nserver: protocol: Define ssmean.

* nserver/src/protocol.c (ssmean): New function.
* nserver/tests/protocol_tests.c (test_ssmean): New test.
(all_tests): ADd test_ssmean.

2 files changed, 36 insertions, 0 deletions

diff --git a/nserver/src/protocol.c b/nserver/src/protocol.c
index a174caf..3c09733 100644
--- a/nserver/src/protocol.c
+++ b/nserver/src/protocol.c
@@ -57,3 +57,22 @@ int sssample(char *key, double s)
     return -1;
 }
 
+double ssmean(char *key)
+{
+    check(hash != NULL, "hash not initialized");
+
+    // 1. create bstring from 'key'.
+    bstring k = bfromcstr(key);
+
+    // 2. try to Stats for key.
+    Stats *st = (Stats *) Hashmap_get(hash, k);
+    check(st != NULL, "stats not found for key");
+
+    // 3. get mean.
+    double m = Stats_mean(st);
+
+    return m;
+ error:
+    return -1;
+}
+
diff --git a/nserver/tests/protocol_tests.c b/nserver/tests/protocol_tests.c
index 75bf614..6fc2831 100644
--- a/nserver/tests/protocol_tests.c
+++ b/nserver/tests/protocol_tests.c
@@ -42,12 +42,29 @@ char *test_sssample()
     return NULL;
 }
 
+char *test_ssmean()
+{
+    double m = 0;
+
+    m = ssmean("crimson");
+    mu_assert(m == 8, "ssmean failed 0");
+
+    m = ssmean("/vermilion");
+    mu_assert(m == 17, "ssmean failed 1");
+
+    m = ssmean("/ruby");
+    mu_assert(m == -1, "ssmean failed 2");
+
+    return NULL;
+}
+
 char *all_tests()
 {
     mu_suite_start();
 
     mu_run_test(test_sscreate);
     mu_run_test(test_sssample);
+    mu_run_test(test_ssmean);
 
     return NULL;
 }