summaryrefslogtreecommitdiff
path: root/lib/kunit/string-stream.c
blob: a6f3616c20486849c030d4817dd7310a5b97f59a (plain)
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
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
// SPDX-License-Identifier: GPL-2.0
/*
 * C++ stream style string builder used in KUnit for building messages.
 *
 * Copyright (C) 2019, Google LLC.
 * Author: Brendan Higgins <brendanhiggins@google.com>
 */

#include <kunit/static_stub.h>
#include <kunit/test.h>
#include <linux/list.h>
#include <linux/slab.h>

#include "string-stream.h"


static struct string_stream_fragment *alloc_string_stream_fragment(int len, gfp_t gfp)
{
	struct string_stream_fragment *frag;

	frag = kzalloc(sizeof(*frag), gfp);
	if (!frag)
		return ERR_PTR(-ENOMEM);

	frag->fragment = kmalloc(len, gfp);
	if (!frag->fragment) {
		kfree(frag);
		return ERR_PTR(-ENOMEM);
	}

	return frag;
}

static void string_stream_fragment_destroy(struct string_stream_fragment *frag)
{
	list_del(&frag->node);
	kfree(frag->fragment);
	kfree(frag);
}

int string_stream_vadd(struct string_stream *stream,
		       const char *fmt,
		       va_list args)
{
	struct string_stream_fragment *frag_container;
	int buf_len, result_len;
	va_list args_for_counting;

	/* Make a copy because `vsnprintf` could change it */
	va_copy(args_for_counting, args);

	/* Evaluate length of formatted string */
	buf_len = vsnprintf(NULL, 0, fmt, args_for_counting);

	va_end(args_for_counting);

	if (buf_len == 0)
		return 0;

	/* Reserve one extra for possible appended newline. */
	if (stream->append_newlines)
		buf_len++;

	/* Need space for null byte. */
	buf_len++;

	frag_container = alloc_string_stream_fragment(buf_len, stream->gfp);
	if (IS_ERR(frag_container))
		return PTR_ERR(frag_container);

	if (stream->append_newlines) {
		/* Don't include reserved newline byte in writeable length. */
		result_len = vsnprintf(frag_container->fragment, buf_len - 1, fmt, args);

		/* Append newline if necessary. */
		if (frag_container->fragment[result_len - 1] != '\n')
			result_len = strlcat(frag_container->fragment, "\n", buf_len);
	} else {
		result_len = vsnprintf(frag_container->fragment, buf_len, fmt, args);
	}

	spin_lock(&stream->lock);
	stream->length += result_len;
	list_add_tail(&frag_container->node, &stream->fragments);
	spin_unlock(&stream->lock);

	return 0;
}

int string_stream_add(struct string_stream *stream, const char *fmt, ...)
{
	va_list args;
	int result;

	va_start(args, fmt);
	result = string_stream_vadd(stream, fmt, args);
	va_end(args);

	return result;
}

void string_stream_clear(struct string_stream *stream)
{
	struct string_stream_fragment *frag_container, *frag_container_safe;

	spin_lock(&stream->lock);
	list_for_each_entry_safe(frag_container,
				 frag_container_safe,
				 &stream->fragments,
				 node) {
		string_stream_fragment_destroy(frag_container);
	}
	stream->length = 0;
	spin_unlock(&stream->lock);
}

char *string_stream_get_string(struct string_stream *stream)
{
	struct string_stream_fragment *frag_container;
	size_t buf_len = stream->length + 1; /* +1 for null byte. */
	char *buf;

	buf = kzalloc(buf_len, stream->gfp);
	if (!buf)
		return NULL;

	spin_lock(&stream->lock);
	list_for_each_entry(frag_container, &stream->fragments, node)
		strlcat(buf, frag_container->fragment, buf_len);
	spin_unlock(&stream->lock);

	return buf;
}

int string_stream_append(struct string_stream *stream,
			 struct string_stream *other)
{
	const char *other_content;
	int ret;

	other_content = string_stream_get_string(other);

	if (!other_content)
		return -ENOMEM;

	ret = string_stream_add(stream, other_content);
	kfree(other_content);

	return ret;
}

bool string_stream_is_empty(struct string_stream *stream)
{
	return list_empty(&stream->fragments);
}

struct string_stream *alloc_string_stream(gfp_t gfp)
{
	struct string_stream *stream;

	stream = kzalloc(sizeof(*stream), gfp);
	if (!stream)
		return ERR_PTR(-ENOMEM);

	stream->gfp = gfp;
	INIT_LIST_HEAD(&stream->fragments);
	spin_lock_init(&stream->lock);

	return stream;
}

void string_stream_destroy(struct string_stream *stream)
{
	KUNIT_STATIC_STUB_REDIRECT(string_stream_destroy, stream);

	if (!stream)
		return;

	string_stream_clear(stream);
	kfree(stream);
}

static void resource_free_string_stream(void *p)
{
	struct string_stream *stream = p;

	string_stream_destroy(stream);
}

struct string_stream *kunit_alloc_string_stream(struct kunit *test, gfp_t gfp)
{
	struct string_stream *stream;

	stream = alloc_string_stream(gfp);
	if (IS_ERR(stream))
		return stream;

	if (kunit_add_action_or_reset(test, resource_free_string_stream, stream) != 0)
		return ERR_PTR(-ENOMEM);

	return stream;
}

void kunit_free_string_stream(struct kunit *test, struct string_stream *stream)
{
	kunit_release_action(test, resource_free_string_stream, (void *)stream);
}