cache fs/thunk paths to more useful filenames

pkg/bass/cache_path.go

@@ -2,8 +2,6 @@ package bass
 
 import (
 	"context"
-	"encoding/base64"
-	"encoding/binary"
 	"fmt"
 	"path/filepath"
 	"strings"
@@ -44,9 +42,7 @@ func (value CachePath) String() string {
 
 // Hash returns a non-cryptographic hash of the cache path's ID.
 func (value CachePath) Hash() string {
-	var sum [8]byte
-	binary.BigEndian.PutUint64(sum[:], xxh3.HashString(value.ID))
-	return base64.URLEncoding.EncodeToString(sum[:])
+	return b64(xxh3.HashString(value.ID))
 }
 
 func (value CachePath) Equal(other Value) bool {

pkg/bass/fspath.go

@@ -108,6 +108,7 @@ func (combiner *FSPath) Call(ctx context.Context, val Value, scope *Scope, cont
 var _ Path = (*FSPath)(nil)
 
 func (path *FSPath) Name() string {
+	// TODO: should this special-case ./ to return the path hash?
 	return path.Path.FilesystemPath().Name()
 }
 
@@ -131,7 +132,7 @@ func (fsp *FSPath) CachePath(ctx context.Context, dest string) (string, error) {
 		return "", err
 	}
 
-	return Cache(ctx, filepath.Join(dest, "fs", hash), fsp)
+	return Cache(ctx, filepath.Join(dest, "fs", hash, fsp.Path.FilesystemPath().FromSlash()), fsp)
 }
 
 func (fsp *FSPath) Open(ctx context.Context) (io.ReadCloser, error) {

pkg/bass/host_path.go

@@ -2,8 +2,6 @@ package bass
 
 import (
 	"context"
-	"encoding/base64"
-	"encoding/binary"
 	"fmt"
 	"io"
 	"os"
@@ -51,9 +49,7 @@ func (value HostPath) String() string {
 
 // Hash returns a non-cryptographic hash of the host path's context dir.
 func (value HostPath) Hash() string {
-	var sum [8]byte
-	binary.BigEndian.PutUint64(sum[:], xxh3.HashString(value.ContextDir))
-	return base64.URLEncoding.EncodeToString(sum[:])
+	return b64(xxh3.HashString(value.ContextDir))
 }
 
 func (value HostPath) Equal(other Value) bool {

pkg/bass/thunk.go

@@ -4,9 +4,7 @@ import (
 	"context"
 	"encoding/base64"
 	"encoding/binary"
-	"encoding/json"
 	"fmt"
-	"hash/fnv"
 	"io"
 	"log"
 	"math/rand"
@@ -490,46 +488,53 @@ func (thunk *Thunk) Platform() *Platform {
 
 // Hash returns a stable, non-cryptographic hash derived from the thunk.
 func (thunk Thunk) Hash() (string, error) {
-	msg, err := thunk.MarshalProto()
+	hash, err := thunk.hash()
 	if err != nil {
 		return "", err
 	}
 
-	payload, err := gproto.Marshal(msg)
-	if err != nil {
-		return "", err
-	}
-
-	var sum [8]byte
-	binary.BigEndian.PutUint64(sum[:], xxh3.Hash(payload))
-	return base64.URLEncoding.EncodeToString(sum[:]), nil
+	return b64(hash), nil
 }
 
 // Avatar returns an ASCII art avatar derived from the thunk.
 func (wl Thunk) Avatar() (*invaders.Invader, error) {
-	payload, err := json.Marshal(wl)
-	if err != nil {
-		return nil, err
-	}
-
-	h := fnv.New64a()
-	_, err = h.Write(payload)
+	hash, err := wl.hash()
 	if err != nil {
 		return nil, err
 	}
 
 	invader := &invaders.Invader{}
-	invader.Set(rand.New(rand.NewSource(int64(h.Sum64()))))
+	invader.Set(rand.New(rand.NewSource(int64(hash))))
 	return invader, nil
 }
 
 var _ Readable = Thunk{}
 
 func (thunk Thunk) CachePath(ctx context.Context, dest string) (string, error) {
-	digest, err := thunk.Hash()
+	hash, err := thunk.Hash()
 	if err != nil {
 		return "", err
 	}
 
-	return Cache(ctx, filepath.Join(dest, "thunk-outputs", digest), thunk)
+	return Cache(ctx, filepath.Join(dest, "thunk-outputs", hash), thunk)
+}
+
+func (thunk Thunk) hash() (uint64, error) {
+	msg, err := thunk.MarshalProto()
+	if err != nil {
+		return 0, err
+	}
+
+	payload, err := gproto.Marshal(msg)
+	if err != nil {
+		return 0, err
+	}
+
+	return xxh3.Hash(payload), nil
+}
+
+func b64(n uint64) string {
+	var sum [8]byte
+	binary.BigEndian.PutUint64(sum[:], n)
+	return base64.URLEncoding.EncodeToString(sum[:])
 }

pkg/bass/thunk_path.go

@@ -3,17 +3,13 @@ package bass
 import (
 	"archive/tar"
 	"context"
-	"encoding/base64"
-	"encoding/binary"
 	"fmt"
 	"io"
 	"path/filepath"
 	"strings"
 
 	"github.com/vito/bass/pkg/proto"
-	"github.com/zeebo/xxh3"
 	"google.golang.org/protobuf/encoding/protojson"
-	gproto "google.golang.org/protobuf/proto"
 )
 
 // A path created by a thunk.
@@ -24,23 +20,6 @@ type ThunkPath struct {
 
 var _ Value = ThunkPath{}
 
-// Hash returns a non-cryptographic hash derived from the thunk path.
-func (thunkPath ThunkPath) Hash() (string, error) {
-	msg, err := thunkPath.MarshalProto()
-	if err != nil {
-		return "", err
-	}
-
-	payload, err := gproto.Marshal(msg)
-	if err != nil {
-		return "", err
-	}
-
-	var sum [8]byte
-	binary.BigEndian.PutUint64(sum[:], xxh3.Hash(payload))
-	return base64.URLEncoding.EncodeToString(sum[:]), nil
-}
-
 func (value ThunkPath) String() string {
 	return fmt.Sprintf("%s/%s", value.Thunk, strings.TrimPrefix(value.Path.Slash(), "./"))
 }
@@ -170,12 +149,12 @@ func (path ThunkPath) Dir() ThunkPath {
 var _ Readable = ThunkPath{}
 
 func (path ThunkPath) CachePath(ctx context.Context, dest string) (string, error) {
-	digest, err := path.Hash()
+	digest, err := path.Thunk.Hash()
 	if err != nil {
 		return "", err
 	}
 
-	return Cache(ctx, filepath.Join(dest, "thunk-paths", digest), path)
+	return Cache(ctx, filepath.Join(dest, "thunk-paths", digest, path.Path.FilesystemPath().FromSlash()), path)
 }
 
 func (path ThunkPath) Open(ctx context.Context) (io.ReadCloser, error) {