aboutsummaryrefslogtreecommitdiffstats
path: root/runtime/solvers/mzn/mzn_solver.py
blob: f3daa2bdb4719aecb628db4dc8c34774d10e43c3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
# -------------------------------------------------------------------------
#   Copyright (c) 2020 AT&T Intellectual Property
#
#   Licensed under the Apache License, Version 2.0 (the "License");
#   you may not use this file except in compliance with the License.
#   You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
#   Unless required by applicable law or agreed to in writing, software
#   distributed under the License is distributed on an "AS IS" BASIS,
#   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#   See the License for the specific language governing permissions and
#   limitations under the License.
#
# -------------------------------------------------------------------------
#

from datetime import datetime
import json

from pymzn import cbc
from pymzn import chuffed
from pymzn import gecode
from pymzn import minizinc
from pymzn import or_tools
from pymzn import Status

from osdf.utils.file_utils import delete_file_folder

error_status_map = {
    Status.INCOMPLETE: "incomplete",
    Status.COMPLETE: "complete",
    Status.UNSATISFIABLE: "unsatisfiable",
    Status.UNKNOWN: "unknown",
    Status.UNBOUNDED: "unbounded",
    Status.UNSATorUNBOUNDED: "unsat_or_unbounded",
    Status.ERROR: "error"
}

solver_dict = {
    'cbc': cbc,
    'geocode': gecode,
    'chuffed': chuffed,
    'cp': chuffed,
    'or_tools': or_tools
}


def map_status(status):
    return error_status_map.get(status, "failed")


def solve(request_json, mzn_content):
    """Given the request and minizinc content.  Translates the json request to the format minizinc understands

    return: returns the optimized solution.
    """
    req_info = request_json['requestInfo']
    opt_info = request_json['optimInfo']
    try:
        mzn_solution = mzn_solver(mzn_content, opt_info)

        response = {
            'transactionId': req_info['transactionId'],
            'requestID': req_info['requestID'],
            'requestStatus': 'done',
            'statusMessage': map_status(mzn_solution.status),
            'solutions': mzn_solution[0] if mzn_solution else {}
        }
        return 200, json.dumps(response)
    except Exception as e:
        response = {
            'transactionId': req_info['transactionId'],
            'requestID': req_info['requestID'],
            'requestStatus': 'failed',
            'statusMessage': 'Failed due to {}'.format(e)
        }
        return 400, json.dumps(response)


def mzn_solver(mzn_content, opt_info):
    """Calls the minizinc optimizer.

    """
    args = opt_info['solverArgs']
    solver = get_mzn_solver(args.pop('solver'))
    mzn_opts = dict()

    try:
        file_name = persist_opt_data(opt_info)
        mzn_opts.update(args)
        return minizinc(mzn_content, file_name, **mzn_opts, solver=solver)

    finally:
        delete_file_folder(file_name)


def persist_opt_data(opt_info):
    """Persist the opt data, if included as part of the request.

    return: file_name path of the optim_data
            returns None if no optData is part of the request
    """
    file_name = None
    if 'optData' in opt_info:
        if opt_info['optData'].get('json'):
            data_content = json.dumps(opt_info['optData']['json'])
            file_name = '/tmp/optim_engine_{}.json'.format(datetime.timestamp(datetime.now()))
            persist_data(data_content, file_name)
        elif opt_info['optData'].get('text'):
            data_content = opt_info['optData']['text']
            file_name = '/tmp/optim_engine_{}.dzn'.format(datetime.timestamp(datetime.now()))
            persist_data(data_content, file_name)
    return file_name


def persist_data(data_content, file_name):
    """Save the dzn data into a file

    """
    with open(file_name, "wt") as data:
        data.write(data_content)


def get_mzn_solver(solver):
    """Returns a solver type object for minizinc optimizers

    solver: solver that is part of the request
    return: solver mapped object
    """
    return solver_dict.get(solver)