1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
|
// Library for pooling common strings.
#include "config.h" // IWYU pragma: keep
#include <pthread.h>
#include <stdbool.h>
#include <stddef.h>
#include <wchar.h>
#include <algorithm>
#include <memory>
#include <vector>
#include "common.h"
#include "fallback.h" // IWYU pragma: keep
#include "intern.h"
/// Comparison function for intern'd strings.
class string_table_compare_t {
public:
bool operator()(const wchar_t *a, const wchar_t *b) const { return wcscmp(a, b) < 0; }
};
// A sorted vector ends up being a little more memory efficient than a std::set for the intern'd
// string table.
#define USE_SET 0
#if USE_SET
/// The table of intern'd strings.
typedef std::set<const wchar_t *, string_table_compare_t> string_table_t;
#else
/// The table of intern'd strings.
typedef std::vector<const wchar_t *> string_table_t;
#endif
static string_table_t string_table;
/// The lock to provide thread safety for intern'd strings.
static pthread_mutex_t intern_lock = PTHREAD_MUTEX_INITIALIZER;
static const wchar_t *intern_with_dup(const wchar_t *in, bool dup) {
if (!in) return NULL;
debug(5, L"intern %ls", in);
scoped_lock lock(intern_lock); //!OCLINT(has side effects)
const wchar_t *result;
#if USE_SET
string_table_t::const_iterator iter = string_table.find(in);
if (iter != string_table.end()) {
result = *iter;
} else {
result = dup ? wcsdup(in) : in;
string_table.insert(result);
}
#else
string_table_t::iterator iter =
std::lower_bound(string_table.begin(), string_table.end(), in, string_table_compare_t());
if (iter != string_table.end() && wcscmp(*iter, in) == 0) {
result = *iter;
} else {
result = dup ? wcsdup(in) : in;
string_table.insert(iter, result);
}
#endif
return result;
}
const wchar_t *intern(const wchar_t *in) { return intern_with_dup(in, true); }
const wchar_t *intern_static(const wchar_t *in) { return intern_with_dup(in, false); }
|
