Use a macro for cases

NonVolatileComputing · Aug 24, 2017 · 535f9ff · 535f9ff
1 parent 1cc43ce
commit 535f9ff
Showing 1 changed file with 13 additions and 22 deletions.
diff --git a/cpp/src/arrow/array.cc b/cpp/src/arrow/array.cc
@@ -367,34 +367,25 @@ DecimalArray::DecimalArray(const std::shared_ptr<DataType>& type, int64_t length
       std::make_shared<ArrayData>(type, length, std::move(buffers), null_count, offset));
 }
 
-const uint8_t* DecimalArray::GetValue(int64_t i) const {
-  return raw_values_ + (i + data_->offset) * byte_width();
-}
+#define DECIMAL_TO_STRING_CASE(bits, bytes, precision, scale) \
+  case bits: {                                                \
+    decimal::Decimal##bits value;                             \
+    decimal::FromBytes((bytes), &value);                      \
+    return decimal::ToString(value, (precision), (scale));    \
+  }
 
 std::string DecimalArray::FormatValue(int64_t i) const {
   const auto& type_ = static_cast<const DecimalType&>(*type());
   const int precision = type_.precision();
   const int scale = type_.scale();
-  const int byte_width = type_.byte_width();
-  const uint8_t* bytes = raw_values_ + (i + data_->offset) * byte_width;
-  switch (byte_width) {
-    case 4: {
-      decimal::Decimal32 value;
-      decimal::FromBytes(bytes, &value);
-      return decimal::ToString(value, precision, scale);
-    }
-    case 8: {
-      decimal::Decimal64 value;
-      decimal::FromBytes(bytes, &value);
-      return decimal::ToString(value, precision, scale);
-    }
-    case 16: {
-      decimal::Decimal128 value;
-      decimal::FromBytes(bytes, &value);
-      return decimal::ToString(value, precision, scale);
-    }
+  const int bit_width = type_.bit_width();
+  const uint8_t* bytes = GetValue(i);
+  switch (bit_width) {
+    DECIMAL_TO_STRING_CASE(32, bytes, precision, scale)
+    DECIMAL_TO_STRING_CASE(64, bytes, precision, scale)
+    DECIMAL_TO_STRING_CASE(128, bytes, precision, scale)
     default: {
-      DCHECK(false) << "Invalid byte width: " << byte_width;
+      DCHECK(false) << "Invalid bit width: " << bit_width;
       return "";
     }
   }