#
# GAMS - General Algebraic Modeling System Python API
#
# Copyright (c) 2023 GAMS Development Corp. <support@gams.com>
# Copyright (c) 2023 GAMS Software GmbH <support@gams.com>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
from __future__ import annotations
import os
import shutil
import uuid
from typing import List
from typing import Optional
from typing import TYPE_CHECKING
from gams import DebugLevel
from gams import GamsEngineConfiguration
from gams import GamsJob
from gams import GamsOptions
from gams.control.workspace import GamsException
from gams.control.workspace import GamsExceptionExecution
from pydantic import BaseModel
import gamspy._backend.backend as backend
from gamspy.exceptions import GamspyException
from gamspy.exceptions import ValidationError
if TYPE_CHECKING:
import io
from gamspy import Container
from gamspy import Model
[docs]class EngineConfig(BaseModel):
host: str
username: Optional[str] = None
password: Optional[str] = None
jwt: Optional[str] = None
namespace: str = "global"
extra_model_files: List[str] = []
engine_options: Optional[dict] = None
remove_results: bool = False
class Config:
extra = "forbid"
def _get_engine_config(self):
return GamsEngineConfiguration(
self.host,
self.username,
self.password,
self.jwt,
self.namespace,
)
class GAMSEngine(backend.Backend):
def __init__(
self,
container: "Container",
config: "EngineConfig" | None,
options: "GamsOptions",
output: Optional[io.TextIOWrapper] = None,
model: Model | None = None,
) -> None:
if config is None:
raise ValidationError(
"`engine_config` must be provided to solve on GAMS Engine"
)
super().__init__(
container,
os.path.basename(container._gdx_in),
os.path.basename(container._gdx_out),
)
self.config = config
self.options = options
self.output = output
self.model = model
def is_async(self):
return False
def solve(self, is_implicit: bool = False, keep_flags: bool = False):
# Generate gams string and write modified symbols to gdx
gams_string, dirty_names = self.preprocess(keep_flags)
# Run the model
self.run(gams_string)
if self.is_async():
return None
# Synchronize GAMSPy with checkpoint and return a summary
summary = self.postprocess(dirty_names, is_implicit)
return summary
def run(self, gams_string: str):
extra_model_files = self._preprocess_extra_model_files()
checkpoint = None
if os.path.exists(self.container._restart_from._checkpoint_file_name):
checkpoint = self.container._restart_from
job = GamsJob(
self.container.workspace,
job_name=f"_job_{uuid.uuid4()}",
source=gams_string,
checkpoint=checkpoint,
)
try:
self.container._job = job
job.run_engine( # type: ignore
engine_configuration=self.config._get_engine_config(),
extra_model_files=extra_model_files,
gams_options=self.options,
checkpoint=self.container._save_to,
output=self.output,
create_out_db=False,
engine_options=self.config.engine_options,
remove_results=self.config.remove_results,
)
if not self.is_async() and self.model:
self.model._update_model_attributes()
except (GamsException, GamsExceptionExecution) as e:
if self.container._debugging_level == "keep_on_error":
self.container.workspace._debug = DebugLevel.KeepFiles
raise GamspyException(str(e))
finally:
self.container._unsaved_statements = []
self.container._delete_autogenerated_symbols()
def postprocess(self, dirty_names: List[str], is_implicit: bool = False):
self.container._load_records_from_gdx(
self.container._gdx_out,
dirty_names + self.container._import_symbols,
)
self.container._swap_checkpoints()
if (
self.config.remove_results
or self.options.traceopt != 3
or is_implicit
):
return None
return self.prepare_summary(
self.container.working_directory, self.options.trace
)
def _preprocess_extra_model_files(self) -> List[str]:
for extra_file in self.config.extra_model_files:
try:
shutil.copy(
extra_file, self.container.workspace.working_directory
)
except shutil.SameFileError:
# extra file might already be in the working directory
pass
extra_model_files = [
os.path.basename(extra_file)
for extra_file in self.config.extra_model_files
]
extra_model_files.append(self.gdx_in)
return extra_model_files
