db: Zero out bounds for key type not present in ScanInternal

Previously, when we were exporting shared files through truncateSharedFile, and we found no point keys in the relevant span but found range keys (or vice versa), we would leave some of the bounds of the not-found key type set. This could trip up logic elsewhere that relied on null key bounds for keys not present.
jbowens · Jun 22, 2023 · b77606f · b77606f
1 parent 73b9c4d
commit b77606f
Show file tree

Hide file tree

Showing 3 changed files with 69 additions and 14 deletions.
diff --git a/scan_internal.go b/scan_internal.go
@@ -770,21 +770,32 @@ func (d *DB) truncateSharedFile(
 		sst.SmallestPointKey.UserKey = sst.SmallestPointKey.UserKey[:0]
 		sst.SmallestPointKey.Trailer = 0
 		key, _ := iter.SeekGE(lower, base.SeekGEFlagsNone)
+		foundPointKey := key != nil
 		if key != nil {
 			sst.SmallestPointKey.CopyFrom(*key)
 		}
 		if rangeDelIter != nil {
 			span := rangeDelIter.SeekGE(lower)
 			if span != nil && (len(sst.SmallestPointKey.UserKey) == 0 || base.InternalCompare(cmp, span.SmallestKey(), sst.SmallestPointKey) < 0) {
 				sst.SmallestPointKey.CopyFrom(span.SmallestKey())
+				foundPointKey = true
 			}
 		}
+		if !foundPointKey {
+			// There are no point keys in the span we're interested in.
+			sst.SmallestPointKey = InternalKey{}
+			sst.LargestPointKey = InternalKey{}
+		}
 		sst.SmallestRangeKey.UserKey = sst.SmallestRangeKey.UserKey[:0]
 		sst.SmallestRangeKey.Trailer = 0
 		if rangeKeyIter != nil {
 			span := rangeKeyIter.SeekGE(lower)
 			if span != nil {
 				sst.SmallestRangeKey.CopyFrom(span.SmallestKey())
+			} else {
+				// There are no range keys in the span we're interested in.
+				sst.SmallestRangeKey = InternalKey{}
+				sst.LargestRangeKey = InternalKey{}
 			}
 		}
 	}
@@ -794,21 +805,32 @@ func (d *DB) truncateSharedFile(
 		sst.LargestPointKey.UserKey = sst.LargestPointKey.UserKey[:0]
 		sst.LargestPointKey.Trailer = 0
 		key, _ := iter.SeekLT(upper, base.SeekLTFlagsNone)
+		foundPointKey := key != nil
 		if key != nil {
 			sst.LargestPointKey.CopyFrom(*key)
 		}
 		if rangeDelIter != nil {
 			span := rangeDelIter.SeekLT(upper)
 			if span != nil && (len(sst.LargestPointKey.UserKey) == 0 || base.InternalCompare(cmp, span.LargestKey(), sst.LargestPointKey) > 0) {
 				sst.LargestPointKey.CopyFrom(span.LargestKey())
+				foundPointKey = true
 			}
 		}
+		if !foundPointKey {
+			// There are no point keys in the span we're interested in.
+			sst.SmallestPointKey = InternalKey{}
+			sst.LargestPointKey = InternalKey{}
+		}
 		sst.LargestRangeKey.UserKey = sst.LargestRangeKey.UserKey[:0]
 		sst.LargestRangeKey.Trailer = 0
 		if rangeKeyIter != nil {
 			span := rangeKeyIter.SeekLT(upper)
 			if span != nil {
 				sst.LargestRangeKey.CopyFrom(span.LargestKey())
+			} else {
+				// There are no range keys in the span we're interested in.
+				sst.SmallestRangeKey = InternalKey{}
+				sst.LargestRangeKey = InternalKey{}
 			}
 		}
 	}

diff --git a/scan_internal_test.go b/scan_internal_test.go
@@ -232,7 +232,7 @@ func TestScanInternal(t *testing.T) {
 					reader = snap
 				case "skip-shared":
 					fileVisitor = func(sst *SharedSSTMeta) error {
-						fmt.Fprintf(&b, "shared file: %s [%s-%s]\n", sst.fileNum, sst.Smallest.String(), sst.Largest.String())
+						fmt.Fprintf(&b, "shared file: %s [%s-%s] [point=%s-%s] [range=%s-%s]\n", sst.fileNum, sst.Smallest.String(), sst.Largest.String(), sst.SmallestPointKey.String(), sst.LargestPointKey.String(), sst.SmallestRangeKey.String(), sst.LargestRangeKey.String())
 						return nil
 					}
 				}

diff --git a/testdata/scan_internal b/testdata/scan_internal
@@ -247,33 +247,33 @@ f@8#13,1 (baz)
 
 scan-internal skip-shared lower=a upper=z
 ----
-shared file: 000005 [a#11,21-e#72057594037927935,15]
+shared file: 000005 [a#11,21-e#72057594037927935,15] [point=b@3#10,1-e#72057594037927935,15] [range=a#11,21-c#72057594037927935,21]
 f@8#13,1 (baz)
 
 scan-internal skip-shared lower=a upper=e
 ----
-shared file: 000005 [a#11,21-e#72057594037927935,15]
+shared file: 000005 [a#11,21-e#72057594037927935,15] [point=b@3#10,1-e#72057594037927935,15] [range=a#11,21-c#72057594037927935,21]
 
 scan-internal skip-shared lower=a upper=d
 ----
-shared file: 000005 [a#11,21-d#72057594037927935,15]
+shared file: 000005 [a#11,21-d#72057594037927935,15] [point=b@3#10,1-d#72057594037927935,15] [range=a#11,21-c#72057594037927935,21]
 
 scan-internal skip-shared lower=a upper=c
 ----
-shared file: 000005 [a#11,21-c#72057594037927935,21]
+shared file: 000005 [a#11,21-c#72057594037927935,21] [point=b@3#10,1-b@3#10,1] [range=a#11,21-c#72057594037927935,21]
 
 scan-internal skip-shared lower=a upper=b
 ----
-shared file: 000005 [a#11,21-b#72057594037927935,21]
+shared file: 000005 [a#11,21-b#72057594037927935,21] [point=#0,0-#0,0] [range=a#11,21-b#72057594037927935,21]
 
 scan-internal skip-shared lower=b upper=z
 ----
-shared file: 000005 [b#11,21-e#72057594037927935,15]
+shared file: 000005 [b#11,21-e#72057594037927935,15] [point=b@3#10,1-e#72057594037927935,15] [range=b#11,21-c#72057594037927935,21]
 f@8#13,1 (baz)
 
 scan-internal skip-shared lower=b upper=bb
 ----
-shared file: 000005 [b#11,21-bb#72057594037927935,21]
+shared file: 000005 [b#11,21-bb#72057594037927935,21] [point=b@3#10,1-b@3#10,1] [range=b#11,21-bb#72057594037927935,21]
 
 scan-internal skip-shared lower=e upper=ff
 ----
@@ -308,24 +308,28 @@ lsm
 scan-internal skip-shared lower=c upper=d
 ----
 
+scan-internal skip-shared lower=a upper=d
+----
+shared file: 000005 [a#10,1-c#72057594037927935,15] [point=a#10,1-c#72057594037927935,15] [range=#0,0-#0,0]
+
 scan-internal skip-shared lower=bb upper=d
 ----
-shared file: 000005 [bb#12,15-c#72057594037927935,15]
+shared file: 000005 [bb#12,15-c#72057594037927935,15] [point=bb#12,15-c#72057594037927935,15] [range=#0,0-#0,0]
 
 scan-internal skip-shared lower=c upper=ea
 ----
-shared file: 000005 [e#13,21-ea#72057594037927935,21]
+shared file: 000005 [e#13,21-ea#72057594037927935,21] [point=#0,0-#0,0] [range=e#13,21-ea#72057594037927935,21]
 
 scan-internal skip-shared lower=c upper=z
 ----
-shared file: 000005 [e#13,21-f#11,1]
+shared file: 000005 [e#13,21-f#11,1] [point=f#11,1-f#11,1] [range=e#13,21-ee#72057594037927935,21]
 
 # An upper bound equalling a file's Largest user key should be reason enough to
 # truncate that file's bounds.
 
 scan-internal skip-shared lower=c upper=f
 ----
-shared file: 000005 [e#13,21-ee#72057594037927935,21]
+shared file: 000005 [e#13,21-ee#72057594037927935,21] [point=#0,0-#0,0] [range=e#13,21-ee#72057594037927935,21]
 
 # Construct a file with an exclusive sentinel as the largest key. Verify that
 # scan-internal with skip-shared and an upper bound at that exclusive sentinel
@@ -351,8 +355,37 @@ compact a-z
 
 scan-internal skip-shared lower=a upper=ee
 ----
-shared file: 000005 [a#10,1-ee#72057594037927935,21]
+shared file: 000005 [a#10,1-ee#72057594037927935,21] [point=a#10,1-c#72057594037927935,15] [range=e#12,21-ee#72057594037927935,21]
 
 scan-internal skip-shared lower=b upper=ee
 ----
-shared file: 000005 [b#11,15-ee#72057594037927935,21]
+shared file: 000005 [b#11,15-ee#72057594037927935,21] [point=b#11,15-c#72057594037927935,15] [range=e#12,21-ee#72057594037927935,21]
+
+# Ensure we don't leave any range key bounds unintentionally set.
+
+reset
+----
+
+batch commit
+range-key-set a aa @5 boop
+set b foo
+set c bar
+set d baz
+----
+committed 4 keys
+
+flush
+----
+
+compact a-z
+----
+6:
+  000005:[a#10,RANGEKEYSET-d#13,SET]
+
+scan-internal skip-shared lower=b upper=e
+----
+shared file: 000005 [b#11,1-d#13,1] [point=b#11,1-d#13,1] [range=#0,0-#0,0]
+
+scan-internal skip-shared lower=a upper=aaa
+----
+shared file: 000005 [a#10,21-aa#72057594037927935,21] [point=#0,0-#0,0] [range=a#10,21-aa#72057594037927935,21]