victory/env.c at master · OrangeTide/victory · GitHub

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
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
/*
 * Copyright (c) 2012 Jon Mayo
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#include <assert.h>
#include <string.h>
#include "env.h"

static int env_load(struct env *env, unsigned ofs, char **name,
	size_t *name_len, char **val, size_t *val_len, unsigned *next)
{
	char *heap = env->heap;
	unsigned name_start, val_start;
	unsigned _name_len, _val_len;

	// TODO: skip over leading \0 characters.

	name_start = ofs;
	assert(name_start < env->cur);
	if (name_start >= env->cur)
		return -1;
	_name_len = strlen(&heap[name_start]) + 1;

	val_start = ofs + _name_len;
	if (val_start >= env->cur)
		return -1;
	_val_len = strlen(&heap[val_start]) + 1;

	if (name)
		*name = env->heap + name_start;
	if (name_len)
		*name_len = _name_len;
	if (val)
		*val = env->heap + val_start;
	if (val_len)
		*val_len = _val_len;
	if (next)
		*next = val_start + _val_len;

	return 0;
}

static int env_find(struct env *env, const char *name, unsigned *ofs, unsigned *len)
{
	unsigned i, next;

	for (i = 0; i < env->cur; i = next) {
		char *cur_name, *cur_val;

		if (env_load(env, i, &cur_name, NULL, &cur_val, NULL, &next))
			return 0; /* weird/corrupt data in buffer */
		if (!strcmp(name, cur_name)) {
			if (ofs)
				*ofs = i;
			if (len)
				*len = next - i; // TODO: check this
			return 1;
		}
	}
	return 0; /* not found */
}

int env_delete(struct env *env, const char *name)
{
	unsigned ofs, len;

	if (env_find(env, name, &ofs, &len)) {
		env->cur -= len;
		memmove(&env->heap[ofs], &env->heap[ofs + len], env->cur);
		return 0;
	}
	return 0;
}

const char *env_get(struct env *env, const char *name)
{
	unsigned ofs;
	char *val;

	if (env_find(env, name, &ofs, NULL)) {
		if (!env_load(env, ofs, NULL, NULL, &val, NULL, NULL))
			return val;
	}
	return NULL;
}

int env_set(struct env *env, const char *name, const char *value)
{
	size_t name_len = strlen(name) + 1;
	size_t val_len = strlen(value) + 1;
	unsigned cur;

	env_delete(env, name);

	cur = env->cur;
	if (cur + name_len + val_len > env->max)
		return -1;

	memcpy(&env->heap[cur], name, name_len);
	cur += name_len;
	memcpy(&env->heap[cur], value, val_len);
	cur += val_len;
	env->cur = cur;

	return 0;
}

int env_next(struct env *env, struct env_iter *iter,
	const char **name, const char **value)
{
	char *_name, *_val;
	unsigned next;

	if (iter->i >= env->cur)
		return 0;

	if (env_load(env, iter->i, &_name, NULL, &_val, NULL, &next))
		return 0; /* weird error - stop */

	iter->i = next;
	if (name)
		*name = _name;
	if (value)
		*value = _val;
	return 1;
}