Add support for filesystem storage on Windows

[fujimotos]

Task Summary

Implement file-chunk storage support using Win32 API.

The goal is to make the following configuration "just work" on Windows platforms.

[SERVICE]
    flush                     1
    log_Level                 info
    storage.path              C:\FluentBit\Storage\
    storage.sync              normal
    storage.checksum          off
    storage.backlog.mem_limit 5M

Memo

• chunkio currently falls back to dummy implementation on Windows.
  • https://github.com/edsiper/chunkio/blob/master/CMakeLists.txt#L32
• Need to implement interfaces in chunkio/cio_file.h using Win32 API.
  • https://github.com/edsiper/chunkio/blob/master/src/cio_file.c

The biggest blockage is the lack of mmap() on Windows.
We need to find some way to share file data among multiple processes.

[fujimotos]

For those who interested in this feature: I started to tinker with
the code to implement this feature today.

[zlymeda]

any updates on this, pls?

[fujimotos]

This task is being tracked by #2738. Hopefully we can make it
into the next v1.7.0 release...

[fujimotos]

Update: The support PR is submitted to #2810 (and fluent/chunkio/pull/59).

[qingling128]

Any plan for a release that will include this change?

[fujimotos]

@qingling128 All the related patches are already in master.

I expect it to be included in the next v1.7.0 release (due February).

[qingling128]

I see. I guess because it's a new feature, it will not be backported to 1.6.*, right?

[fujimotos]

I see. I guess because it's a new feature, it will not be backported to 1.6.*, right?

@qingling128 Right. Since fluent/chunkio/pull/59 contains 1000+ LoC changes,
I don't expect it to be backported.

FWIW, this is the milestone page for the next v1.7 release:
https://github.com/fluent/fluent-bit/milestone/10

[qingling128]

Thanks for the info. That's very helpful!