top: disentangle printing logic

function                                             old     new   delta
print_line_buf                                         -      78     +78
print_line_bold                                        -      50     +50
top_main                                            1043    1091     +48
handle_input                                         708     714      +6
do_stats                                             186     192      +6
.rodata                                           115543  115526     -17
display_topmem_process_list                          748     523    -225
display_process_list                                1432    1186    -246
------------------------------------------------------------------------------
(add/remove: 2/0 grow/shrink: 3/3 up/down: 188/-488)         Total: -300 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 97 insertions, 83 deletions

diff --git a/procps/top.c b/procps/top.c
index 1f1c82b5a..bff9f7c4f 100644
--- a/procps/top.c
+++ b/procps/top.c
@@ -166,12 +166,14 @@ struct globals {
         top_status_t *top;
         int ntop;
         smallint inverted;
+        smallint not_first_line;
 #if ENABLE_FEATURE_TOPMEM
         smallint sort_field;
 #endif
 #if ENABLE_FEATURE_TOP_SMP_CPU
         smallint smp_cpu_info; /* one/many cpu info lines? */
 #endif
+        int lines_remaining;
         unsigned lines;     /* screen height */
         unsigned scr_width; /* width, clamped <= LINE_BUF_SIZE-2 */
 #if ENABLE_FEATURE_TOP_INTERACTIVE
@@ -218,7 +220,6 @@ struct globals {
 #define cpu_prev_jif     (G.cpu_prev_jif      )
 #define num_cpus         (G.num_cpus          )
 #define total_pcpu       (G.total_pcpu        )
-#define line_buf         (G.line_buf          )
 #define INIT_G() do { \
         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
         BUILD_BUG_ON(LINE_BUF_SIZE <= 80); \
@@ -289,9 +290,9 @@ static NOINLINE int read_cpu_jiffy(FILE *fp, jiffy_counts_t *p_jif)
 #endif
         int ret;
 
-        if (!fgets(line_buf, LINE_BUF_SIZE, fp) || line_buf[0] != 'c' /* not "cpu" */)
+        if (!fgets(G.line_buf, LINE_BUF_SIZE, fp) || G.line_buf[0] != 'c' /* not "cpu" */)
                 return 0;
-        ret = sscanf(line_buf, fmt,
+        ret = sscanf(G.line_buf, fmt,
                         &p_jif->usr, &p_jif->nic, &p_jif->sys, &p_jif->idle,
                         &p_jif->iowait, &p_jif->irq, &p_jif->softirq,
                         &p_jif->steal);
@@ -413,6 +414,38 @@ static void do_stats(void)
 
 #endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
 
+static void print_line_buf(void)
+{
+        const char *fmt;
+
+        G.lines_remaining--;
+        fmt = OPT_BATCH_MODE ? "\n""%.*s" : "\n""%.*s"CLREOL;
+        if (!G.not_first_line) {
+                G.not_first_line = 1;
+                /* Go to top */
+                fmt = OPT_BATCH_MODE ? "%.*s" : HOME"%.*s"CLREOL;
+        }
+        printf(fmt, G.scr_width - 1, G.line_buf);
+}
+
+static void print_line_bold(void)
+{
+        G.lines_remaining--;
+//we never print first line in bold
+//      if (!G.not_first_line) {
+//              printf(OPT_BATCH_MODE ? "%.*s" : HOME"%.*s"CLREOL, G.scr_width - 1, G.line_buf);
+//              G.not_first_line = 1;
+//      } else {
+                printf(OPT_BATCH_MODE ? "\n""%.*s" : "\n"REVERSE"%.*s"NORMAL CLREOL, G.scr_width - 1, G.line_buf);
+//      }
+}
+
+static void print_end(void)
+{
+        fputs_stdout(OPT_BATCH_MODE ? "\n" : CLREOS"\r");
+        G.not_first_line = 0; /* next print will be "first line" (will clear the screen) */
+}
+
 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS && ENABLE_FEATURE_TOP_DECIMALS
 /* formats 7 char string (8 with terminating NUL) */
 static char *fmt_100percent_8(char pbuf[8], unsigned value, unsigned total)
@@ -439,7 +472,7 @@ static char *fmt_100percent_8(char pbuf[8], unsigned value, unsigned total)
 #endif
 
 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
-static void display_cpus(char *scrbuf, int *lines_rem_p)
+static void display_cpus(void)
 {
         /*
          * xxx% = (cur_jif.xxx - prev_jif.xxx) / (cur_jif.total - prev_jif.total) * 100%
@@ -475,8 +508,8 @@ static void display_cpus(char *scrbuf, int *lines_rem_p)
 # else
         /* Loop thru CPU(s) */
         n_cpu_lines = smp_cpu_info ? num_cpus : 1;
-        if (n_cpu_lines > *lines_rem_p)
-                n_cpu_lines = *lines_rem_p;
+        if (n_cpu_lines > G.lines_remaining)
+                n_cpu_lines = G.lines_remaining;
 
         for (i = 0; i < n_cpu_lines; i++) {
                 p_jif = &cpu_jif[i];
@@ -494,7 +527,7 @@ static void display_cpus(char *scrbuf, int *lines_rem_p)
                         CALC_STAT(softirq);
                         /*CALC_STAT(steal);*/
 
-                        snprintf(scrbuf, G.scr_width,
+                        sprintf(G.line_buf,
                                 /* Barely fits in 79 chars when in "decimals" mode. */
 # if ENABLE_FEATURE_TOP_SMP_CPU
                                 "CPU%s:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
@@ -507,16 +540,15 @@ static void display_cpus(char *scrbuf, int *lines_rem_p)
                                 /*, SHOW_STAT(steal) - what is this 'steal' thing? */
                                 /* I doubt anyone wants to know it */
                         );
-                        printf(OPT_BATCH_MODE ? "%s\n" : "%s"CLREOL"\n", scrbuf);
+                        print_line_buf();
                 }
         }
 # undef SHOW_STAT
 # undef CALC_STAT
 # undef FMT
-        *lines_rem_p -= i;
 }
 #else  /* !ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS */
-# define display_cpus(scrbuf, lines_rem) ((void)0)
+# define display_cpus() ((void)0)
 #endif
 
 enum {
@@ -570,51 +602,46 @@ static void parse_meminfo(unsigned long meminfo[MI_MAX])
         fclose(f);
 }
 
-static unsigned long display_header(int *lines_rem_p)
+static unsigned long display_header(void)
 {
-        char scrbuf[100]; /* [80] was a bit too low on 8Gb ram box */
         char *buf;
-        unsigned width;
         unsigned long meminfo[MI_MAX];
 
         parse_meminfo(meminfo);
 
         /* Output memory info */
-        width = (G.scr_width > sizeof(scrbuf)) ? sizeof(scrbuf) : G.scr_width;
-        snprintf(scrbuf, width,
+        sprintf(G.line_buf,
                 "Mem: %luK used, %luK free, %luK shrd, %luK buff, %luK cached",
                 meminfo[MI_MEMTOTAL] - meminfo[MI_MEMFREE],
                 meminfo[MI_MEMFREE],
                 meminfo[MI_MEMSHARED] + meminfo[MI_SHMEM],
                 meminfo[MI_BUFFERS],
                 meminfo[MI_CACHED]);
-        /* Go to top & clear to the end of screen */
-        printf(OPT_BATCH_MODE ? "%s\n" : HOME"%s"CLREOL"\n", scrbuf);
-        (*lines_rem_p)--;
+        print_line_buf();
 
         /* Display CPU time split as percentage of total time.
          * This displays either a cumulative line or one line per CPU.
          */
-        display_cpus(scrbuf, lines_rem_p);
+        display_cpus();
 
         /* Read load average as a string */
-        buf = stpcpy(scrbuf, "Load average: ");
-        open_read_close("loadavg", buf, sizeof(scrbuf) - sizeof("Load average: "));
+        buf = stpcpy(G.line_buf, "Load average: ");
+        open_read_close("loadavg", buf, sizeof(G.line_buf) - sizeof("Load average: "));
+        G.line_buf[sizeof(G.line_buf) - 1] = '\0'; /* paranoia */
         strchrnul(buf, '\n')[0] = '\0';
-        printf(OPT_BATCH_MODE ? "%.*s\n" : "%.*s"CLREOL"\n", width - 1, scrbuf);
-        (*lines_rem_p)--;
+        print_line_buf();
 
         return meminfo[MI_MEMTOTAL];
 }
 
-static NOINLINE void display_process_list(int lines_rem)
+static NOINLINE void display_process_list(void)
 {
         enum {
                 BITS_PER_INT = sizeof(int) * 8
         };
 
         top_status_t *s;
-        unsigned long total_memory = display_header(&lines_rem); /* or use total_memsize? */
+        unsigned long total_memory = display_header();
         /* xxx_shift and xxx_scale variables allow us to replace
          * expensive divides with multiply and shift */
         unsigned pmem_shift, pmem_scale, pmem_half;
@@ -626,7 +653,7 @@ static NOINLINE void display_process_list(int lines_rem)
 
 #if ENABLE_FEATURE_TOP_DECIMALS
 # define UPSCALE 1000
-typedef struct { unsigned quot, rem; } bb_div_t;
+        typedef struct { unsigned quot, rem; } bb_div_t;
 /* Used to have "div_t name = div((val), 10)" here
  * (IOW: intended to use libc-compatible way to divide and use
  * both result and remainder, but musl does not inline div()...)
@@ -644,13 +671,11 @@ typedef struct { unsigned quot, rem; } bb_div_t;
 # define FMT "%4u%%"
 #endif
 
-        /* what info of the processes is shown */
-        printf(OPT_BATCH_MODE ? "%.*s" : REVERSE"%.*s"NORMAL CLREOL, G.scr_width - 1,
-                "  PID  PPID USER     STAT   RSS %RSS"
+        strcpy(G.line_buf, "  PID  PPID USER     STAT   RSS %RSS"
                 IF_FEATURE_TOP_SMP_PROCESS(" CPU")
                 IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(" %CPU")
                 " COMMAND");
-        lines_rem--;
+        print_line_bold();
 
         /* %RSS = s->memsize / MemTotal * 100%
          * Calculate this with multiply and shift. Example:
@@ -702,12 +727,12 @@ typedef struct { unsigned quot, rem; } bb_div_t;
         pcpu_half = (1U << pcpu_shift) / (ENABLE_FEATURE_TOP_DECIMALS ? 20 : 2);
         /* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
 #endif
-        if (lines_rem > ntop - G_scroll_ofs)
-                lines_rem = ntop - G_scroll_ofs;
+        if (G.lines_remaining > ntop - G_scroll_ofs)
+                G.lines_remaining = ntop - G_scroll_ofs;
 
         /* Ok, all preliminary data is ready, go through the list */
         s = top + G_scroll_ofs;
-        while (--lines_rem >= 0) {
+        while (G.lines_remaining > 0) {
                 int n;
                 char *ppu;
                 char ppubuf[sizeof(int)*3 * 2 + 12];
@@ -753,7 +778,7 @@ typedef struct { unsigned quot, rem; } bb_div_t;
                         ppu[6+6+8] = '\0'; /* truncate USER */
                 }
  shortened:
-                col = snprintf(line_buf, G.scr_width,
+                col = sprintf(G.line_buf,
                                 "%s %s  %.5s" FMT
                                 IF_FEATURE_TOP_SMP_PROCESS(" %3d")
                                 IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(FMT)
@@ -765,14 +790,13 @@ typedef struct { unsigned quot, rem; } bb_div_t;
                                 IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(, SHOW_STAT(pcpu))
                 );
                 if ((int)(G.scr_width - col) > 1)
-                        read_cmdline(line_buf + col, G.scr_width - col, s->pid, s->comm);
-                printf(OPT_BATCH_MODE ? "\n""%s" : "\n""%s"CLREOL, line_buf);
+                        read_cmdline(G.line_buf + col, G.scr_width - col, s->pid, s->comm);
+                print_line_buf();
                 /* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
                         cur_jif.busy - prev_jif.busy, cur_jif.total - prev_jif.total); */
                 s++;
         }
         /* printf(" %d", hist_iterations); */
-        fputs_stdout(OPT_BATCH_MODE ? "\n" : CLREOS"\r");
 }
 #undef UPSCALE
 #undef SHOW_STAT
@@ -844,36 +868,34 @@ static int topmem_sort(char *a, char *b)
 }
 
 /* display header info (meminfo / loadavg) */
-static void display_topmem_header(int *lines_rem_p)
+static void display_topmem_header(void)
 {
         unsigned long meminfo[MI_MAX];
 
         parse_meminfo(meminfo);
 
-        snprintf(line_buf, LINE_BUF_SIZE,
+        sprintf(G.line_buf,
                 "Mem total:%lu anon:%lu map:%lu free:%lu",
                 meminfo[MI_MEMTOTAL],
                 meminfo[MI_ANONPAGES],
                 meminfo[MI_MAPPED],
                 meminfo[MI_MEMFREE]);
-        printf(OPT_BATCH_MODE ? "%.*s\n" : HOME"%.*s"CLREOL"\n", G.scr_width - 1, line_buf);
+        print_line_buf();
 
-        snprintf(line_buf, LINE_BUF_SIZE,
+        sprintf(G.line_buf,
                 " slab:%lu buf:%lu cache:%lu dirty:%lu write:%lu",
                 meminfo[MI_SLAB],
                 meminfo[MI_BUFFERS],
                 meminfo[MI_CACHED],
                 meminfo[MI_DIRTY],
                 meminfo[MI_WRITEBACK]);
-        printf(OPT_BATCH_MODE ? "%.*s\n" : "%.*s"CLREOL"\n", G.scr_width - 1, line_buf);
+        print_line_buf();
 
-        snprintf(line_buf, LINE_BUF_SIZE,
+        sprintf(G.line_buf,
                 "Swap total:%lu free:%lu", // TODO: % used?
                 meminfo[MI_SWAPTOTAL],
                 meminfo[MI_SWAPFREE]);
-        printf(OPT_BATCH_MODE ? "%.*s\n" : "%.*s"CLREOL"\n", G.scr_width - 1, line_buf);
-
-        (*lines_rem_p) -= 3;
+        print_line_buf();
 }
 
 /* see http://en.wikipedia.org/wiki/Tera */
@@ -886,67 +908,57 @@ static void ulltoa4_and_space(unsigned long long ul, char buf[5])
         smart_ulltoa4(ul, buf, " mgtpezy")[0] = ' ';
 }
 
-static NOINLINE void display_topmem_process_list(int lines_rem)
+static NOINLINE void display_topmem_process_list(void)
 {
 #define HDR_STR "  PID   VSZ VSZRW   RSS (SHR) DIRTY (SHR) STACK"
 #define MIN_WIDTH sizeof(HDR_STR)
         const topmem_status_t *s = topmem + G_scroll_ofs;
         char *cp, ch;
 
-        display_topmem_header(&lines_rem);
+        display_topmem_header();
 
-        strcpy(line_buf, HDR_STR " COMMAND");
+        strcpy(G.line_buf, HDR_STR " COMMAND");
         /* Mark the ^FIELD^ we sort by */
-        cp = &line_buf[5 + sort_field * 6];
+        cp = &G.line_buf[5 + sort_field * 6];
         ch = "^_"[inverted];
         cp[6] = ch;
         do *cp++ = ch; while (*cp == ' ');
+        print_line_bold();
 
-        printf(OPT_BATCH_MODE ? "%.*s" : REVERSE"%.*s"NORMAL CLREOL, G.scr_width - 1, line_buf);
-        lines_rem--;
-
-        if (lines_rem > ntop - G_scroll_ofs)
-                lines_rem = ntop - G_scroll_ofs;
-        while (--lines_rem >= 0) {
+        if (G.lines_remaining > ntop - G_scroll_ofs)
+                G.lines_remaining = ntop - G_scroll_ofs;
+        while (G.lines_remaining > 0) {
                 /* PID VSZ VSZRW RSS (SHR) DIRTY (SHR) COMMAND */
-                int n = sprintf(line_buf, "%5u ", s->pid);
+                int n = sprintf(G.line_buf, "%5u ", s->pid);
                 if (n > 7) {
                         /* PID is 7 chars long (up to 4194304) */
-                        ulltoa4_and_space(s->vsz  , &line_buf[8]);
-                        ulltoa4_and_space(s->vszrw, &line_buf[8+5]);
+                        ulltoa4_and_space(s->vsz  , &G.line_buf[8]);
+                        ulltoa4_and_space(s->vszrw, &G.line_buf[8+5]);
                         /* the next field (RSS) starts at 8+10 = 3*6 */
                 } else {
                         if (n == 7) /* PID is 6 chars long */
-                                ulltoa4_and_space(s->vsz, &line_buf[7]);
+                                ulltoa4_and_space(s->vsz, &G.line_buf[7]);
                                 /* the next field (VSZRW) starts at 7+5 = 2*6 */
                         else /* PID is 5 chars or less */
-                                ulltoa5_and_space(s->vsz, &line_buf[6]);
-                        ulltoa5_and_space(s->vszrw, &line_buf[2*6]);
+                                ulltoa5_and_space(s->vsz, &G.line_buf[6]);
+                        ulltoa5_and_space(s->vszrw, &G.line_buf[2*6]);
                 }
-                ulltoa5_and_space(s->rss     , &line_buf[3*6]);
-                ulltoa5_and_space(s->rss_sh  , &line_buf[4*6]);
-                ulltoa5_and_space(s->dirty   , &line_buf[5*6]);
-                ulltoa5_and_space(s->dirty_sh, &line_buf[6*6]);
-                ulltoa5_and_space(s->stack   , &line_buf[7*6]);
-                line_buf[8*6] = '\0';
+                ulltoa5_and_space(s->rss     , &G.line_buf[3*6]);
+                ulltoa5_and_space(s->rss_sh  , &G.line_buf[4*6]);
+                ulltoa5_and_space(s->dirty   , &G.line_buf[5*6]);
+                ulltoa5_and_space(s->dirty_sh, &G.line_buf[6*6]);
+                ulltoa5_and_space(s->stack   , &G.line_buf[7*6]);
+                G.line_buf[8*6] = '\0';
                 if ((int)(G.scr_width - MIN_WIDTH) > 1)
-                        read_cmdline(&line_buf[8*6], G.scr_width - MIN_WIDTH, s->pid, s->comm);
-                printf(OPT_BATCH_MODE ? "\n""%.*s" : "\n""%.*s"CLREOL, G.scr_width, line_buf);
+                        read_cmdline(&G.line_buf[8*6], G.scr_width - MIN_WIDTH, s->pid, s->comm);
+                print_line_buf();
                 s++;
         }
-        fputs_stdout(OPT_BATCH_MODE ? "\n" : CLREOS"\r");
 #undef HDR_STR
 #undef MIN_WIDTH
 }
 
-#else
-//void display_topmem_process_list(int lines_rem);
-//int topmem_sort(char *a, char *b);
-#endif /* TOPMEM */
-
-/*
- * end TOPMEM support
- */
+#endif /* end TOPMEM support */
 
 enum {
         TOP_MASK = 0
@@ -1228,7 +1240,6 @@ int top_main(int argc UNUSED_PARAM, char **argv)
         }
 #endif
 
-        /* change to /proc */
         xchdir("/proc");
 
 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
@@ -1340,14 +1351,16 @@ int top_main(int argc UNUSED_PARAM, char **argv)
                 }
 #endif
  IF_FEATURE_TOP_INTERACTIVE(redraw:)
+                G.lines_remaining = G.lines;
                 IF_FEATURE_TOPMEM(if (scan_mask != TOPMEM_MASK)) {
-                        display_process_list(G.lines);
+                        display_process_list();
                 }
 #if ENABLE_FEATURE_TOPMEM
                 else { /* TOPMEM */
-                        display_topmem_process_list(G.lines);
+                        display_topmem_process_list();
                 }
 #endif
+                print_end();
                 fflush_all();
                 if (iterations >= 0 && !--iterations)
                         break;
@@ -1369,7 +1382,8 @@ int top_main(int argc UNUSED_PARAM, char **argv)
 #endif
         } /* end of "while (not Q)" */
 
-        bb_putchar('\n');
+        if (!OPT_BATCH_MODE)
+                bb_putchar('\n');
 #if ENABLE_FEATURE_TOP_INTERACTIVE
         reset_term();
 #endif