Test ASAM ODS EXD-API Plugins#
Once you have created your (first) EXD-API Plugin, you can now do a simple test, if it will work in combination with an ASAM ODS server.
Therefore, the meta data will be read first (GetStructure) during the “Import Phase”; afterward the channel/bulk data (GetValues) is being accessed.
Prepare Python Environment to access GRPC Service#
import os
import pathlib
import grpc
from google.protobuf.json_format import MessageToJson
from odsbox.proto import ods_external_data_pb2
from odsbox.proto import ods_external_data_pb2_grpc
EXD-API#
The EXD-API Plugin is running as a RPC service at a given URL.
Running exd_api_server.py´will run the plugin at the given URL.
exd_api_plugin_url = "localhost:50051"
Import Phase#
We will open a MDF4 file using the EXD-API and extract the internal structure of the file to import it into the ASAM ODS server.
data_file_path = os.path.abspath("data/simple.mf4")
if not os.path.exists(data_file_path):
raise Exception("Data file is missing")
import_file_url = pathlib.Path(data_file_path).as_uri()
import_file_parameters = ""
print(import_file_url)
# Will be filled from Structure
access_file_url = None
access_file_parameters = None
file:///c:/Users/AKR/github/asam_ods_exd_api_mdf4/data/simple.mf4
Extract Infos from Structure#
The structure contains infos about groups and channels to create corresponding measurements, submatrices and measurement_quantities
with grpc.insecure_channel(exd_api_plugin_url) as channel:
stub = ods_external_data_pb2_grpc.ExternalDataReaderStub(channel)
# import file into ASAM ODS Server physical storage
import_identifier = ods_external_data_pb2.Identifier(url=import_file_url, parameters=import_file_parameters)
import_handle = stub.Open(import_identifier)
try:
structure = stub.GetStructure(ods_external_data_pb2.StructureRequest(handle=import_handle))
print(MessageToJson(structure))
access_file_url = structure.identifier.url
access_file_parameters = structure.identifier.parameters
for group in structure.groups:
group_id = group.id
for channel in group.channels:
channel_id = channel.id
finally:
stub.Close(import_handle)
{
"identifier": {
"url": "file:///c:/Users/AKR/github/asam_ods_exd_api_mdf4/data/simple.mf4",
"parameters": ""
},
"name": "simple.mf4",
"groups": [
{
"id": "0",
"name": "",
"totalNumberOfChannels": "10",
"numberOfRows": "563",
"channels": [
{
"id": "0",
"name": "time",
"dataType": "DT_DOUBLE",
"unitString": "s",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
""
]
}
}
}
}
},
{
"id": "1",
"name": "abs_time",
"dataType": "DT_LONGLONG",
"unitString": "ns",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
"absolute timestamp in nano seconds"
]
}
}
}
}
},
{
"id": "2",
"name": "acc_x",
"dataType": "DT_LONG",
"unitString": "mg",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
"acceleration x in millie gram"
]
}
}
}
}
},
{
"id": "3",
"name": "acc_y",
"dataType": "DT_LONG",
"unitString": "mg",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
"acceleration y in millie gram"
]
}
}
}
}
},
{
"id": "4",
"name": "acc_z",
"dataType": "DT_LONG",
"unitString": "mg",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
"acceleration z in millie gram"
]
}
}
}
}
},
{
"id": "5",
"name": "light",
"dataType": "DT_LONG",
"unitString": "-",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
"luminosity"
]
}
}
}
}
},
{
"id": "6",
"name": "temp",
"dataType": "DT_LONG",
"unitString": "degC",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
"temperature in degree celsius"
]
}
}
}
}
},
{
"id": "7",
"name": "comp_x",
"dataType": "DT_LONG",
"unitString": "nT",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
"compass x in nano tesla"
]
}
}
}
}
},
{
"id": "8",
"name": "comp_y",
"dataType": "DT_LONG",
"unitString": "nT",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
"compass y in nano tesla"
]
}
}
}
}
},
{
"id": "9",
"name": "comp_z",
"dataType": "DT_LONG",
"unitString": "nT",
"attributes": {
"variables": {
"description": {
"stringArray": {
"values": [
"compass z in nano tesla"
]
}
}
}
}
}
],
"attributes": {}
}
],
"attributes": {}
}
Access Bulk Data#
With the stored information the ASAM ODS server can access the bulk data from the EXD-API Plugin
with grpc.insecure_channel(exd_api_plugin_url) as channel:
stub = ods_external_data_pb2_grpc.ExternalDataReaderStub(channel)
# info from physical storage
access_group_id = 0
access_channel_ids = [0, 1, 2]
access_identifier = ods_external_data_pb2.Identifier(url=access_file_url, parameters=access_file_parameters)
# open bulk access
access_handle = stub.Open(access_identifier)
try:
request = ods_external_data_pb2.ValuesRequest(
handle=access_handle, group_id=access_group_id, channel_ids=access_channel_ids
)
# read first chunk
request.start = 0
request.limit = 3
values = stub.GetValues(request)
print(MessageToJson(values))
# read second chunk
request.start = 3
request.limit = 10
values = stub.GetValues(request)
print(MessageToJson(values))
finally:
stub.Close(access_handle)
{
"channels": [
{
"id": "0",
"values": {
"dataType": "DT_DOUBLE",
"unitId": "0",
"doubleArray": {
"values": [
0.0,
17905500.0,
30515300.0
]
}
}
},
{
"id": "1",
"values": {
"dataType": "DT_LONGLONG",
"unitId": "0",
"longlongArray": {
"values": [
"1686082945335777300",
"1686082945353682800",
"1686082945366292600"
]
}
}
},
{
"id": "2",
"values": {
"dataType": "DT_LONG",
"unitId": "0",
"longArray": {
"values": [
112,
112,
112
]
}
}
}
]
}
{
"channels": [
{
"id": "0",
"values": {
"dataType": "DT_DOUBLE",
"unitId": "0",
"doubleArray": {
"values": [
48317800.0,
66109300.0,
84173500.0,
101965900.0,
121611700.0,
138016000.0,
150423100.0,
168052100.0,
186278500.0,
203702900.0
]
}
}
},
{
"id": "1",
"values": {
"dataType": "DT_LONGLONG",
"unitId": "0",
"longlongArray": {
"values": [
"1686082945384095100",
"1686082945401886600",
"1686082945419950800",
"1686082945437743200",
"1686082945457389000",
"1686082945473793300",
"1686082945486200400",
"1686082945503829400",
"1686082945522055800",
"1686082945539480200"
]
}
}
},
{
"id": "2",
"values": {
"dataType": "DT_LONG",
"unitId": "0",
"longArray": {
"values": [
112,
112,
112,
112,
112,
112,
112,
112,
112,
112
]
}
}
}
]
}
License#
Copyright © 2024 Peak Solution GmbH
The training material in this repository is licensed under a Creative Commons BY-NC-SA 4.0 license. See LICENSE file for more information.