[lttng-dev] [RFC PATCH lttng-tools v4] lttng cli: Accept human readable sizes for --subbuf-size

Mathieu Desnoyers mathieu.desnoyers at efficios.com
Thu Apr 11 13:01:52 EDT 2013


* Simon Marchi (simon.marchi at polymtl.ca) wrote:
> --subbuf-size accepts sizes such as:
> 
> - 123 -> 123
> - 123k -> 123 * 1024
> - 123M -> 123 * 1024 * 1024

* 1024^2

> - 123G -> 123 * 1024 * 1024 * 1024

* 1024^3

> 
> It uses the new parse_size_suffix function, which could probably be used
> at other places, such as tracefile size.
> 
> Unit tests are included.
> 
> Signed-off-by: Simon Marchi <simon.marchi at polymtl.ca>
> ---
> New in v4:
> - Changes following David Goulet's comments
>  - Move stuff in src/common/utils.{c,h}
>  - malloc -> zmalloc
>  - Formatting
> 
>  src/bin/lttng/commands/enable_channels.c |   21 ++++-
>  src/common/utils.c                       |  124 ++++++++++++++++++++++++++++++
>  src/common/utils.h                       |    8 ++
>  tests/unit/Makefile.am                   |   15 +++-
>  tests/unit/test_parse_size_suffix.c      |   73 ++++++++++++++++++
>  5 files changed, 235 insertions(+), 6 deletions(-)
>  create mode 100644 tests/unit/test_parse_size_suffix.c
> 
> diff --git a/src/bin/lttng/commands/enable_channels.c b/src/bin/lttng/commands/enable_channels.c
> index d026af4..dbec8ab 100644
> --- a/src/bin/lttng/commands/enable_channels.c
> +++ b/src/bin/lttng/commands/enable_channels.c
> @@ -66,7 +66,7 @@ static struct poptOption long_options[] = {
>  	{"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
>  	{"discard",        0,   POPT_ARG_NONE, 0, OPT_DISCARD, 0, 0},
>  	{"overwrite",      0,   POPT_ARG_NONE, 0, OPT_OVERWRITE, 0, 0},
> -	{"subbuf-size",    0,   POPT_ARG_DOUBLE, 0, OPT_SUBBUF_SIZE, 0, 0},
> +	{"subbuf-size",    0,   POPT_ARG_STRING, 0, OPT_SUBBUF_SIZE, 0, 0},
>  	{"num-subbuf",     0,   POPT_ARG_INT, 0, OPT_NUM_SUBBUF, 0, 0},
>  	{"switch-timer",   0,   POPT_ARG_INT, 0, OPT_SWITCH_TIMER, 0, 0},
>  	{"read-timer",     0,   POPT_ARG_INT, 0, OPT_READ_TIMER, 0, 0},
> @@ -289,6 +289,7 @@ int cmd_enable_channels(int argc, const char **argv)
>  	int opt, ret = CMD_SUCCESS;
>  	static poptContext pc;
>  	char *session_name = NULL;
> +	char *opt_arg = NULL;
>  
>  	init_channel_config();
>  
> @@ -309,8 +310,22 @@ int cmd_enable_channels(int argc, const char **argv)
>  			DBG("Channel set to overwrite");
>  			break;
>  		case OPT_SUBBUF_SIZE:
> -			/* TODO Replace atol with strtol and check for errors */
> -			chan.attr.subbuf_size = atol(poptGetOptArg(pc));
> +			/* Parse the size */
> +			opt_arg = poptGetOptArg(pc);
> +			if (parse_size_suffix(opt_arg, &chan.attr.subbuf_size) < 0) {
> +				ERR("Wrong value the --subbuf-size parameter: %s", opt_arg);
> +				ret = CMD_ERROR;
> +				goto end;
> +			}
> +
> +			/* Check if power of 2 */
> +			if ((chan.attr.subbuf_size - 1) & chan.attr.subbuf_size) {
> +				ERR("The subbuf size is not a power of 2: %" PRIu64 " (%s)",
> +						chan.attr.subbuf_size, opt_arg);
> +				ret = CMD_ERROR;
> +				goto end;
> +			}
> +
>  			DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
>  			break;
>  		case OPT_NUM_SUBBUF:
> diff --git a/src/common/utils.c b/src/common/utils.c
> index b16cdc9..9e8fd9d 100644
> --- a/src/common/utils.c
> +++ b/src/common/utils.c
> @@ -26,6 +26,7 @@
>  #include <sys/stat.h>
>  #include <unistd.h>
>  #include <inttypes.h>
> +#include <regex.h>
>  
>  #include <common/common.h>
>  #include <common/runas.h>
> @@ -386,3 +387,126 @@ int utils_rotate_stream_file(char *path_name, char *file_name, uint64_t size,
>  error:
>  	return ret;
>  }
> +
> +/**
> + * Prints the error message corresponding to a regex error code.
> + *
> + * @param errcode	The error code.
> + * @param regex		The regex object that produced the error code.
> + */
> +static void regex_print_error(int errcode, regex_t *regex)
> +{
> +	/* Get length of error message and allocate accordingly */
> +	size_t length;
> +	char *buffer;
> +
> +	assert(regex != NULL);
> +
> +	length = regerror(errcode, regex, NULL, 0);

we should probably check if length == 0.

> +	buffer = zmalloc(length);
> +
> +	if (!buffer) {
> +		ERR("regex_print_error: zmalloc failed");
> +		return;
> +	}
> +
> +	/* Get and print error message */
> +	regerror(errcode, regex, buffer, length);
> +	ERR("regex error: %s\n", buffer);
> +	free(buffer);
> +
> +}
> +
> +/**
> + * Parse a string that represents a size in human readable format. It
> + * supports decimal integers suffixed by 'k', 'M' or 'G'.
> + *
> + * The suffix multiply the integer by:
> + * 'k': 1024
> + * 'M': 1024 * 1024

1024^2

> + * 'G': 1024 * 1024 * 1024

1024^3

> + *
> + * @param str	The string to parse.
> + * @param size	Pointer to a size_t that will be filled with the
> + * 	  	resulting size.
> + *
> + * @return 0 on success, -1 on failure.
> + */
> +int parse_size_suffix(char *str, uint64_t *size)

why isn't parse_size_suffix() declared in a header anywhere ?

> +{
> +	regex_t regex;
> +	int ret;
> +	const int nmatch = 2;
> +	regmatch_t suffix_match, matches[nmatch];
> +
> +	if (!str) {
> +		return 0;
> +	}
> +
> +	/* Compile regex */
> +	ret = regcomp(&regex, "^[0-9][0-9]*\\([kKMG]\\{0,1\\}\\)$", 0);
> +
> +	/* Check for regex error */
> +	if (ret != 0) {
> +		regex_print_error(ret, &regex);
> +		ret = -1;
> +		goto end;
> +	}
> +
> +	/* Match regex */
> +	ret = regexec(&regex, str, nmatch, matches, 0);
> +	if (ret != 0) {
> +		/* There is no match (or error) */
> +		ret = -1;
> +		goto free;
> +	}
> +
> +	/* There is a match ! */
> +	unsigned long long base_size;

please don't declare variables in the middle of a scope. I know C99
allows it, but not our coding style.

> +	long shift = 0;

same here.

> +	errno = 0;
> +	base_size = strtoull(str, NULL, 10);

we could use a base of "0", and thus allow stuff like 0x... to be
handled.

> +	/* Check result of conversion */
> +	if (errno != 0) {
> +		PERROR("strtoull");
> +		ret = -1;
> +		goto free;
> +	}
> +
> +	/* Check if there is a suffix */
> +	suffix_match = matches[1];
> +	if (suffix_match.rm_eo - suffix_match.rm_so == 1) {
> +		switch (*(str + suffix_match.rm_so)) {
> +		case 'K':
> +		case 'k':
> +			shift = KIBI_LOG2;
> +			break;
> +		case 'M':
> +			shift = MEBI_LOG2;
> +			break;
> +		case 'G':
> +			shift = GIBI_LOG2;
> +			break;
> +		default:
> +			ERR("parse_human_size: invalid suffix");
> +			ret = -1;
> +			goto free;
> +		}
> +	}
> +
> +	*size = base_size << shift;
> +
> +	/* Check for overflow */
> +	if ((*size >> shift) != base_size) {
> +		ERR("parse_size_suffix: oops, overflow detected.");
> +		ret = -1;
> +		goto free;
> +	}
> +
> +	ret = 0;
> +
> +free:
> +	regfree(&regex);
> +end:
> +	return ret;
> +}
> diff --git a/src/common/utils.h b/src/common/utils.h
> index 2d39cef..61faa4e 100644
> --- a/src/common/utils.h
> +++ b/src/common/utils.h
> @@ -18,6 +18,14 @@
>  #ifndef _COMMON_UTILS_H
>  #define _COMMON_UTILS_H
>  
> +#include <sys/types.h>
> +#include <unistd.h>
> +#include <stdint.h>
> +
> +#define KIBI_LOG2 10
> +#define MEBI_LOG2 20
> +#define GIBI_LOG2 30
> +
>  char *utils_expand_path(const char *path);
>  int utils_create_pipe(int *dst);
>  int utils_create_pipe_cloexec(int *dst);
> diff --git a/tests/unit/Makefile.am b/tests/unit/Makefile.am
> index 67e7fe4..4c15731 100644
> --- a/tests/unit/Makefile.am
> +++ b/tests/unit/Makefile.am
> @@ -14,10 +14,11 @@ LIBCOMMON=$(top_builddir)/src/common/libcommon.la
>  LIBSESSIOND_COMM=$(top_builddir)/src/common/sessiond-comm/libsessiond-comm.la
>  LIBHASHTABLE=$(top_builddir)/src/common/hashtable/libhashtable.la
>  
> +# Define test programs
> +noinst_PROGRAMS = test_uri test_session	test_kernel_data test_parse_size_suffix
> +
>  if HAVE_LIBLTTNG_UST_CTL
> -noinst_PROGRAMS = test_uri test_session test_ust_data test_kernel_data
> -else
> -noinst_PROGRAMS = test_uri test_session	test_kernel_data
> +noinst_PROGRAMS += test_ust_data
>  endif
>  
>  # URI unit tests
> @@ -69,3 +70,11 @@ test_kernel_data_SOURCES = test_kernel_data.c
>  test_kernel_data_LDADD = $(LIBTAP) $(LIBCOMMON) $(LIBSESSIOND_COMM) $(LIBHASHTABLE) \
>  						 -lrt
>  test_kernel_data_LDADD += $(KERN_DATA_TRACE)
> +
> +# parse_size_suffix unit test
> +PARSE_SIZE_SUFFIX=$(top_srcdir)/src/common/utils.o \
> +		$(top_srcdir)/src/common/runas.o
> +
> +test_parse_size_suffix_SOURCES = test_parse_size_suffix.c
> +test_parse_size_suffix_LDADD = $(LIBTAP) $(LIBHASHTABLE) $(LIBCOMMON)
> +test_parse_size_suffix_LDADD += $(PARSE_SIZE_SUFFIX)
> diff --git a/tests/unit/test_parse_size_suffix.c b/tests/unit/test_parse_size_suffix.c
> new file mode 100644
> index 0000000..d3c3bda
> --- /dev/null
> +++ b/tests/unit/test_parse_size_suffix.c
> @@ -0,0 +1,73 @@
> +/*
> + * Copyright (C) - 2013 Simon Marchi <simon.marchi at polymtl.ca>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by as
> + * published by the Free Software Foundation; only version 2 of the License.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program; if not, write to the Free Software Foundation, Inc., 51
> + * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
> + */
> +
> +#include <assert.h>
> +#include <string.h>
> +#include <stdio.h>
> +
> +#include <tap/tap.h>
> +
> +#include <src/common/utils.h>
> +
> +/* For lttngerr.h */
> +int lttng_opt_quiet = 1;
> +int lttng_opt_verbose = 3;
> +
> +/* Valid test cases */
> +static char *valid_tests_inputs[] = { "0", "1234", "16k", "128K", "32M", "1024G" };
> +static uint64_t valid_tests_expected_results[] = {0, 1234, 16384, 131072, 33554432, 1099511627776};
> +static const int num_valid_tests = sizeof(valid_tests_inputs) / sizeof(valid_tests_inputs[0]);
> +
> +/* Invalid test cases */
> +static char *invalid_tests_inputs[] = { "", "-1", "k", "4611686018427387904G" };
> +static const int num_invalid_tests = sizeof(invalid_tests_inputs) / sizeof(invalid_tests_inputs[0]);
> +

static

> +void test_parse_size_suffix(void)
> +{
> +	uint64_t result;
> +	int ret;
> +	int i;
> +
> +	// Test valid cases

// -style comments should be avoided in our coding style. Please use /* */ comments
for single-line comments, and

/*
 * blah blah
 * rest of ...
 */

for multi-line comments.

Thanks,

Mathieu

> +	for (i = 0; i < num_valid_tests; i++) {
> +		char name[100];
> +		sprintf(name, "testing %s", valid_tests_inputs[i]);
> +
> +		ret = parse_size_suffix(valid_tests_inputs[i], &result);
> +		ok(ret == 0 && result == valid_tests_expected_results[i], name);
> +	}
> +
> +	// Test invalid cases
> +	for (i = 0; i < num_invalid_tests; i++) {
> +		char name[100];
> +		sprintf(name, "testing %s", invalid_tests_inputs[i]);
> +
> +		ret = parse_size_suffix(invalid_tests_inputs[i], &result);
> +		ok(ret != 0, name);
> +	}
> +}
> +
> +int main(int argc, char **argv)
> +{
> +	plan_tests(num_valid_tests + num_invalid_tests);
> +
> +	diag("parse_size_suffix tests");
> +
> +	test_parse_size_suffix();
> +
> +	return exit_status();
> +}
> -- 
> 1.7.10.4
> 
> 
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-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com



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