Merge pull request #1833 from keboola/lint-add-prealoc-linter

lint: Add prealoc linter to reduce realocation

build/ci/golangci.yml

@@ -147,6 +147,7 @@ linters:
     - nakedret
     - nilerr
     - noctx
+    - prealloc
     - predeclared
     - promlinter
     - rowserrcheck

internal/pkg/env/map.go

@@ -67,7 +67,7 @@ func (m *Map) ToString() (string, error) {
 }
 
 func (m *Map) ToSlice() []string {
-	var out []string
+	out := make([]string, 0, len(m.Keys()))
 	for _, k := range m.Keys() {
 		v := m.Get(k)
 		out = append(out, fmt.Sprintf(`%s=%s`, k, v))
@@ -85,7 +85,7 @@ func (m *Map) ToMap() map[string]string {
 }
 
 func (m *Map) Keys() []string {
-	keys := make([]string, 0)
+	keys := make([]string, 0, len(m.data))
 	for k := range m.data {
 		keys = append(keys, k)
 	}

internal/pkg/filesystem/knownpaths/paths.go

@@ -127,7 +127,7 @@ func (p *Paths) TrackedPaths() []string {
 	p.lock.Lock()
 	defer p.lock.Unlock()
 
-	var tracked []string
+	tracked := make([]string, 0, len(p.tracked))
 	for path := range p.tracked {
 		tracked = append(tracked, path)
 	}
@@ -140,7 +140,7 @@ func (p *Paths) UntrackedPaths() []string {
 	p.lock.Lock()
 	defer p.lock.Unlock()
 
-	var untracked []string
+	untracked := make([]string, 0, len(p.all))
 	for path := range p.all {
 		if _, ok := p.tracked[path]; !ok {
 			untracked = append(untracked, path)

internal/pkg/log/logger.go

@@ -154,7 +154,7 @@ func (l *zapLogger) logInLevel(level string, message string, fields ...zap.Field
 }
 
 func (l *zapLogger) message(ctx context.Context, message string) string {
-	var replacements []string
+	replacements := make([]string, 0, len(ctxattr.Attributes(ctx).ToSlice()))
 	for _, kv := range ctxattr.Attributes(ctx).ToSlice() {
 		replacements = append(replacements, "<"+string(kv.Key)+">", kv.Value.Emit())
 	}

internal/pkg/mapper/orchestrator/local_save_test.go

@@ -27,7 +27,7 @@ func TestOrchestratorMapper_MapBeforeLocalSave(t *testing.T) {
 	assert.Empty(t, logger.WarnAndErrorMessages())
 
 	// Minify JSON + remove file description
-	var files []filesystem.File
+	files := make([]filesystem.File, 0, len(recipe.Files.All()))
 	for _, file := range recipe.Files.All() {
 		var fileRaw *filesystem.RawFile
 		if f, ok := file.(*filesystem.JSONFile); ok {

internal/pkg/mapper/orchestrator/sort.go

@@ -75,7 +75,7 @@ func (s *phasesSorter) sortPhases() ([]*model.Phase, error) {
 	}
 
 	// Generate slice
-	var phases []*model.Phase
+	phases := make([]*model.Phase, 0, len(order))
 	for phaseIndex, keyRaw := range order {
 		key := keyRaw.(string)
 		phase := s.phaseByKey[key]

internal/pkg/mapper/sharedcode/links/links_test.go

@@ -150,7 +150,7 @@ func createRemoteTranWithSharedCode(t *testing.T, sharedCodeKey model.ConfigKey,
 	t.Helper()
 
 	// Rows -> rows IDs
-	var rows []any
+	rows := make([]any, 0, len(sharedCodeRowsKeys))
 	for _, row := range sharedCodeRowsKeys {
 		rows = append(rows, row.ID.String())
 	}

internal/pkg/mapper/transformation/local_save_test.go

@@ -149,7 +149,7 @@ func TestTransformationMapper_MapBeforeLocalSave(t *testing.T) {
 	assert.Empty(t, logger.WarnAndErrorMessages())
 
 	// Minify JSON + remove file description
-	var files []filesystem.File
+	files := make([]filesystem.File, 0, len(recipe.Files.All()))
 	for _, file := range recipe.Files.All() {
 		var fileRaw *filesystem.RawFile
 		if f, ok := file.(*filesystem.JSONFile); ok {

internal/pkg/model/diff.go

@@ -77,7 +77,7 @@ func (v ChangedFields) Remove(field string) {
 }
 
 func (v ChangedFields) String() string {
-	var out []string
+	out := make([]string, 0, len(v))
 	for field := range v {
 		out = append(out, field)
 	}

internal/pkg/model/orchestrator.go

@@ -44,7 +44,7 @@ func (p Phase) String() string {
 	buf := new(bytes.Buffer)
 	_, _ = fmt.Fprintf(buf, "#  %03d %s\n", p.Index+1, p.Name)
 
-	var dependsOn []string
+	dependsOn := make([]string, 0, len(p.DependsOn))
 	for _, dependsOnKey := range p.DependsOn {
 		dependsOn = append(dependsOn, cast.ToString(dependsOnKey.Index+1))
 	}

internal/pkg/model/relation.go

@@ -262,7 +262,7 @@ func (v *Relations) UnmarshalJSON(data []byte) error {
 }
 
 func (v Relations) MarshalJSON() ([]byte, error) {
-	var out []*orderedmap.OrderedMap
+	out := make([]*orderedmap.OrderedMap, 0, len(v))
 	for _, relation := range v {
 		// Validate, only manifest side should be serialized to JSON
 		if !relation.IsDefinedInManifest() {

internal/pkg/model/transformation.go

@@ -55,7 +55,7 @@ type StaticScript struct {
 }
 
 func (v UsedSharedCodeRows) IdsSlice() []any {
-	var ids []any
+	ids := make([]any, 0, len(v))
 	for _, rowKey := range v {
 		ids = append(ids, rowKey.ID.String())
 	}
@@ -112,15 +112,15 @@ func (c Code) String() string {
 }
 
 func (v Scripts) Slice() []any {
-	var out []any
+	out := make([]any, 0, len(v))
 	for _, script := range v {
 		out = append(out, script.Content())
 	}
 	return out
 }
 
 func (v Scripts) String(componentID keboola.ComponentID) string {
-	var items []string
+	items := make([]string, 0, len(v))
 	for _, script := range v {
 		items = append(items, strings.TrimRight(script.Content(), " \r\n\t"))
 	}
@@ -135,7 +135,7 @@ func (v Scripts) String(componentID keboola.ComponentID) string {
 
 // MarshalJSON converts Scripts to JSON []string.
 func (v Scripts) MarshalJSON() ([]byte, error) {
-	var scripts []string
+	scripts := make([]string, 0, len(v))
 	for _, script := range v {
 		scripts = append(scripts, script.(StaticScript).Value)
 	}
@@ -152,7 +152,7 @@ func (v *Scripts) UnmarshalJSON(data []byte) error {
 		return err
 	}
 
-	*v = make(Scripts, 0)
+	*v = make(Scripts, 0, len(scripts))
 	for _, item := range scripts {
 		*v = append(*v, StaticScript{Value: item})
 	}
@@ -185,7 +185,7 @@ func ScriptsFromStr(content string, componentID keboola.ComponentID) Scripts {
 }
 
 func ScriptsFromSlice(items []any) Scripts {
-	var scripts Scripts
+	scripts := make(Scripts, 0, len(items))
 	for _, item := range items {
 		scripts = append(scripts, StaticScript{Value: cast.ToString(item)})
 	}

internal/pkg/plan/persist/persist_test.go

@@ -37,7 +37,7 @@ func TestPersistNoChange(t *testing.T) {
 	t.Parallel()
 	tc := testCase{
 		inputDir:       `persist-no-change`,
-		untrackedPaths: nil,
+		untrackedPaths: []string{},
 		expectedPlan:   nil,
 	}
 	tc.run(t)
@@ -243,7 +243,7 @@ func TestPersistDeleted(t *testing.T) {
 	t.Parallel()
 	tc := testCase{
 		inputDir:       `persist-deleted`,
-		untrackedPaths: nil,
+		untrackedPaths: []string{},
 		expectedPlan: []action{
 			&deleteManifestRecordAction{
 				ObjectManifest: &model.ConfigManifest{

internal/pkg/platform/schema/compiler/extension/primarykey/generatekey.go

@@ -58,7 +58,7 @@ func generateKey(targetDir string, schema *load.Schema, pkAnnotation PKAnnotatio
 	for _, field := range pkAnnotation.Fields {
 		importsMap[field.GoType.PkgPath] = struct{}{}
 	}
-	var importPkg []string
+	importPkg := make([]string, 0, len(importsMap))
 	for pkgPath := range importsMap {
 		importPkg = append(importPkg, pkgPath)
 	}

internal/pkg/platform/schema/compiler/extension/primarykey/mixin.go

@@ -140,7 +140,7 @@ func (v *Mixin) Edges() []ent.Edge {
 
 // Indexes method generates index for composed primary key.
 func (v *Mixin) Indexes() (indexes []ent.Index) {
-	var fields []string
+	fields := make([]string, 0, len(v.pkFields))
 	for _, f := range v.pkFields {
 		fields = append(fields, f.Name)
 		indexes = append(indexes, index.Fields(f.Name).Annotations(PKFieldAnnotation{}))

internal/pkg/project/manifest/file.go

@@ -104,7 +104,7 @@ func (c *file) validate(ctx context.Context) error {
 }
 
 func (c *file) records() []model.ObjectManifest {
-	var out []model.ObjectManifest
+	out := make([]model.ObjectManifest, 0, 1024)
 	for _, branch := range c.Branches {
 		out = append(out, branch)
 	}
@@ -124,8 +124,8 @@ func (c *file) setRecords(records []model.ObjectManifest) {
 	// Convert records map to slices
 	branchesMap := make(map[string]*model.BranchManifest)
 	configsMap := make(map[string]*model.ConfigManifestWithRows)
-	c.Branches = make([]*model.BranchManifest, 0)
-	c.Configs = make([]*model.ConfigManifestWithRows, 0)
+	c.Branches = make([]*model.BranchManifest, 0, len(records))
+	c.Configs = make([]*model.ConfigManifestWithRows, 0, len(records))
 
 	for _, manifest := range records {
 		// Skip invalid (eg. missing config file)

internal/pkg/service/cli/cmd/cmd.go

@@ -265,7 +265,7 @@ func (root *RootCommand) Execute() (exitCode int) {
 
 func (root *RootCommand) listAliases() string {
 	// Join aliases to single line
-	var lines []string
+	lines := make([]string, 0, len(root.aliases.Keys()))
 	var maxLength int
 	for _, cmd := range root.aliases.Keys() {
 		aliasesRaw, _ := root.aliases.Get(cmd)

internal/pkg/service/cli/cmd/cmd_test.go

@@ -48,8 +48,9 @@ func TestCliSubCommandsAndAliases(t *testing.T) {
 	root, _ := newTestRootCommand(aferofs.NewMemoryFs())
 
 	// Map commands to names
-	var names []string
-	for _, cmd := range root.Commands() {
+	cmds := root.Commands()
+	names := make([]string, 0, len(cmds))
+	for _, cmd := range cmds {
 		names = append(names, cmd.Name())
 	}
 

internal/pkg/service/cli/cmd/remote/table/create/dialog.go

@@ -194,7 +194,7 @@ func ParseJSONInputForCreateTable(filePath string) ([]keboola.Column, error) {
 
 // getOptionCreateRequest returns Options.CreateTableRequest from the flags (columns, primary keys, table name). It is used if the `columns-from` flag is not specified.
 func getOptionCreateRequest(columns []string) []keboola.Column {
-	var c []keboola.Column
+	c := make([]keboola.Column, 0, len(columns))
 	for _, column := range columns {
 		var col keboola.Column
 		col.Name = column

internal/pkg/service/cli/cmd/template/create/dialog.go

@@ -305,7 +305,7 @@ func (d *templateIdsDialog) parse(result string) ([]create.ConfigDef, error) {
 		return nil, errs.ErrorOrNil()
 	}
 
-	var defs []create.ConfigDef
+	defs := make([]create.ConfigDef, 0, len(d.configs))
 	for _, c := range d.configs {
 		// Config definition
 		id := idByKey[c.Key().String()]

internal/pkg/service/cli/dialog/inputs.go

@@ -56,9 +56,9 @@ func (p *Dialogs) AskNewTemplateInputs(ctx context.Context, deps inputsDialogDep
 type inputFields map[string]input.ObjectField
 
 func (f inputFields) Write(out *strings.Builder) {
-	var table []inputFieldLine
 	var inputIDMaxLength int
 	var fieldPathMaxLength int
+	table := make([]inputFieldLine, 0, len(f))
 
 	// Convert and get max lengths for padding
 	for _, field := range f {

internal/pkg/service/cli/dialog/table.go

@@ -69,7 +69,7 @@ func (p *Dialogs) AskTable(allTables []*keboola.Table, id configmap.Value[string
 		return nil, errors.Errorf(`table with ID "%s" not found in the project`, tableID)
 	}
 
-	var selectOpts []string
+	selectOpts := make([]string, 0, len(allTables)+1)
 	if config.allowCreateNew {
 		selectOpts = []string{"Create a new table"}
 	}

internal/pkg/service/common/etcdop/session_test.go

@@ -116,7 +116,7 @@ func TestSessionBackoff(t *testing.T) {
 	b.RandomizationFactor = 0
 
 	// Get all delays without sleep
-	var delays []time.Duration
+	delays := make([]time.Duration, 0, 14)
 	for range 14 {
 		delay := b.NextBackOff()
 		if delay == backoff.Stop {

internal/pkg/service/common/etcdop/watch_test.go

@@ -553,7 +553,7 @@ func TestWatchBackoff(t *testing.T) {
 	b.RandomizationFactor = 0
 
 	// Get all delays without sleep
-	var delays []time.Duration
+	delays := make([]time.Duration, 0, 14)
 	for range 14 {
 		delay := b.NextBackOff()
 		if delay == backoff.Stop {

internal/pkg/service/stream/api/service/aggregation.go

@@ -30,7 +30,7 @@ func (s *service) AggregationSources(ctx context.Context, d dependencies.BranchR
 
 func (s *service) addSinksToAggregationResponse(ctx context.Context, d dependencies.BranchRequestScope, response *stream.AggregatedSourcesResult) error {
 	// Collect source IDs
-	var sourceKeys []key.SourceKey
+	sourceKeys := make([]key.SourceKey, 0, len(response.Sources))
 	for _, source := range response.Sources {
 		sourceKey := key.SourceKey{
 			BranchKey: d.BranchKey(),

internal/pkg/service/stream/components.go

@@ -146,10 +146,11 @@ func ParseComponentsList(args []string) (Components, error) {
 }
 
 func (v Components) String() string {
-	var names []string
+	names := make([]string, 0, len(v))
 	for _, n := range v {
 		names = append(names, string(n))
 	}
+
 	sort.Strings(names)
 	return strings.Join(names, ",")
 }

internal/pkg/service/stream/mapping/jsonnet/jsonnet.go

@@ -307,8 +307,8 @@ func bodyPathInternalFn(vm *jsonnet.VM[recordctx.Context]) *jsonnet.NativeFuncti
 }
 
 func applyNativeFn(fnName string, args ...ast.Node) ast.Node {
-	var freeVars []ast.Identifier
-	var fnArgs []ast.CommaSeparatedExpr
+	freeVars := make([]ast.Identifier, 0, len(args))
+	fnArgs := make([]ast.CommaSeparatedExpr, 0, len(args))
 	for _, item := range args {
 		fnArgs = append(fnArgs, ast.CommaSeparatedExpr{Expr: item})
 		// Build list of the freeVars manually, so we can skip parser.PreprocessAst step, it is faster

internal/pkg/service/stream/mapping/table/column/columns.go

@@ -25,8 +25,7 @@ func (v Columns) PrimaryKey() []string {
 }
 
 func (v Columns) MarshalJSON() ([]byte, error) {
-	var items []json.RawMessage
-
+	items := make([]json.RawMessage, 0, len(v))
 	for _, column := range v {
 		typ := column.ColumnType()
 

internal/pkg/service/stream/storage/level/local/volume/assignment/assigner.go

@@ -51,7 +51,7 @@ func VolumesFor(all []volume.Metadata, cfg Config, randomSeed int64) (out Assign
 
 	// Convert map to slice and sort node volumes by the preferred priority.
 	// Volumes with the most preferred volume type are first.
-	var perNode []*nodeVolumes
+	perNode := make([]*nodeVolumes, 0, len(byNode))
 	for nodeID, volumes := range byNode {
 		typePriority.Sort(volumes, randomSeed)
 		perNode = append(perNode, &nodeVolumes{nodeID: nodeID, volumes: newStack[volume.Metadata](volumes)})

internal/pkg/service/stream/storage/node/writernode/diskcleanup/diskcleanup.go

@@ -252,7 +252,7 @@ func (n *Node) volumeDiskDirs(volume *diskwriter.Volume) (out []string, err erro
 }
 
 func (n *Node) removeEmptyDirs(ctx context.Context, dirsMap map[string]bool) error {
-	var dirs []string
+	dirs := make([]string, 0, len(dirsMap))
 	for dir := range dirsMap {
 		dirs = append(dirs, dir)
 	}

internal/pkg/service/stream/storage/statistics/repository/stats_put_test.go

@@ -60,7 +60,7 @@ func TestRepository_Put(t *testing.T) {
 
 	// Many
 	nodeID3 := "test-node-3"
-	var records []statistics.PerSlice
+	records := make([]statistics.PerSlice, 0, 150)
 	start := utctime.MustParse("2000-01-21T00:00:00.000Z")
 	for i := range 150 {
 		openedAt := start.Add(time.Duration(i) * time.Second)

internal/pkg/state/registry/registry.go

@@ -87,7 +87,7 @@ func (s *Registry) All() []ObjectState {
 		return aKey < bKey
 	})
 
-	var out []ObjectState
+	out := make([]ObjectState, 0, len(s.objects.Keys()))
 	for _, key := range s.objects.Keys() {
 		// Get value
 		v, _ := s.objects.Get(key)

internal/pkg/template/context/create/context.go

@@ -126,8 +126,7 @@ func replacementsForCreate(sourceBranch model.BranchKey, configs []ConfigDef) *r
 }
 
 func remoteFilterForCreate(sourceBranch model.BranchKey, configs []ConfigDef) model.ObjectsFilter {
-	var keys []model.Key
-
+	keys := make([]model.Key, 0, len(configs)+1)
 	// Branch
 	keys = append(keys, sourceBranch)