diff options
Diffstat (limited to 'lib/kunit/string-stream.c')
-rw-r--r-- | lib/kunit/string-stream.c | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/lib/kunit/string-stream.c b/lib/kunit/string-stream.c new file mode 100644 index 000000000000..54f4fdcbfac8 --- /dev/null +++ b/lib/kunit/string-stream.c @@ -0,0 +1,207 @@ +// 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/static_stub.h> +#include <kunit/test.h> +#include <linux/list.h> +#include <linux/slab.h> + +#include "string-stream.h" + + +static struct string_stream_fragment *alloc_string_stream_fragment(int len, gfp_t gfp) +{ + struct string_stream_fragment *frag; + + frag = kzalloc(sizeof(*frag), gfp); + if (!frag) + return ERR_PTR(-ENOMEM); + + frag->fragment = kmalloc(len, gfp); + if (!frag->fragment) { + kfree(frag); + return ERR_PTR(-ENOMEM); + } + + return frag; +} + +static void string_stream_fragment_destroy(struct string_stream_fragment *frag) +{ + list_del(&frag->node); + kfree(frag->fragment); + kfree(frag); +} + +int string_stream_vadd(struct string_stream *stream, + const char *fmt, + va_list args) +{ + struct string_stream_fragment *frag_container; + 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 */ + buf_len = vsnprintf(NULL, 0, fmt, args_for_counting); + + va_end(args_for_counting); + + if (buf_len == 0) + return 0; + + /* Reserve one extra for possible appended newline. */ + if (stream->append_newlines) + buf_len++; + + /* Need space for null byte. */ + buf_len++; + + frag_container = alloc_string_stream_fragment(buf_len, stream->gfp); + if (IS_ERR(frag_container)) + return PTR_ERR(frag_container); + + 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 += result_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; +} + +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 = kzalloc(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; + int ret; + + other_content = string_stream_get_string(other); + + if (!other_content) + return -ENOMEM; + + ret = string_stream_add(stream, other_content); + kfree(other_content); + + return ret; +} + +bool string_stream_is_empty(struct string_stream *stream) +{ + return list_empty(&stream->fragments); +} + +struct string_stream *alloc_string_stream(gfp_t gfp) +{ + struct string_stream *stream; + + stream = kzalloc(sizeof(*stream), gfp); + if (!stream) + return ERR_PTR(-ENOMEM); + + stream->gfp = gfp; + INIT_LIST_HEAD(&stream->fragments); + spin_lock_init(&stream->lock); + + return stream; +} + +void string_stream_destroy(struct string_stream *stream) +{ + KUNIT_STATIC_STUB_REDIRECT(string_stream_destroy, stream); + + if (IS_ERR_OR_NULL(stream)) + return; + + string_stream_clear(stream); + kfree(stream); +} + +static void resource_free_string_stream(void *p) +{ + struct string_stream *stream = p; + + string_stream_destroy(stream); +} + +struct string_stream *kunit_alloc_string_stream(struct kunit *test, gfp_t gfp) +{ + struct string_stream *stream; + + stream = alloc_string_stream(gfp); + if (IS_ERR(stream)) + return stream; + + if (kunit_add_action_or_reset(test, resource_free_string_stream, stream) != 0) + return ERR_PTR(-ENOMEM); + + return stream; +} + +void kunit_free_string_stream(struct kunit *test, struct string_stream *stream) +{ + kunit_release_action(test, resource_free_string_stream, (void *)stream); +} |