1 /*
2 * Copyright 2019 The Hafnium Authors.
3 *
4 * Use of this source code is governed by a BSD-style
5 * license that can be found in the LICENSE file or at
6 * https://opensource.org/licenses/BSD-3-Clause.
7 */
8
9 #include "hf/string.h"
10
11 #include "hf/std.h"
12
string_init_empty(struct string * str)13 void string_init_empty(struct string *str)
14 {
15 static_assert(sizeof(str->data) >= 1, "String buffer too small");
16 str->data[0] = '\0';
17 }
18
19 /**
20 * Caller must guarantee that `data` points to a NULL-terminated string.
21 * The constructor checks that it fits into the internal buffer and copies
22 * the string there.
23 */
string_init(struct string * str,const struct memiter * data)24 enum string_return_code string_init(struct string *str,
25 const struct memiter *data)
26 {
27 const char *base = memiter_base(data);
28 size_t size = memiter_size(data);
29
30 /*
31 * Require that the value contains exactly one NULL character and that
32 * it is the last byte.
33 */
34 if (size < 1 || memchr(base, '\0', size) != &base[size - 1]) {
35 return STRING_ERROR_INVALID_INPUT;
36 }
37
38 if (size > sizeof(str->data)) {
39 return STRING_ERROR_TOO_LONG;
40 }
41
42 memcpy_s(str->data, sizeof(str->data), base, size);
43 return STRING_SUCCESS;
44 }
45
string_is_empty(const struct string * str)46 bool string_is_empty(const struct string *str)
47 {
48 return str->data[0] == '\0';
49 }
50
string_data(const struct string * str)51 const char *string_data(const struct string *str)
52 {
53 return str->data;
54 }
55
56 /**
57 * Returns true if the iterator `data` contains string `str`.
58 * Only characters until the first null terminator are compared.
59 */
string_eq(const struct string * str,const struct memiter * data)60 bool string_eq(const struct string *str, const struct memiter *data)
61 {
62 const char *base = memiter_base(data);
63 size_t len = memiter_size(data);
64
65 return (len <= sizeof(str->data)) &&
66 (strncmp(str->data, base, len) == 0);
67 }
68