amend

be/src/vec/functions/function_compress.cpp

@@ -16,6 +16,7 @@
 // under the License.
 #include <glog/logging.h>
 
+#include <array>
 #include <cctype>
 #include <cstddef>
 #include <cstring>
@@ -52,7 +53,8 @@ class FunctionContext;
 namespace doris::vectorized {
 
 class FunctionCompress : public IFunction {
-    string hex_itoc = "0123456789ABCDEF";
+    std::array<char, 16> hex_itoc = {'0', '1', '2', '3', '4', '5', '6', '7',
+                                     '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'};
 
 public:
     static constexpr auto name = "compress";
@@ -96,9 +98,6 @@ class FunctionCompress : public IFunction {
             size_t length = arg_offset[row] - arg_offset[row - 1];
             data = Slice(arg_begin + arg_offset[row - 1], length);
 
-            // Z_MEM_ERROR and Z_BUF_ERROR are already handled in compress, making sure st is always Z_OK
-            auto st = compression_codec->compress(data, &compressed_str);
-
             size_t idx = col_data.size();
             if (!length) { // data is ''
                 col_data.resize(col_data.size() + 2);
@@ -107,6 +106,9 @@ class FunctionCompress : public IFunction {
                 continue;
             }
 
+            // Z_MEM_ERROR and Z_BUF_ERROR are already handled in compress, making sure st is always Z_OK
+            auto st = compression_codec->compress(data, &compressed_str);
+
             // first ten digits represent the length of the uncompressed string
             col_data.resize(col_data.size() + 10 + 2 * compressed_str.size());
             col_data[idx] = '0', col_data[idx + 1] = 'x';