[PATCH v5 3/6] perf util: Create function to parse time percent

Jin Yao
2017-10-20T15:32:09Z

Current perf report/script/... have a --time option to limit the time
range of output. But right now it only supports absolute time.

For easy using, now it can support a percent of time usage.

For example:

1. Select the second 10% time slice
perf report --time 10%/2

2. Select from 0% to 10% time slice
perf report --time 0%-10%

It also support the multiple time ranges.

3. Select the first and second 10% time slices
perf report --time 10%/1,10%/2

4. Select from 0% to 10% and 30% to 40% slices
perf report --time 0%-10%,30%-40%

Change log:
-----------
v4: An issue is found. Following passes.
perf script --time 10%/10x12321xsdfdasfdsafdsafdsa

Now it uses strtol to replace atoi.

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
---
tools/perf/util/time-utils.c | 205 ++++++++++++++++++++++++++++++++++++++++---
tools/perf/util/time-utils.h | 3 +
2 files changed, 196 insertions(+), 12 deletions(-)

diff --git a/tools/perf/util/time-utils.c b/tools/perf/util/time-utils.c
index 5b5d021..79e4281 100644
--- a/tools/perf/util/time-utils.c
+++ b/tools/perf/util/time-utils.c
@@ -5,6 +5,7 @@
#include <time.h>
#include <errno.h>
#include <inttypes.h>
+#include <math.h>

#include "perf.h"
#include "debug.h"
@@ -59,11 +60,10 @@ static int parse_timestr_sec_nsec(struct perf_time_interval *ptime,
return 0;
}

-int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr)
+static int split_start_end(char **start, char **end, const char *ostr, char ch)
{
char *start_str, *end_str;
char *d, *str;
- int rc = 0;

if (ostr == NULL || *ostr == '\0')
return 0;
@@ -73,25 +73,35 @@ int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr)
if (str == NULL)
return -ENOMEM;

- ptime->start = 0;
- ptime->end = 0;
-
- /* str has the format: <start>,<stop>
- * variations: <start>,
- * ,<stop>
- * ,
- */
start_str = str;
- d = strchr(start_str, ',');
+ d = strchr(start_str, ch);
if (d) {
*d = '\0';
++d;
}
end_str = d;

+ *start = start_str;
+ *end = end_str;
+
+ return 0;
+}
+
+int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr)
+{
+ char *start_str = NULL, *end_str;
+ int rc;
+
+ rc = split_start_end(&start_str, &end_str, ostr, ',');
+ if (rc || !start_str)
+ return rc;
+
+ ptime->start = 0;
+ ptime->end = 0;
+
rc = parse_timestr_sec_nsec(ptime, start_str, end_str);

- free(str);
+ free(start_str);

/* make sure end time is after start time if it was given */
if (rc == 0 && ptime->end && ptime->end < ptime->start)
@@ -103,6 +113,177 @@ int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr)
return rc;
}

+static int parse_percent(double *pcnt, char *str)
+{
+ char *c;
+
+ c = strchr(str, '%');
+ if (c)
+ *c = '\0';
+ else
+ return -1;
+
+ *pcnt = atof(str) / 100.0;
+
+ return 0;
+}
+
+static int percent_slash_split(char *str, struct perf_time_interval *ptime,
+ u64 start, u64 end)
+{
+ char *p, *end_str;
+ double pcnt, start_pcnt, end_pcnt;
+ u64 total = end - start;
+ int i;
+
+ /*
+ * Example:
+ * 10%/2: select the second 10% slice and the third 10% slice
+ */
+
+ /* We can modify this string since the original one is copied */
+ p = strchr(str, '/');
+ if (!p)
+ return -1;
+
+ *p = '\0';
+ if (parse_percent(&pcnt, str) < 0)
+ return -1;
+
+ p++;
+ i = (int)strtol(p, &end_str, 10);
+ if (*end_str)
+ return -1;
+
+ if (pcnt <= 0.0)
+ return -1;
+
+ start_pcnt = pcnt * (i - 1);
+ end_pcnt = pcnt * i;
+
+ if (start_pcnt < 0.0 || start_pcnt > 1.0 ||
+ end_pcnt < 0.0 || end_pcnt > 1.0) {
+ return -1;
+ }
+
+ ptime->start = start + round(start_pcnt * total);
+ ptime->end = start + round(end_pcnt * total);
+
+ return 0;
+}
+
+static int percent_dash_split(char *str, struct perf_time_interval *ptime,
+ u64 start, u64 end)
+{
+ char *start_str = NULL, *end_str;
+ double start_pcnt, end_pcnt;
+ u64 total = end - start;
+ int ret;
+
+ /*
+ * Example: 0%-10%
+ */
+
+ ret = split_start_end(&start_str, &end_str, str, '-');
+ if (ret || !start_str)
+ return ret;
+
+ if ((parse_percent(&start_pcnt, start_str) != 0) ||
+ (parse_percent(&end_pcnt, end_str) != 0)) {
+ free(start_str);
+ return -1;
+ }
+
+ free(start_str);
+
+ if (start_pcnt < 0.0 || start_pcnt > 1.0 ||
+ end_pcnt < 0.0 || end_pcnt > 1.0 ||
+ start_pcnt > end_pcnt) {
+ return -1;
+ }
+
+ ptime->start = start + round(start_pcnt * total);
+ ptime->end = start + round(end_pcnt * total);
+
+ return 0;
+}
+
+typedef int (*time_pecent_split)(char *, struct perf_time_interval *,
+ u64 start, u64 end);
+
+static int percent_comma_split(struct perf_time_interval *ptime_buf, int num,
+ const char *ostr, u64 start, u64 end,
+ time_pecent_split func)
+{
+ char *str, *p1, *p2;
+ int len, ret, i = 0;
+
+ str = strdup(ostr);
+ if (str == NULL)
+ return -ENOMEM;
+
+ len = strlen(str);
+ p1 = str;
+
+ while (p1 < str + len) {
+ if (i >= num) {
+ free(str);
+ return -1;
+ }
+
+ p2 = strchr(p1, ',');
+ if (p2)
+ *p2 = '\0';
+
+ ret = (func)(p1, &ptime_buf[i], start, end);
+ if (ret < 0) {
+ free(str);
+ return -1;
+ }
+
+ pr_debug("start time %d: %" PRIu64 ", ", i, ptime_buf[i].start);
+ pr_debug("end time %d: %" PRIu64 "\n", i, ptime_buf[i].end);
+
+ i++;
+
+ if (p2)
+ p1 = p2 + 1;
+ else
+ break;
+ }
+
+ free(str);
+ return i;
+}
+
+int perf_time__percent_parse_str(struct perf_time_interval *ptime_buf, int num,
+ const char *ostr, u64 start, u64 end)
+{
+ char *c;
+
+ /*
+ * ostr example:
+ * 10%/2,10%/3: select the second 10% slice and the third 10% slice
+ * 0%-10%,30%-40%: multiple time range
+ */
+
+ memset(ptime_buf, 0, sizeof(*ptime_buf) * num);
+
+ c = strchr(ostr, '/');
+ if (c) {
+ return percent_comma_split(ptime_buf, num, ostr, start,
+ end, percent_slash_split);
+ }
+
+ c = strchr(ostr, '-');
+ if (c) {
+ return percent_comma_split(ptime_buf, num, ostr, start,
+ end, percent_dash_split);
+ }
+
+ return -1;
+}
+
bool perf_time__skip_sample(struct perf_time_interval *ptime, u64 timestamp)
{
/* if time is not set don't drop sample */
diff --git a/tools/perf/util/time-utils.h b/tools/perf/util/time-utils.h
index 8656be0..fd018e2 100644
--- a/tools/perf/util/time-utils.h
+++ b/tools/perf/util/time-utils.h
@@ -12,6 +12,9 @@ int parse_nsec_time(const char *str, u64 *ptime);

int perf_time__parse_str(struct perf_time_interval *ptime, const char *ostr);

+int perf_time__percent_parse_str(struct perf_time_interval *ptime_buf, int num,
+ const char *ostr, u64 start, u64 end);
+
bool perf_time__skip_sample(struct perf_time_interval *ptime, u64 timestamp);

int timestamp__scnprintf_usec(u64 timestamp, char *buf, size_t sz);
--
2.7.4