Use tiles-space coords

api/layout/paths.go

@@ -27,32 +27,37 @@ const (
 	CheckpointPath = "checkpoint"
 )
 
-// EntriesPath builds the local path at which the leaf with the given index lives in.
+// EntriesPathForLogIndex() builds the local path at which the leaf with the given index lives in.
 // Note that this will be an entry bundle containing up to 256 entries and thus multiple
 // indices can map to the same output path.
 //
 // TODO(mhutchinson): revisit to consider how partial tile suffixes should be added.
-func EntriesPath(seq uint64) string {
+func EntriesPathForLogIndex(seq uint64) string {
 	seq = seq / 256
+	return EntriesPath(seq)
+}
+
+func EntriesPath(bundleIndex uint64) string {
 	frag := []string{
 		"tile",
 		"entries",
-		fmt.Sprintf("x%03x", (seq>>16)&0xff),
-		fmt.Sprintf("x%03x", (seq>>8)&0xff),
-		fmt.Sprintf("%03x", seq&0xff),
+		fmt.Sprintf("x%03x", (bundleIndex>>16)&0xff),
+		fmt.Sprintf("x%03x", (bundleIndex>>8)&0xff),
+		fmt.Sprintf("%03x", bundleIndex&0xff),
 	}
 	return filepath.Join(frag...)
 }
 
-// TilePath builds the path to the subtree tile with the given level and index.
-func TilePath(level, index uint64) string {
-	seq := index / 256
+// TilePath builds the path to the subtree tile with the given level and index in tile space.
+//
+// Note that NodeCoordsToTileAddress can be used to convert from node- to tile-space.
+func TilePath(tileLevel, tileIndex uint64) string {
 	frag := []string{
 		"tile",
-		fmt.Sprintf("%d", level),
-		fmt.Sprintf("x%03x", (seq>>16)&0xff),
-		fmt.Sprintf("x%03x", (seq>>8)&0xff),
-		fmt.Sprintf("%03x", seq&0xff),
+		fmt.Sprintf("%d", tileLevel),
+		fmt.Sprintf("x%03x", (tileIndex>>16)&0xff),
+		fmt.Sprintf("x%03x", (tileIndex>>8)&0xff),
+		fmt.Sprintf("%03x", tileIndex&0xff),
 	}
 	return filepath.Join(frag...)
 }

api/layout/paths_test.go

@@ -19,7 +19,7 @@ import (
 	"testing"
 )
 
-func TestEntriesPath(t *testing.T) {
+func TestEntriesPathForLogIndex(t *testing.T) {
 	for _, test := range []struct {
 		seq      uint64
 		wantPath string
@@ -37,6 +37,35 @@ func TestEntriesPath(t *testing.T) {
 			seq:      0xffeeddccbb,
 			wantPath: "tile/entries/x0ee/x0dd/0cc",
 		},
+	} {
+		desc := fmt.Sprintf("seq %d", test.seq)
+		t.Run(desc, func(t *testing.T) {
+			gotPath := EntriesPathForLogIndex(test.seq)
+			if gotPath != test.wantPath {
+				t.Errorf("got file %q want %q", gotPath, test.wantPath)
+			}
+		})
+	}
+}
+
+func TestEntriesPath(t *testing.T) {
+	for _, test := range []struct {
+		seq      uint64
+		wantPath string
+	}{
+		{
+			seq:      0,
+			wantPath: "tile/entries/x000/x000/000",
+		}, {
+			seq:      255,
+			wantPath: "tile/entries/x000/x000/0ff",
+		}, {
+			seq:      256,
+			wantPath: "tile/entries/x000/x001/000",
+		}, {
+			seq:      0xdccbb,
+			wantPath: "tile/entries/x00d/x0cc/0bb",
+		},
 	} {
 		desc := fmt.Sprintf("seq %d", test.seq)
 		t.Run(desc, func(t *testing.T) {
@@ -61,7 +90,7 @@ func TestTilePath(t *testing.T) {
 		}, {
 			level:    15,
 			index:    0x455667,
-			wantPath: "tile/15/x000/x045/056",
+			wantPath: "tile/15/x045/x056/067",
 		},
 	} {
 		desc := fmt.Sprintf("level %x index %x", test.level, test.index)