perf tools: Introduce Zstd streaming based compression API

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@linux.intel.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/18bf36f3-b85a-1fe2-dd83-10e0c6069568@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/tools/perf/util/zstd.c b/tools/perf/util/zstd.c
new file mode 100644
index 000000000000..359ec9a9d306
--- /dev/null
+++ b/tools/perf/util/zstd.c
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <string.h>
+
+#include "util/compress.h"
+#include "util/debug.h"
+
+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;
+}