|
1
|
|
|
from asyncua import ua |
|
2
|
|
|
|
|
3
|
|
|
class UaFile: |
|
4
|
|
|
def __init__(self, file_node): |
|
5
|
|
|
self._file_node = file_node |
|
6
|
|
|
|
|
7
|
|
|
async def open(self, open_mode): |
|
8
|
|
|
""" open file method """ |
|
9
|
|
|
open_node = await self._file_node.get_child("Open") |
|
10
|
|
|
arg = ua.Variant(open_mode, ua.VariantType.Byte) |
|
11
|
|
|
return await self._file_node.call_method(open_node, arg) |
|
12
|
|
|
|
|
13
|
|
|
async def get_size(self): |
|
14
|
|
|
""" gets size of file """ |
|
15
|
|
|
size_node = await self._file_node.get_child("Size") |
|
16
|
|
|
return await size_node.read_value() |
|
17
|
|
|
|
|
18
|
|
|
async def close(self, handle): |
|
19
|
|
|
""" close file method """ |
|
20
|
|
|
read_node = await self._file_node.get_child("Close") |
|
21
|
|
|
arg1 = ua.Variant(handle, ua.VariantType.UInt32) |
|
22
|
|
|
return await self._file_node.call_method(read_node, arg1) |
|
23
|
|
|
|
|
24
|
|
|
async def read(self, handle, size): |
|
25
|
|
|
""" |
|
26
|
|
|
:param handle: handle from open() |
|
27
|
|
|
:param size: size of file from from get_size() |
|
28
|
|
|
""" |
|
29
|
|
|
read_node = await self._file_node.get_child("Read") |
|
30
|
|
|
arg1 = ua.Variant(handle, ua.VariantType.UInt32) |
|
31
|
|
|
arg2 = ua.Variant(size, ua.VariantType.Int32) |
|
32
|
|
|
return await self._file_node.call_method(read_node, arg1, arg2) |
|
33
|
|
|
|
|
34
|
|
|
async def read_once(self): |
|
35
|
|
|
""" open, read, close in one operation """ |
|
36
|
|
|
handle = await self.open(ua.OpenFileMode.Read.value) |
|
37
|
|
|
size = await self.get_size() |
|
38
|
|
|
contents = await self.read(handle, size) |
|
39
|
|
|
await self.close(handle) |
|
40
|
|
|
return contents |
|
41
|
|
|
|
FreeOpcUa /
opcua-asyncio
