1 // Copyright 2022 The Go Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style
3 // license that can be found in the LICENSE file.
4 5 package calloc
6 7 // This package contains a simple "batch" allocator for allocating
8 // coverage counters (slices of uint32 basically), for working with
9 // coverage data files. Collections of counter arrays tend to all be
10 // live/dead over the same time period, so a good fit for batch
11 // allocation.
12 13 type BatchCounterAlloc struct {
14 pool []uint32
15 }
16 17 func (ca *BatchCounterAlloc) AllocateCounters(n int) []uint32 {
18 const chunk = 8192
19 if n > cap(ca.pool) {
20 siz := chunk
21 if n > chunk {
22 siz = n
23 }
24 ca.pool = []uint32{:siz}
25 }
26 rv := ca.pool[:n]
27 ca.pool = ca.pool[n:]
28 return rv
29 }
30