fix(filter): create hybrid scheme (#164)

Taskfile.yml

@@ -80,7 +80,7 @@ tasks:
     cmds:
       - go test ./core
 
-  tf-filter:
+  tf:
     cmds:
       - go test ./internal/filtering
 
@@ -191,7 +191,6 @@ tasks:
       - mkdir -p ./internal/kernel/coverage
       - mkdir -p ./internal/level/coverage
       - mkdir -p ./internal/measure/coverage
-      - mkdir -p ./internal/override/coverage
       - mkdir -p ./internal/services/coverage
       - mkdir -p ./internal/level/coverage
       - mkdir -p ./internal/third/bus/coverage

builders.go

@@ -4,7 +4,6 @@ import (
 	"github.com/snivilised/traverse/enums"
 	"github.com/snivilised/traverse/internal/kernel"
 	"github.com/snivilised/traverse/internal/measure"
-	"github.com/snivilised/traverse/internal/override"
 	"github.com/snivilised/traverse/internal/third/lo"
 	"github.com/snivilised/traverse/internal/types"
 	"github.com/snivilised/traverse/pref"
@@ -18,6 +17,7 @@ type buildArtefacts struct {
 }
 
 type Builders struct {
+	using     *pref.Using
 	readerFS  pref.ReadDirFileSystemBuilder
 	queryFS   pref.QueryStatusFileSystemBuilder
 	options   optionsBuilder
@@ -48,22 +48,6 @@ func (bs *Builders) buildAll() (*buildArtefacts, error) {
 
 	// BUILD NAVIGATOR
 	//
-	actions := &override.Actions{
-		HandleChildren: override.NewActionCtrl[override.HandleChildrenInterceptor](
-			func(inspection override.Inspection, mums measure.MutableMetrics) {
-				// [KEEP-FILTER-IN-SYNC] keep this in sync with filter-plugin/childScheme.init
-				files := inspection.Sort(enums.EntryTypeFile)
-				inspection.AssignChildren(files)
-
-				// The behaviour of this default child handler is to assign
-				// the children and tick the metrics. However, when filtering is
-				// active, then this handler should be overridden by the filter
-				// to only tick the child metric, if their parent is filtered in.
-				//
-				mums[enums.MetricNoChildFilesFound].Times(uint(len(files)))
-			},
-		),
-	}
 
 	artefacts, navErr := bs.navigator.Build(o, &types.Resources{
 		FS: FileSystems{
@@ -72,7 +56,6 @@ func (bs *Builders) buildAll() (*buildArtefacts, error) {
 			R: ext.resFS(),
 		},
 		Supervisor: measure.New(),
-		Actions:    actions,
 	})
 
 	if navErr != nil {
@@ -86,6 +69,7 @@ func (bs *Builders) buildAll() (*buildArtefacts, error) {
 	// BUILD PLUGINS
 	//
 	plugins, pluginsErr := bs.plugins.build(o,
+		bs.using,
 		artefacts.Mediator,
 		artefacts.Kontroller,
 		ext.plugin(artefacts),
@@ -109,7 +93,6 @@ func (bs *Builders) buildAll() (*buildArtefacts, error) {
 	order := manifest(active)
 	artefacts.Mediator.Arrange(active, order)
 	pi := &types.PluginInit{
-		Actions:  actions,
 		O:        o,
 		Controls: artefacts.Mediator.Controls(),
 	}

director.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/snivilised/traverse/internal/feat/filter"
 	"github.com/snivilised/traverse/internal/feat/hiber"
+	"github.com/snivilised/traverse/internal/feat/nanny"
 	"github.com/snivilised/traverse/internal/feat/resume"
 	"github.com/snivilised/traverse/internal/feat/sampling"
 	"github.com/snivilised/traverse/internal/kernel"
@@ -13,12 +14,12 @@ import (
 	"github.com/snivilised/traverse/pref"
 )
 
-type ifActive func(o *pref.Options, mediator types.Mediator) types.Plugin
+type ifActive func(o *pref.Options, using *pref.Using, mediator types.Mediator) types.Plugin
 
 // features interrogates options and invokes requests on behalf of the user
 // to activate features according to option selections. other plugins will
 // be initialised after primary plugins
-func features(o *pref.Options, mediator types.Mediator,
+func features(o *pref.Options, using *pref.Using, mediator types.Mediator,
 	kc types.KernelController,
 	others ...types.Plugin,
 ) (plugins []types.Plugin, err error) {
@@ -29,7 +30,7 @@ func features(o *pref.Options, mediator types.Mediator,
 			// order. How can we decouple ourselves from this
 			// requirement? => the cure is worse than the disease
 			//
-			hiber.IfActive, filter.IfActive, sampling.IfActive,
+			hiber.IfActive, nanny.IfActive, filter.IfActive, sampling.IfActive,
 		}
 	)
 
@@ -44,7 +45,7 @@ func features(o *pref.Options, mediator types.Mediator,
 		},
 		lo.Reduce(all,
 			func(acc []types.Plugin, query ifActive, _ int) []types.Plugin {
-				if plugin := query(o, mediator); plugin != nil {
+				if plugin := query(o, using, mediator); plugin != nil {
 					acc = append(acc, plugin)
 				}
 				return acc
@@ -73,6 +74,7 @@ func Prime(using *pref.Using, settings ...pref.Option) *Builders {
 	// by a panic.
 	//
 	return &Builders{
+		using: using,
 		readerFS: pref.CreateReadDirFS(func() fs.ReadDirFS {
 			if using.GetReadDirFS != nil {
 				return using.GetReadDirFS()
@@ -129,6 +131,7 @@ func Resume(was *Was, settings ...pref.Option) *Builders {
 	// path was.
 	//
 	return &Builders{
+		using: &was.Using,
 		readerFS: pref.CreateReadDirFS(func() fs.ReadDirFS {
 			if was.Using.GetReadDirFS != nil {
 				return was.Using.GetReadDirFS()

enums/metric-en.go

@@ -7,9 +7,11 @@ type Metric uint
 // if new metrics are added, ensure that navigationMetricsFactory.new is kept
 // in sync.
 const (
+	_ Metric = iota
+
 	// MetricNoFilesInvoked represents the no of files invoked for during traversal
 	//
-	MetricNoFilesInvoked Metric = iota // metric-no-of-files
+	MetricNoFilesInvoked // metric-no-of-files
 
 	// MetricNoFilesFilteredOut represents the no of files filtered out
 	//

enums/role-en.go

@@ -10,4 +10,5 @@ const (
 	RoleClientFilter             // client-filter-role
 	RoleHibernate                // hibernate-role
 	RoleSampler                  // sampler-role
+	RoleNanny                    // nanny-role
 )

internal-traverse-defs.go

@@ -21,24 +21,27 @@ func (fn optionals) build(ext extent) (*pref.Options, error) {
 // pluginsBuilder
 type pluginsBuilder interface {
 	build(o *pref.Options,
+		using *pref.Using,
 		mediator types.Mediator,
 		kc types.KernelController,
 		others ...types.Plugin,
 	) ([]types.Plugin, error)
 }
 
 type activated func(*pref.Options,
+	*pref.Using,
 	types.Mediator,
 	types.KernelController,
 	...types.Plugin,
 ) ([]types.Plugin, error)
 
 func (fn activated) build(o *pref.Options,
+	using *pref.Using,
 	mediator types.Mediator,
 	kc types.KernelController,
 	others ...types.Plugin,
 ) ([]types.Plugin, error) {
-	return fn(o, mediator, kc, others...)
+	return fn(o, using, mediator, kc, others...)
 }
 
 type fsBuilder interface {

internal/feat/filter/errors.go

@@ -0,0 +1,20 @@
+package filter
+
+import (
+	"github.com/pkg/errors"
+)
+
+// ❌ InvalidNotificationMuteRequested error: this scenario should
+// never happen, if it does then its an internal issue to be
+// addressed here in the filter plugin.
+
+// IsNoSubordinateHybridSchemesDefinedError uses errors.Is to check
+// if the err's error tree contains the core error:
+// InvalidNotificationMuteRequestedError
+func IsNoSubordinateHybridSchemesDefinedError(err error) bool {
+	return errors.Is(err, ErrNoSubordinateHybridSchemesDefined)
+}
+
+var ErrNoSubordinateHybridSchemesDefined = errors.New(
+	"invalid filter scheme, both primary and child not set",
+)

internal/feat/filter/filter-plugin.go

@@ -7,14 +7,13 @@ import (
 	"github.com/snivilised/traverse/enums"
 	"github.com/snivilised/traverse/internal/kernel"
 	"github.com/snivilised/traverse/internal/measure"
-	"github.com/snivilised/traverse/internal/override"
 	"github.com/snivilised/traverse/internal/types"
 	"github.com/snivilised/traverse/pref"
 )
 
-func IfActive(o *pref.Options, mediator types.Mediator) types.Plugin {
+func IfActive(o *pref.Options, _ *pref.Using, mediator types.Mediator) types.Plugin {
 	if o.Filter.IsFilteringActive() {
-		return &Plugin{
+		return &plugin{
 			BasePlugin: kernel.BasePlugin{
 				O:             o,
 				Mediator:      mediator,
@@ -28,28 +27,31 @@ func IfActive(o *pref.Options, mediator types.Mediator) types.Plugin {
 	return nil
 }
 
-// Plugin manages all filtering aspects of navigation
-type Plugin struct {
+// plugin manages all filtering aspects of navigation
+type plugin struct {
 	kernel.BasePlugin
 	sink   pref.FilteringSink
 	crate  measure.Crate
 	scheme scheme
 }
 
-func (p *Plugin) Name() string {
+func (p *plugin) Name() string {
 	return "filtering"
 }
 
-func (p *Plugin) Register(kc types.KernelController) error {
-	p.Kontroller = kc
+func (p *plugin) Register(kc types.KernelController) error {
+	if err := p.BasePlugin.Register(kc); err != nil {
+		return err
+	}
+
 	return p.scheme.create()
 }
 
-func (p *Plugin) Next(node *core.Node, inspection override.Inspection) (bool, error) {
+func (p *plugin) Next(node *core.Node, inspection types.Inspection) (bool, error) {
 	return p.scheme.next(node, inspection)
 }
 
-func (p *Plugin) Init(pi *types.PluginInit) error {
+func (p *plugin) Init(pi *types.PluginInit) error {
 	p.crate.Mums = p.Mediator.Supervisor().Many(
 		enums.MetricNoFoldersFilteredOut,
 		enums.MetricNoFilesFilteredOut,

internal/feat/filter/scheme-custom.go

@@ -0,0 +1,49 @@
+package filter
+
+import (
+	"github.com/snivilised/traverse/core"
+	"github.com/snivilised/traverse/enums"
+	"github.com/snivilised/traverse/internal/measure"
+	"github.com/snivilised/traverse/internal/third/lo"
+	"github.com/snivilised/traverse/internal/types"
+	"github.com/snivilised/traverse/pref"
+)
+
+type customScheme struct {
+	common
+	filter core.TraverseFilter
+}
+
+func (s *customScheme) create() error {
+	s.filter = s.o.Filter.Custom
+
+	if s.o.Filter.Sink != nil {
+		s.o.Filter.Sink(pref.FilterReply{
+			Node: s.filter,
+		})
+	}
+
+	return s.filter.Validate()
+}
+
+func (s *customScheme) next(node *core.Node,
+	_ types.Inspection,
+) (bool, error) {
+	return matchNext(s.filter, node, s.crate)
+}
+
+func matchNext(filter core.TraverseFilter,
+	node *core.Node, crate *measure.Crate,
+) (bool, error) {
+	matched := filter.IsMatch(node)
+
+	if !matched {
+		filteredOutMetric := lo.Ternary(node.IsFolder(),
+			enums.MetricNoFoldersFilteredOut,
+			enums.MetricNoFilesFilteredOut,
+		)
+		crate.Mums[filteredOutMetric].Tick()
+	}
+
+	return matched, nil
+}