Store AST directly in provider mappings (#6114) (#6158)

* Store AST directly in dynamic provider mappings

* Store AST directly in context provider mappings

(cherry picked from commit fe0f6b0)

Co-authored-by: Mikołaj Świątek <mail@mikolajswiatek.com>

Author: mergify[bot]

internal/pkg/agent/transpiler/ast.go

@@ -825,6 +825,9 @@ func (a *AST) HashStr() string {
 
 // Equal check if two AST are equals by using the computed hash.
 func (a *AST) Equal(other *AST) bool {
+	if a.root == nil || other.root == nil {
+		return a.root == other.root
+	}
 	return bytes.Equal(a.Hash(), other.Hash())
 }
 

internal/pkg/composable/benchmark_test.go

@@ -5,12 +5,13 @@
 package composable
 
 import (
-	"maps"
 	"os"
 	"path/filepath"
 	"strings"
 	"testing"
 
+	"github.com/elastic/elastic-agent/internal/pkg/agent/transpiler"
+
 	"gopkg.in/yaml.v3"
 	"k8s.io/apimachinery/pkg/util/uuid"
 
@@ -54,7 +55,8 @@ func BenchmarkGenerateVars100Pods(b *testing.B) {
 				mappings: make(map[string]dynamicProviderMapping),
 			}
 			for i := 0; i < podCount; i++ {
-				podData := maps.Clone(providerMapping)
+				podData, err := transpiler.NewAST(providerMapping)
+				require.NoError(b, err)
 				podUID := uuid.NewUUID()
 				podMapping := dynamicProviderMapping{
 					mapping: podData,
@@ -63,8 +65,10 @@ func BenchmarkGenerateVars100Pods(b *testing.B) {
 			}
 			c.dynamicProviders[providerName] = providerState
 		} else {
+			providerAst, err := transpiler.NewAST(providerData[providerName])
+			require.NoError(b, err)
 			providerState := &contextProviderState{
-				mapping: providerData[providerName],
+				mapping: providerAst,
 			}
 			c.contextProviders[providerName] = providerState
 		}

internal/pkg/composable/controller.go

@@ -79,10 +79,12 @@ func New(log *logger.Logger, c *config.Config, managed bool) (Controller, error)
 		if err != nil {
 			return nil, errors.New(err, fmt.Sprintf("failed to build provider '%s'", name), errors.TypeConfig, errors.M("provider", name))
 		}
+		emptyMapping, _ := transpiler.NewAST(nil)
 		contextProviders[name] = &contextProviderState{
 			// Safe for Context to be nil here because it will be filled in
 			// by (*controller).Run before the provider is started.
 			provider: provider,
+			mapping:  emptyMapping,
 		}
 	}
 
@@ -275,20 +277,17 @@ func (c *controller) Close() {
 func (c *controller) generateVars(fetchContextProviders mapstr.M) []*transpiler.Vars {
 	// build the vars list of mappings
 	vars := make([]*transpiler.Vars, 1)
-	mapping := map[string]interface{}{}
+	mapping, _ := transpiler.NewAST(map[string]any{})
 	for name, state := range c.contextProviders {
-		mapping[name] = state.Current()
+		_ = mapping.Insert(state.Current(), name)
 	}
-	// this is ensured not to error, by how the mappings states are verified
-	mappingAst, _ := transpiler.NewAST(mapping)
-	vars[0] = transpiler.NewVarsFromAst("", mappingAst, fetchContextProviders)
+	vars[0] = transpiler.NewVarsFromAst("", mapping, fetchContextProviders)
 
 	// add to the vars list for each dynamic providers mappings
 	for name, state := range c.dynamicProviders {
 		for _, mappings := range state.Mappings() {
-			local := mappingAst.ShallowClone()
-			dynamicAst, _ := transpiler.NewAST(mappings.mapping)
-			_ = local.Insert(dynamicAst, name)
+			local := mapping.ShallowClone()
+			_ = local.Insert(mappings.mapping, name)
 			id := fmt.Sprintf("%s-%s", name, mappings.id)
 			v := transpiler.NewVarsWithProcessorsFromAst(id, local, name, mappings.processors, fetchContextProviders)
 			vars = append(vars, v)
@@ -302,7 +301,7 @@ type contextProviderState struct {
 
 	provider corecomp.ContextProvider
 	lock     sync.RWMutex
-	mapping  map[string]interface{}
+	mapping  *transpiler.AST
 	signal   chan bool
 }
 
@@ -324,30 +323,25 @@ func (c *contextProviderState) Signal() {
 // Set sets the current mapping.
 func (c *contextProviderState) Set(mapping map[string]interface{}) error {
 	var err error
-	mapping, err = cloneMap(mapping)
-	if err != nil {
-		return err
-	}
-	// ensure creating vars will not error
-	_, err = transpiler.NewVars("", mapping, nil)
+	ast, err := transpiler.NewAST(mapping)
 	if err != nil {
 		return err
 	}
 
 	c.lock.Lock()
 	defer c.lock.Unlock()
 
-	if reflect.DeepEqual(c.mapping, mapping) {
+	if c.mapping != nil && c.mapping.Equal(ast) {
 		// same mapping; no need to update and signal
 		return nil
 	}
-	c.mapping = mapping
+	c.mapping = ast
 	c.Signal()
 	return nil
 }
 
 // Current returns the current mapping.
-func (c *contextProviderState) Current() map[string]interface{} {
+func (c *contextProviderState) Current() *transpiler.AST {
 	c.lock.RLock()
 	defer c.lock.RUnlock()
 	return c.mapping
@@ -356,7 +350,7 @@ func (c *contextProviderState) Current() map[string]interface{} {
 type dynamicProviderMapping struct {
 	id         string
 	priority   int
-	mapping    map[string]interface{}
+	mapping    *transpiler.AST
 	processors transpiler.Processors
 }
 
@@ -376,31 +370,25 @@ type dynamicProviderState struct {
 // to ensure that matching of variables occurs on the lower priority mappings first.
 func (c *dynamicProviderState) AddOrUpdate(id string, priority int, mapping map[string]interface{}, processors []map[string]interface{}) error {
 	var err error
-	mapping, err = cloneMap(mapping)
-	if err != nil {
-		return err
-	}
 	processors, err = cloneMapArray(processors)
 	if err != nil {
 		return err
 	}
-	// ensure creating vars will not error
-	_, err = transpiler.NewVars("", mapping, nil)
+	ast, err := transpiler.NewAST(mapping)
 	if err != nil {
 		return err
 	}
-
 	c.lock.Lock()
 	defer c.lock.Unlock()
 	curr, ok := c.mappings[id]
-	if ok && reflect.DeepEqual(curr.mapping, mapping) && reflect.DeepEqual(curr.processors, processors) {
+	if ok && curr.mapping.Equal(ast) && reflect.DeepEqual(curr.processors, processors) {
 		// same mapping; no need to update and signal
 		return nil
 	}
 	c.mappings[id] = dynamicProviderMapping{
 		id:         id,
 		priority:   priority,
-		mapping:    mapping,
+		mapping:    ast,
 		processors: processors,
 	}
 
@@ -458,22 +446,6 @@ func (c *dynamicProviderState) Mappings() []dynamicProviderMapping {
 	return mappings
 }
 
-func cloneMap(source map[string]interface{}) (map[string]interface{}, error) {
-	if source == nil {
-		return nil, nil
-	}
-	bytes, err := json.Marshal(source)
-	if err != nil {
-		return nil, fmt.Errorf("failed to clone: %w", err)
-	}
-	var dest map[string]interface{}
-	err = json.Unmarshal(bytes, &dest)
-	if err != nil {
-		return nil, fmt.Errorf("failed to clone: %w", err)
-	}
-	return dest, nil
-}
-
 func cloneMapArray(source []map[string]interface{}) ([]map[string]interface{}, error) {
 	if source == nil {
 		return nil, nil