projects/linux·blob v5.6 · refs

218 lines · 4.8 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->allocation = 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->allocation;
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_resource_destroy(frag->test,
69 kunit_resource_instance_match,
70 string_stream_fragment_free,
71 frag);
72}
73
74int string_stream_vadd(struct string_stream *stream,
75 const char *fmt,
76 va_list args)
77{
78 struct string_stream_fragment *frag_container;
79 int len;
80 va_list args_for_counting;
81
82 /* Make a copy because `vsnprintf` could change it */
83 va_copy(args_for_counting, args);
84
85 /* Need space for null byte. */
86 len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1;
87
88 va_end(args_for_counting);
89
90 frag_container = alloc_string_stream_fragment(stream->test,
91 len,
92 stream->gfp);
93 if (!frag_container)
94 return -ENOMEM;
95
96 len = vsnprintf(frag_container->fragment, len, fmt, args);
97 spin_lock(&stream->lock);
98 stream->length += len;
99 list_add_tail(&frag_container->node, &stream->fragments);
100 spin_unlock(&stream->lock);
101
102 return 0;
103}
104
105int string_stream_add(struct string_stream *stream, const char *fmt, ...)
106{
107 va_list args;
108 int result;
109
110 va_start(args, fmt);
111 result = string_stream_vadd(stream, fmt, args);
112 va_end(args);
113
114 return result;
115}
116
117static void string_stream_clear(struct string_stream *stream)
118{
119 struct string_stream_fragment *frag_container, *frag_container_safe;
120
121 spin_lock(&stream->lock);
122 list_for_each_entry_safe(frag_container,
123 frag_container_safe,
124 &stream->fragments,
125 node) {
126 string_stream_fragment_destroy(frag_container);
127 }
128 stream->length = 0;
129 spin_unlock(&stream->lock);
130}
131
132char *string_stream_get_string(struct string_stream *stream)
133{
134 struct string_stream_fragment *frag_container;
135 size_t buf_len = stream->length + 1; /* +1 for null byte. */
136 char *buf;
137
138 buf = kunit_kzalloc(stream->test, buf_len, stream->gfp);
139 if (!buf)
140 return NULL;
141
142 spin_lock(&stream->lock);
143 list_for_each_entry(frag_container, &stream->fragments, node)
144 strlcat(buf, frag_container->fragment, buf_len);
145 spin_unlock(&stream->lock);
146
147 return buf;
148}
149
150int string_stream_append(struct string_stream *stream,
151 struct string_stream *other)
152{
153 const char *other_content;
154
155 other_content = string_stream_get_string(other);
156
157 if (!other_content)
158 return -ENOMEM;
159
160 return string_stream_add(stream, other_content);
161}
162
163bool string_stream_is_empty(struct string_stream *stream)
164{
165 return list_empty(&stream->fragments);
166}
167
168struct string_stream_alloc_context {
169 struct kunit *test;
170 gfp_t gfp;
171};
172
173static int string_stream_init(struct kunit_resource *res, void *context)
174{
175 struct string_stream *stream;
176 struct string_stream_alloc_context *ctx = context;
177
178 stream = kunit_kzalloc(ctx->test, sizeof(*stream), ctx->gfp);
179 if (!stream)
180 return -ENOMEM;
181
182 res->allocation = stream;
183 stream->gfp = ctx->gfp;
184 stream->test = ctx->test;
185 INIT_LIST_HEAD(&stream->fragments);
186 spin_lock_init(&stream->lock);
187
188 return 0;
189}
190
191static void string_stream_free(struct kunit_resource *res)
192{
193 struct string_stream *stream = res->allocation;
194
195 string_stream_clear(stream);
196}
197
198struct string_stream *alloc_string_stream(struct kunit *test, gfp_t gfp)
199{
200 struct string_stream_alloc_context context = {
201 .test = test,
202 .gfp = gfp
203 };
204
205 return kunit_alloc_resource(test,
206 string_stream_init,
207 string_stream_free,
208 gfp,
209 &context);
210}
211
212int string_stream_destroy(struct string_stream *stream)
213{
214 return kunit_resource_destroy(stream->test,
215 kunit_resource_instance_match,
216 string_stream_free,
217 stream);
218}