trustgraph/trustgraph-base/trustgraph/base/triples_query_service.py
2026-04-16 10:10:58 +01:00

128 lines
3.8 KiB
Python

"""
Triples query service. Input is a (s, p, o) triple, some values may be
null. Output is a list of triples.
"""
from __future__ import annotations
from argparse import ArgumentParser
import logging
from .. schema import TriplesQueryRequest, TriplesQueryResponse, Error
from .. schema import Term, Triple
from . flow_processor import FlowProcessor
from . consumer_spec import ConsumerSpec
from . producer_spec import ProducerSpec
# Module logger
logger = logging.getLogger(__name__)
default_ident = "triples-query"
default_concurrency = 10
class TriplesQueryService(FlowProcessor):
def __init__(self, **params):
id = params.get("id")
concurrency = params.get("concurrency", default_concurrency)
super(TriplesQueryService, self).__init__(**params | { "id": id })
self.register_specification(
ConsumerSpec(
name = "request",
schema = TriplesQueryRequest,
handler = self.on_message,
concurrency = concurrency,
)
)
self.register_specification(
ProducerSpec(
name = "response",
schema = TriplesQueryResponse,
)
)
async def on_message(self, msg, consumer, flow):
try:
request = msg.value()
# Sender-produced ID
id = msg.properties()["id"]
logger.debug(f"Handling triples query request {id}...")
if request.streaming:
# Streaming mode: send batches
async for batch, is_final in self.query_triples_stream(request):
r = TriplesQueryResponse(
triples=batch,
error=None,
is_final=is_final,
)
await flow("response").send(r, properties={"id": id})
logger.debug("Triples query streaming completed")
else:
# Non-streaming mode: single response
triples = await self.query_triples(request)
logger.debug("Sending triples query response...")
r = TriplesQueryResponse(triples=triples, error=None)
await flow("response").send(r, properties={"id": id})
logger.debug("Triples query request completed")
except Exception as e:
logger.error(f"Exception in triples query service: {e}", exc_info=True)
logger.info("Sending error response...")
r = TriplesQueryResponse(
error = Error(
type = "triples-query-error",
message = str(e),
),
triples = None,
)
await flow("response").send(r, properties={"id": id})
async def query_triples_stream(self, request):
"""
Streaming query - yields (batch, is_final) tuples.
Default implementation batches results from query_triples.
Override for true streaming from backend.
"""
triples = await self.query_triples(request)
batch_size = request.batch_size if request.batch_size > 0 else 20
for i in range(0, len(triples), batch_size):
batch = triples[i:i + batch_size]
is_final = (i + batch_size >= len(triples))
yield batch, is_final
# Handle empty result
if len(triples) == 0:
yield [], True
@staticmethod
def add_args(parser: ArgumentParser) -> None:
FlowProcessor.add_args(parser)
parser.add_argument(
'-c', '--concurrency',
type=int,
default=default_concurrency,
help=f'Number of concurrent requests (default: {default_concurrency})'
)
def run() -> None:
Processor.launch(default_ident, __doc__)