top: nested function allows us to reuse some code

(not everyone likes them - but code does get smaller).

display_generic                                        -     761    +761
static.fmt_100percent_8                                -     111    +111
fmt_100percent_8                                     101       -    -101
display_status                                      1489     581    -908
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 0/1 up/down: 872/-1009)        Total: -137 bytes
   text    data     bss     dec     hex filename
 677020    3344   13936  694300   a981c busybox_old
 676876    3344   13936  694156   a978c busybox_unstripped

diff --git a/procps/Config.in b/procps/Config.in
index b834fbf964ce8e88ede542abb9e56cfb5d238a8a..f041b5d721b8821cb9b1083b98bb02ce3e6b47d0 100644 (file)
--- a/procps/Config.in
+++ b/procps/Config.in
@@ -122,7 +122,7 @@ config FEATURE_TOP_CPU_GLOBAL_PERCENTS
          Makes top display "CPU: NN% usr NN% sys..." line.
 
 config FEATURE_TOP_DECIMALS
-       bool "Show 1/10th of a percent in CPU/mem statistics (adds 0.5k bytes)"
+       bool "Show 1/10th of a percent in CPU/mem statistics (adds 0.3k bytes)"
        default n
        depends on FEATURE_TOP_CPU_USAGE_PERCENTAGE
        help

diff --git a/procps/top.c b/procps/top.c
index 70e479a804ed4b559065f2777254e3990471033d..e9ccac0cdcc9417446324087b9a712c575dcb879 100644 (file)
--- a/procps/top.c
+++ b/procps/top.c
@@ -212,30 +212,6 @@ static void do_stats(void)
 }
 #endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 
-#if ENABLE_FEATURE_TOP_DECIMALS
-/* formats 7 char string (8 with terminating NUL) */
-static char *fmt_100percent_8(char buf[8], unsigned value_10)
-{
-       unsigned  t;
-       if (value_10 >= 1000) {
-               strcpy(buf, "  100% ");
-               return buf;
-       }
-       /* else generate " [N/space]N.N% " string */
-       t = value_10 / 100;
-       value_10 = value_10 % 100;
-       buf[0] = ' ';
-       buf[1] = t ? t + '0' : ' ';
-       buf[2] = '0' + (value_10 / 10);
-       buf[3] = '.';
-       buf[4] = '0' + (value_10 % 10);
-       buf[5] = '%';
-       buf[6] = ' ';
-       buf[7] = '\0';
-       return buf;
-}
-#endif
-               
 /* display generic info (meminfo / loadavg) */
 static unsigned long display_generic(int scr_width)
 {
@@ -243,6 +219,34 @@ static unsigned long display_generic(int scr_width)
        char buf[80];
        char scrbuf[80];
        unsigned long total, used, mfree, shared, buffers, cached;
+       unsigned total_diff;
+
+#if ENABLE_FEATURE_TOP_DECIMALS
+       /* formats 7 char string (8 with terminating NUL) */
+       /* using GCCism (nested function) - we need to access total_diff */
+       /* This produces more than 100 bytes smaller code */
+       char *fmt_100percent_8(char pbuf[8], unsigned value)
+       {
+               unsigned t;
+               if (value >= total_diff) { /* 100% ? */
+                       strcpy(pbuf, "  100% ");
+                       return pbuf;
+               }
+               /* else generate " [N/space]N.N% " string */
+               value = 1000 * value / total_diff;
+               t = value / 100;
+               value = value % 100;
+               pbuf[0] = ' ';
+               pbuf[1] = t ? t + '0' : ' ';
+               pbuf[2] = '0' + (value / 10);
+               pbuf[3] = '.';
+               pbuf[4] = '0' + (value % 10);
+               pbuf[5] = '%';
+               pbuf[6] = ' ';
+               pbuf[7] = '\0';
+               return pbuf;
+       }
+#endif
 
        /* read memory info */
        fp = xfopen("meminfo", "r");
@@ -292,60 +296,60 @@ static unsigned long display_generic(int scr_width)
        }
        fclose(fp);
 
-       /* read load average as a string */
-       buf[0] = '\0';
-       open_read_close("loadavg", buf, sizeof("N.NN N.NN N.NN")-1);
-       buf[sizeof("N.NN N.NN N.NN")-1] = '\0';
-
-       /* output memory info and load average */
-       /* clear screen & go to top */
+       /* output memory info */
        if (scr_width > sizeof(scrbuf))
                scr_width = sizeof(scrbuf);
        snprintf(scrbuf, scr_width,
                "Mem: %luK used, %luK free, %luK shrd, %luK buff, %luK cached",
                used, mfree, shared, buffers, cached);
-
+       /* clear screen & go to top */
        printf(OPT_BATCH_MODE ? "%s\n" : "\e[H\e[J%s\n", scrbuf);
 
        if (ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS) {
                /*
                 * xxx% = (jif.xxx - prev_jif.xxx) / (jif.total - prev_jif.total) * 100%
                 */
-               /* using (unsigned) casts to make operations cheaper cheaper */
-               unsigned total_diff = ((unsigned)(jif.total - prev_jif.total) ? : 1);
+               /* using (unsigned) casts to make operations cheaper */
+               total_diff = ((unsigned)(jif.total - prev_jif.total) ? : 1);
 #if ENABLE_FEATURE_TOP_DECIMALS
-/* Generated code is approx +0.5k */
+/* Generated code is approx +0.3k */
 #define CALC_STAT(xxx) char xxx[8]
-#define SHOW_STAT(xxx) fmt_100percent_8(xxx, 1000 * (unsigned)(jif.xxx - prev_jif.xxx) / total_diff)
+#define SHOW_STAT(xxx) fmt_100percent_8(xxx, (unsigned)(jif.xxx - prev_jif.xxx))
 #define FMT "%s"
 #else
 #define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(jif.xxx - prev_jif.xxx) / total_diff
 #define SHOW_STAT(xxx) xxx
 #define FMT "%4u%% "
 #endif
-               CALC_STAT(usr);
-               CALC_STAT(sys);
-               CALC_STAT(nic);
-               CALC_STAT(idle);
-               CALC_STAT(iowait);
-               CALC_STAT(irq);
-               CALC_STAT(softirq);
-               //CALC_STAT(steal);
-
-               snprintf(scrbuf, scr_width,
-                       /* Barely fits in 79 chars when in "decimals" mode. */
-                       "CPU:"FMT"usr"FMT"sys"FMT"nice"FMT"idle"FMT"io"FMT"irq"FMT"softirq",
-                       SHOW_STAT(usr), SHOW_STAT(sys), SHOW_STAT(nic), SHOW_STAT(idle),
-                       SHOW_STAT(iowait), SHOW_STAT(irq), SHOW_STAT(softirq)
-                       //, SHOW_STAT(steal) - what is this 'steal' thing?
-                       // I doubt anyone wants to know it
-               );
+               { /* need block: CALC_STAT are declarations */
+                       CALC_STAT(usr);
+                       CALC_STAT(sys);
+                       CALC_STAT(nic);
+                       CALC_STAT(idle);
+                       CALC_STAT(iowait);
+                       CALC_STAT(irq);
+                       CALC_STAT(softirq);
+                       //CALC_STAT(steal);
+
+                       snprintf(scrbuf, scr_width,
+                               /* Barely fits in 79 chars when in "decimals" mode. */
+                               "CPU:"FMT"usr"FMT"sys"FMT"nice"FMT"idle"FMT"io"FMT"irq"FMT"softirq",
+                               SHOW_STAT(usr), SHOW_STAT(sys), SHOW_STAT(nic), SHOW_STAT(idle),
+                               SHOW_STAT(iowait), SHOW_STAT(irq), SHOW_STAT(softirq)
+                               //, SHOW_STAT(steal) - what is this 'steal' thing?
+                               // I doubt anyone wants to know it
+                       );
+               }
                puts(scrbuf);
 #undef SHOW_STAT
 #undef CALC_STAT
 #undef FMT
        }
 
+       /* read load average as a string */
+       buf[0] = '\0';
+       open_read_close("loadavg", buf, sizeof("N.NN N.NN N.NN")-1);
+       buf[sizeof("N.NN N.NN N.NN")-1] = '\0';
        snprintf(scrbuf, scr_width, "Load average: %s", buf);
        puts(scrbuf);