feat: update cloudstorageconfiguration to improve copy accross cross-bucket performance

[suraj-qlogic]

Fixes #60

[codecov]

Codecov Report

Merging #168 into master will increase coverage by 0.66%.
The diff coverage is 88.23%.

@@             Coverage Diff              @@
##             master     #168      +/-   ##
============================================
+ Coverage     71.13%   71.79%   +0.66%     
- Complexity      481      495      +14     
============================================
  Files            29       29              
  Lines          1642     1656      +14     
  Branches        265      268       +3     
============================================
+ Hits           1168     1189      +21     
+ Misses          348      342       -6     
+ Partials        126      125       -1     

Impacted Files	Coverage Δ	Complexity Δ
...ud/storage/contrib/nio/CloudStorageFileSystem.java	72.60% <88.23%> (+6.50%)	36.00 <9.00> (+9.00)
...ge/contrib/nio/CloudStorageFileSystemProvider.java	62.91% <0.00%> (+0.46%)	76.00% <0.00%> (+3.00%)
...age/contrib/nio/SeekableByteChannelPrefetcher.java	66.25% <0.00%> (+3.12%)	23.00% <0.00%> (+2.00%)

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[elharo]

IOException should fail test; i.e. don't catch it

[suraj-qlogic]

Done

[dmitry-fa]

Your change does not fix the original issue which requests not creating a new CloudStorageFileSystem for a bucket and a provider, if such file system has been already created.

To achieve that you need to remember all created file systems and before creating a new one in the forBucket() method do search among previously created.

The code could look like:

private static final Map<String, CloudStorageFileSystem> fileSystemMap = new HashMap<>();
...

public static CloudStorageFileSystem forBucket(
      String bucket, CloudStorageConfiguration config, @Nullable StorageOptions storageOptions) {
   ...
   CloudStorageFileSystem  existing = getExisitngCloudStorageFileSystem(bucket, config, storageOptions);
   if (existing == null) {
      exiting = new CloudStorageFileSystem (bucket, config, storageOptions);
      fileSystemMap.put(bucket, existing);
   }
   return existing;
}

[dmitry-fa]

Method name getExistingCloudStorageConfiguration implies returning existing configuration, you return FileSystem and create it each time.

[suraj-qlogic]

Done

[dmitry-fa]

this.cloudStorageFileSystem = this does not work as you probably expect. Each time a new CloudStorageFileSystem object is created the static field cloudStorageFileSystem will be overridden.

[suraj-qlogic]

Done

[suraj-qlogic]

@dmitry-fa @frankyn ,PTAL

[dmitry-fa]

Looks good to me, thanks for addressing all my comments. Please wait for a review from a Googler

[suraj-qlogic]

@frankyn ,gentle ping