iostat: code shrink

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>

1 files changed, 117 insertions, 120 deletions

diff --git a/procps/iostat.c b/procps/iostat.c
index cd233c72f..51c5fac08 100644
--- a/procps/iostat.c
+++ b/procps/iostat.c
@@ -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);
         }