Added max_nesting_depth to csv_options

danielaparker · Jan 26, 2025 · ae3c018 · ae3c018
1 parent 4179f2b
commit ae3c018
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Showing 4 changed files with 31 additions and 1 deletion.
diff --git a/doc/ref/csv/basic_csv_options.md b/doc/ref/csv/basic_csv_options.md
@@ -16,6 +16,8 @@ Specifies options for reading and writing CSV data.
 
 Option|Reading|Writing
 ------|-------|----------
+flat (since 1.2.0)|&nbsp;|Indicates whether the encoder should process JSON as "flat" (without navigating through nested structures).
+max_nesting_depth (since 1.2.0)|&npsp;|Maximum nesting depth allowed in the input when encoding nested JSON to CSV 
 nan_to_str|Substitute string with `NaN`, if enabled|Sets a string replacement for `NaN` when writing JSON
 inf_to_str|Substitute string with `infinity`, if enabled|Sets a string replacement for infinity when writing JSON
 neginf_to_str|Substitute string with `negative infinity`, if enabled|Sets a string replacement for negative infinity when writing JSON

diff --git a/include/jsoncons_ext/csv/csv_encoder.hpp b/include/jsoncons_ext/csv/csv_encoder.hpp
@@ -106,6 +106,7 @@ class basic_csv_encoder final : public basic_json_visitor<CharT>
 
     Sink sink_;
     bool flat_;
+    std::size_t max_nesting_depth_;
     bool has_column_mapping_;
     bool has_column_names_;
     char_type field_delimiter_;
@@ -156,6 +157,7 @@ class basic_csv_encoder final : public basic_json_visitor<CharT>
         const Allocator& alloc = Allocator())
       : sink_(std::forward<Sink>(sink)),
         flat_(options.flat()),
+        max_nesting_depth_(options.max_nesting_depth()),
         has_column_mapping_(!options.column_mapping().empty()),
         has_column_names_(!options.column_names().empty()),
         field_delimiter_(options.field_delimiter()),
@@ -279,6 +281,11 @@ class basic_csv_encoder final : public basic_json_visitor<CharT>
             }
             return true;
         }
+        if (JSONCONS_UNLIKELY(stack_.size() >= max_nesting_depth_))
+        {
+            ec = csv_errc::max_nesting_depth_exceeded;
+            return false;
+        } 
 
         // legacy        
         if (has_column_names_ && stack_.back().count_ == 0)
@@ -498,6 +505,11 @@ class basic_csv_encoder final : public basic_json_visitor<CharT>
             }
             return true;
         }
+        if (JSONCONS_UNLIKELY(stack_.size() >= max_nesting_depth_))
+        {
+            ec = csv_errc::max_nesting_depth_exceeded;
+            return false;
+        }
         // legacy        
         if (has_column_names_ && stack_.back().count_ == 0)
         {

diff --git a/include/jsoncons_ext/csv/csv_error.hpp b/include/jsoncons_ext/csv/csv_error.hpp
@@ -22,7 +22,8 @@ namespace jsoncons { namespace csv {
         syntax_error,
         invalid_parse_state,
         invalid_escaped_char,
-        unexpected_char_between_fields
+        unexpected_char_between_fields,
+        max_nesting_depth_exceeded
     };
 
 class csv_error_category_impl
@@ -51,6 +52,8 @@ class csv_error_category_impl
                 return "Invalid character following quote escape character";
             case csv_errc::unexpected_char_between_fields:
                 return "Unexpected character between fields";
+            case csv_errc::max_nesting_depth_exceeded:
+                return "Data item nesting exceeds limit in options";
             default:
                 return "Unknown CSV parser error";
         }

diff --git a/include/jsoncons_ext/csv/csv_options.hpp b/include/jsoncons_ext/csv/csv_options.hpp
@@ -294,6 +294,7 @@ class basic_csv_options_common
     string_type neginf_to_str_;
     string_type column_names_;
     std::vector<std::pair<std::string,std::string>> column_mapping_; 
+    std::size_t max_nesting_depth_{1024};
 
 protected:
     basic_csv_options_common()
@@ -322,6 +323,11 @@ class basic_csv_options_common
         return flat_;
     }
 
+    std::size_t max_nesting_depth() const 
+    {
+        return max_nesting_depth_;
+    }
+
     char_type field_delimiter() const 
     {
         return field_delimiter_;
@@ -687,6 +693,7 @@ class basic_csv_options final : public basic_csv_decode_options<CharT>, public b
     using basic_csv_decode_options<CharT>::inf_to_num;
     using basic_csv_decode_options<CharT>::neginf_to_num;
     using basic_csv_decode_options<CharT>::flat;
+    using basic_csv_decode_options<CharT>::max_nesting_depth;
     using basic_csv_decode_options<CharT>::field_delimiter;
     using basic_csv_decode_options<CharT>::subfield_delimiter;
     using basic_csv_decode_options<CharT>::quote_char;
@@ -836,6 +843,12 @@ class basic_csv_options final : public basic_csv_decode_options<CharT>, public b
         return *this;
     }
 
+    basic_csv_options& max_nesting_depth(std::size_t value)
+    {
+        this->max_nesting_depth_ = value;
+        return *this;
+    }
+
     basic_csv_options& field_delimiter(char_type value)
     {
         this->field_delimiter_ = value;