Added stats settings.

Stats settings gives a dump of the overall settings of the server.
This is useful for verifying the effect of commandline parameters as
well as helping others debug odd behaviors.

5 files changed, 153 insertions, 2 deletions

diff --git a/doc/protocol.txt b/doc/protocol.txt
index 9bfe901..743b4ac 100644
--- a/doc/protocol.txt
+++ b/doc/protocol.txt
@@ -408,6 +408,43 @@ integers separated by a colon (treat this as a floating point number).
 |                       |         | (see doc/threads.txt)                     |
 |-----------------------+---------+-------------------------------------------|
 
+Settings statistics
+-------------------
+CAVEAT: This section describes statistics which are subject to change in the
+future.
+
+The "stats" command with the argument of "settings" returns details of
+the settings of the running memcached.  This is primarily made up of
+the results of processing commandline options.
+
+Note that these are not guaranteed to return in any specific order and
+this list may not be exhaustive.  Otherwise, this returns like any
+other stats command.
+
+|-----------------+----------+----------------------------------------------|
+| Name            | Type     | Meaning                                      |
+|-----------------+----------+----------------------------------------------|
+| maxbytes        | size_t   | Maximum number of bytes allows in this cache |
+| maxconns        | 32       | Maximum number of clients allowed.           |
+| tcpport         | 32       | TCP listen port.                             |
+| udpport         | 32       | UDP listen port.                             |
+| inter           | string   | Listen interface.                            |
+| verbosity       | 32       | 0 = none, 1 = some, 2 = lots                 |
+| oldest          | 32u      | Age of the oldest honored object.            |
+| evictions       | on/off   | When off, LRU evictions are disabled.        |
+| domain_socket   | string   | Path to the domain socket (if any).          |
+| umask           | 32 (oct) | umask for the creation of the domain socket. |
+| growth_factor   | float    | Chunk size growth factor.                    |
+| chunk_size      | 32       | Minimum space allocated for key+value+flags  |
+| num_threads     | 32       | Number of threads (including dispatch).      |
+| stat_key_prefix | char     | Stats prefix separator character.            |
+| detail_enabled  | bool     | If yes, stats detail is enabled.             |
+| reqs_per_event  | 32       | Max num IO ops processed within an event.    |
+| cas_enabled     | bool     | When no, CAS is not enabled for this server. |
+| tcp_backlog     | 32       | TCP listen backlog.
+|-----------------+----------+----------------------------------------------|
+
+
 Item statistics
 ---------------
 CAVEAT: This section describes statistics which are subject to change in the
diff --git a/memcached.c b/memcached.c
index 1772b8c..1612668 100644
--- a/memcached.c
+++ b/memcached.c
@@ -69,6 +69,14 @@ static char *server_stats(uint32_t (*add_stats)(char *buf, const char *key,
                           const uint16_t klen, const char *val,
                           const uint32_t vlen, void *cookie), conn *c,
                           int *buflen);
+static char *process_stat_settings(uint32_t (*add_stats)(char *buf,
+                                                        const char *k,
+                                                        const uint16_t kl,
+                                                        const char *v,
+                                                        const uint32_t vl,
+                                                        void *cookie),
+                                   void *c, int *buflen);
+
 
 /* defaults */
 static void settings_init(void);
@@ -1367,6 +1375,23 @@ static void process_bin_stat(conn *c) {
 
         append_bin_stats(buf, NULL, 0, NULL, 0, (void *)c);
         write_and_free(c, buf, sizeof(header->response));
+    } else if (strncmp(subcommand, "settings", 8) == 0) {
+        int buflen = 0;
+        char *buf = NULL, *ptr = NULL;
+
+        if ((buf = process_stat_settings(&append_bin_stats, (void *)c,
+                                         &buflen)) == NULL) {
+            write_bin_error(c, PROTOCOL_BINARY_RESPONSE_ENOMEM, 0);
+            return;
+        }
+
+        /* XXX:  append termination packet Like all these, assume it
+           fits. :/ */
+        ptr = buf + buflen;
+        append_bin_stats(ptr, NULL, 0, NULL, 0, (void *)c);
+
+        write_and_free(c, buf, buflen + sizeof(header->response));
+        return;
     } else if (strncmp(subcommand, "detail", 6) == 0) {
         char *subcmd_pos = subcommand + 6;
         char *bufpos;
@@ -2306,6 +2331,61 @@ uint32_t append_ascii_stats(char *buf, const char *key, const uint16_t klen,
     return nbytes;
 }
 
+/* Local macro existing specifically to process stats */
+#define APPEND_STAT(fmt, name, val) \
+    vlen = sprintf(val_str, fmt, val); \
+    size = add_stats(pos, name, strlen(name), val_str, vlen, c); \
+    *buflen += size; \
+    pos += size; \
+    assert(*buflen < allocated);
+
+static char *process_stat_settings(uint32_t (*add_stats)(char *buf,
+                                                         const char *k,
+                                                         const uint16_t kl,
+                                                         const char *v,
+                                                         const uint32_t vl,
+                                                         void *cookie),
+                                   void *c, int *buflen) {
+    char *buf = NULL, *pos = NULL;
+    char val_str[128];
+    int size = 0, vlen = 0, allocated = 2048;
+    *buflen = 0;
+
+    assert(add_stats);
+
+    buf = calloc(allocated, 1);
+    if (!buf) {
+        return NULL;
+    }
+
+    pos = buf;
+
+    APPEND_STAT("%u", "maxbytes", (unsigned int)settings.maxbytes);
+    APPEND_STAT("%d", "maxconns", settings.maxconns);
+    APPEND_STAT("%d", "tcpport", settings.port);
+    APPEND_STAT("%d", "udpport", settings.udpport);
+    APPEND_STAT("%s", "inter", settings.inter ? settings.inter : "NULL");
+    APPEND_STAT("%d", "verbosity", settings.verbose);
+    APPEND_STAT("%lu", "oldest", (unsigned long)settings.oldest_live);
+    APPEND_STAT("%s", "evictions", settings.evict_to_free ? "on" : "off");
+    APPEND_STAT("%s", "domain_socket",
+                settings.socketpath ? settings.socketpath : "NULL");
+    APPEND_STAT("%o", "umask", settings.access);
+    APPEND_STAT("%.2f", "growth_factor", settings.factor);
+    APPEND_STAT("%d", "chunk_size", settings.chunk_size);
+    APPEND_STAT("%d", "num_threads", settings.num_threads);
+    APPEND_STAT("%c", "stat_key_prefix", settings.prefix_delimiter);
+    APPEND_STAT("%s", "detail_enabled",
+                settings.detail_enabled ? "yes" : "no");
+    APPEND_STAT("%d", "reqs_per_event", settings.reqs_per_event);
+    APPEND_STAT("%s", "cas_enabled", settings.use_cas ? "yes" : "no");
+    APPEND_STAT("%d", "tcp_backlog", settings.backlog);
+
+    return buf;
+}
+
+#undef APPEND_STAT
+
 static void process_stat(conn *c, token_t *tokens, const size_t ntokens) {
     char *command;
     char *subcommand;
@@ -2380,6 +2460,23 @@ static void process_stat(conn *c, token_t *tokens, const size_t ntokens) {
         return;
     }
 
+    if (strcmp(subcommand, "settings") == 0) {
+        int buflen = 0;
+        char *buf = NULL, *ptr = NULL;
+
+        if ((buf = process_stat_settings(&append_ascii_stats, (void *)c,
+                                         &buflen)) == NULL) {
+            out_string(c, "SERVER_ERROR out of memory writing stats");
+            return;
+        }
+
+        ptr = buf + buflen;
+        /* XXX:  append terminator (assumes space) */
+        buflen += append_ascii_stats(ptr, NULL, 0, NULL, 0, (void *)c);
+
+        write_and_free(c, buf, buflen);
+        return;
+    }
 
     if (strcmp(subcommand, "cachedump") == 0) {
 
diff --git a/memcached.h b/memcached.h
index 0b2f0df..9298192 100644
--- a/memcached.h
+++ b/memcached.h
@@ -103,6 +103,7 @@ struct stats {
 
 #define MAX_VERBOSITY_LEVEL 2
 
+/* When adding a setting, be sure to update process_stat_settings */
 struct settings {
     size_t maxbytes;
     int maxconns;
diff --git a/t/binary.t b/t/binary.t
index c0605ca..2f0396b 100755
--- a/t/binary.t
+++ b/t/binary.t
@@ -2,7 +2,7 @@
 
 use strict;
 use warnings;
-use Test::More tests => 797;
+use Test::More tests => 857;
 use FindBin qw($Bin);
 use lib "$Bin/lib";
 use MemcachedTest;
@@ -333,6 +333,16 @@ $mc->silent_mutation(::CMD_ADDQ, 'silentadd', 'silentaddval');
     }
 }
 
+# diag "Test stats settings."
+{
+    my %stats = $mc->stats('settings');
+
+    is(1024, $stats{'maxconns'});
+    is('NULL', $stats{'domain_socket'});
+    is('on', $stats{'evictions'});
+    is('yes', $stats{'cas_enabled'});
+}
+
 # Along with the assertion added to the code to verify we're staying
 # within bounds when we do a stats detail dump (detail turned on at
 # the top).
diff --git a/t/stats.t b/t/stats.t
index e5d3af8..28f9133 100755
--- a/t/stats.t
+++ b/t/stats.t
@@ -1,7 +1,7 @@
 #!/usr/bin/perl
 
 use strict;
-use Test::More tests => 70;
+use Test::More tests => 74;
 use FindBin qw($Bin);
 use lib "$Bin/lib";
 use MemcachedTest;
@@ -146,3 +146,9 @@ is(scalar <$sock>, "STORED\r\n", "good cas");
 check_cas_stats(1, 1, 1);
 my ($newid, $v) = mem_gets($sock, 'c');
 is('z', $v, 'got the expected value');
+
+my $settings = mem_stats($sock, ' settings');
+is(1024, $settings->{'maxconns'});
+is('NULL', $settings->{'domain_socket'});
+is('on', $settings->{'evictions'});
+is('yes', $settings->{'cas_enabled'});