top: code shrink, -26 bytes

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

1 files 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;
 }