Since Filesystem inherited std::enable_shared_from_this , it is dangerous to create native point of FileSystem.
To avoid this behavior, making the constructor of XxxFileSystem a private method and using the static method create(...) to get a new FileSystem object.
The main purpose of this pr is to import `fileCache` for lakehouse reading remote files.
Use the local disk as the cache for reading remote file, so the next time this file is read,
the data can be obtained directly from the local disk.
In addition, this pr includes a few other minor changes
Import File Cache:
1. The imported `fileCache` is called `block_file_cache`, which uses lru replacement policy.
2. Implement a new FileRereader `CachedRemoteFilereader`, so that the logic of `file cache` is hidden under `CachedRemoteFilereader`.
Other changes:
1. Add a new interface `fs()` for `FileReader`.
2. `IOContext` adds some statistical information to count the situation of `FileCache`
Co-authored-by: Lightman <31928846+Lchangliang@users.noreply.github.com>
Refactor the usage of file cache
### Motivation
There may be many kinds of file cache for different scenarios.
So the logic of the file cache should be hidden inside the file reader,
so that for the upper-layer caller, the change of the file cache does not need to
modify the upper-layer calling logic.
### Details
1. Add `FileReaderOptions` param for `fs->open_file()`, and in `FileReaderOptions`
1. `CachePathPolicy`
Determine the cache file path for a given file path.
We can implement different `CachePathPolicy` for different file cache.
2. `FileCacheType`
Specified file cache type: SUB_FILE_CACHE, WHOLE_FILE_CACHE, FILE_BLOCK_SIZE, etc.
2. Hide the cache logic inside the file reader.
The `RemoteFileSystem` will handle the `CacheOptions` and determine whether to
return a `CachedFileReader` or a `RemoteFileReader`.
And the file cache is managed by `CachedFileReader`
