On 5/1/19 5:01 PM, Brendan Higgins wrote:
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.
Signed-off-by: Brendan Higgins brendanhiggins@google.com
include/kunit/string-stream.h | 51 ++++++++++++ kunit/Makefile | 3 +- kunit/string-stream.c | 144 ++++++++++++++++++++++++++++++++++ 3 files changed, 197 insertions(+), 1 deletion(-) create mode 100644 include/kunit/string-stream.h create mode 100644 kunit/string-stream.c
diff --git a/include/kunit/string-stream.h b/include/kunit/string-stream.h new file mode 100644 index 0000000000000..567a4629406da --- /dev/null +++ b/include/kunit/string-stream.h @@ -0,0 +1,51 @@ +/* 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/types.h> +#include <linux/spinlock.h> +#include <linux/kref.h> +#include <stdarg.h>
+struct string_stream_fragment {
- 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 kref refcount;
+};
+struct string_stream *new_string_stream(void);
+void destroy_string_stream(struct string_stream *stream);
+void string_stream_get(struct string_stream *stream);
+int string_stream_put(struct string_stream *stream);
+int string_stream_add(struct string_stream *this, const char *fmt, ...);
+int string_stream_vadd(struct string_stream *this,
const char *fmt,va_list args);+char *string_stream_get_string(struct string_stream *this);
+void string_stream_clear(struct string_stream *this);
+bool string_stream_is_empty(struct string_stream *this);
+#endif /* _KUNIT_STRING_STREAM_H */ diff --git a/kunit/Makefile b/kunit/Makefile index 5efdc4dea2c08..275b565a0e81f 100644 --- a/kunit/Makefile +++ b/kunit/Makefile @@ -1 +1,2 @@ -obj-$(CONFIG_KUNIT) += test.o +obj-$(CONFIG_KUNIT) += test.o \
string-stream.odiff --git a/kunit/string-stream.c b/kunit/string-stream.c new file mode 100644 index 0000000000000..7018194ecf2fa --- /dev/null +++ b/kunit/string-stream.c @@ -0,0 +1,144 @@ +// 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 *fragment;
Since there is field with the same name, please use a different name. Using the same name for the struct which contains a field of the same name get very confusing and will hard to maintain the code.
- 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);
- fragment = kmalloc(sizeof(*fragment), GFP_KERNEL);
- if (!fragment)
return -ENOMEM;- fragment->fragment = kmalloc(len, GFP_KERNEL);
This is confusing. See above comment.
- if (!fragment->fragment) {
kfree(fragment);return -ENOMEM;- }
- len = vsnprintf(fragment->fragment, len, fmt, args);
- spin_lock_irqsave(&this->lock, flags);
- this->length += len;
- list_add_tail(&fragment->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 *fragment, *fragment_safe;
- unsigned long flags;
- spin_lock_irqsave(&this->lock, flags);
- list_for_each_entry_safe(fragment,
fragment_safe,&this->fragments,node) {list_del(&fragment->node);kfree(fragment->fragment);kfree(fragment);
This is what git me down the road of checking the structure name to begin with. :)
- }
- this->length = 0;
- spin_unlock_irqrestore(&this->lock, flags);
+}
+char *string_stream_get_string(struct string_stream *this) +{
- struct string_stream_fragment *fragment;
- 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(fragment, &this->fragments, node)
strlcat(buf, fragment->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);
+}
thanks, -- Shuah