def execute_query(query, default_graph_uri, next_link, dataset, mimetype, url):
"""Execute a query using the SageEngine and returns the appropriate HTTP response"""
graph_name = format_graph_uri(default_graph_uri, url)
if not dataset.has_graph(graph_name):
return sage_http_error(
"No RDF graph matching the default URI provided was found.")
graph = dataset.get_graph(graph_name)
# decode next_link or build query execution plan
cardinalities = dict()
start = time()
if next_link is not None:
plan = load(decode_saved_plan(next_link), dataset)
else:
plan, cardinalities = parse_query(query, dataset, graph_name, url)
loading_time = (time() - start) * 1000
# execute query
engine = SageEngine()
quota = graph.quota / 1000
max_results = graph.max_results
bindings, saved_plan, is_done = engine.execute(plan, quota, max_results)
# compute controls for the next page
start = time()
next_page = None
if not is_done:
next_page = encode_saved_plan(saved_plan)
exportTime = (time() - start) * 1000
stats = {
"cardinalities": cardinalities,
"import": loading_time,
"export": exportTime
}
# send response
if mimetype == "application/sparql-results+json":
return Response(responses.w3c_json_streaming(bindings, next_page,
stats, url),
content_type='application/json')
if mimetype == "application/xml" or mimetype == "application/sparql-results+xml":
return Response(responses.w3c_xml(bindings, next_page, stats),
content_type="application/xml")
if mimetype == "application/json":
return Response(responses.raw_json_streaming(bindings, next_page,
stats, url),
content_type='application/json')
# otherwise, return the HTML version
return render_template("sage_page.html",
query=query,
default_graph_uri=default_graph_uri,
bindings=bindings,
next_page=next_page,
stats=stats)
def sparql_query(graph_name):
"""WARNING: old API, deprecated"""
graph = dataset.get_graph(graph_name)
if graph is None:
abort(404)
logger.debug('[/sparql/] Corresponding dataset found')
mimetype = request.accept_mimetypes.best_match([
"application/json", "application/xml",
"application/sparql-results+json", "application/sparql-results+xml"
])
url = secure_url(request.url)
try:
# A GET request always returns the homepage of the dataset
if request.method == "GET" or (not request.is_json):
dinfo = graph.describe(url)
dinfo['@id'] = url
void_desc = {
"nt": VoidDescriptor(url, graph).describe("ntriples"),
"ttl": VoidDescriptor(url, graph).describe("turtle"),
"xml": VoidDescriptor(url, graph).describe("xml")
}
return render_template("website/sage_dataset.html",
dataset_info=dinfo,
void_desc=void_desc)
engine = SageEngine()
post_query, err = QueryRequest().load(request.get_json())
if err is not None and len(err) > 0:
return Response(format_marshmallow_errors(err), status=400)
quota = graph.quota / 1000
max_results = graph.max_results
# Load next link
next_link = None
if 'next' in post_query:
next_link = decode_saved_plan(post_query["next"])
# build physical query plan, then execute it with the given quota
start = time()
plan, cardinalities = build_query_plan(post_query["query"],
dataset, graph_name,
next_link)
loading_time = (time() - start) * 1000 # convert in milliseconds
bindings, saved_plan, is_done = engine.execute(
plan, quota, max_results)
# compute controls for the next page
start = time()
next_page = None
if not is_done:
next_page = encode_saved_plan(saved_plan)
exportTime = (time() - start) * 1000 # convert in milliseconds
stats = {
"cardinalities": cardinalities,
"import": loading_time,
"export": exportTime
}
if mimetype == "application/sparql-results+json":
res = Response(responses.w3c_json_streaming(
bindings, next_page, stats, url),
content_type='application/json')
if mimetype == "application/xml" or mimetype == "application/sparql-results+xml":
res = Response(responses.w3c_xml(bindings, next_page, stats),
content_type="application/xml")
else:
res = Response(responses.raw_json_streaming(
bindings, next_page, stats, url),
content_type='application/json')
# set deprecation warning in headers
res.headers.add(
"Warning",
"199 SaGe/2.0 \"You are using a deprecated API. Consider uppgrading to the SaGe SPARQL query API. See http://sage.univ-nantes.fr/documentation fore more details.\""
)
return res
except Exception as e:
logger.error(e)
abort(500)