blob: d4e4252dc10b8ab5c8eebf1ea56b703ba51122f6 [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 <linux/list.h>
#include <linux/slab.h>
#include <kunit/string-stream.h>
int string_stream_vadd(struct string_stream *this,
const char *fmt,
va_list args)
{
struct string_stream_fragment *frag_container;
int len;
va_list args_for_counting;
unsigned long flags;
/* 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 = kmalloc(sizeof(*frag_container), GFP_KERNEL);
if (!frag_container)
return -ENOMEM;
frag_container->fragment = kmalloc(len, GFP_KERNEL);
if (!frag_container->fragment) {
kfree(frag_container);
return -ENOMEM;
}
len = vsnprintf(frag_container->fragment, len, fmt, args);
spin_lock_irqsave(&this->lock, flags);
this->length += len;
list_add_tail(&frag_container->node, &this->fragments);
spin_unlock_irqrestore(&this->lock, flags);
return 0;
}
int string_stream_add(struct string_stream *this, const char *fmt, ...)
{
va_list args;
int result;
va_start(args, fmt);
result = string_stream_vadd(this, fmt, args);
va_end(args);
return result;
}
void string_stream_clear(struct string_stream *this)
{
struct string_stream_fragment *frag_container, *frag_container_safe;
unsigned long flags;
spin_lock_irqsave(&this->lock, flags);
list_for_each_entry_safe(frag_container,
frag_container_safe,
&this->fragments,
node) {
list_del(&frag_container->node);
kfree(frag_container->fragment);
kfree(frag_container);
}
this->length = 0;
spin_unlock_irqrestore(&this->lock, flags);
}
char *string_stream_get_string(struct string_stream *this)
{
struct string_stream_fragment *frag_container;
size_t buf_len = this->length + 1; /* +1 for null byte. */
char *buf;
unsigned long flags;
buf = kzalloc(buf_len, GFP_KERNEL);
if (!buf)
return NULL;
spin_lock_irqsave(&this->lock, flags);
list_for_each_entry(frag_container, &this->fragments, node)
strlcat(buf, frag_container->fragment, buf_len);
spin_unlock_irqrestore(&this->lock, flags);
return buf;
}
bool string_stream_is_empty(struct string_stream *this)
{
bool is_empty;
unsigned long flags;
spin_lock_irqsave(&this->lock, flags);
is_empty = list_empty(&this->fragments);
spin_unlock_irqrestore(&this->lock, flags);
return is_empty;
}
void destroy_string_stream(struct string_stream *stream)
{
string_stream_clear(stream);
kfree(stream);
}
static void string_stream_destroy(struct kref *kref)
{
struct string_stream *stream = container_of(kref,
struct string_stream,
refcount);
destroy_string_stream(stream);
}
struct string_stream *new_string_stream(void)
{
struct string_stream *stream = kzalloc(sizeof(*stream), GFP_KERNEL);
if (!stream)
return NULL;
INIT_LIST_HEAD(&stream->fragments);
spin_lock_init(&stream->lock);
kref_init(&stream->refcount);
return stream;
}
void string_stream_get(struct string_stream *stream)
{
kref_get(&stream->refcount);
}
int string_stream_put(struct string_stream *stream)
{
return kref_put(&stream->refcount, &string_stream_destroy);
}