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authorBrendan Higgins <brendanhiggins@google.com>2019-09-23 02:02:33 -0700
committerShuah Khan <skhan@linuxfoundation.org>2019-09-30 17:35:00 -0600
commitd1fadef194008b22d7d9608426cad29d4bb69ab9 (patch)
tree6b95896245d9b87ec2a4128aeac14b99fd43b9e4 /lib/kunit/string-stream.c
parent0a756853586ce185ee1bb9ccbe5ec03e103e594f (diff)
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: Brendan Higgins <brendanhiggins@google.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Diffstat (limited to 'lib/kunit/string-stream.c')
-rw-r--r--lib/kunit/string-stream.c217
1 files changed, 217 insertions, 0 deletions
diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c
new file mode 100644
index 000000000000..e6d17aacca30
--- /dev/null
+++ b/lib/kunit/string-stream.c
@@ -0,0 +1,217 @@
+// 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);
+}