nserver: Add Stats_unstringify.

* nserver/src/stats.c (Stats_unstringify): New function definition.
* nserver/src/stats.h (Stats_unstringify): New function declaration.
* nserver/tests/stats_tests.c (tests_stats_unstringify): Test for
Stats_unstringify.
(tests_stats_unstringify): st_str is now a static variable. Don't free
it; it's done in tests_stats_unstringify.
(st_str): New static variable.

3 files changed, 65 insertions, 4 deletions

diff --git a/nserver/src/stats.c b/nserver/src/stats.c
index c2d3c34..9610301 100644
--- a/nserver/src/stats.c
+++ b/nserver/src/stats.c
@@ -1,7 +1,5 @@
 #include <math.h>
 #include <stats.h>
-#include <stdlib.h>
-#include <dbg.h>
 
 Stats *Stats_recreate(double sum, double sumsq, unsigned long n,
                       double min, double max)
@@ -87,3 +85,38 @@ char *Stats_stringify(Stats *st)
     }
     return NULL;
 }
+
+
+Stats *Stats_unstringify(char *st_str)
+{
+    Stats *st = NULL;
+
+    check(st_str != NULL, "st_str invalid");
+
+    bstring st_bstr = bfromcstr(st_str);
+    check(st_bstr != NULL, "st_str bstring convert failed");
+
+    struct bstrList *st_list = bsplit(st_bstr, ':');
+    check(st_list != NULL, "st_bstr split failed");
+    check(st_list->qty == 5, "wrong number of st parts");
+
+    st = Stats_create();
+    check(st != NULL, "stats creation failed");
+
+    st->sum = atof(bdata(st_list->entry[0]));
+    st->sumsq = atof(bdata(st_list->entry[1]));
+    st->n = atoi(bdata(st_list->entry[2]));
+    st->min = atof(bdata(st_list->entry[3]));
+    st->max = atof(bdata(st_list->entry[4]));
+
+    // clean up.
+    int rc = bstrListDestroy(st_list);
+    check(rc == BSTR_OK, "st_list destroy failed");
+
+    return st;
+ error:
+    if (st) {
+        free(st);
+    }
+    return NULL;
+}
diff --git a/nserver/src/stats.h b/nserver/src/stats.h
index 8fc971e..96bc2b4 100644
--- a/nserver/src/stats.h
+++ b/nserver/src/stats.h
@@ -1,6 +1,10 @@
 #ifndef stats_h
 #define stats_h
+
 #include <math.h>
+#include <stdlib.h>
+#include <bstrlib.h>
+#include <dbg.h>
 
 typedef struct Stats {
     double sum;
@@ -21,6 +25,8 @@ char *Stats_dump(Stats *st);
 
 char *Stats_stringify(Stats *st);
 
+Stats *Stats_unstringify(char *st_str);
+
 static inline double Stats_mean(Stats *st)
 {
     return st->sum / st->n;
diff --git a/nserver/tests/stats_tests.c b/nserver/tests/stats_tests.c
index e136ab3..3ed92de 100644
--- a/nserver/tests/stats_tests.c
+++ b/nserver/tests/stats_tests.c
@@ -7,6 +7,8 @@
  * ../../liblcthw/tests/stats_tests.c
  */
 
+static char *st_str = NULL;
+
 char *test_stats_stringify()
 {
     Stats *st = Stats_create();
@@ -19,7 +21,7 @@ char *test_stats_stringify()
     st->min =  28.3921;
     st->max = 238.27;
 
-    char *st_str = Stats_stringify(st);
+    st_str = Stats_stringify(st);
     mu_assert(st_str != NULL, "stats stringify failed");
 
     char *expected_st_str = "8238.34:4260238.83:28:28.39:238.27";
@@ -27,17 +29,37 @@ char *test_stats_stringify()
               "stringified str invalid");
 
     // cleanup
-    free(st_str);
     free(st);
 
     return NULL;
 }
 
+char *test_stats_unstringify()
+{
+    mu_assert(st_str != NULL, "st_str not initialized");
+
+    Stats *st = Stats_unstringify(st_str);
+    mu_assert(st != NULL, "stats unstringify failed");
+
+    mu_assert(st->sum == 8238.34, "stats sum incorrect");
+    mu_assert(st->sumsq == 4260238.83, "stats sumsq incorrect");
+    mu_assert(st->n == 28, "stats n incorrect");
+    mu_assert(st->min == 28.39, "stats min incorrect");
+    mu_assert(st->max == 238.27, "stats max incorrect");
+
+    // clean up
+    free(st);
+    free(st_str);
+
+    return NULL;
+}
+
 char *all_tests()
 {
     mu_suite_start();
 
     mu_run_test(test_stats_stringify);
+    mu_run_test(test_stats_unstringify);
 
     return NULL;
 }