1 files changed, 14 insertions, 74 deletions

diff --git a/internal/pkg/pkg.go b/internal/pkg/pkg.go
index 76bae916..154e20b0 100644
--- a/internal/pkg/pkg.go
+++ b/internal/pkg/pkg.go
@@ -65,35 +65,6 @@ func MustDecode(s string) (checksum Checksum) {
 	return
 }
 
-// IContext is passed to [Artifact.Params] and provides identifier information
-// and the target [hash.Hash] for writing params into.
-//
-// Methods of IContext are safe for concurrent use. IContext is valid
-// until [Artifact.Params] returns.
-type IContext struct {
-	// Address of underlying [Cache], should be zeroed or made unusable after
-	// [Artifact.Params] returns and must not be exposed directly.
-	cache *Cache
-	// Made available for writing, should be zeroed after [Artifact.Params]
-	// returns. Internal state must not be inspected.
-	h hash.Hash
-}
-
-// Unwrap returns the underlying [context.Context].
-func (i *IContext) Unwrap() context.Context { return i.cache.ctx }
-
-// GetHash returns the underlying [hash.Hash] for writing. Callers must not
-// attempt to inspect its internal state.
-func (i *IContext) GetHash() hash.Hash { return i.h }
-
-// WriteIdent writes the identifier of [Artifact] to the underlying [hash.Hash].
-func (i *IContext) WriteIdent(a Artifact) {
-	buf := i.cache.getIdentBuf()
-	*(*ID)(buf[wordSize:]) = i.cache.Ident(a).Value()
-	i.h.Write(buf[wordSize:])
-	i.cache.putIdentBuf(buf)
-}
-
 // TContext is passed to [TrivialArtifact.Cure] and provides information and
 // methods required for curing the [TrivialArtifact].
 //
@@ -238,10 +209,12 @@ type Artifact interface {
 	// [Artifact] is allowed to return the same [Kind] value.
 	Kind() Kind
 
-	// Params writes opaque bytes that describes [Artifact]. Implementations
+	// Params writes deterministic values describing [Artifact]. Implementations
 	// must guarantee that these values are unique among differing instances
-	// of the same implementation with the same dependencies. Callers must not
-	// attempt to interpret these params.
+	// of the same implementation with identical dependencies and conveys enough
+	// information to create another instance of [Artifact] identical to the
+	// instance emitting these values. The new instance created via [IRReadFunc]
+	// from these values must then produce identical IR values.
 	//
 	// Result must remain identical across multiple invocations.
 	Params(ctx *IContext)
@@ -564,47 +537,13 @@ func (c *Cache) unsafeIdent(a Artifact, encodeKind bool) (
 		return
 	}
 
-	deps := a.Dependencies()
-	idents := make([]*extIdent, len(deps))
-	for i, d := range deps {
-		dbuf, did := c.unsafeIdent(d, true)
-		if dbuf == nil {
-			dbuf = c.getIdentBuf()
-			binary.LittleEndian.PutUint64(dbuf[:], uint64(d.Kind()))
-			*(*ID)(dbuf[wordSize:]) = did.Value()
-		} else {
-			c.storeIdent(d, dbuf)
-		}
-		defer c.putIdentBuf(dbuf)
-		idents[i] = dbuf
-	}
-	slices.SortFunc(idents, func(a, b *extIdent) int {
-		return bytes.Compare(a[:], b[:])
-	})
-	idents = slices.CompactFunc(idents, func(a, b *extIdent) bool {
-		return *a == *b
-	})
-
 	buf = c.getIdentBuf()
 	h := sha512.New384()
-	binary.LittleEndian.PutUint64(buf[:], uint64(a.Kind()))
-	h.Write(buf[:wordSize])
-	for _, dn := range idents {
-		h.Write(dn[:])
-	}
-	kcBuf := c.getIdentBuf()
-	if kc, ok := a.(KnownChecksum); ok {
-		*(*Checksum)(kcBuf[:]) = kc.Checksum()
-	} else {
-		*(*Checksum)(kcBuf[:]) = Checksum{}
+	if err := c.Encode(h, a); err != nil {
+		// unreachable
+		panic(err)
 	}
-	h.Write((*Checksum)(kcBuf[:])[:])
-	c.putIdentBuf(kcBuf)
-
-	i := IContext{c, h}
-	a.Params(&i)
-	i.cache, i.h = nil, nil
-
+	binary.LittleEndian.PutUint64(buf[:], uint64(a.Kind()))
 	h.Sum(buf[wordSize:wordSize])
 	return
 }
@@ -1000,8 +939,9 @@ func (c *Cache) openFile(f FileArtifact) (r io.ReadCloser, err error) {
 	return
 }
 
-// InvalidFileModeError describes an [Artifact.Cure] that did not result in
-// a regular file or directory located at the work pathname.
+// InvalidFileModeError describes a [FloodArtifact.Cure] or
+// [TrivialArtifact.Cure] that did not result in a regular file or directory
+// located at the work pathname.
 type InvalidFileModeError fs.FileMode
 
 // Error returns a constant string.
@@ -1009,8 +949,8 @@ func (e InvalidFileModeError) Error() string {
 	return "artifact did not produce a regular file or directory"
 }
 
-// NoOutputError describes an [Artifact.Cure] that did not populate its
-// work pathname despite completing successfully.
+// NoOutputError describes a [FloodArtifact.Cure] or [TrivialArtifact.Cure]
+// that did not populate its work pathname despite completing successfully.
 type NoOutputError struct{}
 
 // Unwrap returns [os.ErrNotExist].