Allow the binding protocol to be specified.

Instead of always binding as autonegotiate, allow the user to specify
which protocol the server will run.

doc/memcached.1

@@ -118,6 +118,12 @@ Try to use large memory pages (if available). Increasing the memory page size
 could reduce the number of TLB misses and improve the performance. In order to
 get large pages from the OS, memcached will allocate the total item-cache in
 one large chunk. Only available if supported on your OS.
+.TP
+.B \-B <proto>
+Specify the binding protocol to use.  By default, the server will
+autonegotiate client connections.  By using this option, you can
+specify the protocol clients must speak.  Possible options are "auto"
+(the default, autonegotiation behavior), "ascii" and "binary".
 .br
 .SH LICENSE
 The memcached daemon is copyright Danga Interactive and is distributed under 

memcached.c

@@ -192,6 +192,7 @@ static void settings_init(void) {
     settings.detail_enabled = 0;
     settings.reqs_per_event = 20;
     settings.backlog = 1024;
+    settings.binding_protocol = negotiating_prot;
 }
 
 /*
@@ -363,7 +364,7 @@ conn *conn_new(const int sfd, enum conn_states init_state,
     }
 
     c->transport = transport;
-    c->protocol = negotiating_prot;
+    c->protocol = settings.binding_protocol;
 
     /* unix socket mode doesn't need this, so zeroed out.  but why
      * is this done for every command?  presumably for UDP
@@ -2136,6 +2137,8 @@ static void process_stat_settings(ADD_STAT add_stats, void *c) {
     APPEND_STAT("reqs_per_event", "%d", settings.reqs_per_event);
     APPEND_STAT("cas_enabled", "%s", settings.use_cas ? "yes" : "no");
     APPEND_STAT("tcp_backlog", "%d", settings.backlog);
+    APPEND_STAT("binding_protocol", "%s",
+                prot_text(settings.binding_protocol));
 }
 
 static void process_stat(conn *c, token_t *tokens, const size_t ntokens) {
@@ -3721,6 +3724,7 @@ static void usage(void) {
            "              to prevent starvation.  default 20\n");
     printf("-C            Disable use of CAS\n");
     printf("-b            Set the backlog queue limit (default 1024)\n");
+    printf("-B            Binding protocol - one of ascii, binary, or auto (default)\n");
     return;
 }
 
@@ -3930,6 +3934,7 @@ int main (int argc, char **argv) {
           "R:"  /* max requests per event */
           "C"   /* Disable use of CAS */
           "b:"  /* backlog queue limit */
+          "B:"  /* Binding protocol */
         ))) {
         switch (c) {
         case 'a':
@@ -4031,6 +4036,19 @@ int main (int argc, char **argv) {
         case 'b' :
             settings.backlog = atoi(optarg);
             break;
+        case 'B':
+            if (strcmp(optarg, "auto") == 0) {
+                settings.binding_protocol = negotiating_prot;
+            } else if (strcmp(optarg, "binary") == 0) {
+                settings.binding_protocol = binary_prot;
+            } else if (strcmp(optarg, "ascii") == 0) {
+                settings.binding_protocol = ascii_prot;
+            } else {
+                fprintf(stderr, "Invalid value for binding protocol: %s\n"
+                        " -- should be one of auto, binary, or ascii\n", optarg);
+                exit(EX_USAGE);
+            }
+            break;
         default:
             fprintf(stderr, "Illegal argument \"%c\"\n", c);
             return 1;

memcached.h

@@ -256,6 +256,7 @@ struct settings {
     int reqs_per_event;     /* Maximum number of io to process on each
                                io-event. */
     bool use_cas;
+    enum protocol binding_protocol;
     int backlog;
 };
 

t/00-startup.t

@@ -1,7 +1,7 @@
 #!/usr/bin/perl
 
 use strict;
-use Test::More tests => 8;
+use Test::More tests => 14;
 use FindBin qw($Bin);
 use lib "$Bin/lib";
 use MemcachedTest;
@@ -35,3 +35,24 @@ eval {
     is('8675', $stats->{'tcp_backlog'});
 };
 is($@, '', "-b works");
+
+foreach my $val ('auto', 'ascii') {
+    eval {
+        my $server = new_memcached("-B $val");
+        my $stats = mem_stats($server->sock, 'settings');
+        ok($stats->{'binding_protocol'} =~ /$val/, "$val works");
+    };
+    is($@, '', "$val works");
+}
+
+# For the binary test, we just verify it starts since we don't have an easy bin client.
+eval {
+    my $server = new_memcached("-B binary");
+};
+is($@, '', "binary works");
+
+# Should blow up with something invalid.
+eval {
+    my $server = new_memcached("-B http");
+};
+ok($@, "Died with illegal -B arg.");

t/binary.t

@@ -2,7 +2,7 @@
 
 use strict;
 use warnings;
-use Test::More tests => 857;
+use Test::More tests => 860;
 use FindBin qw($Bin);
 use lib "$Bin/lib";
 use MemcachedTest;