blob: a608746020a997735b638fc6f37be106ff766c97 [file] [log] [blame]
// 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/test.h>
#include <linux/list.h>
#include <linux/slab.h>
#include "string-stream.h"
static struct string_stream_fragment *alloc_string_stream_fragment(
struct kunit *test, int len, gfp_t gfp)
{
struct string_stream_fragment *frag;
frag = kunit_kzalloc(test, sizeof(*frag), gfp);
if (!frag)
return ERR_PTR(-ENOMEM);
frag->fragment = kunit_kmalloc(test, len, gfp);
if (!frag->fragment)
return ERR_PTR(-ENOMEM);
return frag;
}
static void string_stream_fragment_destroy(struct kunit *test,
struct string_stream_fragment *frag)
{
list_del(&frag->node);
kunit_kfree(test, frag->fragment);
kunit_kfree(test, frag);
}
int string_stream_vadd(struct string_stream *stream,
const char *fmt,
va_list args)
{
struct string_stream_fragment *frag_container;
int len;
va_list args_for_counting;
/* Make a copy because `vsnprintf` could change it */
va_copy(args_for_counting, args);
/* Need space for null byte. */
len = vsnprintf(NULL, 0, fmt, args_for_counting) + 1;
va_end(args_for_counting);
frag_container = alloc_string_stream_fragment(stream->test,
len,
stream->gfp);
if (IS_ERR(frag_container))
return PTR_ERR(frag_container);
len = vsnprintf(frag_container->fragment, len, fmt, args);
spin_lock(&stream->lock);
stream->length += 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;
}
static 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(stream->test, 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 = kunit_kzalloc(stream->test, 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;
other_content = string_stream_get_string(other);
if (!other_content)
return -ENOMEM;
return string_stream_add(stream, other_content);
}
bool string_stream_is_empty(struct string_stream *stream)
{
return list_empty(&stream->fragments);
}
struct string_stream_alloc_context {
struct kunit *test;
gfp_t gfp;
};
struct string_stream *alloc_string_stream(struct kunit *test, gfp_t gfp)
{
struct string_stream *stream;
stream = kunit_kzalloc(test, sizeof(*stream), gfp);
if (!stream)
return ERR_PTR(-ENOMEM);
stream->gfp = gfp;
stream->test = test;
INIT_LIST_HEAD(&stream->fragments);
spin_lock_init(&stream->lock);
return stream;
}
void string_stream_destroy(struct string_stream *stream)
{
string_stream_clear(stream);
}