[PATCH v7 06/12] perf util: introduce Zstd based streaming compression API

From: Alexey Budankov
Date: Tue Mar 12 2019 - 01:23:50 EST



Implemented functions are based on Zstd streaming compression API.
The functions are used in runtime to compress data that come from
mmaped kernel buffer. zstd_init(), zstd_fini() are used for
initialization and finalization to allocate and deallocate internal
zstd objects. zstd_compress_stream_to_records() is used to convert
parts of mmaped kernel buffer into an array of PERF_RECORD_COMPRESSED
records.

Signed-off-by: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
---
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