chore: revert custom index in favor of key_Split

Signed-off-by: Keith Zantow <keith.zantow@anchore.com>

internal/archive/notify.go

@@ -6,54 +6,15 @@ import (
 
 // Notify receives structured events from archive extraction. A nil Notify is the no-op.
 //
-// The signature is deliberately `func(any)` rather than a set of typed callbacks or an interface with
-// a method per event. Extraction is a hot path - a scan of a big image enters thousands of archives -
-// and what instrumentation costs there has to be nothing when it is off. A single func field is one
-// nil check, and a handler that cares about one event type asserts for it and ignores the rest, so
-// adding an event never changes a signature or breaks a handler that did not ask for it.
-//
-// Guard the call rather than relying on a nil check inside the callee:
+// func(any) rather than typed callbacks so adding an event changes no signature: a handler asserts
+// for the events it wants and ignores the rest. Boxing into an any allocates, so on this hot path
+// guard the call rather than relying on a nil check inside the callee:
 //
 //	if notify != nil {
 //		notify(EntriesOverflowed{Archive: name, Bytes: n})
 //	}
-//
-// Building the event value is what costs - putting a struct in an `any` allocates - so the guard is
-// what makes "off" free rather than merely cheap. Send exists for the paths where that does not
-// matter.
 type Notify func(msg any)
 
-// Send delivers one event, doing nothing when there is no handler. Convenient, but it builds the
-// event whether or not anyone is listening: on a hot path, guard the call instead.
-func (n Notify) Send(msg any) {
-	if n == nil {
-		return
-	}
-	n(msg)
-}
-
-// Tee returns a Notify that delivers to each of the given handlers, skipping the nil ones, and nil
-// when none of them are live - so a tee of nothing stays free.
-func Tee(handlers ...Notify) Notify {
-	var live []Notify
-	for _, h := range handlers {
-		if h != nil {
-			live = append(live, h)
-		}
-	}
-	switch len(live) {
-	case 0:
-		return nil
-	case 1:
-		return live[0]
-	}
-	return func(msg any) {
-		for _, h := range live {
-			h(msg)
-		}
-	}
-}
-
 // OverflowReason says why content was written to disk rather than held.
 type OverflowReason string
 
@@ -61,12 +22,12 @@ const (
 	// MemoryLimitReached means the scan was already holding as much as the memory limit admits.
 	MemoryLimitReached OverflowReason = "memory limit reached"
 
-	// MemoryHoldsNothing means the memory limit is zero, so nothing is ever held and every archive's
-	// content goes to disk by policy rather than by pressure.
+	// MemoryHoldsNothing means the memory limit is zero, so content goes to disk by policy rather than
+	// under pressure.
 	MemoryHoldsNothing OverflowReason = "memory limit is zero"
 )
 
-// ContentOverflowed reports that one archive's own bytes were written to disk instead of being held in
+// ContentOverflowed reports that one archive's own bytes were written to disk rather than held in
 // memory. Bytes is the size of the archive.
 type ContentOverflowed struct {
 	Archive string
@@ -74,9 +35,9 @@ type ContentOverflowed struct {
 	Reason  OverflowReason
 }
 
-// EntriesOverflowed reports that the entries an archive's store was holding have been written to its
-// overflow blob. Entries and Bytes are what moved, not what the archive holds in total: a store spills
-// everything it is holding at once, and may spill more than once as it fills again.
+// EntriesOverflowed reports that the entries a store was holding were written to its overflow blob.
+// Entries and Bytes are what moved in this spill, not the archive's totals: a store spills everything
+// it holds at once, and may spill again as it refills.
 type EntriesOverflowed struct {
 	Archive string
 	Entries int
@@ -84,23 +45,21 @@ type EntriesOverflowed struct {
 	Reason  OverflowReason
 }
 
-// Skipped reports that an archive contributed nothing, and why. Not a failure - the scan
-// continues - but the packages inside it are absent from the SBOM, which is worth being able to see.
+// Skipped reports that an archive contributed nothing, and why. The scan continues, but any packages
+// inside that archive are absent from the SBOM.
 type Skipped struct {
 	Archive string
 	Reason  string
 }
 
-// Truncated reports that an archive was cataloged from part of its contents, naming the bound
-// that stopped it.
+// Truncated reports that an archive was cataloged from part of its contents, naming the bound that
+// stopped it.
 type Truncated struct {
 	Archive string
 	Reason  TruncationReason
 }
 
-// LogNotify is the default handler: it writes each event to the debug log. Anything it does not
-// recognize is ignored rather than logged blindly, so an event added for one consumer does not turn
-// into noise for everyone.
+// LogNotify is the default handler: it writes each known event to the debug log and ignores the rest.
 func LogNotify(msg any) {
 	switch e := msg.(type) {
 	case ContentOverflowed: