The broker scan node has two tuple descriptors:
One is dest tuple and the other is src tuple.
The src tuple is used to read the lines of the original file,
and the dest tuple is used to save the converted lines.
The preceding filter is executed on the src tuple, so src tuple descriptor should be used
to initialize the filter expression
Support conditional filtering of original data in broker load and routine load
eg:
```
LOAD LABEL `label1`
(
DATA INFILE ('bos://cmy-repo/1.csv')
INTO TABLE tbl2
COLUMNS TERMINATED BY '\t'
(event_day, product_id, ocpc_stage, user_id)
SET (
ocpc_stage = ocpc_stage + 100
)
PRECEDING FILTER user_id = 1381035
WHERE ocpc_stage > 30
)
...
```
We make all MemTrackers shared, in order to show MemTracker real-time consumptions on the web.
As follows:
1. nearly all MemTracker raw ptr -> shared_ptr
2. Use CreateTracker() to create new MemTracker(in order to add itself to its parent)
3. RowBatch & MemPool still use raw ptrs of MemTracker, it's easy to ensure RowBatch & MemPool destructor exec
before MemTracker's destructor. So we don't change these code.
4. MemTracker can use RuntimeProfile's counter to calc consumption. So RuntimeProfile's counter need to be shared
too. We add a shared counter pool to store the shared counter, don't change other counters of RuntimeProfile.
Note that, this PR doesn't change the MemTracker tree structure. So there still have some orphan trackers, e.g. RowBlockV2's MemTracker. If you find some shared MemTrackers are little memory consumption & too time-consuming, you could make them be the orphan, then it's fine to use the raw ptr.
* Add UserFunctionCache to cache UDF's library
This patch replace LibCache with UserFunctionCache. LibCache use HDFS
URL to identify a UDF's Library, and when BE process restart all of
downloaded library should be loaded another time. We use function id
corresponding to a library, and when process restart, all downloaded
libraries can be loaded without another downloading.
* update
