httpd: shrink mime type matching code (suggested by Bernhard)

function                                             old     new   delta
static.suffixTable                                   100     231    +131
send_file_and_exit                                   625     658     +33
handle_incoming_and_exit                            2749    2745      -4
send_cgi_and_exit                                    936     901     -35
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/2 up/down: 164/-39)           Total: 125 bytes
   text    data     bss     dec     hex filename
 824631     458    6956  832045   cb22d busybox_old
 824550     458    6956  831964   cb1dc busybox_unstripped

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

2 files changed, 56 insertions, 43 deletions

diff --git a/libbb/isdirectory.c b/libbb/isdirectory.c
index 28ed3ec29..4a2961e0d 100644
--- a/libbb/isdirectory.c
+++ b/libbb/isdirectory.c
@@ -15,7 +15,7 @@
  * Return TRUE if fileName is a directory.
  * Nonexistent files return FALSE.
  */
-int FAST_FUNC is_directory(const char *fileName, const int followLinks, struct stat *statBuf)
+int FAST_FUNC is_directory(const char *fileName, int followLinks, struct stat *statBuf)
 {
         int status;
         struct stat astatBuf;
diff --git a/networking/httpd.c b/networking/httpd.c
index 07dcd71ff..a2a52b58a 100644
--- a/networking/httpd.c
+++ b/networking/httpd.c
@@ -20,14 +20,14 @@
  * httpd -p 80 -u 80 -h /www -c /etc/httpd.conf -r "Web Server Authentication"
  *
  *
- * When a url starts by "/cgi-bin/" it is assumed to be a cgi script.  The
+ * When an url starts by "/cgi-bin/" it is assumed to be a cgi script.  The
  * server changes directory to the location of the script and executes it
  * after setting QUERY_STRING and other environment variables.
  *
  * Doc:
  * "CGI Environment Variables": http://hoohoo.ncsa.uiuc.edu/cgi/env.html
  *
- * The applet can also be invoked as a url arg decoder and html text encoder
+ * The applet can also be invoked as an url arg decoder and html text encoder
  * as follows:
  *  foo=`httpd -d $foo`           # decode "Hello%20World" as "Hello World"
  *  bar=`httpd -e "<Hello World>"`  # encode as "&#60Hello&#32World&#62"
@@ -1325,10 +1325,8 @@ static void send_cgi_and_exit(
         /* Check for [dirs/]script.cgi/PATH_INFO */
         script = (char*)url;
         while ((script = strchr(script + 1, '/')) != NULL) {
-                struct stat sb;
-
                 *script = '\0';
-                if (!is_directory(url + 1, 1, &sb)) {
+                if (!is_directory(url + 1, 1, NULL)) {
                         /* not directory, found script.cgi/PATH_INFO */
                         *script = '/';
                         break;
@@ -1504,32 +1502,8 @@ static void send_cgi_and_exit(
  */
 static NOINLINE void send_file_and_exit(const char *url, int what)
 {
-        static const char *const suffixTable[] = {
-        /* Warning: shorter equivalent suffix in one line must be first */
-                ".htm.html", "text/html",
-                ".jpg.jpeg", "image/jpeg",
-                ".gif",      "image/gif",
-                ".png",      "image/png",
-                ".txt.h.c.cc.cpp", "text/plain",
-                ".css",      "text/css",
-                ".wav",      "audio/wav",
-                ".avi",      "video/x-msvideo",
-                ".qt.mov",   "video/quicktime",
-                ".mpe.mpeg", "video/mpeg",
-                ".mid.midi", "audio/midi",
-                ".mp3",      "audio/mpeg",
-#if 0                        /* unpopular */
-                ".au",       "audio/basic",
-                ".pac",      "application/x-ns-proxy-autoconfig",
-                ".vrml.wrl", "model/vrml",
-#endif
-                NULL
-        };
-
         char *suffix;
         int fd;
-        const char *const *table;
-        const char *try_suffix;
         ssize_t count;
 
         fd = open(url, O_RDONLY);
@@ -1547,22 +1521,61 @@ static NOINLINE void send_file_and_exit(const char *url, int what)
          * (happens if you abort downloads from local httpd): */
         signal(SIGPIPE, SIG_IGN);
 
-        suffix = strrchr(url, '.');
-
-        /* If not found, set default as "application/octet-stream";  */
+        /* If not found, default is "application/octet-stream" */
         found_mime_type = "application/octet-stream";
+        suffix = strrchr(url, '.');
         if (suffix) {
+                static const char suffixTable[] ALIGN1 =
+                        /* Shorter suffix must be first:
+                         * ".html.htm" will fail for ".htm"
+                         */
+                        ".txt.h.c.cc.cpp\0" "text/plain\0"
+                        /* .htm line must be after .h line */
+                        ".htm.html\0" "text/html\0"
+                        ".jpg.jpeg\0" "image/jpeg\0"
+                        ".gif\0"      "image/gif\0"
+                        ".png\0"      "image/png\0"
+                        /* .css line must be after .c line */
+                        ".css\0"      "text/css\0"
+                        ".wav\0"      "audio/wav\0"
+                        ".avi\0"      "video/x-msvideo\0"
+                        ".qt.mov\0"   "video/quicktime\0"
+                        ".mpe.mpeg\0" "video/mpeg\0"
+                        ".mid.midi\0" "audio/midi\0"
+                        ".mp3\0"      "audio/mpeg\0"
+#if 0  /* unpopular */
+                        ".au\0"       "audio/basic\0"
+                        ".pac\0"      "application/x-ns-proxy-autoconfig\0"
+                        ".vrml.wrl\0" "model/vrml\0"
+#endif
+                        /* compiler adds another "\0" here */
+                ;
                 Htaccess *cur;
-                for (table = suffixTable; *table; table += 2) {
-                        try_suffix = strstr(table[0], suffix);
-                        if (try_suffix) {
-                                try_suffix += strlen(suffix);
-                                if (*try_suffix == '\0' || *try_suffix == '.') {
-                                        found_mime_type = table[1];
-                                        break;
-                                }
+
+                /* Examine built-in table */
+                const char *table = suffixTable;
+                const char *table_next;
+                for (; *table; table = table_next) {
+                        const char *try_suffix;
+                        const char *mime_type;
+                        mime_type  = table + strlen(table) + 1;
+                        table_next = mime_type + strlen(mime_type) + 1;
+                        try_suffix = strstr(table, suffix);
+                        if (!try_suffix)
+                                continue;
+                        try_suffix += strlen(suffix);
+                        if (*try_suffix == '\0' || *try_suffix == '.') {
+                                found_mime_type = mime_type;
+                                break;
                         }
+                        /* Example: strstr(table, ".av") != NULL, but it
+                         * does not match ".avi" after all and we end up here.
+                         * The table is arranged so that in this case we know
+                         * that it can't match anything in the following lines,
+                         * and we stop the search: */
+                        break;
                 }
+                /* ...then user's table */
                 for (cur = mime_a; cur; cur = cur->next) {
                         if (strcmp(cur->before_colon, suffix) == 0) {
                                 found_mime_type = cur->after_colon;
@@ -1919,7 +1932,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
 
         /* If URL is a directory, add '/' */
         if (urlp[-1] != '/') {
-                if (is_directory(urlcopy + 1, 1, &sb)) {
+                if (is_directory(urlcopy + 1, 1, NULL)) {
                         found_moved_temporarily = urlcopy;
                 }
         }
@@ -1933,7 +1946,7 @@ static void handle_incoming_and_exit(const len_and_sockaddr *fromAddr)
         while (ip_allowed && (tptr = strchr(tptr + 1, '/')) != NULL) {
                 /* have path1/path2 */
                 *tptr = '\0';
-                if (is_directory(urlcopy + 1, 1, &sb)) {
+                if (is_directory(urlcopy + 1, 1, NULL)) {
                         /* may have subdir config */
                         parse_conf(urlcopy + 1, SUBDIR_PARSE);
                         ip_allowed = checkPermIP();