make chunkSize a parameter

[kevin-lot]

I have some issues with old (and maybe bad) servers.

Through a VPN when sending files, the only way to make an upload work without stopping it during the progress is to change the chunksize. I did it "hard" in the library source code, but with this branch, I could more easily set it.

I don't have much knowledge about network, and I don't know if I respect or not a standard or a convention with this branch.

But here is my little contribution.

[codecov[bot]]

Codecov Report

Merging #59 (00ce0fa) into master (f872cc2) will decrease coverage by 11.34%. The diff coverage is 0.00%.

:exclamation: Current head 00ce0fa differs from pull request most recent head 354f533. Consider uploading reports for the commit 354f533 to get more accurate results

@@             Coverage Diff             @@
##           master      #59       +/-   ##
===========================================
- Coverage   44.08%   32.75%   -11.34%     
===========================================
  Files          55       52        -3     
  Lines        3974     3774      -200     
===========================================
- Hits         1752     1236      -516     
- Misses       2222     2538      +316     

Impacted Files	Coverage Δ
lib/src/sftp/sftp_client.dart	0.00% <0.00%> (-26.67%)	:arrow_down:
lib/src/sftp/sftp_stream_io.dart	0.00% <0.00%> (-86.21%)	:arrow_down:
lib/src/sftp/sftp_request_id.dart	0.00% <0.00%> (-100.00%)	:arrow_down:
lib/src/utils/async_queue.dart	0.00% <0.00%> (-66.67%)	:arrow_down:
lib/src/utils/stream.dart	0.00% <0.00%> (-65.91%)	:arrow_down:
lib/src/ssh_channel_id.dart	8.33% <0.00%> (-58.34%)	:arrow_down:
lib/src/sftp/sftp_file_open_mode.dart	50.00% <0.00%> (-50.00%)	:arrow_down:
lib/src/ssh_channel.dart	0.00% <0.00%> (-47.90%)	:arrow_down:
lib/src/utils/int.dart	28.57% <0.00%> (-28.58%)	:arrow_down:
... and 12 more

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[kevin-lot]

@xtyxtyx What's next, regarding the coverage ?

[xtyxtyx]

SO sorry for the delayed response. I just got too many things to do at work...

Do you know the version of SSH server (for example OpenSSH_9.0p1) and VPN server that you have problems with when using dartssh2 ? From the specification it should be safe to set chunk size up to 32768 bytes. So I guess there may be other problems that causes the issue you encountered.

[kevin-lot]

I will look for the SSH version soon.

However, it's going to be difficult regarding the VPN features, I already know it's a Cisco product called Anyconnect. I would try to find logs in this software.

For information, without this modification, the file upload does not work, it stops in progress.

[kevin-lot]

I rebased this branch. But I saw so many updates.

Can you explain the goal of "resume/pause" in "_handleLocalData" ? It seems that this PR becomes useless. I'm going to try the new version to see if it's fixed my issues.