httpd: optimize example CGIsbusybox

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

2 files changed, 25 insertions, 37 deletions

diff --git a/networking/httpd_indexcgi.c b/networking/httpd_indexcgi.c
index 3965bb5e0..2e4e0b80e 100644
--- a/networking/httpd_indexcgi.c
+++ b/networking/httpd_indexcgi.c
@@ -71,6 +71,19 @@ struct linux_dirent64 {
         char           d_name[];
 };
 
+static void full_write(int fd, const void *buf, size_t len)
+{
+        ssize_t cc;
+
+        while (len) {
+                cc = write(fd, buf, len);
+                if (cc < 0)
+                        return;
+                buf = ((const char *)buf) + cc;
+                len -= cc;
+        }
+}
+
 /* Appearance of the table is controlled by style sheet *ONLY*,
  * formatting code uses <TAG class=CLASS> to apply style
  * to elements. Edit stylesheet to your liking and recompile. */
@@ -144,7 +157,6 @@ enum {
         BUFFER_SIZE = 8 * 1024*1024,
 //one dirent is typically <= 100 bytes, 1M is enough for ~10k files
 //FIXME: change code to *iterate* getdents64 if need to support giant file lists
-        HEADROOM = 64,
 };
 
 static char *buffer;
@@ -168,33 +180,19 @@ static char *dst;
 # define RETURN_DST return dst
 #endif
 
-/* After this call, you have at least size + HEADROOM bytes available
- * ahead of dst */
-static CHARP guarantee(CHARP_DST int size)
-{
-        if (buffer + (BUFFER_SIZE-HEADROOM) - dst < size) {
-                write(STDOUT_FILENO, buffer, dst - buffer);
-                dst = buffer;
-        }
-        RETURN_DST;
-}
-
 /* NB: formatters do not store terminating NUL! */
 
 static CHARP fmt_str(CHARP_DST const char *src)
 {
         unsigned len = strlen(src);
-        SET_DST guarantee(DST len);
         dst = mempcpy(dst, src, len);
         RETURN_DST;
 }
 
-/* HEADROOM bytes after dst are available after this call */
 static CHARP fmt_url(CHARP_DST const char *name)
 {
         while (*name) {
                 unsigned c = (unsigned char)*name++;
-                SET_DST guarantee(DST 3);
                 if ((c - '0') > 9 /* not a digit */
                  && ((c|0x20) - 'a') > ('z' - 'a') /* not A-Z or a-z */
                  && !strchr("._-+@", c)
@@ -208,7 +206,6 @@ static CHARP fmt_url(CHARP_DST const char *name)
         RETURN_DST;
 }
 
-/* HEADROOM bytes are available after dst after this call */
 static CHARP fmt_html(CHARP_DST const char *name)
 {
         while (*name) {
@@ -220,7 +217,6 @@ static CHARP fmt_html(CHARP_DST const char *name)
                 else if (c == '&') {
                         SET_DST fmt_str(DST "&amp;");
                 } else {
-                        SET_DST guarantee(DST 1);
                         *dst++ = c;
                         continue;
                 }
@@ -244,7 +240,6 @@ static CHARP fmt_ull(CHARP_DST unsigned long long n)
         RETURN_DST;
 }
 
-/* Does not call guarantee - eats into headroom instead */
 static CHARP fmt_02u(CHARP_DST unsigned n)
 {
         /* n %= 100; - not needed, callers don't pass big n */
@@ -254,7 +249,6 @@ static CHARP fmt_02u(CHARP_DST unsigned n)
         RETURN_DST;
 }
 
-/* Does not call guarantee - eats into headroom instead */
 static CHARP fmt_04u(CHARP_DST unsigned n)
 {
         /* n %= 10000; - not needed, callers don't pass big n */
@@ -401,7 +395,7 @@ int main(int argc, char **argv)
                         SET_DST fmt_ull(DST cdir->D_SIZE);
                 SET_DST fmt_str(DST "<td class=dt>");
                 if (sizeof(cdir->D_MTIME) == sizeof(tt))
-                        ptm = gmtime(&cdir->D_MTIME);
+                        ptm = gmtime((time_t*)&cdir->D_MTIME);
                 else {
                         tt = cdir->D_MTIME;
                         ptm = gmtime(&tt);
@@ -413,6 +407,12 @@ int main(int argc, char **argv)
                 SET_DST fmt_02u(DST ptm->tm_min); *dst++ = ':';
                 SET_DST fmt_02u(DST ptm->tm_sec);
                 *dst++ = '\n';
+
+                /* Flush after every 256 files (typically around 50k of output) */
+                if ((dir_list_count & 0xff) == 0) {
+                        full_write(STDOUT_FILENO, buffer, dst - buffer);
+                        dst = buffer;
+                }
         }
 
         SET_DST fmt_str(DST "<tr class=foot><th class=cnt>Files: ");
@@ -424,7 +424,8 @@ int main(int argc, char **argv)
         SET_DST fmt_ull(DST size_total);
         SET_DST fmt_str(DST "<th class=dt>\n");
         /* "</table></body></html>" - why bother? */
-        SET_DST guarantee(DST BUFFER_SIZE * 2); /* flush */
+
+        full_write(STDOUT_FILENO, buffer, dst - buffer);
 
         return 0;
     }
diff --git a/networking/httpd_ratelimit_cgi.c b/networking/httpd_ratelimit_cgi.c
index 96702131e..cadaf5a07 100644
--- a/networking/httpd_ratelimit_cgi.c
+++ b/networking/httpd_ratelimit_cgi.c
@@ -39,31 +39,18 @@ httpd_ratelimit_cgi.c -o httpd_ratelimit_cgi
 #include <sys/stat.h> /* mkdir */
 #include <limits.h>
 
-static ssize_t full_write(int fd, const void *buf, size_t len)
+static void full_write(int fd, const void *buf, size_t len)
 {
         ssize_t cc;
-        ssize_t total;
-
-        total = 0;
 
         while (len) {
                 cc = write(fd, buf, len);
 
-                if (cc < 0) {
-                        if (total) {
-                                /* we already wrote some! */
-                                /* user can do another write to know the error code */
-                                return total;
-                        }
-                        return cc;  /* write() returns -1 on failure. */
-                }
-
-                total += cc;
+                if (cc < 0)
+                        return;
                 buf = ((const char *)buf) + cc;
                 len -= cc;
         }
-
-        return total;
 }
 
 static void full_write2(int fd, const char *msg, const char *msg2)