Commit d1fadef1 authored by Brendan Higgins's avatar Brendan Higgins Committed by Shuah Khan

kunit: test: add string_stream a std::stream like string builder

A number of test features need to do pretty complicated string printing
where it may not be possible to rely on a single preallocated string
with parameters.

So provide a library for constructing the string as you go similar to
C++'s std::string. string_stream is really just a string builder,
nothing more.
Signed-off-by: default avatarBrendan Higgins <brendanhiggins@google.com>
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarStephen Boyd <swboyd@chromium.org>
Signed-off-by: default avatarShuah Khan <skhan@linuxfoundation.org>
parent 0a756853
/* 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>
*/
#ifndef _KUNIT_STRING_STREAM_H
#define _KUNIT_STRING_STREAM_H
#include <linux/spinlock.h>
#include <linux/types.h>
#include <stdarg.h>
struct string_stream_fragment {
struct kunit *test;
struct list_head node;
char *fragment;
};
struct string_stream {
size_t length;
struct list_head fragments;
/* length and fragments are protected by this lock */
spinlock_t lock;
struct kunit *test;
gfp_t gfp;
};
struct kunit;
struct string_stream *alloc_string_stream(struct kunit *test, gfp_t gfp);
int __printf(2, 3) string_stream_add(struct string_stream *stream,
const char *fmt, ...);
int string_stream_vadd(struct string_stream *stream,
const char *fmt,
va_list args);
char *string_stream_get_string(struct string_stream *stream);
int string_stream_append(struct string_stream *stream,
struct string_stream *other);
bool string_stream_is_empty(struct string_stream *stream);
int string_stream_destroy(struct string_stream *stream);
#endif /* _KUNIT_STRING_STREAM_H */
obj-$(CONFIG_KUNIT) += test.o
obj-$(CONFIG_KUNIT) += test.o \
string-stream.o
// 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/string-stream.h>
#include <kunit/test.h>
#include <linux/list.h>
#include <linux/slab.h>
struct string_stream_fragment_alloc_context {
struct kunit *test;
int len;
gfp_t gfp;
};
static int string_stream_fragment_init(struct kunit_resource *res,
void *context)
{
struct string_stream_fragment_alloc_context *ctx = context;
struct string_stream_fragment *frag;
frag = kunit_kzalloc(ctx->test, sizeof(*frag), ctx->gfp);
if (!frag)
return -ENOMEM;
frag->test = ctx->test;
frag->fragment = kunit_kmalloc(ctx->test, ctx->len, ctx->gfp);
if (!frag->fragment)
return -ENOMEM;
res->allocation = frag;
return 0;
}
static void string_stream_fragment_free(struct kunit_resource *res)
{
struct string_stream_fragment *frag = res->allocation;
list_del(&frag->node);
kunit_kfree(frag->test, frag->fragment);
kunit_kfree(frag->test, frag);
}
static struct string_stream_fragment *alloc_string_stream_fragment(
struct kunit *test, int len, gfp_t gfp)
{
struct string_stream_fragment_alloc_context context = {
.test = test,
.len = len,
.gfp = gfp
};
return kunit_alloc_resource(test,
string_stream_fragment_init,
string_stream_fragment_free,
gfp,
&context);
}
static int string_stream_fragment_destroy(struct string_stream_fragment *frag)
{
return kunit_resource_destroy(frag->test,
kunit_resource_instance_match,
string_stream_fragment_free,
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 (!frag_container)
return -ENOMEM;
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(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;
};
static int string_stream_init(struct kunit_resource *res, void *context)
{
struct string_stream *stream;
struct string_stream_alloc_context *ctx = context;
stream = kunit_kzalloc(ctx->test, sizeof(*stream), ctx->gfp);
if (!stream)
return -ENOMEM;
res->allocation = stream;
stream->gfp = ctx->gfp;
stream->test = ctx->test;
INIT_LIST_HEAD(&stream->fragments);
spin_lock_init(&stream->lock);
return 0;
}
static void string_stream_free(struct kunit_resource *res)
{
struct string_stream *stream = res->allocation;
string_stream_clear(stream);
}
struct string_stream *alloc_string_stream(struct kunit *test, gfp_t gfp)
{
struct string_stream_alloc_context context = {
.test = test,
.gfp = gfp
};
return kunit_alloc_resource(test,
string_stream_init,
string_stream_free,
gfp,
&context);
}
int string_stream_destroy(struct string_stream *stream)
{
return kunit_resource_destroy(stream->test,
kunit_resource_instance_match,
string_stream_free,
stream);
}
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