Add sanity_check API for ObNumber

deps/oblib/src/lib/number/ob_number_v2.h

@@ -184,6 +184,24 @@ public:
   // v2: algorithmic optimization edition
   // v3: engineering optimization edition
 
+  int sanity_check()
+  {
+    int ret = OB_SUCCESS;
+    if (d_.len_ > OB_MAX_DECIMAL_DIGIT) {
+      ret = OB_ERR_UNEXPECTED;
+      _OB_LOG(WARN, "Invalid digit len %u", d_.len_);
+    } else if (d_.len_ > 0 && digits_ != nullptr) {
+      for (auto i = 0; OB_SUCC(ret) && i < d_.len_; i++) {
+        if (digits_[i] >= BASE) {
+          ret = OB_ERR_UNEXPECTED;
+          _OB_LOG(WARN, "Invalid value %u", digits_[i]);
+        } else {
+          _OB_LOG(DEBUG, "Digit value %u", digits_[i]);
+        }
+      }
+    }
+    return ret;
+  }
   template <class T>
   int from(const int64_t value, T& allocator);
   template <class T>