Add an optional feature to string_stream that will append a newline to any added string that does not already end with a newline. The purpose of this is so that string_stream can be used to collect log lines.
This is enabled/disabled by calling string_stream_set_append_newlines().
Signed-off-by: Richard Fitzgerald rf@opensource.cirrus.com --- lib/kunit/string-stream.c | 28 +++++++++++++++++++++------- lib/kunit/string-stream.h | 7 +++++++ 2 files changed, 28 insertions(+), 7 deletions(-)
diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c index ed24d86af9f5..1dcf6513b692 100644 --- a/lib/kunit/string-stream.c +++ b/lib/kunit/string-stream.c @@ -44,32 +44,46 @@ int string_stream_vadd(struct string_stream *stream, va_list args) { struct string_stream_fragment *frag_container; - int len; + int buf_len, result_len; va_list args_for_counting;
/* Make a copy because `vsnprintf` could change it */ va_copy(args_for_counting, args);
/* Evaluate length of formatted string */ - len = vsnprintf(NULL, 0, fmt, args_for_counting); + buf_len = vsnprintf(NULL, 0, fmt, args_for_counting);
va_end(args_for_counting);
- if (len == 0) + if (buf_len == 0) return 0;
+ /* Reserve one extra for possible appended newline. */ + if (stream->append_newlines) + buf_len++; + /* Need space for null byte. */ - len++; + buf_len++;
frag_container = alloc_string_stream_fragment(stream->test, - len, + buf_len, stream->gfp); if (IS_ERR(frag_container)) return PTR_ERR(frag_container);
- len = vsnprintf(frag_container->fragment, len, fmt, args); + if (stream->append_newlines) { + /* Don't include reserved newline byte in writeable length. */ + result_len = vsnprintf(frag_container->fragment, buf_len - 1, fmt, args); + + /* Append newline if necessary. */ + if (frag_container->fragment[result_len - 1] != '\n') + result_len = strlcat(frag_container->fragment, "\n", buf_len); + } else { + result_len = vsnprintf(frag_container->fragment, buf_len, fmt, args); + } + spin_lock(&stream->lock); - stream->length += len; + stream->length += result_len; list_add_tail(&frag_container->node, &stream->fragments); spin_unlock(&stream->lock);
diff --git a/lib/kunit/string-stream.h b/lib/kunit/string-stream.h index b669f9a75a94..048930bf97f0 100644 --- a/lib/kunit/string-stream.h +++ b/lib/kunit/string-stream.h @@ -25,6 +25,7 @@ struct string_stream { spinlock_t lock; struct kunit *test; gfp_t gfp; + bool append_newlines; };
struct kunit; @@ -47,4 +48,10 @@ bool string_stream_is_empty(struct string_stream *stream);
void string_stream_destroy(struct string_stream *stream);
+static inline void string_stream_set_append_newlines(struct string_stream *stream, + bool append_newlines) +{ + stream->append_newlines = append_newlines; +} + #endif /* _KUNIT_STRING_STREAM_H */