sqlstats: rename sizeUnsafe -> sizeUnsafeLocked

This function accesses data behind a mutex without acquring it.
Ensure that this is clearly communicated so this fn is not
misused.

Epic: none

Release note: None

pkg/sql/sqlstats/ssmemstorage/ss_mem_storage.go

@@ -400,7 +400,7 @@ type stmtStats struct {
  }
 }
 
-func (s *stmtStats) sizeUnsafe() int64 {
+func (s *stmtStats) sizeUnsafeLocked() int64 {
  const stmtStatsShallowSize = int64(unsafe.Sizeof(stmtStats{}))
  databaseNameSize := int64(len(s.mu.database))
 
@@ -832,7 +832,7 @@ func (s *Container) Add(ctx context.Context, other *Container) (err error) {
  // If we created a new entry for the fingerprint, we check if we have
  // exceeded our memory budget.
  if created {
- estimatedAllocBytes := stats.sizeUnsafe() + k.size() + 8 /* stmtKey hash */
+ estimatedAllocBytes := stats.sizeUnsafeLocked() + k.size() + 8 /* stmtKey hash */
  // We still want to continue this loop to merge stats that are already
  // present in our map that do not require allocation.
  if latestErr := func() error {

pkg/sql/sqlstats/ssmemstorage/ss_mem_writer.go

@@ -173,7 +173,7 @@ func (s *Container) RecordStatement(
 
  if created {
  // stats size + stmtKey size + hash of the statementKey
- estimatedMemoryAllocBytes := stats.sizeUnsafe() + statementKey.size() + 8
+ estimatedMemoryAllocBytes := stats.sizeUnsafeLocked() + statementKey.size() + 8
 
  // We also account for the memory used for s.sampledPlanMetadataCache.
  // timestamp size + key size + hash.