Add carquet_schema_node_type_length() for FIXED_LEN_BYTE_ARRAY support

Author: Vitruves

include/carquet/carquet.h

@@ -742,6 +742,20 @@ int16_t carquet_schema_node_max_def_level(const carquet_schema_node_t* node);
 CARQUET_API CARQUET_PURE CARQUET_NONNULL(1)
 int16_t carquet_schema_node_max_rep_level(const carquet_schema_node_t* node);
 
+/**
+ * @brief Get the type length for a FIXED_LEN_BYTE_ARRAY column.
+ *
+ * Returns the fixed byte length of each value. This is needed to allocate
+ * correctly sized buffers for carquet_column_read_batch().
+ *
+ * @param[in] node Schema node (must be a leaf)
+ * @return Type length in bytes, or 0 if not a FIXED_LEN_BYTE_ARRAY
+ *
+ * @note Thread-safe: Yes (read-only)
+ */
+CARQUET_API CARQUET_PURE CARQUET_NONNULL(1)
+int32_t carquet_schema_node_type_length(const carquet_schema_node_t* node);
+
 /* ============================================================================
  * Reader API
  * ============================================================================

src/metadata/schema.c

@@ -299,3 +299,9 @@ int16_t carquet_schema_node_max_rep_level(const carquet_schema_node_t* node) {
     const parquet_schema_element_t* elem = (const parquet_schema_element_t*)node;
     return (elem->repetition_type == CARQUET_REPETITION_REPEATED) ? 1 : 0;
 }
+
+int32_t carquet_schema_node_type_length(const carquet_schema_node_t* node) {
+    /* node is nonnull per API contract */
+    const parquet_schema_element_t* elem = (const parquet_schema_element_t*)node;
+    return elem->type_length;
+}