remove("things")
 				tCtx.GetLogRecord().Attributes().Remove("conflict.conflict1")
 				tCtx.GetLogRecord().Attributes().Remove("conflict")
+				tCtx.GetLogRecord().Attributes().Remove("slice2")
 			},
 		},
 		{
@@ -74,6 +75,7 @@ func Test_e2e_editors(t *testing.T) {
 				tCtx.GetLogRecord().Attributes().Remove("things")
 				tCtx.GetLogRecord().Attributes().Remove("conflict.conflict1")
 				tCtx.GetLogRecord().Attributes().Remove("conflict")
+				tCtx.GetLogRecord().Attributes().Remove("slice2")
 			},
 		},
 		{
@@ -93,6 +95,12 @@ func Test_e2e_editors(t *testing.T) {
 				tCtx.GetLogRecord().Attributes().PutInt("things.0.value", 2)
 				tCtx.GetLogRecord().Attributes().PutStr("things.1.name", "bar")
 				tCtx.GetLogRecord().Attributes().PutInt("things.1.value", 5)
+
+				tCtx.GetLogRecord().Attributes().Remove("slice2")
+				tCtx.GetLogRecord().Attributes().PutStr("slice2.0", "val")
+				tCtx.GetLogRecord().Attributes().PutStr("slice2.1", "foo")
+				tCtx.GetLogRecord().Attributes().PutStr("slice2.2", "bar")
+				tCtx.GetLogRecord().Attributes().PutStr("slice2.3", "baz")
 			},
 		},
 		{
@@ -117,6 +125,11 @@ func Test_e2e_editors(t *testing.T) {
 				m.PutInt("test.things.0.value", 2)
 				m.PutStr("test.things.1.name", "bar")
 				m.PutInt("test.things.1.value", 5)
+
+				m.PutStr("test.slice2.0", "val")
+				m.PutStr("test.slice2.1", "foo")
+				m.PutStr("test.slice2.2", "bar")
+				m.PutStr("test.slice2.3", "baz")
 				m.CopyTo(tCtx.GetLogRecord().Attributes())
 			},
 		},
@@ -145,6 +158,11 @@ func Test_e2e_editors(t *testing.T) {
 				m.PutStr("test.things.1.name", "bar")
 				m.PutInt("test.things.1.value", 5)
 
+				m.PutStr("test.slice2", "val")
+				m.PutStr("test.slice2.0", "foo")
+				m.PutStr("test.slice2.1", "bar")
+				m.PutStr("test.slice2.2", "baz")
+
 				m.CopyTo(tCtx.GetLogRecord().Attributes())
 			},
 		},
@@ -161,6 +179,10 @@ func Test_e2e_editors(t *testing.T) {
 				m.PutStr("foo.flags", "pass")
 				m.PutStr("foo.bar", "pass")
 				m.PutStr("foo.flags", "pass")
+				m.PutStr("slice2.0", "val")
+				m.PutStr("slice2.1", "foo")
+				m.PutStr("slice2.2", "bar")
+				m.PutStr("slice2.3", "baz")
 				m.PutEmptySlice("foo.slice").AppendEmpty().SetStr("val")
 				m.PutStr("conflict.conflict1.conflict2", "nopass")
 				mm := m.PutEmptyMap("conflict.conflict1")
@@ -189,6 +211,7 @@ func Test_e2e_editors(t *testing.T) {
 				tCtx.GetLogRecord().Attributes().Remove("things")
 				tCtx.GetLogRecord().Attributes().Remove("conflict.conflict1")
 				tCtx.GetLogRecord().Attributes().Remove("conflict")
+				tCtx.GetLogRecord().Attributes().Remove("slice2")
 			},
 		},
 		{
@@ -206,6 +229,7 @@ func Test_e2e_editors(t *testing.T) {
 				tCtx.GetLogRecord().Attributes().Remove("things")
 				tCtx.GetLogRecord().Attributes().Remove("conflict.conflict1")
 				tCtx.GetLogRecord().Attributes().Remove("conflict")
+				tCtx.GetLogRecord().Attributes().Remove("slice2")
 			},
 		},
 		{
@@ -393,6 +417,47 @@ func Test_e2e_editors(t *testing.T) {
 				s.AppendEmpty().SetInt(6)
 			},
 		},
+		{
+			statement: `delete(attributes["slice2"], 0)`,
+			want: func(tCtx *ottllog.TransformContext) {
+				v, _ := tCtx.GetLogRecord().Attributes().Get("slice2")
+				s := v.Slice()
+				// :ToDo: Implement RemoveAt and RemoveRange in pcommon.Slice
+				s.RemoveIf(func(v pcommon.Value) bool {
+					return v.Str() == "val"
+				})
+			},
+		},
+		{
+			statement: `delete(attributes["slice2"], Len(attributes["slice2"]) - 1)`,
+			want: func(tCtx *ottllog.TransformContext) {
+				v, _ := tCtx.GetLogRecord().Attributes().Get("slice2")
+				s := v.Slice()
+				s.RemoveIf(func(v pcommon.Value) bool {
+					return v.Str() == "baz"
+				})
+			},
+		},
+		{
+			statement: `delete(attributes["slice2"], 1, endIndex=3)`,
+			want: func(tCtx *ottllog.TransformContext) {
+				v, _ := tCtx.GetLogRecord().Attributes().Get("slice2")
+				s := v.Slice()
+				s.RemoveIf(func(v pcommon.Value) bool {
+					return (v.Str() == "foo" || v.Str() == "bar")
+				})
+			},
+		},
+		{
+			statement: `delete(attributes["slice2"], Index(attributes["slice2"], "foo"))`,
+			want: func(tCtx *ottllog.TransformContext) {
+				v, _ := tCtx.GetLogRecord().Attributes().Get("slice2")
+				s := v.Slice()
+				s.RemoveIf(func(v pcommon.Value) bool {
+					return v.Str() == "foo"
+				})
+			},
+		},
 	}
 
 	for _, tt := range tests {
@@ -2154,6 +2219,12 @@ func constructLogTransformContextEditors() *ottllog.TransformContext {
 	thing2.PutStr("name", "bar")
 	thing2.PutInt("value", 5)
 
+	s3 := logRecord.Attributes().PutEmptySlice("slice2")
+	s3.AppendEmpty().SetStr("val")
+	s3.AppendEmpty().SetStr("foo")
+	s3.AppendEmpty().SetStr("bar")
+	s3.AppendEmpty().SetStr("baz")
+
 	return ottllog.NewTransformContextPtr(rLogs, rLogs.ScopeLogs().At(0), logRecord)
 }
 

pkg/ottl/ottlfuncs/README.md

@@ -46,6 +46,7 @@ Editors:
 Available Editors:
 
 - [append](#append)
+- [delete](#delete)
 - [delete_key](#delete_key)
 - [delete_matching_keys](#delete_matching_keys)
 - [keep_matching_keys](#keep_matching_keys)
@@ -73,6 +74,22 @@ Resulting field is always of type `pcommon.Slice` and will not convert the types
 - `append(log.attributes["tags"], values = ["staging", "staging:east"])`
 - `append(log.attributes["tags_copy"], log.attributes["tags"])`
 
+### delete
+
+`delete(target, startIndex, Optional[endIndex])`
+
+The `delete` function removes elements from a slice. It deletes elements in the range `[startIndex, endIndex)` (startIndex inclusive, endIndex exclusive). If `endIndex` is not provided, only the element at `target[startIndex]` is deleted. If `startIndex` equals `endIndex`, no changes are applied to the target, following the behavior of Go's `slices.Delete(s, i, j)` function.
+
+Examples:
+
+- `delete(attributes["tags"], 0)` # delete first
+
+- `delete(attributes["tags"], Len(attributes["tags"]) - 1)` # delete last
+
+- `delete(attributes["tags"], 0, 3)` # delete indices 0, 1, & 2
+
+- `delete(attributes["tags"], Index(attributes["tags"], "unparsed"))` # delete first occurrence of "unparsed"
+
 ### delete_key
 
 `delete_key(target, key)`

pkg/ottl/ottlfuncs/func_delete.go

@@ -0,0 +1,99 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package ottlfuncs // import "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl/ottlfuncs"
+
+import (
+	"context"
+	"errors"
+	"fmt"
+
+	"go.opentelemetry.io/collector/pdata/pcommon"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/ottl"
+)
+
+type DeleteArguments[K any] struct {
+	Target     ottl.PSliceGetSetter[K]
+	StartIndex ottl.IntGetter[K]
+	EndIndex   ottl.Optional[ottl.IntGetter[K]]
+}
+
+func NewDeleteFactory[K any]() ottl.Factory[K] {
+	return ottl.NewFactory("delete", &DeleteArguments[K]{}, createDeleteFunction[K])
+}
+
+func createDeleteFunction[K any](_ ottl.FunctionContext, oArgs ottl.Arguments) (ottl.ExprFunc[K], error) {
+	args, ok := oArgs.(*DeleteArguments[K])
+	if !ok {
+		return nil, errors.New("DeleteFactory args must be of type *DeleteArguments[K]")
+	}
+
+	return deleteFrom(args.Target, args.StartIndex, args.EndIndex), nil
+}
+
+func deleteFrom[K any](target ottl.PSliceGetSetter[K], startIndexGetter ottl.IntGetter[K], endIndexGetter ottl.Optional[ottl.IntGetter[K]]) ottl.ExprFunc[K] {
+	return func(ctx context.Context, tCtx K) (any, error) {
+		t, err := target.Get(ctx, tCtx)
+		if err != nil {
+			return nil, err
+		}
+
+		startIndex, err := startIndexGetter.Get(ctx, tCtx)
+		if err != nil {
+			return nil, err
+		}
+
+		sliceLen := int64(t.Len())
+		endIndex := startIndex + 1
+		if !endIndexGetter.IsEmpty() {
+			endIndex, err = endIndexGetter.Get().Get(ctx, tCtx)
+			if err != nil {
+				return nil, err
+			}
+		}
+
+		if startIndex == 0 && endIndex == sliceLen {
+			// If deleting all elements, return an empty slice without looping
+			return nil, target.Set(ctx, tCtx, pcommon.NewSlice())
+		}
+
+		err = validateBounds(startIndex, endIndex, sliceLen)
+		if err != nil {
+			return nil, err
+		}
+
+		if startIndex == endIndex {
+			// No elements to delete
+			return nil, target.Set(ctx, tCtx, t)
+		}
+
+		resSlice := pcommon.NewSlice()
+		resSlice.EnsureCapacity(int(sliceLen - (endIndex - startIndex)))
+
+		for i := range startIndex {
+			t.At(int(i)).MoveTo(resSlice.AppendEmpty())
+		}
+
+		for i := endIndex; i < sliceLen; i++ {
+			t.At(int(i)).MoveTo(resSlice.AppendEmpty())
+		}
+
+		return nil, target.Set(ctx, tCtx, resSlice)
+	}
+}
+
+func validateBounds(startIndex, endIndex, sliceLen int64) error {
+	if startIndex < 0 || startIndex >= sliceLen {
+		return fmt.Errorf("startIndex %d out of bounds for slice of length %d", startIndex, sliceLen)
+	}
+
+	if endIndex < startIndex {
+		return fmt.Errorf("endIndex %d cannot be less than startIndex %d", endIndex, startIndex)
+	}
+
+	if endIndex > sliceLen {
+		return fmt.Errorf("deletion range [%d:%d] out of bounds for slice of length %d", startIndex, endIndex, sliceLen)
+	}
+	return nil
+}