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AQuery/common/projection.py

180 lines
7.6 KiB

from common.ast import ColRef, TableInfo, ast_node, Context, include
from common.groupby import groupby
from common.join import join
from common.expr import expr
from common.orderby import assumption, orderby
from common.scan import filter
from common.utils import base62uuid, enlist, base62alp, has_other
from common.ddl import create_table, outfile
import copy
class projection(ast_node):
name='select'
def __init__(self, parent:ast_node, node, context:Context = None, outname = None, disp = True):
self.disp = disp
self.outname = outname
self.group_node = None
self.assumptions = None
self.where = None
ast_node.__init__(self, parent, node, context)
def init(self, _):
if self.outname is None:
self.outname = self.context.gen_tmptable()
def produce(self, node):
p = node['select']
self.projections = p if type(p) is list else [p]
self.context.Info(node)
def spawn(self, node):
self.datasource = None
if 'from' in node:
from_clause = node['from']['table_source']
if type(from_clause) is list:
# from joins
join(self, from_clause)
elif type(from_clause) is dict:
if 'value' in from_clause:
value = from_clause['value']
if type(value) is dict:
if 'select' in value:
# from subquery
projection(self, from_clause, disp = False)
else:
# TODO: from func over table
print(f'from func over table{node}')
elif type(value) is str:
self.datasource = self.context.tables_byname[value]
if 'name' in value:
self.datasource.add_alias(value['name'])
if 'assuming' in node['from']:
self.assumptions = enlist(node['from']['assuming'])
elif type(from_clause) is str:
self.datasource = self.context.tables_byname[from_clause]
if self.datasource is None:
raise ValueError('spawn error: from clause')
if self.datasource is not None:
self.datasource_changed = True
self.prev_datasource = self.context.datasource
self.context.datasource = self.datasource
if 'where' in node:
self.where = filter(self, node['where'], True)
# self.datasource = filter(self, node['where'], True).output
# self.context.datasource = self.datasource
if 'groupby' in node:
self.group_node = groupby(self, node['groupby'])
self.datasource = copy.copy(self.datasource) # shallow copy
self.datasource.groupinfo = self.group_node
else:
self.group_node = None
def consume(self, node):
self.inv = True
disp_varname = 'd'+base62uuid(7)
has_groupby = self.group_node is not None
cexprs = []
flatten = False
cols = []
self.out_table = TableInfo('out_'+base62uuid(4), [], self.context)
if 'outfile' in node:
flatten = True
new_names = []
proj_raw_cols = []
for i, proj in enumerate(self.projections):
cname = ''
compound = False
self.datasource.rec = set()
if type(proj) is dict:
if 'value' in proj:
e = proj['value']
sname = expr(self, e)
if type(sname.raw_col) is ColRef:
proj_raw_cols.append(sname.raw_col)
sname = sname._expr
fname = expr.toCExpr(sname) # fastest access method at innermost context
absname = expr(self, e, abs_col=True)._expr # absolute name at function scope
# TODO: Make it single pass here.
compound = True # compound column
cexprs.append(fname)
cname = e if type(e) is str else ''.join([a if a in base62alp else '' for a in expr.toCExpr(absname)()])
if 'name' in proj: # renaming column by AS keyword
cname = proj['name']
new_names.append(cname)
elif type(proj) is str:
col = self.datasource.get_col_d(proj)
if type(col) is ColRef:
col.reference()
compound = compound and has_groupby and has_other(self.datasource.rec, self.group_node.referenced)
self.datasource.rec = None
typename = f'decays<decltype({absname})>'
if not compound:
typename = f'value_type<{typename}>'
cols.append(ColRef(cname, expr.toCExpr(typename)(), self.out_table, 0, None, cname, i, compound=compound))
self.out_table.add_cols(cols, False)
lineage = None
if has_groupby:
create_table(self, self.out_table) # creates empty out_table.
if self.assumptions is not None:
self.assumptions = assumption(self, self.assumptions, exclude=self.group_node.raw_groups)
if not self.assumptions.empty():
self.group_node.deal_with_assumptions(self.assumptions, self.out_table)
self.assumptions = None
self.group_node.finalize(cexprs, self.out_table)
else:
# if all assumptions in projections, treat as orderby
lineage = self.assumptions is not None and has_other(self.assumptions, proj_raw_cols)
spawn = create_table(self, self.out_table, cexprs = cexprs, lineage = lineage) # create and populate out_table.
if lineage and type(spawn.lineage) is str:
lineage = spawn.lineage
self.assumptions = orderby(self, self.assumptions) # do not exclude proj_raw_cols
else:
lineage = None
if self.where is not None:
self.where.finalize()
if type(lineage) is str:
order = 'order_' + base62uuid(6)
self.emit(f'auto {order} = {self.datasource.cxt_name}->order_by<{self.assumptions.result()}>({lineage});')
self.emit(f'{self.out_table.cxt_name}->materialize(*{order});')
self.assumptions = None
if self.assumptions is not None:
orderby_node = orderby(self, self.assumptions)
else:
orderby_node = None
if 'orderby' in node:
self.datasource = self.out_table
self.context.datasource = self.out_table # discard current ds
orderbys = node['orderby']
orderby_node = orderby(self, orderbys) if orderby_node is None else orderby_node.merge(orderbys)
if orderby_node is not None:
self.emit(f'auto {disp_varname} = {self.out_table.reference()}->order_by_view<{orderby_node.result()}>();')
else:
disp_varname = f'*{self.out_table.cxt_name}'
if self.disp:
self.emit(f'print({disp_varname});')
if flatten:
outfile(self, node['outfile'])
if self.datasource_changed:
self.context.datasource = self.prev_datasource
import sys
include(sys.modules[__name__])