Fix to_string(cb::durability::Requirements)

It is used to print invalid values in setPendingSyncWrite,
but it does not handle the case where the level represents
an invalid value.

Change-Id: I355931564105b82fc257ee27dc72f2bde6c12d57
Reviewed-on: http://review.couchbase.org/111955
Tested-by: Build Bot <[email protected]>
Reviewed-by: Dave Rigby <[email protected]>

Author: trondn

include/memcached/durability_spec.h

@@ -195,6 +195,7 @@ bool operator==(const Requirements& lhs, const Requirements& rhs);
 static constexpr Requirements NoRequirements = {Level::None, Timeout{}};
 
 std::string to_string(Requirements r);
+std::string to_string(Level l);
 
 } // namespace durability
 } // namespace cb

utilities/durability_spec.cc

@@ -48,23 +48,23 @@ bool operator==(const Requirements& lhs, const Requirements& rhs) {
 }
 
 std::string to_string(Requirements r) {
-    std::string desc = "{";
-    switch (r.getLevel()) {
+    std::string desc = "{" + to_string(r.getLevel()) + ", ";
+    desc += "timeout=" + to_string(r.getTimeout()) + "}";
+    return desc;
+}
+
+std::string to_string(Level l) {
+    switch (l) {
     case Level::None:
-        desc += "None, ";
-        break;
+        return "None";
     case Level::Majority:
-        desc += "Majority, ";
-        break;
+        return "Majority";
     case Level::MajorityAndPersistOnMaster:
-        desc += "MajorityAndPersistOnMaster, ";
-        break;
+        return "MajorityAndPersistOnMaster";
     case Level::PersistToMajority:
-        desc += "PersistToMajority, ";
-        break;
+        return "PersistToMajority";
     }
-    desc += "timeout=" + to_string(r.getTimeout()) + "}";
-    return desc;
+    return "<invalid:" + std::to_string(int(l)) + ">";
 }
 
 Requirements::Requirements(cb::const_byte_buffer buffer) {