colblk: show iter commands

It's pretty hard to look at an `iter` testcase and see which key
matches which command. This commit adds a `ShowCommands` option and
uses it for the data block tests.

internal/itertest/datadriven.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/cockroachdb/crlib/crstrings"
 	"github.com/cockroachdb/datadriven"
 	"github.com/cockroachdb/pebble/internal/base"
 	"github.com/cockroachdb/pebble/internal/keyspan"
@@ -22,6 +23,7 @@ import (
 
 type iterCmdOpts struct {
 	fmtKV           formatKV
+	showCommands    bool
 	withoutNewlines bool
 	stats           *base.InternalIteratorStats
 }
@@ -39,6 +41,12 @@ func Condensed(opts *iterCmdOpts) {
 	opts.withoutNewlines = true
 }
 
+// ShowCommands configures RunInternalIterCmd to show the command in each output
+// line (so you don't have to visually match the line to the command).
+func ShowCommands(opts *iterCmdOpts) {
+	opts.showCommands = true
+}
+
 // Verbose configures RunInternalIterCmd to output verbose results.
 func Verbose(opts *iterCmdOpts) { opts.fmtKV = verboseFormatKV }
 
@@ -125,11 +133,13 @@ func RunInternalIterCmdWriter(
 		require.NoError(t, err)
 		return &kv.K, v
 	}
-	for _, line := range strings.Split(d.Input, "\n") {
+	lines := crstrings.Lines(d.Input)
+	maxCmdLen := 1
+	for _, line := range lines {
+		maxCmdLen = max(maxCmdLen, len(line))
+	}
+	for _, line := range lines {
 		parts := strings.Fields(line)
-		if len(parts) == 0 {
-			continue
-		}
 		var key *base.InternalKey
 		var value []byte
 		switch parts[0] {
@@ -222,6 +232,9 @@ func RunInternalIterCmdWriter(
 			fmt.Fprintf(w, "unknown op: %s", parts[0])
 			return
 		}
+		if o.showCommands {
+			fmt.Fprintf(w, "%*s: ", min(maxCmdLen, 40), line)
+		}
 		o.fmtKV(w, key, value, iter)
 		if !o.withoutNewlines {
 			fmt.Fprintln(w)

sstable/colblk/data_block_test.go

@@ -100,15 +100,21 @@ func TestDataBlock(t *testing.T) {
 				fmt.Fprintf(&buf, "LastKey: %s\n%s", lastKey.Pretty(testkeys.Comparer.FormatKey), f.String())
 				return buf.String()
 			case "iter":
-				var transforms block.IterTransforms
 				var seqNum uint64
+				var syntheticPrefix, syntheticSuffix string
 				td.MaybeScanArgs(t, "synthetic-seq-num", &seqNum)
-				transforms.SyntheticSeqNum = block.SyntheticSeqNum(seqNum)
-				transforms.HideObsoletePoints = td.HasArg("hide-obsolete-points")
+				td.MaybeScanArgs(t, "synthetic-prefix", &syntheticPrefix)
+				td.MaybeScanArgs(t, "synthetic-suffix", &syntheticSuffix)
+				transforms := block.IterTransforms{
+					SyntheticSeqNum:    block.SyntheticSeqNum(seqNum),
+					HideObsoletePoints: td.HasArg("hide-obsolete-points"),
+					SyntheticPrefix:    []byte(syntheticPrefix),
+					SyntheticSuffix:    []byte(syntheticSuffix),
+				}
 				it.Init(&r, testKeysSchema.NewKeySeeker(), getLazyValuer(func([]byte) base.LazyValue {
 					return base.LazyValue{ValueOrHandle: []byte("mock external value")}
 				}), transforms)
-				var o []itertest.IterOpt
+				o := []itertest.IterOpt{itertest.ShowCommands}
 				if td.HasArg("verbose") {
 					o = append(o, itertest.Verbose)
 				}

sstable/colblk/testdata/data_block/bundle_search

@@ -528,11 +528,11 @@ seek-ge bac
 seek-ge bacl
 seek-ge bacu
 ----
-backache:v
-backslide:v
-backslide:v
-backhanded:v
-backhanded:v
-bacchanal:v
-bacteria:v
-.
+  seek-ge backache: backache:v
+ seek-ge backslide: backslide:v
+  seek-ge backslid: backslide:v
+seek-ge backhanded: backhanded:v
+ seek-ge backhande: backhanded:v
+       seek-ge bac: bacchanal:v
+      seek-ge bacl: bacteria:v
+      seek-ge bacu: .

sstable/colblk/testdata/data_block/external_value

@@ -290,27 +290,27 @@ next
 next
 next
 ----
-blockprefix_apple@98:apple98
-blockprefix_apple@52:mock external value
-blockprefix_apple@23:mock external value
-blockprefix_apple@11:mock external value
-blockprefix_banana@94:banana94
-blockprefix_banana@93:
-blockprefix_banana@93:mock external value
-blockprefix_banana@72:mock external value
-blockprefix_banana@9:mock external value
-blockprefix_banana@1:mock external value
-blockprefix_coconut:coconut
-blockprefix_coconut@92:mock external value
-blockprefix_coconut@35:mock external value
-blockprefix_coconut@22:mock external value
-blockprefix_coconut@21:mock external value
-blockprefix_coconut@1:mock external value
-blockprefix_guava@99:mock external value
-blockprefix_kiwi@99:mock external value
-blockprefix_kiwi@98:mock external value
-blockprefix_lemon@92:
-.
+first: blockprefix_apple@98:apple98
+ next: blockprefix_apple@52:mock external value
+ next: blockprefix_apple@23:mock external value
+ next: blockprefix_apple@11:mock external value
+ next: blockprefix_banana@94:banana94
+ next: blockprefix_banana@93:
+ next: blockprefix_banana@93:mock external value
+ next: blockprefix_banana@72:mock external value
+ next: blockprefix_banana@9:mock external value
+ next: blockprefix_banana@1:mock external value
+ next: blockprefix_coconut:coconut
+ next: blockprefix_coconut@92:mock external value
+ next: blockprefix_coconut@35:mock external value
+ next: blockprefix_coconut@22:mock external value
+ next: blockprefix_coconut@21:mock external value
+ next: blockprefix_coconut@1:mock external value
+ next: blockprefix_guava@99:mock external value
+ next: blockprefix_kiwi@99:mock external value
+ next: blockprefix_kiwi@98:mock external value
+ next: blockprefix_lemon@92:
+ next: .
 
 # Scan across the block using next prefix.
 
@@ -323,17 +323,17 @@ next-prefix
 next-prefix
 next-prefix
 ----
-blockprefix_apple@98:apple98
-blockprefix_banana@94:banana94
-blockprefix_coconut:coconut
-blockprefix_guava@99:mock external value
-blockprefix_kiwi@99:mock external value
-blockprefix_lemon@92:
-.
+      first: blockprefix_apple@98:apple98
+next-prefix: blockprefix_banana@94:banana94
+next-prefix: blockprefix_coconut:coconut
+next-prefix: blockprefix_guava@99:mock external value
+next-prefix: blockprefix_kiwi@99:mock external value
+next-prefix: blockprefix_lemon@92:
+next-prefix: .
 
 iter
 seek-ge blockprefix_banana@73
 next-prefix
 ----
-blockprefix_banana@72:mock external value
-blockprefix_coconut:coconut
+seek-ge blockprefix_banana@73: blockprefix_banana@72:mock external value
+                  next-prefix: blockprefix_coconut:coconut

sstable/colblk/testdata/data_block/finish_without_final_row

@@ -127,12 +127,12 @@ next
 next
 next
 ----
-a@10:apple
-b@5:banana
-b@2:blueberry
-c@9:coconut
-c@6:cantelope
-.
+first: a@10:apple
+ next: b@5:banana
+ next: b@2:blueberry
+ next: c@9:coconut
+ next: c@6:cantelope
+ next: .
 
 init
 ----

sstable/colblk/testdata/data_block/next_prefix

@@ -252,17 +252,17 @@ next-prefix
 next-prefix
 next-prefix
 ----
-blockprefix_apple@98:apple98
-blockprefix_banana@94:banana94
-blockprefix_coconut:coconut
-blockprefix_guava@99:guava99
-blockprefix_kiwi@99:kiwi99
-blockprefix_lemon@92:
-.
+      first: blockprefix_apple@98:apple98
+next-prefix: blockprefix_banana@94:banana94
+next-prefix: blockprefix_coconut:coconut
+next-prefix: blockprefix_guava@99:guava99
+next-prefix: blockprefix_kiwi@99:kiwi99
+next-prefix: blockprefix_lemon@92:
+next-prefix: .
 
 iter
 seek-ge blockprefix_banana@73
 next-prefix
 ----
-blockprefix_banana@72:banana72
-blockprefix_coconut:coconut
+seek-ge blockprefix_banana@73: blockprefix_banana@72:banana72
+                  next-prefix: blockprefix_coconut:coconut