Currently, there are some useless includes in the codebase. We can use a tool named include-what-you-use to optimize these includes. By using a strict include-what-you-use policy, we can get lots of benefits from it.
Formerly S3FileWriter has to write each buffer with 5MB or more then upload one part, after all these works are done it could then process the incoming data, it's blocking and inefficient. This pr brings one bufferpool where the data could write into memory buffer immediately if has free buffer and then it would be uploaded into the S3.
This pr doesn't provide the ability to elegantly support cases where there is no free buffer, i'll leave it as one future work.
Follow #17586.
This PR mainly changes:
Remove env/
Remove FileUtils/FilesystemUtils
Some methods are moved to LocalFileSystem
Remove olap/file_cache
Add s3 client cache for s3 file system
In my test, the time of open s3 file can be reduced significantly
Fix cold/hot separation bug for s3 fs.
This is the last PR of #17764.
After this, all IO operation should be in io/fs.
Except for tests in #17586, I also tested some case related to fs io:
clone
concurrency query on local/s3/hdfs
load error log create and clean
disk metrics
