Merge pull request #18057 from pr00se/symbol-table-too-large-errors

tsdb/index: export sentinel error for symbol table size exceeded

tsdb/index/index.go

@@ -101,6 +101,9 @@ var ErrPostingsOffsetTableTooLarge = errors.New("length size exceeds 4 bytes")
 // ErrIndexExceeds64GiB is returned when the index file would exceed the 64GiB limit.
 var ErrIndexExceeds64GiB = errors.New("exceeding max size of 64GiB")
 
+// ErrSymbolTableTooLarge is returned when the symbol table size exceeds 4 bytes (4GiB limit).
+var ErrSymbolTableTooLarge = fmt.Errorf("symbol table size exceeds %d bytes", uint32(math.MaxUint32))
+
 // The table gets initialized with sync.Once but may still cause a race
 // with any other use of the crc32 package anywhere. Thus we initialize it
 // before.
@@ -550,7 +553,7 @@ func (w *Writer) finishSymbols() error {
 	symbolTableSize := w.f.pos - w.toc.Symbols - 4
 	// The symbol table's <len> part is 4 bytes. So the total symbol table size must be less than or equal to 2^32-1
 	if symbolTableSize > math.MaxUint32 {
-		return fmt.Errorf("symbol table size exceeds %d bytes: %d", uint32(math.MaxUint32), symbolTableSize)
+		return fmt.Errorf("%w: %d", ErrSymbolTableTooLarge, symbolTableSize)
 	}
 
 	// Write out the length and symbol count.