diff options
Diffstat (limited to 'generator/proto/__init__.py')
| -rw-r--r-- | generator/proto/__init__.py | 124 |
1 files changed, 101 insertions, 23 deletions
diff --git a/generator/proto/__init__.py b/generator/proto/__init__.py index e2e8000..cfab910 100644 --- a/generator/proto/__init__.py +++ b/generator/proto/__init__.py @@ -1,34 +1,37 @@ -'''This file automatically rebuilds the proto definitions for Python.''' +'''This file dynamically builds the proto definitions for Python.''' from __future__ import absolute_import +import os import os.path import sys - +import tempfile +import shutil +import traceback import pkg_resources - from ._utils import has_grpcio_protoc, invoke_protoc, print_versions -dirname = os.path.dirname(__file__) -protosrc = os.path.join(dirname, "nanopb.proto") -protodst = os.path.join(dirname, "nanopb_pb2.py") -rebuild = False +# Compatibility layer to make TemporaryDirectory() available on Python 2. +try: + from tempfile import TemporaryDirectory +except ImportError: + class TemporaryDirectory: + '''TemporaryDirectory fallback for Python 2''' + def __init__(self, prefix = 'tmp', dir = None): + self.prefix = prefix + self.dir = dir -if os.path.isfile(protosrc): - src_date = os.path.getmtime(protosrc) - if not os.path.isfile(protodst) or os.path.getmtime(protodst) < src_date: - rebuild = True + def __enter__(self): + self.dir = tempfile.mkdtemp(prefix = self.prefix, dir = self.dir) + return self.dir -if not rebuild: - try: - from . import nanopb_pb2 - except AttributeError as e: - rebuild = True - sys.stderr.write("Failed to import nanopb_pb2.py: " + str(e) + "\n" - "Will automatically attempt to rebuild this.\n" - "Verify that python-protobuf and protoc versions match.\n") - print_versions() + def __exit__(self, *args): + shutil.rmtree(self.dir) + +def build_nanopb_proto(protosrc, dirname): + '''Try to build a .proto file for python-protobuf. + Returns True if successful. + ''' -if rebuild: cmd = [ "protoc", "--python_out={}".format(dirname), @@ -40,11 +43,86 @@ if rebuild: # grpcio-tools has an extra CLI argument # from grpc.tools.protoc __main__ invocation. _builtin_proto_include = pkg_resources.resource_filename('grpc_tools', '_proto') - cmd.append("-I={}".format(_builtin_proto_include)) + try: invoke_protoc(argv=cmd) except: sys.stderr.write("Failed to build nanopb_pb2.py: " + ' '.join(cmd) + "\n") - raise + sys.stderr.write(traceback.format_exc() + "\n") + return False + + return True + +def load_nanopb_pb2(): + # To work, the generator needs python-protobuf built version of nanopb.proto. + # There are three methods to provide this: + # + # 1) Load a previously generated generator/proto/nanopb_pb2.py + # 2) Use protoc to build it and store it permanently generator/proto/nanopb_pb2.py + # 3) Use protoc to build it, but store only temporarily in system-wide temp folder + # + # By default these are tried in numeric order. + # If NANOPB_PB2_TEMP_DIR environment variable is defined, the 2) is skipped. + # If the value of the $NANOPB_PB2_TEMP_DIR exists as a directory, it is used instead + # of system temp folder. + + build_error = None + proto_ok = False + tmpdir = os.getenv("NANOPB_PB2_TEMP_DIR") + temporary_only = (tmpdir is not None) + dirname = os.path.dirname(__file__) + protosrc = os.path.join(dirname, "nanopb.proto") + protodst = os.path.join(dirname, "nanopb_pb2.py") + proto_ok = False + + if tmpdir is not None and not os.path.isdir(tmpdir): + tmpdir = None # Use system-wide temp dir + + if os.path.isfile(protosrc): + src_date = os.path.getmtime(protosrc) + if not os.path.isfile(protodst) or os.path.getmtime(protodst) < src_date: + # Outdated, rebuild + proto_ok = False + else: + try: + from . import nanopb_pb2 as nanopb_pb2_mod + proto_ok = True + except Exception as e: + sys.stderr.write("Failed to import nanopb_pb2.py: " + str(e) + "\n" + "Will automatically attempt to rebuild this.\n" + "Verify that python-protobuf and protoc versions match.\n") + print_versions() + + # Try to rebuild into generator/proto directory + if not proto_ok and not temporary_only: + proto_ok = build_nanopb_proto(protosrc, dirname) + + try: + from . import nanopb_pb2 as nanopb_pb2_mod + except: + sys.stderr.write("Failed to import generator/proto/nanopb_pb2.py:\n") + sys.stderr.write(traceback.format_exc() + "\n") + + # Try to rebuild into temporary directory + if not proto_ok: + with TemporaryDirectory(prefix = 'nanopb-', dir = tmpdir) as protodir: + proto_ok = build_nanopb_proto(protosrc, protodir) + + if protodir not in sys.path: + sys.path.insert(0, protodir) + + try: + import nanopb_pb2 as nanopb_pb2_mod + except: + sys.stderr.write("Failed to import %s/nanopb_pb2.py:\n" % protodir) + sys.stderr.write(traceback.format_exc() + "\n") + + # If everything fails + if not proto_ok: + sys.stderr.write("\n\nGenerating nanopb_pb2.py failed.\n") + sys.stderr.write("Make sure that a protoc generator is available and matches python-protobuf version.\n") + print_versions() + sys.exit(1) + return nanopb_pb2_mod |