From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-qt1-x849.google.com ([2607:f8b0:4864:20::849]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1gF6ab-0004BT-L0 for linux-um@lists.infradead.org; Tue, 23 Oct 2018 23:59:59 +0000 Received: by mail-qt1-x849.google.com with SMTP id f20-v6so3786765qta.16 for ; Tue, 23 Oct 2018 16:59:46 -0700 (PDT) Date: Tue, 23 Oct 2018 16:57:39 -0700 In-Reply-To: <20181023235750.103146-1-brendanhiggins@google.com> Message-Id: <20181023235750.103146-4-brendanhiggins@google.com> Mime-Version: 1.0 References: <20181023235750.103146-1-brendanhiggins@google.com> Subject: [RFC v2 03/14] kunit: test: add string_stream a std::stream like string builder From: Brendan Higgins List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+geert=linux-m68k.org@lists.infradead.org To: gregkh@linuxfoundation.org, keescook@google.com, mcgrof@kernel.org, shuah@kernel.org Cc: brakmo@fb.com, robh@kernel.org, richard@nod.at, dri-devel@lists.freedesktop.org, linux-nvdimm@lists.01.org, mpe@ellerman.id.au, Tim.Bird@sony.com, linux-um@lists.infradead.org, linux-kernel@vger.kernel.org, rostedt@goodmis.org, kieran.bingham@ideasonboard.com, julia.lawall@lip6.fr, joel@jms.id.au, linux-kselftest@vger.kernel.org, khilman@baylibre.com, joe@perches.com, daniel@ffwll.ch, dan.j.williams@intel.com, jdike@addtoit.com, Brendan Higgins , kunit-dev@googlegroups.com 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 --- include/kunit/string-stream.h | 44 ++++++++++ kunit/Makefile | 2 +- kunit/string-stream.c | 149 ++++++++++++++++++++++++++++++++++ 3 files changed, 194 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..933ed5740cf07 --- /dev/null +++ b/include/kunit/string-stream.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * C++ stream style string builder used in KUnit for building messages. + * + * Copyright (C) 2018, Google LLC. + * Author: Brendan Higgins + */ + +#ifndef _KUNIT_STRING_STREAM_H +#define _KUNIT_STRING_STREAM_H + +#include +#include +#include +#include + +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; + int (*add)(struct string_stream *this, const char *fmt, ...); + int (*vadd)(struct string_stream *this, const char *fmt, va_list args); + char *(*get_string)(struct string_stream *this); + void (*clear)(struct string_stream *this); + bool (*is_empty)(struct string_stream *this); +}; + +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); + +#endif /* _KUNIT_STRING_STREAM_H */ diff --git a/kunit/Makefile b/kunit/Makefile index dd7a0299514b7..7fc613a9b383b 100644 --- a/kunit/Makefile +++ b/kunit/Makefile @@ -1 +1 @@ -obj-$(CONFIG_KUNIT) += test.o +obj-$(CONFIG_KUNIT) += test.o string-stream.o diff --git a/kunit/string-stream.c b/kunit/string-stream.c new file mode 100644 index 0000000000000..1e7efa630cc35 --- /dev/null +++ b/kunit/string-stream.c @@ -0,0 +1,149 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * C++ stream style string builder used in KUnit for building messages. + * + * Copyright (C) 2018, Google LLC. + * Author: Brendan Higgins + */ + +#include +#include +#include + +static int string_stream_vadd(struct string_stream *this, + const char *fmt, + va_list args) +{ + struct string_stream_fragment *fragment; + 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); + 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; +} + +static 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; +} + +static 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->length = 0; + spin_unlock_irqrestore(&this->lock, flags); +} + +static 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; +} + +static 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) +{ + 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); + stream->add = string_stream_add; + stream->vadd = string_stream_vadd; + stream->get_string = string_stream_get_string; + stream->clear = string_stream_clear; + stream->is_empty = string_stream_is_empty; + 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); +} + -- 2.19.1.568.g152ad8e336-goog _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um