1/*
2 * I'm tired of doing "vsnprintf()" etc just to open a
3 * file, so here's a "return static buffer with printf"
4 * interface for paths.
5 *
6 * It's obviously not thread-safe. Sue me. But it's quite
7 * useful for doing things like
8 *
9 *   f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
10 *
11 * which is what it's designed for.
12 */
13#include "cache.h"
14
15static char bad_path[] = "/bad-path/";
16/*
17 * Two hacks:
18 */
19
20static const char *get_perf_dir(void)
21{
22	return ".";
23}
24
25#ifdef NO_STRLCPY
26size_t strlcpy(char *dest, const char *src, size_t size)
27{
28	size_t ret = strlen(src);
29
30	if (size) {
31		size_t len = (ret >= size) ? size - 1 : ret;
32		memcpy(dest, src, len);
33		dest[len] = '\0';
34	}
35	return ret;
36}
37#endif
38
39static char *get_pathname(void)
40{
41	static char pathname_array[4][PATH_MAX];
42	static int idx;
43
44	return pathname_array[3 & ++idx];
45}
46
47static char *cleanup_path(char *path)
48{
49	/* Clean it up */
50	if (!memcmp(path, "./", 2)) {
51		path += 2;
52		while (*path == '/')
53			path++;
54	}
55	return path;
56}
57
58static char *perf_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
59{
60	const char *perf_dir = get_perf_dir();
61	size_t len;
62
63	len = strlen(perf_dir);
64	if (n < len + 1)
65		goto bad;
66	memcpy(buf, perf_dir, len);
67	if (len && !is_dir_sep(perf_dir[len-1]))
68		buf[len++] = '/';
69	len += vsnprintf(buf + len, n - len, fmt, args);
70	if (len >= n)
71		goto bad;
72	return cleanup_path(buf);
73bad:
74	strlcpy(buf, bad_path, n);
75	return buf;
76}
77
78char *perf_pathdup(const char *fmt, ...)
79{
80	char path[PATH_MAX];
81	va_list args;
82	va_start(args, fmt);
83	(void)perf_vsnpath(path, sizeof(path), fmt, args);
84	va_end(args);
85	return xstrdup(path);
86}
87
88char *mkpath(const char *fmt, ...)
89{
90	va_list args;
91	unsigned len;
92	char *pathname = get_pathname();
93
94	va_start(args, fmt);
95	len = vsnprintf(pathname, PATH_MAX, fmt, args);
96	va_end(args);
97	if (len >= PATH_MAX)
98		return bad_path;
99	return cleanup_path(pathname);
100}
101
102char *perf_path(const char *fmt, ...)
103{
104	const char *perf_dir = get_perf_dir();
105	char *pathname = get_pathname();
106	va_list args;
107	unsigned len;
108
109	len = strlen(perf_dir);
110	if (len > PATH_MAX-100)
111		return bad_path;
112	memcpy(pathname, perf_dir, len);
113	if (len && perf_dir[len-1] != '/')
114		pathname[len++] = '/';
115	va_start(args, fmt);
116	len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
117	va_end(args);
118	if (len >= PATH_MAX)
119		return bad_path;
120	return cleanup_path(pathname);
121}
122
123/* strip arbitrary amount of directory separators at end of path */
124static inline int chomp_trailing_dir_sep(const char *path, int len)
125{
126	while (len && is_dir_sep(path[len - 1]))
127		len--;
128	return len;
129}
130
131/*
132 * If path ends with suffix (complete path components), returns the
133 * part before suffix (sans trailing directory separators).
134 * Otherwise returns NULL.
135 */
136char *strip_path_suffix(const char *path, const char *suffix)
137{
138	int path_len = strlen(path), suffix_len = strlen(suffix);
139
140	while (suffix_len) {
141		if (!path_len)
142			return NULL;
143
144		if (is_dir_sep(path[path_len - 1])) {
145			if (!is_dir_sep(suffix[suffix_len - 1]))
146				return NULL;
147			path_len = chomp_trailing_dir_sep(path, path_len);
148			suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
149		}
150		else if (path[--path_len] != suffix[--suffix_len])
151			return NULL;
152	}
153
154	if (path_len && !is_dir_sep(path[path_len - 1]))
155		return NULL;
156	return strndup(path, chomp_trailing_dir_sep(path, path_len));
157}
158