db: use testkeys comparer in TestTracing

We need a comparer that supports suffixes to extend the test with
range keys. Note that the testkeys comparer has a worse `Separator`
implementation when there are no suffixes, leading to the slightly
larger index block.

Author: RaduBerinde

db_test.go

@@ -25,6 +25,7 @@ import (
 	"github.com/cockroachdb/fifo"
 	"github.com/cockroachdb/pebble/internal/base"
 	"github.com/cockroachdb/pebble/internal/cache"
+	"github.com/cockroachdb/pebble/internal/testkeys"
 	"github.com/cockroachdb/pebble/internal/testutils"
 	"github.com/cockroachdb/pebble/objstorage/objstorageprovider"
 	"github.com/cockroachdb/pebble/sstable"
@@ -1447,6 +1448,7 @@ func TestTracing(t *testing.T) {
 			}
 			db = testutils.CheckErr(Open("", &Options{
 				FS:              vfs.NewMem(),
+				Comparer:        testkeys.Comparer,
 				Cache:           cache,
 				LoggerAndTracer: &tracer,
 			}))

testdata/tracing

@@ -7,8 +7,8 @@ hello
 ----
 reading footer of 53 bytes took 5ms
 reading block of 37 bytes took 5ms (<redacted>)
-reading block of 419 bytes took 5ms (<redacted>)
-reading block of 27 bytes took 5ms (<redacted>)
+reading block of 417 bytes took 5ms (<redacted>)
+reading block of 31 bytes took 5ms (<redacted>)
 reading block of 32 bytes took 5ms (<redacted>)
 hello:foo
 
@@ -21,20 +21,20 @@ hello:foo
 iter
 seek-ge hello
 ----
-reading block of 27 bytes took 5ms (<redacted>)
+reading block of 31 bytes took 5ms (<redacted>)
 reading block of 32 bytes took 5ms (<redacted>)
 hello: (foo, .)
 
 snapshot-iter
 seek-ge hello
 ----
-reading block of 27 bytes took 5ms (<redacted>)
+reading block of 31 bytes took 5ms (<redacted>)
 reading block of 32 bytes took 5ms (<redacted>)
 hello: (foo, .)
 
 indexed-batch-iter
 seek-ge hello
 ----
-reading block of 27 bytes took 5ms (<redacted>)
+reading block of 31 bytes took 5ms (<redacted>)
 reading block of 32 bytes took 5ms (<redacted>)
 hello: (foo, .)