refractor DataTypeArray from_string, make it more clear;
support ',' and ']' inside string element, for example: ['hello,,,', 'world][]']
support empty elements, such as [,] ==> [0,0]
Co-authored-by: cambyzju <zhuxiaoli01@baidu.com>
Issue Number: close#12574
This pr adds `NewJsonReader` which implements GenericReader interface to support read json format file.
TODO:
1. modify `_scann_eof` later.
2. Rename `NewJsonReader` to `JsonReader` when `JsonReader` is deleted.
1. remove FE config `enable_array_type`
2. limit the nested depth of array in FE side.
3. Fix bug that when loading array from parquet, the decimal type is treated as bigint
4. Fix loading array from csv(vec-engine), handle null and "null"
5. Change the csv array loading behavior, if the array string format is invalid in csv, it will be converted to null.
6. Remove `check_array_format()`, because it's logic is wrong and meaningless
7. Add stream load csv test cases and more parquet broker load tests
1. Refactor the file reader creation in FileFactory, for simplicity.
Previously, FileFactory had too many `create_file_reader` interfaces.
Now unified into two categories: the interface used by the previous BrokerScanNode,
and the interface used by the new FileScanNode.
And separate the creation methods of readers that read `StreamLoadPipe` and other readers that read files.
2. Modify the StreamLoadPlanner on FE side to support using ExternalFileScanNode
3. Now for generic reader, the file reader will be created inside the reader, not passed from the outside.
4. Add some test cases for csv stream load, the behavior is same as the old broker scanner.
when config::enable_simdjson_parser=true in vec streamload, may lead to core dump when json input invalid format string like '{ "a', or all the fields is null like '{}', this may lead to simdjson lib throw some unhandled expection like `Objects and arrays can only be iterated when they are first encountered`.We should take care of these cases
Signed-off-by: eldenmoon <15605149486@163.com>
