[PATCH v4 10/14] box: introduce JSON indexes

[Vladimir Davydov]

On Thu, Oct 11, 2018 at 10:58:42AM +0300, Kirill Shcherbatov wrote:
> @@ -477,34 +833,39 @@ tuple_init_field_map(struct tuple_format *format, uint32_t *field_map,
>  	}
>  
>  	/* first field is simply accessible, so we do not store offset to it */
> -	enum mp_type mp_type = mp_typeof(*pos);
> -	const struct tuple_field *field = &format->fields[0];
> -	if (key_mp_type_validate(field->type, mp_type, ER_FIELD_TYPE,
> -				 TUPLE_INDEX_BASE, field->is_nullable))
> -		return -1;
> -	mp_next(&pos);
> -	/* other fields...*/
> -	++field;
> -	uint32_t i = 1;
> -	uint32_t defined_field_count = MIN(field_count, format->field_count);
> -	if (field_count < format->index_field_count) {
> +	struct tuple_field *field = &format->fields[0];
> +	uint32_t i = 0;
> +	if (field_count < format->index_field_count ||
> +	    json_tree_node_children_count(&field->path_tree_node) == 0) {
>  		/*
> -		 * Nullify field map to be able to detect by 0,
> -		 * which key fields are absent in tuple_field().
> -		 */
> +		* Nullify field map to be able to detect by 0,
> +		* which key fields are absent in tuple_field().
> +		*/
>  		memset((char *)field_map - format->field_map_size, 0,
> -		       format->field_map_size);
> +		format->field_map_size);
>  	}
> -	for (; i < defined_field_count; ++i, ++field) {
> -		mp_type = mp_typeof(*pos);
> +	if (json_tree_node_children_count(&field->path_tree_node) == 0) {
> +		enum mp_type mp_type = mp_typeof(*pos);
>  		if (key_mp_type_validate(field->type, mp_type, ER_FIELD_TYPE,
> -					 i + TUPLE_INDEX_BASE,
> -					 field->is_nullable))
> +					TUPLE_INDEX_BASE, field->is_nullable))
> +			return -1;
> +		mp_next(&pos);
> +		++field;
> +		++i;
> +	}
> +	size_t off_stack_size =
> +		format->max_path_tree_depth * sizeof(const char *);
> +	const char **off_stack = region_alloc(&fiber()->gc, off_stack_size);
> +	if (off_stack == NULL) {
> +		diag_set(OutOfMemory, off_stack_size, "region_alloc",
> +			"off_stack");
> +		return -1;
> +	}
> +	uint32_t defined_field_count = MIN(field_count, format->field_count);
> +	for (; i < defined_field_count; ++i, ++field) {
> +		if (tuple_field_tree_parse_raw(field, pos, tuple, i, field_map,
> +					       off_stack) != 0)
>  			return -1;
> -		if (field->offset_slot != TUPLE_OFFSET_SLOT_NIL) {
> -			field_map[field->offset_slot] =
> -				(uint32_t) (pos - tuple);
> -		}
>  		mp_next(&pos);
>  	}
>  	return 0;

> @@ -108,6 +109,10 @@ struct tuple_field {
>  	bool is_key_part;
>  	/** True, if a field can store NULL. */
>  	bool is_nullable;
> +	/** JSON path tree max depth. */
> +	uint32_t path_tree_depth;
> +	/** JSON root path tree node for registered indexes. */
> +	struct json_tree_node path_tree_node;
>  };

For the record. After discussion with Kostja, we agreed that a json tree
should be rooted at struct tuple_format rather than tuple_field so that
top level fields are accessed in the same fashion as nested fields.

Also, a tuple field map should be initialized as msgpack gets parsed
rather than walking over a json tree and looking up fields in msgpack,
because that would be more efficient.