perf tools: Add new perf_atoll() function to parse string representing size in bytes

This patch modifies util/string.[ch] to add new function:
perf_atoll() to parse string representing size in bytes.

This function parses (\d+)(b|B|kb|KB|mb|MB|gb|GB) (e.g. "256MB")
and returns its numeric value. (e.g. 268435456)

Signed-off-by: Hitoshi Mitake <mitake@dcl.info.waseda.ac.jp>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <1258285013-4759-1-git-send-email-mitake@dcl.info.waseda.ac.jp>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 84 insertions, 0 deletions

diff --git a/tools/perf/util/string.c b/tools/perf/util/string.c
index 04743d3e9039..227043577e06 100644
--- a/tools/perf/util/string.c
+++ b/tools/perf/util/string.c
@@ -1,5 +1,7 @@
 #include <string.h>
+#include <stdlib.h>
 #include "string.h"
+#include "util.h"
 
 static int hex(char ch)
 {
@@ -43,3 +45,85 @@ char *strxfrchar(char *s, char from, char to)
 
         return s;
 }
+
+#define K 1024LL
+/*
+ * perf_atoll()
+ * Parse (\d+)(b|B|kb|KB|mb|MB|gb|GB|tb|TB) (e.g. "256MB")
+ * and return its numeric value
+ */
+s64 perf_atoll(const char *str)
+{
+        unsigned int i;
+        s64 length = -1, unit = 1;
+
+        if (!isdigit(str[0]))
+                goto out_err;
+
+        for (i = 1; i < strlen(str); i++) {
+                switch (str[i]) {
+                case 'B':
+                case 'b':
+                        break;
+                case 'K':
+                        if (str[i + 1] != 'B')
+                                goto out_err;
+                        else
+                                goto kilo;
+                case 'k':
+                        if (str[i + 1] != 'b')
+                                goto out_err;
+kilo:
+                        unit = K;
+                        break;
+                case 'M':
+                        if (str[i + 1] != 'B')
+                                goto out_err;
+                        else
+                                goto mega;
+                case 'm':
+                        if (str[i + 1] != 'b')
+                                goto out_err;
+mega:
+                        unit = K * K;
+                        break;
+                case 'G':
+                        if (str[i + 1] != 'B')
+                                goto out_err;
+                        else
+                                goto giga;
+                case 'g':
+                        if (str[i + 1] != 'b')
+                                goto out_err;
+giga:
+                        unit = K * K * K;
+                        break;
+                case 'T':
+                        if (str[i + 1] != 'B')
+                                goto out_err;
+                        else
+                                goto tera;
+                case 't':
+                        if (str[i + 1] != 'b')
+                                goto out_err;
+tera:
+                        unit = K * K * K * K;
+                        break;
+                case '\0':      /* only specified figures */
+                        unit = 1;
+                        break;
+                default:
+                        if (!isdigit(str[i]))
+                                goto out_err;
+                        break;
+                }
+        }
+
+        length = atoll(str) * unit;
+        goto out;
+
+out_err:
+        length = -1;
+out:
+        return length;
+}