Re: [PATCH v5 06/10] perf util: introduce Zstd based streaming compression API

Jiri Olsa
2019-03-05T12:26:21Z

On Fri, Mar 01, 2019 at 06:52:10PM +0300, Alexey Budankov wrote:
>
> Implemented functions are based on Zstd streaming compression API.
> The functions are used in runtime to compress data that come from
> mmaped kernel buffer data and then stored into a trace.

please describe the usage of the api in the changelog

thanks,
jirka

>
> Signed-off-by: Alexey Budankov <alexey.budankov@linux.intel.com>
> ---
> tools/perf/util/Build | 2 +
> tools/perf/util/compress.h | 18 ++++++++
> tools/perf/util/zstd.c | 95 ++++++++++++++++++++++++++++++++++++++
> 3 files changed, 115 insertions(+)
> create mode 100644 tools/perf/util/zstd.c
>
> diff --git a/tools/perf/util/Build b/tools/perf/util/Build
> index 8dd3102301ea..920ee8bebd83 100644
> --- a/tools/perf/util/Build
> +++ b/tools/perf/util/Build
> @@ -145,6 +145,8 @@ perf-y += scripting-engines/
>
> perf-$(CONFIG_ZLIB) += zlib.o
> perf-$(CONFIG_LZMA) += lzma.o
> +perf-y += zstd.o
> +
> perf-y += demangle-java.o
> perf-y += demangle-rust.o
>
> diff --git a/tools/perf/util/compress.h b/tools/perf/util/compress.h
> index 892e92e7e7fc..e0987616db94 100644
> --- a/tools/perf/util/compress.h
> +++ b/tools/perf/util/compress.h
> @@ -2,6 +2,11 @@
> #ifndef PERF_COMPRESS_H
> #define PERF_COMPRESS_H
>
> +#include <stdbool.h>
> +#ifdef HAVE_ZSTD_SUPPORT
> +#include <zstd.h>
> +#endif
> +
> #ifdef HAVE_ZLIB_SUPPORT
> int gzip_decompress_to_file(const char *input, int output_fd);
> bool gzip_is_compressed(const char *input);
> @@ -12,4 +17,17 @@ int lzma_decompress_to_file(const char *input, int output_fd);
> bool lzma_is_compressed(const char *input);
> #endif
>
> +struct zstd_data {
> +#ifdef HAVE_ZSTD_SUPPORT
> + ZSTD_CStream *cstream;
> +#endif
> +};
> +
> +int zstd_init(struct zstd_data *data, int level);
> +int zstd_fini(struct zstd_data *data);
> +
> +size_t zstd_compress_stream_to_records(struct zstd_data *data,
> + void *dst, size_t dst_size, void *src, size_t src_size, size_t max_record_size,
> + size_t process_header(void *record, size_t increment));
> +
> #endif /* PERF_COMPRESS_H */
> diff --git a/tools/perf/util/zstd.c b/tools/perf/util/zstd.c
> new file mode 100644
> index 000000000000..e5d44d0f6b5d
> --- /dev/null
> +++ b/tools/perf/util/zstd.c
> @@ -0,0 +1,95 @@
> +// SPDX-License-Identifier: GPL-2.0
> +
> +#include <string.h>
> +
> +#include "util/compress.h"
> +#include "util/debug.h"
> +
> +#ifdef HAVE_ZSTD_SUPPORT
> +
> +int zstd_init(struct zstd_data *data, int level)
> +{
> + size_t ret;
> +
> + data->cstream = ZSTD_createCStream();
> + if (data->cstream == NULL) {
> + pr_err("Couldn't create compression stream.\n");
> + return -1;
> + }
> +
> + ret = ZSTD_initCStream(data->cstream, level);
> + if (ZSTD_isError(ret)) {
> + pr_err("Failed to initialize compression stream: %s\n", ZSTD_getErrorName(ret));
> + return -1;
> + }
> +
> + return 0;
> +}
> +
> +int zstd_fini(struct zstd_data *data)
> +{
> + if (data->cstream) {
> + ZSTD_freeCStream(data->cstream);
> + data->cstream = NULL;
> + }
> +
> + return 0;
> +}
> +
> +size_t zstd_compress_stream_to_records(struct zstd_data *data,
> + void *dst, size_t dst_size, void *src, size_t src_size, size_t max_record_size,
> + size_t process_header(void *record, size_t increment))
> +{
> + size_t ret, size, compressed = 0;
> + ZSTD_inBuffer input = { src, src_size, 0 };
> + ZSTD_outBuffer output;
> + void *record;
> +
> + while (input.pos < input.size) {
> + record = dst;
> + size = process_header(record, 0);
> + compressed += size;
> + dst += size;
> + dst_size -= size;
> + output = (ZSTD_outBuffer){ dst, (dst_size > max_record_size) ?
> + max_record_size : dst_size, 0 };
> + ret = ZSTD_compressStream(data->cstream, &output, &input);
> + ZSTD_flushStream(data->cstream, &output);
> + if (ZSTD_isError(ret)) {
> + pr_err("failed to compress %ld bytes: %s\n",
> + (long)src_size, ZSTD_getErrorName(ret));
> + memcpy(dst, src, src_size);
> + return src_size;
> + }
> + size = output.pos;
> + size = process_header(record, size);
> + compressed += size;
> + dst += size;
> + dst_size -= size;
> + }
> +
> + return compressed;
> +}
> +
> +#else /* !HAVE_ZSTD_SUPPORT */
> +
> +int zstd_init(struct zstd_data *data __maybe_unused, int level __maybe_unused)
> +{
> + return 0;
> +}
> +
> +int zstd_fini(struct zstd_data *data __maybe_unused)
> +{
> + return 0;
> +}
> +
> +size_t zstd_compress_stream_to_records(struct zstd_data *data __maybe_unused,
> + void *dst __maybe_unused, size_t dst_size __maybe_unused,
> + void *src __maybe_unused, size_t src_size __maybe_unused,
> + size_t max_record_size __maybe_unused,
> + size_t process_header(void *record, size_t increment) __maybe_unused)
> +{
> + return 0;
> +}
> +
> +#endif
> --
> 2.20.1
>