FS-11189: [core] add func to parse cpu string

diff --git a/src/include/switch_utils.h b/src/include/switch_utils.h
index dd5adcbd896367a2e5723cf9df5ab5a94ab2900d..7e812bb1309be43dd5bef0a4d288c9285b3fefaf 100644 (file)
--- a/src/include/switch_utils.h
+++ b/src/include/switch_utils.h
@@ -1084,6 +1084,61 @@ static inline int32_t switch_parse_bandwidth_string(const char *bwv)
        return (int32_t) roundf(bw);
 }
 
+static inline uint32_t switch_parse_cpu_string(const char *cpu)
+{
+       int cpu_count = switch_core_cpu_count();
+       int ncpu = cpu_count;
+
+       if (!cpu) return 1;
+
+       if (!strcasecmp(cpu, "auto")) {
+               if (cpu_count > 4) return 4;
+               if (cpu_count <= 2) return 1;
+
+               return (uint32_t)(cpu_count / 2);
+       }
+
+       if (!strncasecmp(cpu, "cpu/", 4)) { /* cpu/2 or cpu/2/<max>  */
+               const char *has_max = cpu;
+               float divisor;
+               int max = cpu_count;
+
+               cpu +=4;
+
+               has_max = strchr(cpu, '/');
+
+               if (has_max > cpu) {
+                       max = atoi(has_max + 1);
+               }
+
+               divisor = atof(cpu);
+
+               if (divisor <= 0) divisor = 1;
+
+               ncpu = cpu_count / divisor;
+
+               if (ncpu <= 0) return 1;
+
+               if (ncpu > max) return (uint32_t)max;
+
+               return (uint32_t)ncpu;
+       } else if (!strcasecmp(cpu, "cpu")) {
+               ncpu = cpu_count;
+       } else {
+               ncpu = atoi(cpu);
+
+               if (cpu && strrchr(cpu, '%')) {
+                       ncpu = (int) (cpu_count * ((float)ncpu / 100));
+               }
+       }
+
+       if (ncpu > cpu_count) return (uint32_t)cpu_count;
+
+       if (ncpu <= 0) return 1;
+
+       return ncpu;
+}
+
 static inline int switch_needs_url_encode(const char *s)
 {
        const char hex[] = "0123456789ABCDEF";