Commit c9dc580c authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

tools api: Add io__getline 



Reads a line to allocated memory up to a newline following the getline
API.

Committer notes:

It also adds this new function to the 'api io' 'perf test' entry:

  $ perf test "api io"
   64: Test api io                                                     : Ok
  $

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Tested-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tom Rix <trix@redhat.com>
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230403184033.1836023-2-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 98b7ce0e

tools/lib/api/io.h

+45 −0
Original line number Diff line number Diff line
@@ -7,7 +7,9 @@ 
#ifndef __API_IO__

#define __API_IO__



#include <errno.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>



struct io {
@@ -112,4 +114,47 @@ static inline int io__get_dec(struct io *io, __u64 *dec) 
	}

}



/* Read up to and including the first newline following the pattern of getline. */

static inline ssize_t io__getline(struct io *io, char **line_out, size_t *line_len_out)

{

	char buf[128];

	int buf_pos = 0;

	char *line = NULL, *temp;

	size_t line_len = 0;

	int ch = 0;



	/* TODO: reuse previously allocated memory. */

	free(*line_out);

	while (ch != '\n') {

		ch = io__get_char(io);



		if (ch < 0)

			break;



		if (buf_pos == sizeof(buf)) {

			temp = realloc(line, line_len + sizeof(buf));

			if (!temp)

				goto err_out;

			line = temp;

			memcpy(&line[line_len], buf, sizeof(buf));

			line_len += sizeof(buf);

			buf_pos = 0;

		}

		buf[buf_pos++] = (char)ch;

	}

	temp = realloc(line, line_len + buf_pos + 1);

	if (!temp)

		goto err_out;

	line = temp;

	memcpy(&line[line_len], buf, buf_pos);

	line[line_len + buf_pos] = '\0';

	line_len += buf_pos;

	*line_out = line;

	*line_len_out = line_len;

	return line_len;

err_out:

	free(line);

	return -ENOMEM;

}



#endif /* __API_IO__ */

tools/perf/tests/api-io.c

+36 −0
Original line number Diff line number Diff line
@@ -289,6 +289,40 @@ static int test_get_dec(void) 
	return ret;

}



static int test_get_line(void)

{

	char path[PATH_MAX];

	struct io io;

	char test_string[1024];

	char *line = NULL;

	size_t i, line_len = 0;

	size_t buf_size = 128;

	int ret = 0;



	for (i = 0; i < 512; i++)

		test_string[i] = 'a';

	test_string[512] = '\n';

	for (i = 513; i < 1023; i++)

		test_string[i] = 'b';

	test_string[1023] = '\0';



	if (setup_test(path, test_string, buf_size, &io))

		return -1;



	EXPECT_EQUAL((int)io__getline(&io, &line, &line_len), 513);

	EXPECT_EQUAL((int)strlen(line), 513);

	for (i = 0; i < 512; i++)

		EXPECT_EQUAL(line[i], 'a');

	EXPECT_EQUAL(line[512], '\n');

	EXPECT_EQUAL((int)io__getline(&io, &line, &line_len), 510);

	for (i = 0; i < 510; i++)

		EXPECT_EQUAL(line[i], 'b');



	free(line);

	cleanup_test(path, &io);

	return ret;

}



static int test__api_io(struct test_suite *test __maybe_unused,

			int subtest __maybe_unused)

{
@@ -300,6 +334,8 @@ static int test__api_io(struct test_suite *test __maybe_unused, 
		ret = TEST_FAIL;

	if (test_get_dec())

		ret = TEST_FAIL;

	if (test_get_line())

		ret = TEST_FAIL;

	return ret;

}