iostat: code shrink
authorMaksym Kryzhanovskyy <xmaks@email.cz>
Sun, 5 Jun 2011 01:37:14 +0000 (03:37 +0200)
committerDenys Vlasenko <vda.linux@googlemail.com>
Sun, 5 Jun 2011 01:37:14 +0000 (03:37 +0200)
function                                             old     new   delta
iostat_main                                         2048    2400    +352
is_partition                                          48       -     -48
print_stats_dev_struct                               350       -    -350

Signed-off-by: Maksym Kryzhanovskyy <xmaks@email.cz>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
procps/iostat.c

index cd233c72f4de77d40fb981488fbc21a7b0a52031..51c5fac08c43f240405fca15eb645684ae708a90 100644 (file)
@@ -7,23 +7,24 @@
  * Licensed under GPLv2, see file LICENSE in this source tree.
  */
 
-//applet:IF_IOSTAT(APPLET(iostat, BB_DIR_BIN, BB_SUID_DROP))
-
-//kbuild:lib-$(CONFIG_IOSTAT) += iostat.o
-
 //config:config IOSTAT
 //config:      bool "iostat"
 //config:      default y
 //config:      help
 //config:        Report CPU and I/O statistics
 
+//applet:IF_IOSTAT(APPLET(iostat, BB_DIR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_IOSTAT) += iostat.o
+
 #include "libbb.h"
-#include <sys/utsname.h>  /* Need struct utsname */
+#include <sys/utsname.h>  /* struct utsname */
 
 //#define debug(fmt, ...) fprintf(stderr, fmt, ## __VA_ARGS__)
 #define debug(fmt, ...) ((void)0)
 
 #define MAX_DEVICE_NAME 12
+#define MAX_DEVICE_NAME_STR "12"
 
 #if 1
 typedef unsigned long long cputime_t;
@@ -64,21 +65,27 @@ typedef struct {
        cputime_t itv;
 } stats_cpu_pair_t;
 
-struct stats_dev {
-       char dname[MAX_DEVICE_NAME];
+typedef struct {
        unsigned long long rd_sectors;
        unsigned long long wr_sectors;
        unsigned long rd_ops;
        unsigned long wr_ops;
-};
+} stats_dev_data_t;
+
+typedef struct stats_dev {
+       struct stats_dev *next;
+       char dname[MAX_DEVICE_NAME + 1];
+       stats_dev_data_t prev_data;
+       stats_dev_data_t curr_data;
+} stats_dev_t;
 
 /* Globals. Sort by size and access frequency. */
 struct globals {
        smallint show_all;
        unsigned total_cpus;            /* Number of CPUs */
        unsigned clk_tck;               /* Number of clock ticks per second */
-       llist_t *dev_list;              /* List of devices entered on the command line */
-       struct stats_dev *saved_stats_dev;
+       llist_t *dev_name_list;         /* List of devices entered on the command line */
+       stats_dev_t *stats_dev_list;
        struct tm tmtime;
        struct {
                const char *str;
@@ -114,7 +121,7 @@ static ALWAYS_INLINE int this_is_smp(void)
 
 static void print_header(void)
 {
-       char buf[16];
+       char buf[32];
        struct utsname uts;
 
        uname(&uts); /* never fails */
@@ -136,7 +143,7 @@ static void get_localtime(struct tm *ptm)
 
 static void print_timestamp(void)
 {
-       char buf[20];
+       char buf[64];
        /* %x: date representation for the current locale */
        /* %X: time representation for the current locale */
        strftime(buf, sizeof(buf), "%x %X", &G.tmtime);
@@ -162,18 +169,22 @@ static cputime_t get_smp_uptime(void)
 static void get_cpu_statistics(stats_cpu_t *sc)
 {
        FILE *fp;
-       char buf[1024], *ibuf = buf + 4;
+       char buf[1024];
 
        fp = xfopen_for_read("/proc/stat");
 
        memset(sc, 0, sizeof(*sc));
 
        while (fgets(buf, sizeof(buf), fp)) {
-               /* Does the line starts with "cpu "? */
+               int i;
+               char *ibuf;
+
+               /* Does the line start with "cpu "? */
                if (!starts_with_cpu(buf) || buf[3] != ' ') {
                        continue;
                }
-               for (int i = STATS_CPU_USER; i <= STATS_CPU_GUEST; i++) {
+               ibuf = buf + 4;
+               for (i = STATS_CPU_USER; i <= STATS_CPU_GUEST; i++) {
                        ibuf = skip_whitespace(ibuf);
                        sscanf(ibuf, "%"FMT_DATA"u", &sc->vector[i]);
                        if (i != STATS_CPU_GUEST) {
@@ -233,7 +244,7 @@ static void print_stats_cpu_struct(stats_cpu_pair_t *stats)
 {
        cputime_t *p = stats->prev->vector;
        cputime_t *c = stats->curr->vector;
-       printf("         %6.2f  %6.2f  %6.2f  %6.2f  %6.2f  %6.2f\n",
+       printf("        %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f\n",
                percent_value(p[STATS_CPU_USER]  , c[STATS_CPU_USER]  , stats->itv),
                percent_value(p[STATS_CPU_NICE]  , c[STATS_CPU_NICE]  , stats->itv),
                percent_value(p[STATS_CPU_SYSTEM] + p[STATS_CPU_SOFTIRQ] + p[STATS_CPU_IRQ],
@@ -244,36 +255,40 @@ static void print_stats_cpu_struct(stats_cpu_pair_t *stats)
        );
 }
 
-static void print_stats_dev_struct(const struct stats_dev *p,
-               const struct stats_dev *c, cputime_t itv)
+static void cpu_report(stats_cpu_pair_t *stats)
 {
+       /* Always print a header */
+       puts("avg-cpu:  %user   %nice %system %iowait  %steal   %idle");
+
+       /* Print current statistics */
+       print_stats_cpu_struct(stats);
+}
+
+static void print_stats_dev_struct(stats_dev_t *stats_dev, cputime_t itv)
+{
+       stats_dev_data_t *p = &stats_dev->prev_data;
+       stats_dev_data_t *c = &stats_dev->curr_data;
        if (option_mask32 & OPT_z)
                if (p->rd_ops == c->rd_ops && p->wr_ops == c->wr_ops)
                        return;
 
-       printf("%-13s %8.2f %12.2f %12.2f %10llu %10llu \n", c->dname,
-               percent_value(p->rd_ops + p->wr_ops ,
-               /**/              c->rd_ops + c->wr_ops , itv),
+       printf("%-13s %8.2f %12.2f %12.2f %10llu %10llu\n",
+               stats_dev->dname,
+               percent_value(p->rd_ops + p->wr_ops, c->rd_ops + c->wr_ops, itv),
                percent_value(p->rd_sectors, c->rd_sectors, itv) / G.unit.div,
                percent_value(p->wr_sectors, c->wr_sectors, itv) / G.unit.div,
                (c->rd_sectors - p->rd_sectors) / G.unit.div,
-               (c->wr_sectors - p->wr_sectors) / G.unit.div);
-}
-
-static void cpu_report(stats_cpu_pair_t *stats)
-{
-       /* Always print a header */
-       puts("avg-cpu:  %user   %nice %system %iowait  %steal   %idle");
-
-       /* Print current statistics */
-       print_stats_cpu_struct(stats);
+               (c->wr_sectors - p->wr_sectors) / G.unit.div
+       );
 }
 
 static void print_devstat_header(void)
 {
-       printf("Device:%15s%6s%s/s%6s%s/s%6s%s%6s%s\n", "tps",
+       printf("Device:%15s%6s%s/s%6s%s/s%6s%s%6s%s\n",
+               "tps",
                G.unit.str, "_read", G.unit.str, "_wrtn",
-               G.unit.str, "_read", G.unit.str, "_wrtn");
+               G.unit.str, "_read", G.unit.str, "_wrtn"
+       );
 }
 
 /*
@@ -285,61 +300,81 @@ static int is_partition(const char *dev)
        return ((dev[0] - 's') | (dev[1] - 'd') | (dev[2] - 'a')) == 0 && isdigit(dev[3]);
 }
 
+static stats_dev_t *stats_dev_find_or_new(const char *dev_name)
+{
+       stats_dev_t **curr = &G.stats_dev_list;
+
+       while (*curr != NULL) {
+               if (strcmp((*curr)->dname, dev_name) == 0)
+                       return *curr;
+               curr = &(*curr)->next;
+       }
+
+       *curr = xzalloc(sizeof(stats_dev_t));
+       strncpy((*curr)->dname, dev_name, MAX_DEVICE_NAME);
+       return *curr;
+}
+
+static void stats_dev_free(stats_dev_t *stats_dev)
+{
+       if (stats_dev) {
+               stats_dev_free(stats_dev->next);
+               free(stats_dev);
+       }
+}
+
 static void do_disk_statistics(cputime_t itv)
 {
+       char buf[128];
+       char dev_name[MAX_DEVICE_NAME + 1];
+       unsigned long long rd_sec_or_dummy;
+       unsigned long long wr_sec_or_dummy;
+       stats_dev_data_t *curr_data;
+       stats_dev_t *stats_dev;
        FILE *fp;
        int rc;
-       int i = 0;
-       char buf[128];
-       unsigned major, minor;
-       unsigned long wr_ops, dummy; /* %*lu for suppress the conversion wouldn't work */
-       unsigned long long rd_sec_or_wr_ops;
-       unsigned long long rd_sec_or_dummy, wr_sec_or_dummy, wr_sec;
-       struct stats_dev sd;
 
        fp = xfopen_for_read("/proc/diskstats");
-
        /* Read and possibly print stats from /proc/diskstats */
        while (fgets(buf, sizeof(buf), fp)) {
-               rc = sscanf(buf, "%u %u %s %lu %llu %llu %llu %lu %lu %llu %lu %lu %lu %lu",
-                       &major, &minor, sd.dname, &sd.rd_ops,
-                       &rd_sec_or_dummy, &rd_sec_or_wr_ops, &wr_sec_or_dummy,
-                       &wr_ops, &dummy, &wr_sec, &dummy, &dummy, &dummy, &dummy);
-
-               switch (rc) {
-               case 14:
-                       sd.wr_ops = wr_ops;
-                       sd.rd_sectors = rd_sec_or_wr_ops;
-                       sd.wr_sectors = wr_sec;
-                       break;
-               case 7:
-                       sd.rd_sectors = rd_sec_or_dummy;
-                       sd.wr_ops = (unsigned long)rd_sec_or_wr_ops;
-                       sd.wr_sectors = wr_sec_or_dummy;
-                       break;
-               default:
-                       break;
+               sscanf(buf, "%*s %*s %"MAX_DEVICE_NAME_STR"s", dev_name);
+               if (G.dev_name_list) {
+                       /* Is device name in list? */
+                       if (!llist_find_str(G.dev_name_list, dev_name))
+                               continue;
+               } else if (is_partition(dev_name)) {
+                       continue;
                }
 
-               if (!G.dev_list && !is_partition(sd.dname)) {
-                       /* User didn't specify device */
-                       if (!G.show_all && !sd.rd_ops && !sd.wr_ops) {
-                               /* Don't print unused device */
-                               continue;
-                       }
-                       print_stats_dev_struct(&G.saved_stats_dev[i], &sd, itv);
-                       G.saved_stats_dev[i] = sd;
-                       i++;
-               } else {
-                       /* Is device in device list? */
-                       if (llist_find_str(G.dev_list, sd.dname)) {
-                               /* Print current statistics */
-                               print_stats_dev_struct(&G.saved_stats_dev[i], &sd, itv);
-                               G.saved_stats_dev[i] = sd;
-                               i++;
-                       } else
-                               continue;
+               stats_dev = stats_dev_find_or_new(dev_name);
+               curr_data = &stats_dev->curr_data;
+
+               rc = sscanf(buf, "%*s %*s %*s %lu %llu %llu %llu %lu %*s %llu",
+                       &curr_data->rd_ops,
+                       &rd_sec_or_dummy,
+                       &curr_data->rd_sectors,
+                       &wr_sec_or_dummy,
+                       &curr_data->wr_ops,
+                       &curr_data->wr_sectors);
+               if (rc != 6) {
+                       curr_data->rd_sectors = rd_sec_or_dummy;
+                       curr_data->wr_sectors = wr_sec_or_dummy;
+                       //curr_data->rd_ops = ;
+                       curr_data->wr_ops = (unsigned long)curr_data->rd_sectors;
                }
+
+               if (!G.dev_name_list /* User didn't specify device */
+                && !G.show_all
+                && curr_data->rd_ops == 0
+                && curr_data->wr_ops == 0
+               ) {
+                       /* Don't print unused device */
+                       continue;
+               }
+
+               /* Print current statistics */
+               print_stats_dev_struct(stats_dev, itv);
+               stats_dev->prev_data = *curr_data;
        }
 
        fclose(fp);
@@ -354,35 +389,6 @@ static void dev_report(cputime_t itv)
        do_disk_statistics(itv);
 }
 
-static unsigned get_number_of_devices(void)
-{
-       FILE *fp;
-       char buf[128];
-       int rv;
-       unsigned n = 0;
-       unsigned long rd_ops, wr_ops;
-       char dname[MAX_DEVICE_NAME];
-
-       fp = xfopen_for_read("/proc/diskstats");
-
-       while (fgets(buf, sizeof(buf), fp)) {
-               rv = sscanf(buf, "%*d %*d %s %lu %*u %*u %*u %lu",
-                               dname, &rd_ops, &wr_ops);
-               if (rv == 2 || is_partition(dname))
-                       /* A partition */
-                       continue;
-               if (!rd_ops && !wr_ops) {
-                       /* Unused device */
-                       if (!G.show_all)
-                               continue;
-               }
-               n++;
-       }
-
-       fclose(fp);
-       return n;
-}
-
 //usage:#define iostat_trivial_usage
 //usage:       "[-c] [-d] [-t] [-z] [-k|-m] [ALL|BLOCKDEV...] [INTERVAL [COUNT]]"
 //usage:#define iostat_full_usage "\n\n"
@@ -398,7 +404,7 @@ static unsigned get_number_of_devices(void)
 int iostat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int iostat_main(int argc UNUSED_PARAM, char **argv)
 {
-       int opt, dev_num;
+       int opt;
        unsigned interval;
        int count;
        stats_cpu_t stats_data[2];
@@ -427,14 +433,12 @@ int iostat_main(int argc UNUSED_PARAM, char **argv)
        argv += optind;
 
        /* Store device names into device list */
-       dev_num = 0;
        while (*argv && !isdigit(*argv[0])) {
                if (strcmp(*argv, "ALL") != 0) {
                        /* If not ALL, save device name */
                        char *dev_name = skip_dev_pfx(*argv);
-                       if (!llist_find_str(G.dev_list, dev_name)) {
-                               llist_add_to(&G.dev_list, dev_name);
-                               dev_num++;
+                       if (!llist_find_str(G.dev_name_list, dev_name)) {
+                               llist_add_to(&G.dev_name_list, dev_name);
                        }
                } else {
                        G.show_all = 1;
@@ -454,13 +458,6 @@ int iostat_main(int argc UNUSED_PARAM, char **argv)
                        count = xatoi_positive(*argv);
        }
 
-       /* Allocate space for device stats */
-       if (opt & OPT_d) {
-               G.saved_stats_dev = xzalloc(sizeof(G.saved_stats_dev[0]) *
-                               (dev_num ? dev_num : get_number_of_devices())
-               );
-       }
-
        if (opt & OPT_m) {
                G.unit.str = " MB";
                G.unit.div = 2048;
@@ -530,8 +527,8 @@ int iostat_main(int argc UNUSED_PARAM, char **argv)
        }
 
        if (ENABLE_FEATURE_CLEAN_UP) {
-               llist_free(G.dev_list, NULL);
-               free(G.saved_stats_dev);
+               llist_free(G.dev_name_list, NULL);
+               stats_dev_free(G.stats_dev_list);
                free(&G);
        }