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
5package 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
13type BatchCounterAlloc struct {
14	pool []uint32
15}
16
17func (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 = make([]uint32, siz)
25	}
26	rv := ca.pool[:n]
27	ca.pool = ca.pool[n:]
28	return rv
29}
30