From d94332f2b6615e30a8a4d3420407dbd938885b7b Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 6 Jun 2010 17:40:54 +0200 Subject: [PATCH] top: code shrink, -26 bytes Signed-off-by: Denys Vlasenko --- procps/top.c | 60 +++++++++++++++++++++++----------------------------- 1 file changed, 27 insertions(+), 33 deletions(-) diff --git a/procps/top.c b/procps/top.c index 51b167171..04dd82633 100644 --- a/procps/top.c +++ b/procps/top.c @@ -103,11 +103,11 @@ struct globals { }; //FIX_ALIASING; - large code growth enum { LINE_BUF_SIZE = COMMON_BUFSIZE - offsetof(struct globals, line_buf) }; #define G (*(struct globals*)&bb_common_bufsiz1) -#define INIT_G() do { \ - struct G_sizecheck { \ - char G_sizecheck[sizeof(G) > COMMON_BUFSIZE ? -1 : 1]; \ - }; \ -} while (0) +struct BUG_bad_size { + char BUG_G_too_big[sizeof(G) <= COMMON_BUFSIZE ? 1 : -1]; + char BUG_line_buf_too_small[LINE_BUF_SIZE > 80 ? 1 : -1]; +}; +#define INIT_G() do { } while (0) #define top (G.top ) #define ntop (G.ntop ) #define sort_field (G.sort_field ) @@ -705,7 +705,7 @@ static void display_topmem_header(int scr_width, int *lines_rem_p) MWRITE, ANON, MAP, SLAB, NUM_FIELDS }; - static const char match[NUM_FIELDS][11] = { + static const char match[NUM_FIELDS][12] = { "\x09" "MemTotal:", // TOTAL "\x08" "MemFree:", // MFREE "\x08" "Buffers:", // BUF @@ -718,52 +718,46 @@ static void display_topmem_header(int scr_width, int *lines_rem_p) "\x07" "Mapped:", // MAP "\x05" "Slab:", // SLAB }; -//TODO? Note that fields always appear in the above order. -//Thus, as each new line read from /proc/meminfo, we can compare it *once* -//with match[last_matched+1], instead of looping thru all match[i]'s. -//If it matches, memorize its data and last_matched++ (and if == NUM_FIELDS, -//we're done with reading /proc/meminfo!); otherwise fgets next line. -//The code below is slower, but is robust against a case when /proc/meminfo -//gets reordered in the future. - char Z[NUM_FIELDS][sizeof(long long)*3]; - char linebuf[128]; + char meminfo_buf[4 * 1024]; + const char *Z[NUM_FIELDS]; unsigned i; - FILE *fp; + int sz; - memset(&Z, 0, sizeof(Z)); for (i = 0; i < NUM_FIELDS; i++) - Z[i][0] = '?'; + Z[i] = "?"; /* read memory info */ - fp = xfopen_for_read("meminfo"); - while (fgets(linebuf, sizeof(linebuf), fp)) { + sz = open_read_close("meminfo", meminfo_buf, sizeof(meminfo_buf) - 1); + if (sz >= 0) { + char *p = meminfo_buf; + meminfo_buf[sz] = '\0'; + /* Note that fields always appear in the match[] order */ for (i = 0; i < NUM_FIELDS; i++) { - unsigned sz = (unsigned char)match[i][0]; - if (strncmp(linebuf, match[i] + 1, sz) == 0) { + char *found = strstr(p, match[i] + 1); + if (found) { /* Cut "NNNN" out of " NNNN kb" */ - char *s = skip_whitespace(linebuf + sz); - skip_non_whitespace(s)[0] = '\0'; - safe_strncpy(Z[i], s, sizeof(Z[i])); - break; + char *s = skip_whitespace(found + match[i][0]); + p = skip_non_whitespace(s); + *p++ = '\0'; + Z[i] = s; } } } - fclose(fp); - snprintf(linebuf, sizeof(linebuf), + snprintf(line_buf, LINE_BUF_SIZE, "Mem total:%s anon:%s map:%s free:%s", Z[TOTAL], Z[ANON], Z[MAP], Z[MFREE]); - printf(OPT_BATCH_MODE ? "%.*s\n" : "\033[H\033[J%.*s\n", scr_width, linebuf); + printf(OPT_BATCH_MODE ? "%.*s\n" : "\033[H\033[J%.*s\n", scr_width, line_buf); - snprintf(linebuf, sizeof(linebuf), + snprintf(line_buf, LINE_BUF_SIZE, " slab:%s buf:%s cache:%s dirty:%s write:%s", Z[SLAB], Z[BUF], Z[CACHE], Z[DIRTY], Z[MWRITE]); - printf("%.*s\n", scr_width, linebuf); + printf("%.*s\n", scr_width, line_buf); - snprintf(linebuf, sizeof(linebuf), + snprintf(line_buf, LINE_BUF_SIZE, "Swap total:%s free:%s", // TODO: % used? Z[SWAPTOTAL], Z[SWAPFREE]); - printf("%.*s\n", scr_width, linebuf); + printf("%.*s\n", scr_width, line_buf); (*lines_rem_p) -= 3; }