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AQuery/engine/projection.py

132 lines
5.4 KiB

from engine.ast import ColRef, TableInfo, ast_node, Context, include
from engine.groupby import groupby
from engine.join import join
from engine.expr import expr
from engine.scan import filter
from engine.utils import base62uuid, enlist, base62alp
from engine.ddl import outfile
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
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]
print(node)
def spawn(self, node):
self.datasource = None
if 'from' in node:
from_clause = node['from']
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 'assumptions' in from_clause:
for assumption in enlist(from_clause['assumptions']):
ord = assumption['ord'] == 'asc'
attrib = assumption['attrib']
ord = '^' if ord else '|^'
# TODO: generate view of table by order
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.datasource = filter(self, node['where'], True).output
self.context.datasource = self.datasource
if 'groupby' in node:
self.group_node = groupby(self, node['groupby'])
else:
self.group_node = None
def consume(self, node):
disp_varname = 'd'+base62uuid(7)
pcolrefs = []
if type(self.group_node) is groupby:
grp_table = self.group_node.group
grp_refs = self.group_node.referenced
for i, proj in enumerate(self.projections):
self.datasource.rec = []
cname = ''
if type(proj) is dict:
if 'value' in proj:
e = proj['value']
if type(e) is str:
cname = self.datasource.parse_tablenames(proj['value'])
elif type(e) is dict:
cname = expr(self, e).k9expr
cname = ''.join([a if a in base62alp else '' for a in cname])
pcolrefs.append(self.datasource.rec)
self.datasource.rec = None
keys = 'k'+base62uuid(7)
self.emit(f'{keys}:!{grp_table}')
fn = 'fn' + base62uuid(6)
# self.emit
self.emit_no_ln(f'{disp_varname}:(')
flatten = False
cols = []
self.out_table = TableInfo('out_'+base62uuid(4), [], self.context)
if 'outfile' in node:
flatten = True
for i, proj in enumerate(self.projections):
cname = ''
if type(proj) is dict:
if 'value' in proj:
e = proj['value']
if type(e) is str:
cname = self.datasource.parse_tablenames(proj['value'])
self.emit_no_ln(f"{cname}")
elif type(e) is dict:
cname = expr(self, e).k9expr
self.emit_no_ln(f"{cname}")
cname = ''.join([a if a in base62alp else '' for a in cname])
self.emit_no_ln(';'if i < len(self.projections)-1 else '')
cols.append(ColRef(f'(+{disp_varname})[{i}]', 'generic', self.out_table, 0, None, cname, i))
self.emit(')')
if flatten:
self.emit_no_ln(f'{disp_varname}:' if flatten else '')
if flatten or self.disp:
if len(self.projections) > 1:
self.emit(f"+{disp_varname}")
else:
self.emit(f'+,(,{disp_varname})')
if flatten:
self.emit(f'{disp_varname}')
if flatten:
self.out_table.columns = cols
outfile(self, node['outfile'])
if self.datasource_changed:
self.context.datasource = self.prev_datasource
import sys
include(sys.modules[__name__])