projects/linux·blob v5.14 · refs

216 lines · 4.7 KiB

1// SPDX-License-Identifier: GPL-2.0
2/*
3 * C++ stream style string builder used in KUnit for building messages.
4 *
5 * Copyright (C) 2019, Google LLC.
6 * Author: Brendan Higgins <[email protected]>
7 */
8
9#include <kunit/test.h>
10#include <linux/list.h>
11#include <linux/slab.h>
12
13#include "string-stream.h"
14
15struct string_stream_fragment_alloc_context {
16 struct kunit *test;
17 int len;
18 gfp_t gfp;
19};
20
21static int string_stream_fragment_init(struct kunit_resource *res,
22 void *context)
23{
24 struct string_stream_fragment_alloc_context *ctx = context;
25 struct string_stream_fragment *frag;
26
27 frag = kunit_kzalloc(ctx->test, sizeof(*frag), ctx->gfp);
28 if (!frag)
29 return -ENOMEM;
30
31 frag->test = ctx->test;
32 frag->fragment = kunit_kmalloc(ctx->test, ctx->len, ctx->gfp);
33 if (!frag->fragment)
34 return -ENOMEM;
35
36 res->data = frag;
37
38 return 0;
39}
40
41static void string_stream_fragment_free(struct kunit_resource *res)
42{
43 struct string_stream_fragment *frag = res->data;
44
45 list_del(&frag->node);
46 kunit_kfree(frag->test, frag->fragment);
47 kunit_kfree(frag->test, frag);
48}
49
50static struct string_stream_fragment *alloc_string_stream_fragment(
51 struct kunit *test, int len, gfp_t gfp)
52{
53 struct string_stream_fragment_alloc_context context = {
54 .test = test,
55 .len = len,
56 .gfp = gfp
57 };
58
59 return kunit_alloc_resource(test,
60 string_stream_fragment_init,
61 string_stream_fragment_free,
62 gfp,
63 &context);
64}
65
66static int string_stream_fragment_destroy(struct string_stream_fragment *frag)
67{
68 return kunit_destroy_resource(frag->test,
69 kunit_resource_instance_match,
70 frag);
71}
72
73int string_stream_vadd(struct string_stream *stream,
74 const char *fmt,
75 va_list args)
76{
77 struct string_stream_fragment *frag_container;
78 int len;
79 va_list args_for_counting;
80
81 /* Make a copy because `vsnprintf` could change it */
82 va_copy(args_for_counting, args);
83
84 /* Need space for null byte. */
85 len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1;
86
87 va_end(args_for_counting);
88
89 frag_container = alloc_string_stream_fragment(stream->test,
90 len,
91 stream->gfp);
92 if (!frag_container)
93 return -ENOMEM;
94
95 len = vsnprintf(frag_container->fragment, len, fmt, args);
96 spin_lock(&stream->lock);
97 stream->length += len;
98 list_add_tail(&frag_container->node, &stream->fragments);
99 spin_unlock(&stream->lock);
100
101 return 0;
102}
103
104int string_stream_add(struct string_stream *stream, const char *fmt, ...)
105{
106 va_list args;
107 int result;
108
109 va_start(args, fmt);
110 result = string_stream_vadd(stream, fmt, args);
111 va_end(args);
112
113 return result;
114}
115
116static void string_stream_clear(struct string_stream *stream)
117{
118 struct string_stream_fragment *frag_container, *frag_container_safe;
119
120 spin_lock(&stream->lock);
121 list_for_each_entry_safe(frag_container,
122 frag_container_safe,
123 &stream->fragments,
124 node) {
125 string_stream_fragment_destroy(frag_container);
126 }
127 stream->length = 0;
128 spin_unlock(&stream->lock);
129}
130
131char *string_stream_get_string(struct string_stream *stream)
132{
133 struct string_stream_fragment *frag_container;
134 size_t buf_len = stream->length + 1; /* +1 for null byte. */
135 char *buf;
136
137 buf = kunit_kzalloc(stream->test, buf_len, stream->gfp);
138 if (!buf)
139 return NULL;
140
141 spin_lock(&stream->lock);
142 list_for_each_entry(frag_container, &stream->fragments, node)
143 strlcat(buf, frag_container->fragment, buf_len);
144 spin_unlock(&stream->lock);
145
146 return buf;
147}
148
149int string_stream_append(struct string_stream *stream,
150 struct string_stream *other)
151{
152 const char *other_content;
153
154 other_content = string_stream_get_string(other);
155
156 if (!other_content)
157 return -ENOMEM;
158
159 return string_stream_add(stream, other_content);
160}
161
162bool string_stream_is_empty(struct string_stream *stream)
163{
164 return list_empty(&stream->fragments);
165}
166
167struct string_stream_alloc_context {
168 struct kunit *test;
169 gfp_t gfp;
170};
171
172static int string_stream_init(struct kunit_resource *res, void *context)
173{
174 struct string_stream *stream;
175 struct string_stream_alloc_context *ctx = context;
176
177 stream = kunit_kzalloc(ctx->test, sizeof(*stream), ctx->gfp);
178 if (!stream)
179 return -ENOMEM;
180
181 res->data = stream;
182 stream->gfp = ctx->gfp;
183 stream->test = ctx->test;
184 INIT_LIST_HEAD(&stream->fragments);
185 spin_lock_init(&stream->lock);
186
187 return 0;
188}
189
190static void string_stream_free(struct kunit_resource *res)
191{
192 struct string_stream *stream = res->data;
193
194 string_stream_clear(stream);
195}
196
197struct string_stream *alloc_string_stream(struct kunit *test, gfp_t gfp)
198{
199 struct string_stream_alloc_context context = {
200 .test = test,
201 .gfp = gfp
202 };
203
204 return kunit_alloc_resource(test,
205 string_stream_init,
206 string_stream_free,
207 gfp,
208 &context);
209}
210
211int string_stream_destroy(struct string_stream *stream)
212{
213 return kunit_destroy_resource(stream->test,
214 kunit_resource_instance_match,
215 stream);
216}