Add extraction function support for Druid queries (apache#4740)

* add extraction fn support for Druid queries

* bump pydruid version to get extraction fn commits

* update and add tests for druid for filters with extraction fns

* conform to flake8 rules

* fix flake8 issues

* bump pyruid version for extraction function features

requirements.txt

@@ -22,7 +22,7 @@ pandas==0.22.0
 parsedatetime==2.0.0
 pathlib2==2.3.0
 polyline==1.3.2
-pydruid==0.4.1
+pydruid==0.4.2
 pyhive==0.5.0
 python-dateutil==2.6.1
 python-geohash==0.8.5

superset/connectors/druid/models.py

@@ -21,7 +21,8 @@
 from flask_babel import lazy_gettext as _
 from pydruid.client import PyDruid
 from pydruid.utils.aggregators import count
-from pydruid.utils.filters import Bound, Dimension, Filter
+from pydruid.utils.dimensions import MapLookupExtraction, RegexExtraction
+from pydruid.utils.filters import Dimension, Filter
 from pydruid.utils.having import Aggregation
 from pydruid.utils.postaggregator import (
     Const, Field, HyperUniqueCardinality, Postaggregator, Quantile, Quantiles,
@@ -960,8 +961,25 @@ def _add_filter_from_pre_query_data(self, df, dimensions, dim_filter):
             for unused, row in df.iterrows():
                 fields = []
                 for dim in dimensions:
-                    f = Dimension(dim) == row[dim]
-                    fields.append(f)
+                    f = None
+                    # Check if this dimension uses an extraction function
+                    # If so, create the appropriate pydruid extraction object
+                    if isinstance(dim, dict) and 'extractionFn' in dim:
+                        (col, extraction_fn) = DruidDatasource._create_extraction_fn(dim)
+                        dim_val = dim['outputName']
+                        f = Filter(
+                            dimension=col,
+                            value=row[dim_val],
+                            extraction_function=extraction_fn,
+                        )
+                    elif isinstance(dim, dict):
+                        dim_val = dim['outputName']
+                        if dim_val:
+                            f = Dimension(dim_val) == row[dim_val]
+                    else:
+                        f = Dimension(dim) == row[dim]
+                    if f:
+                        fields.append(f)
                 if len(fields) > 1:
                     term = Filter(type='and', fields=fields)
                     new_filters.append(term)
@@ -1065,7 +1083,9 @@ def _dimensions_to_values(dimensions):
         values = []
         for dimension in dimensions:
             if isinstance(dimension, dict):
-                if 'dimension' in dimension:
+                if 'extractionFn' in dimension:
+                    values.append(dimension)
+                elif 'dimension' in dimension:
                     values.append(dimension['dimension'])
             else:
                 values.append(dimension)
@@ -1132,7 +1152,7 @@ def run_query(  # noqa / druid
             intervals=self.intervals_from_dttms(from_dttm, to_dttm),
         )
 
-        filters = DruidDatasource.get_filters(filter, self.num_cols)
+        filters = DruidDatasource.get_filters(filter, self.num_cols, columns_dict)
         if filters:
             qry['filter'] = filters
 
@@ -1217,7 +1237,14 @@ def run_query(  # noqa / druid
 
                 pre_qry = deepcopy(qry)
                 pre_qry_dims = self._dimensions_to_values(qry['dimensions'])
-                pre_qry['dimensions'] = list(set(pre_qry_dims))
+
+                # Can't use set on an array with dicts
+                # Use set with non-dict items only
+                non_dict_dims = list(
+                    set([x for x in pre_qry_dims if not isinstance(x, dict)]),
+                )
+                dict_dims = [x for x in pre_qry_dims if isinstance(x, dict)]
+                pre_qry['dimensions'] = non_dict_dims + dict_dims
 
                 order_by = metrics[0] if metrics else pre_qry_dims[0]
 
@@ -1341,8 +1368,31 @@ def increment_timestamp(ts):
             query=query_str,
             duration=datetime.now() - qry_start_dttm)
 
+    @staticmethod
+    def _create_extraction_fn(dim_spec):
+        extraction_fn = None
+        if dim_spec and 'extractionFn' in dim_spec:
+            col = dim_spec['dimension']
+            fn = dim_spec['extractionFn']
+            ext_type = fn.get('type')
+            if ext_type == 'lookup' and fn['lookup'].get('type') == 'map':
+                replace_missing_values = fn.get('replaceMissingValueWith')
+                retain_missing_values = fn.get('retainMissingValue', False)
+                injective = fn.get('isOneToOne', False)
+                extraction_fn = MapLookupExtraction(
+                    fn['lookup']['map'],
+                    replace_missing_values=replace_missing_values,
+                    retain_missing_values=retain_missing_values,
+                    injective=injective,
+                )
+            elif ext_type == 'regex':
+                extraction_fn = RegexExtraction(fn['expr'])
+            else:
+                raise Exception(_('Unsupported extraction function: ' + ext_type))
+        return (col, extraction_fn)
+
     @classmethod
-    def get_filters(cls, raw_filters, num_cols):  # noqa
+    def get_filters(cls, raw_filters, num_cols, columns_dict):  # noqa
         """Given Superset filter data structure, returns pydruid Filter(s)"""
         filters = None
         for flt in raw_filters:
@@ -1354,21 +1404,42 @@ def get_filters(cls, raw_filters, num_cols):  # noqa
                     not op or
                     (eq is None and op not in ('IS NULL', 'IS NOT NULL'))):
                 continue
+
+            # Check if this dimension uses an extraction function
+            # If so, create the appropriate pydruid extraction object
+            column_def = columns_dict.get(col)
+            dim_spec = column_def.dimension_spec if column_def else None
+            extraction_fn = None
+            if dim_spec and 'extractionFn' in dim_spec:
+                (col, extraction_fn) = DruidDatasource._create_extraction_fn(dim_spec)
+
             cond = None
             is_numeric_col = col in num_cols
             is_list_target = op in ('in', 'not in')
             eq = cls.filter_values_handler(
                 eq, is_list_target=is_list_target,
                 target_column_is_numeric=is_numeric_col)
+
+            # For these two ops, could have used Dimension,
+            # but it doesn't support extraction functions
             if op == '==':
-                cond = Dimension(col) == eq
+                cond = Filter(dimension=col, value=eq, extraction_function=extraction_fn)
             elif op == '!=':
-                cond = Dimension(col) != eq
+                cond = ~Filter(dimension=col, value=eq, extraction_function=extraction_fn)
             elif op in ('in', 'not in'):
                 fields = []
                 # ignore the filter if it has no value
                 if not len(eq):
                     continue
+                # if it uses an extraction fn, use the "in" operator
+                # as Dimension isn't supported
+                elif extraction_fn is not None:
+                    cond = Filter(
+                        dimension=col,
+                        values=eq,
+                        type='in',
+                        extraction_function=extraction_fn,
+                    )
                 elif len(eq) == 1:
                     cond = Dimension(col) == eq[0]
                 else:
@@ -1378,20 +1449,58 @@ def get_filters(cls, raw_filters, num_cols):  # noqa
                 if op == 'not in':
                     cond = ~cond
             elif op == 'regex':
-                cond = Filter(type='regex', pattern=eq, dimension=col)
+                cond = Filter(
+                    extraction_function=extraction_fn,
+                    type='regex',
+                    pattern=eq,
+                    dimension=col,
+                )
+
+            # For the ops below, could have used pydruid's Bound,
+            # but it doesn't support extraction functions
             elif op == '>=':
-                cond = Bound(col, eq, None, alphaNumeric=is_numeric_col)
+                cond = Filter(
+                    type='bound',
+                    extraction_function=extraction_fn,
+                    dimension=col,
+                    lowerStrict=False,
+                    upperStrict=False,
+                    lower=eq,
+                    upper=None,
+                    alphaNumeric=is_numeric_col,
+                )
             elif op == '<=':
-                cond = Bound(col, None, eq, alphaNumeric=is_numeric_col)
+                cond = Filter(
+                    type='bound',
+                    extraction_function=extraction_fn,
+                    dimension=col,
+                    lowerStrict=False,
+                    upperStrict=False,
+                    lower=None,
+                    upper=eq,
+                    alphaNumeric=is_numeric_col,
+                )
             elif op == '>':
-                cond = Bound(
-                    col, eq, None,
-                    lowerStrict=True, alphaNumeric=is_numeric_col,
+                cond = Filter(
+                    type='bound',
+                    extraction_function=extraction_fn,
+                    lowerStrict=True,
+                    upperStrict=False,
+                    dimension=col,
+                    lower=eq,
+                    upper=None,
+                    alphaNumeric=is_numeric_col,
                 )
             elif op == '<':
-                cond = Bound(
-                    col, None, eq,
-                    upperStrict=True, alphaNumeric=is_numeric_col,
+                cond = Filter(
+                    type='bound',
+                    extraction_function=extraction_fn,
+                    upperStrict=True,
+                    lowerStrict=False,
+                    dimension=col,
+                    lower=None,
+                    upper=eq,
+                    alphaNumeric=is_numeric_col,
                 )
             elif op == 'IS NULL':
                 cond = Dimension(col) == None  # NOQA