tools/perf/util/zstd.c

Source file repositories/reference/linux-study-clean/tools/perf/util/zstd.c

File Facts

System
Linux kernel
Corpus path
tools/perf/util/zstd.c
Extension
.c
Size
2794 bytes
Lines
115
Domain
Support Tooling And Documentation
Bucket
tools
Inferred role
Support Tooling And Documentation: implementation source
Status
source implementation candidate

Why This File Exists

Repository support layer: documentation, build tooling, samples, user-space helper tools, generated initramfs support, licenses, and validation utilities.

Dependency Surface

Detected Declarations

Annotated Snippet

if (data->cstream == NULL) {
			pr_err("Couldn't create compression stream.\n");
			return -1;
		}

		ret = ZSTD_initCStream(data->cstream, data->comp_level);
		if (ZSTD_isError(ret)) {
			pr_err("Failed to initialize compression stream: %s\n",
				ZSTD_getErrorName(ret));
			return -1;
		}
	}

	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;
}

size_t zstd_decompress_stream(struct zstd_data *data, void *src, size_t src_size,
			      void *dst, size_t dst_size)
{
	size_t ret;
	ZSTD_inBuffer input = { src, src_size, 0 };
	ZSTD_outBuffer output = { dst, dst_size, 0 };

	if (!data->dstream) {
		data->dstream = ZSTD_createDStream();
		if (data->dstream == NULL) {
			pr_err("Couldn't create decompression stream.\n");
			return 0;
		}

		ret = ZSTD_initDStream(data->dstream);
		if (ZSTD_isError(ret)) {
			pr_err("Failed to initialize decompression stream: %s\n",
				ZSTD_getErrorName(ret));
			return 0;
		}
	}
	while (input.pos < input.size) {
		ret = ZSTD_decompressStream(data->dstream, &output, &input);
		if (ZSTD_isError(ret)) {
			pr_err("failed to decompress (B): %zd -> %zd, dst_size %zd : %s\n",
			       src_size, output.size, dst_size, ZSTD_getErrorName(ret));
			break;
		}
		output.dst  = dst + output.pos;
		output.size = dst_size - output.pos;
	}

	return output.pos;
}

Annotation

Implementation Notes