sstable,colblk: minor bug fixes

sstable/colblk/cockroach_test.go

@@ -60,9 +60,13 @@ type cockroachKeyWriter struct {
 }
 
 func (kw *cockroachKeyWriter) ComparePrev(key []byte) KeyComparison {
- lp := kw.prefixes.UnsafeGet(kw.prefixes.Rows() - 1)
  var cmpv KeyComparison
  cmpv.PrefixLen = int32(crdbtest.Split(key)) // TODO(jackson): Inline
+ if kw.prefixes.Rows() == 0 {
+ cmpv.UserKeyComparison = 1
+ return cmpv
+ }
+ lp := kw.prefixes.UnsafeGet(kw.prefixes.Rows() - 1)
  cmpv.CommonPrefixLen = int32(crbytes.CommonPrefix(lp, key[:cmpv.PrefixLen]))
  if cmpv.CommonPrefixLen == cmpv.PrefixLen {
  cmpv.UserKeyComparison = int32(crdbtest.CompareSuffixes(key[cmpv.PrefixLen:], kw.prevSuffix))

sstable/colblk/data_block.go

@@ -48,6 +48,9 @@ type KeyWriter interface {
  // key. The returned KeyComparison's UserKeyComparison field is equivalent
  // to Compare(key, prevKey) where prevKey is the last key passed to
  // WriteKey.
+ //
+ // If no key has been written yet, ComparePrev returns a KeyComparison with
+ // PrefixLen set and UserKeyComparison=1.
  ComparePrev(key []byte) KeyComparison
  // WriteKey writes a user key into the KeyWriter's columns. The
  // keyPrefixLenSharedWithPrev parameter takes the number of bytes prefixing
@@ -169,15 +172,15 @@ type defaultKeyWriter struct {
 }
 
 func (w *defaultKeyWriter) ComparePrev(key []byte) KeyComparison {
- lp := w.prefixes.UnsafeGet(w.prefixes.nKeys - 1)
-
  var cmpv KeyComparison
  cmpv.PrefixLen = int32(w.comparer.Split(key))
- cmpv.CommonPrefixLen = int32(crbytes.CommonPrefix(lp, key[:cmpv.PrefixLen]))
- if len(lp) == 0 {
+ if w.prefixes.nKeys == 0 {
  // The first key has no previous key to compare to.
+ cmpv.UserKeyComparison = 1
  return cmpv
  }
+ lp := w.prefixes.UnsafeGet(w.prefixes.nKeys - 1)
+ cmpv.CommonPrefixLen = int32(crbytes.CommonPrefix(lp, key[:cmpv.PrefixLen]))
 
  if invariants.Enabled && bytes.Compare(lp, key[:cmpv.PrefixLen]) > 0 {
  panic(errors.AssertionFailedf("keys are not in order: %q > %q", lp, key[:cmpv.PrefixLen]))

sstable/colblk_writer.go

@@ -662,6 +662,7 @@ func (w *RawColumnWriter) flushBufferedIndexBlocks() (rootIndex block.Handle, er
  // writing a large file or the index separators happen to be excessively
  // long, we may have several index blocks and need to construct a
  // "two-level" index structure.
+ w.props.IndexPartitions = uint64(len(w.indexBuffering.partitions))
  switch len(w.indexBuffering.partitions) {
  case 0:
  // This is impossible because we'll flush the index block immediately

sstable/suffix_rewriter_test.go

@@ -240,3 +240,16 @@ func BenchmarkRewriteSST(b *testing.B) {
  })
  }
 }
+
+var test4bSuffixComparer = func() *base.Comparer {
+ c := new(base.Comparer)
+ *c = *base.DefaultComparer
+ c.Split = func(key []byte) int {
+ if len(key) > 4 {
+ return len(key) - 4
+ }
+ return len(key)
+ }
+ c.Name = "comparer-split-4b-suffix"
+ return c
+}()