bug: the timestamp property value get from edge is not correct

[acezen]

Describe your problem

When there is a edge table which contains a timestamp property column. Iterate the edges and get the timestamp property values, the values are not correct.

Here is a test that can reproduce the problem. You can run the test follow:

# create a vineyard instance

# run the test with ipc_socket
./bin/arrow_fragment_timestamp_test /tmp/vineyard.sock 1  

the edges iteration output timestamp value in my environment:

I0325 17:06:18.228264 1235171 arrow_fragment_test.cc:152]   edge 0 0 timestamp 139644795977304
I0325 17:06:18.228277 1235171 arrow_fragment_test.cc:152]   edge 1 1 timestamp 94683640594048
I0325 17:06:18.228282 1235171 arrow_fragment_test.cc:152]   edge 2 2 timestamp 94683640594032
I0325 17:06:18.228287 1235171 arrow_fragment_test.cc:152]   edge 3 3 timestamp 0
I0325 17:06:18.228292 1235171 arrow_fragment_test.cc:152]   edge 4 4 timestamp 139622139058240
I0325 17:06:18.228297 1235171 arrow_fragment_test.cc:152]   edge 5 5 timestamp 33
I0325 17:06:18.228303 1235171 arrow_fragment_test.cc:152]   edge 6 6 timestamp 139644788192768
I0325 17:06:18.228312 1235171 arrow_fragment_test.cc:152]   edge 7 7 timestamp 8589934593
I0325 17:06:18.228318 1235171 arrow_fragment_test.cc:152]   edge 8 8 timestamp 94683640594472
I0325 17:06:18.228327 1235171 arrow_fragment_test.cc:152]   edge 9 9 timestamp 49

is not same with the initialized timestamp column in the beginning.

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If is is a bug report, to help us reproducing this bug, please provide information below:

1. Your Operation System version (uname -a): ubuntu20.04
2. The version of vineyard you use (vineyard.__version__): v0.21.5
3. Versions of crucial packages, such as gcc, numpy, pandas, etc.:
4. Full stack of the error (if there are a crash):
5. Minimized code to reproduce the error:

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What is the problem:

The behaviour that you expect to work:

Additional context

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