internal/pkg: append user-facing name in messages

This makes verbose messages much more useful.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/pkg/net.go

@@ -3,8 +3,10 @@ package pkg
 import (
 	"context"
 	"crypto/sha512"
+	"fmt"
 	"io"
 	"net/http"
+	"path"
 	"sync"
 )
 
@@ -30,6 +32,7 @@ type httpArtifact struct {
 }
 
 var _ KnownChecksum = new(httpArtifact)
+var _ fmt.Stringer = new(httpArtifact)
 
 // NewHTTPGet returns a new [File] backed by the supplied client. A GET request
 // is set up for url. If c is nil, [http.DefaultClient] is used instead.
@@ -57,6 +60,9 @@ func (a *httpArtifact) Dependencies() []Artifact { return nil }
 // Checksum returns the caller-supplied checksum.
 func (a *httpArtifact) Checksum() Checksum { return a.checksum }
 
+// String returns [path.Base] over the backing url.
+func (a *httpArtifact) String() string { return path.Base(a.url) }
+
 // ResponseStatusError is returned for a response returned by an [http.Client]
 // with a status code other than [http.StatusOK].
 type ResponseStatusError int

internal/pkg/pkg.go

@@ -8,6 +8,7 @@ import (
 	"encoding/base64"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"io"
 	"io/fs"
 	"os"
@@ -278,6 +279,20 @@ func Ident(a Artifact) ID {
 	return a.Kind().Ident(a.Params(), a.Dependencies()...)
 }
 
+// reportNameIdent is like reportName but does not recompute [ID].
+func reportNameIdent(a Artifact, id ID) string {
+	r := Encode(id)
+	if s, ok := a.(fmt.Stringer); ok {
+		if name := s.String(); name != "" {
+			r += "-" + name
+		}
+	}
+	return r
+}
+
+// reportName returns a string describing [Artifact] presented to the user.
+func reportName(a Artifact) string { return reportNameIdent(a, Ident(a)) }
+
 // Kind corresponds to the concrete type of [Artifact] and is used to create
 // identifier for an [Artifact] with dependencies.
 type Kind uint64
@@ -725,6 +740,9 @@ func (c *Cache) openFile(f File) (r io.ReadCloser, err error) {
 		if !errors.Is(err, os.ErrNotExist) {
 			return
 		}
+		if c.msg.IsVerbose() {
+			c.msg.Verbosef("curing %s to memory...", reportName(f))
+		}
 		var data []byte
 		if data, err = f.Cure(c.ctx); err != nil {
 			return
@@ -917,7 +935,7 @@ func (c *Cache) Cure(a Artifact) (
 	}
 
 	if c.msg.IsVerbose() {
-		c.msg.Verbosef("curing %s...", Encode(id))
+		c.msg.Verbosef("curing %s...", reportNameIdent(a, id))
 	}
 
 	// cure File outside type switch to skip TContext initialisation

internal/pkg/tar.go

@@ -6,6 +6,7 @@ import (
 	"compress/gzip"
 	"encoding/binary"
 	"errors"
+	"fmt"
 	"io"
 	"io/fs"
 	"net/http"
@@ -32,11 +33,29 @@ type tarArtifact struct {
 	compression uint64
 }
 
+// tarArtifactNamed embeds tarArtifact for a [fmt.Stringer] tarball.
+type tarArtifactNamed struct {
+	tarArtifact
+	// Copied from tarArtifact.f.
+	name string
+}
+
+var _ fmt.Stringer = new(tarArtifactNamed)
+
+// String returns the name of the underlying [Artifact] suffixed with unpack.
+func (a *tarArtifactNamed) String() string { return a.name + "-unpack" }
+
 // NewTar returns a new [Artifact] backed by the supplied [Artifact] and
 // compression method. The source [Artifact] must be compatible with
 // [TContext.Open].
 func NewTar(a Artifact, compression uint64) Artifact {
-	return &tarArtifact{a, compression}
+	ta := tarArtifact{a, compression}
+	if s, ok := a.(fmt.Stringer); ok {
+		if name := s.String(); name != "" {
+			return &tarArtifactNamed{ta, name}
+		}
+	}
+	return &ta
 }
 
 // NewHTTPGetTar is abbreviation for NewHTTPGet passed to NewTar.