Fix bug 39784090: Its no effect when decrease the datafile_size

.gitignore

@@ -106,3 +106,7 @@ cmake-build-release
 
 ###### OSX dir files
 .DS_Store
+
+###### Debug bin and configuration
+tools/deploy/bin
+tools/deploy/config2.py

src/sql/resolver/cmd/ob_alter_system_resolver.cpp

@@ -2299,6 +2299,12 @@ int ObSetConfigResolver::check_param_valid(int64_t tenant_id, const ObString& na
       }
 #endif
     }
+    else if (0 == name.case_compare("datafile_size")) {
+      if(OB_FAIL(OB_STORE_FILE.validate_datafile_size(value.ptr()))){
+        ret = OB_INVALID_CONFIG;
+        LOG_WARN("datafile_size is not valid", K(ret));
+      }
+    }
   }
   return ret;
 }

src/storage/blocksstable/ob_store_file.cpp

@@ -1349,6 +1349,30 @@ int ObStoreFile::resize_file(const int64_t new_data_file_size, const int64_t new
   return ret;
 }
 
+int ObStoreFile::validate_datafile_size(const char* config_data_file_size)
+{
+  int ret = OB_SUCCESS;
+  if (OB_ISNULL(store_file_system_)) {
+    ret = OB_ERR_UNEXPECTED;
+    LOG_WARN("The OB store file instance is not exist", K(ret));
+  } else {
+    bool valid = false;
+    int64_t new_data_file_size = ObConfigCapacityParser::get(config_data_file_size, valid);
+    if(!valid){
+      ret = OB_ERR_PARSE_SQL;
+      LOG_USER_ERROR(OB_INVALID_CONFIG, "datafile_size can not be parsed");
+    } else {
+      const int64_t original_file_size = store_file_system_->get_total_data_size();
+      if (new_data_file_size < original_file_size) {
+        ret = OB_ERR_UNEXPECTED;
+        LOG_WARN("datafile_size is smaller than the original configuration", K(ret));
+        LOG_USER_ERROR(OB_INVALID_CONFIG, "datafile_size can not be smaller than the original configuration");
+      }
+    }  
+  }
+  return ret;
+}
+
 int ObStoreFile::alloc_memory(const int64_t total_macro_block_cnt, uint32_t*& free_block_array,
     uint64_t*& macro_block_bitmap, ObSegmentArray<ObMacroBlockInfo>& macro_block_info_array)
 {

src/storage/blocksstable/ob_store_file.h

@@ -361,6 +361,7 @@ public:
   int drop_disk(const common::ObString& diskgroup_name, const common::ObString& alias_name);
   int is_free_block(const int64_t block_index, bool& is_free);
   int resize_file(const int64_t new_data_file_size, const int64_t new_data_file_disk_percentage);
+  int validate_datafile_size(const char* config_data_file_size);
 
 private:
   friend class ObStoreFileGCTask;