tools/perf/util/lzma.c

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

File Facts

System
Linux kernel
Corpus path
tools/perf/util/lzma.c
Extension
.c
Size
2790 bytes
Lines
130
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 (strm.avail_in == 0 && !feof(infile)) {
			strm.next_in  = buf_in;
			strm.avail_in = fread(buf_in, 1, sizeof(buf_in), infile);

			if (ferror(infile)) {
				pr_debug("lzma: read error: %m\n");
				goto err_lzma_end;
			}

			if (feof(infile))
				action = LZMA_FINISH;
		}

		ret = lzma_code(&strm, action);

		if (strm.avail_out == 0 || ret == LZMA_STREAM_END) {
			ssize_t write_size = sizeof(buf_out) - strm.avail_out;

			if (writen(output_fd, buf_out, write_size) != write_size) {
				pr_debug("lzma: write error: %m\n");
				goto err_lzma_end;
			}

			strm.next_out  = buf_out;
			strm.avail_out = sizeof(buf_out);
		}

		if (ret != LZMA_OK) {
			if (ret == LZMA_STREAM_END)
				break;

			pr_debug("lzma: failed %s\n", lzma_strerror(ret));
			goto err_lzma_end;
		}
	}

	err = 0;
err_lzma_end:
	lzma_end(&strm);
	return err;
}

int lzma_decompress_to_file(const char *input, int output_fd)
{
	FILE *infile;
	int ret;

	infile = fopen(input, "rb");
	if (!infile) {
		pr_debug("lzma: fopen failed on %s: '%m'\n", input);
		return -1;
	}

	ret = lzma_decompress_stream_to_file(infile, output_fd);
	fclose(infile);
	return ret;
}

bool lzma_is_compressed(const char *input)
{
	int fd = open(input, O_RDONLY);
	const uint8_t magic[6] = { 0xFD, '7', 'z', 'X', 'Z', 0x00 };
	char buf[6] = { 0 };
	ssize_t rc;

	if (fd < 0)
		return false;

	rc = read(fd, buf, sizeof(buf));
	close(fd);
	return rc == sizeof(buf) ?
	       memcmp(buf, magic, sizeof(buf)) == 0 : false;
}

Annotation

Implementation Notes