forked from Minki/linux
f24c1d7523
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>
71 lines
1.6 KiB
C
71 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <string.h>
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#include "util/compress.h"
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#include "util/debug.h"
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int zstd_init(struct zstd_data *data, int level)
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{
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size_t ret;
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data->cstream = ZSTD_createCStream();
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if (data->cstream == NULL) {
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pr_err("Couldn't create compression stream.\n");
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return -1;
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}
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ret = ZSTD_initCStream(data->cstream, level);
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if (ZSTD_isError(ret)) {
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pr_err("Failed to initialize compression stream: %s\n", ZSTD_getErrorName(ret));
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return -1;
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}
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return 0;
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}
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int zstd_fini(struct zstd_data *data)
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{
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if (data->cstream) {
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ZSTD_freeCStream(data->cstream);
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data->cstream = NULL;
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}
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return 0;
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}
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size_t zstd_compress_stream_to_records(struct zstd_data *data, void *dst, size_t dst_size,
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void *src, size_t src_size, size_t max_record_size,
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size_t process_header(void *record, size_t increment))
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{
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size_t ret, size, compressed = 0;
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ZSTD_inBuffer input = { src, src_size, 0 };
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ZSTD_outBuffer output;
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void *record;
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while (input.pos < input.size) {
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record = dst;
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size = process_header(record, 0);
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compressed += size;
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dst += size;
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dst_size -= size;
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output = (ZSTD_outBuffer){ dst, (dst_size > max_record_size) ?
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max_record_size : dst_size, 0 };
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ret = ZSTD_compressStream(data->cstream, &output, &input);
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ZSTD_flushStream(data->cstream, &output);
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if (ZSTD_isError(ret)) {
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pr_err("failed to compress %ld bytes: %s\n",
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(long)src_size, ZSTD_getErrorName(ret));
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memcpy(dst, src, src_size);
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return src_size;
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}
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size = output.pos;
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size = process_header(record, size);
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compressed += size;
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dst += size;
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dst_size -= size;
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}
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return compressed;
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}
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