[lttng-dev] [PATCH v2 lttng-tools] lttng cli: Accept human readable sizes for --subbuf-size
Simon Marchi
simon.marchi at polymtl.ca
Wed Apr 3 21:30:47 EDT 2013
--subbuf-size accepts sizes such as:
- 123 -> 123
- 123k -> 123 * 1024
- 123M -> 123 * 1024 * 1024
- 123G -> 123 * 1024 * 1024 * 1024
It uses the new parse_human_size function, which could probably be used
at other places, such as tracefile size.
I wanted to add some unit tests for parse_human_size, but the current
test system does not make it easy. They will come later.
Signed-off-by: Simon Marchi <simon.marchi at polymtl.ca>
---
src/bin/lttng/commands/enable_channels.c | 21 ++++-
src/bin/lttng/utils.c | 129 +++++++++++++++++++++++++++++-
src/bin/lttng/utils.h | 6 ++
3 files changed, 152 insertions(+), 4 deletions(-)
diff --git a/src/bin/lttng/commands/enable_channels.c b/src/bin/lttng/commands/enable_channels.c
index d026af4..c2e9c89 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_human_size(opt_arg, &chan.attr.subbuf_size)) {
+ 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/bin/lttng/utils.c b/src/bin/lttng/utils.c
index b7f5170..d17fa9c 100644
--- a/src/bin/lttng/utils.c
+++ b/src/bin/lttng/utils.c
@@ -16,9 +16,11 @@
*/
#define _GNU_SOURCE
-#include <stdlib.h>
+#include <assert.h>
#include <ctype.h>
#include <limits.h>
+#include <regex.h>
+#include <stdlib.h>
#include <common/error.h>
@@ -77,3 +79,128 @@ void list_cmd_options(FILE *ofp, struct poptOption *options)
}
}
}
+
+/**
+ * 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.
+ */
+void regex_print_error(int errcode, regex_t *regex)
+{
+ /* Get length of error message and allocate accordingly */
+ size_t length = regerror(errcode, regex, NULL, 0);
+ char *buffer = malloc(length);
+
+ if (buffer) {
+ /* Get and print error message */
+ regerror(errcode, regex, buffer, length);
+ ERR("regex error: %s\n", buffer);
+ free(buffer);
+ } else {
+ ERR("regex_print_error: malloc failed");
+ }
+}
+
+/**
+ * Parse a string that represents a size in human readable format. It
+ * support decimal integers suffixed by 'k', 'M' or 'G'.
+ *
+ * The suffix multiply the integer by:
+ * 'k': 1024
+ * 'M': 1024 * 1024
+ * 'G': 1024 * 1024 * 1024
+ *
+ * @param str The string to parse.
+ * @param size Pointer to a size_t that will be filled with the
+ * resulting size.
+ *
+ * @return 1 on success, 0 on failure.
+ */
+int parse_human_size(char *str, uint64_t *size)
+{
+ regex_t regex;
+ int ret;
+ const int nmatch = 2;
+ regmatch_t matches[nmatch];
+
+ if (!str)
+ return 0;
+
+ /* Compile regex */
+ ret = regcomp(®ex, "^[0-9][0-9]*\\([kKMG]\\{0,1\\}\\)$", 0);
+
+ /* Check for regex error */
+ if (ret != 0) {
+ regex_print_error(ret, ®ex);
+
+ ret = 0;
+ goto end;
+ }
+
+ /* Match regex */
+ ret = regexec(®ex, str, nmatch, matches, 0);
+ if (ret == 0) {
+ /* There is a match ! */
+ long long base_size;
+ long multiplier = 1;
+ errno = 0;
+ base_size = strtoll(str, NULL, 10);
+
+ /* Check result of conversion */
+ if (errno == ERANGE) {
+ ERR("parse_human_size: the value %s caused strtol to overflow. "
+ "Please use a smaller numerical value.", str);
+ ret = 0;
+ goto end;
+ } else if (errno == EINVAL) {
+ ERR("parse_human_size: strtol failed (%s)", str);
+ ret = 0;
+ goto end;
+ }
+
+ /* We should be safe because of the regex */
+ assert(base_size > 0);
+
+ /* Check if there is a suffix */
+ regmatch_t suffix_match = matches[1];
+ if (suffix_match.rm_eo - suffix_match.rm_so > 0) {
+ switch (*(str + suffix_match.rm_so)) {
+ case 'K':
+ case 'k':
+ multiplier = KIBI;
+ break;
+ case 'M':
+ multiplier = MEBI;
+ break;
+ case 'G':
+ multiplier = GIBI;
+ break;
+ default:
+ ERR("parse_human_size: invalid suffix");
+ ret = 0;
+ goto end;
+ }
+ }
+
+ *size = base_size * multiplier;
+
+ /* Check for overflow */
+ if (*size / base_size != multiplier) {
+ ERR("parse_human_size: oops, overflow detected.");
+ ret = 0;
+ goto end;
+ }
+
+ ret = 1;
+ goto end;
+ } else {
+ /* There is no match (or error) */
+ ret = 0;
+ goto end;
+ }
+
+end:
+ regfree(®ex);
+ return ret;
+}
diff --git a/src/bin/lttng/utils.h b/src/bin/lttng/utils.h
index 9f7bfcc..cb57b93 100644
--- a/src/bin/lttng/utils.h
+++ b/src/bin/lttng/utils.h
@@ -19,8 +19,14 @@
#define _LTTNG_UTILS_H
#include <popt.h>
+#include <stdint.h>
+
+#define KIBI 1024
+#define MEBI (1024 * 1024)
+#define GIBI (1024 * 1024 * 1024)
char *get_session_name(void);
void list_cmd_options(FILE *ofp, struct poptOption *options);
+int parse_human_size(char *str, uint64_t *size);
#endif /* _LTTNG_UTILS_H */
--
1.7.1
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