slurp_utils.py

import sys
from contextlib import AbstractContextManager

from ShExJSG import ShExJ
from rdflib import Graph
from sparqlslurper import SlurpyGraph

from pyshex.shape_expressions_language.p5_context import Context
from pyshex.shapemap_structure_and_language.p1_notation_and_terminology import Node


class slurper(AbstractContextManager):

    def __init__(self, cntxt: Context, n: Node, S: ShExJ.Shape):
        self.graph: SlurpyGraph = cntxt.graph
        self.tracing = isinstance(self.graph, SlurpyGraph) and cntxt.debug_context.trace_slurps
        self.n = n
        self.S = S

    def __enter__(self) -> Graph:
        if self.tracing:
            self.g_triples = self.graph.total_triples
            self.g_time = self.graph.total_slurptime
            print(f"# ← <{self.n}>@{self.S.id} ", end="")
            sys.stdout.flush()
        return self.graph

    def __exit__(self, exctype, excinst, exctb):
        if self.tracing:
            new_triples = self.graph.total_triples - self.g_triples
            if new_triples:
                print(f" {new_triples} triples "
                      f"({int((self.graph.total_slurptime - self.g_time) * 1000)} μs)")
            else:
                print(f" (Cached)")