Buckets Operations

[indianwhocodes]

Description

This is the current dev branch for Buckets that I have been working on which consists of operations (API calls) that MantaClient within the Java SDK will eventually support once it's past the testing phase.

NOTE: #544 is currently not review-ready but proactive feedback while I am still working on it will be very much appreciated.

Manta Java SDK Operations

Citing RFD#155, the operations for buckets are as follows:

• create bucket.
• list buckets.
• delete bucket.
• head bucket.
• move bucket.
• list objects.
• head object.
• put object(s).
• get object(s).
• delete object(s).

Note: Some complex operations will be potentially included in later stages:

• destroy bucket
• check whether bucket is empty.

AWS S3 Java SDK Buckets Operations:

• s3.createBucket(bucket_name).
• s3.listBuckets().
• s3.deleteBucket(bucket_name).
• s3.doesBucketExist(bucket_name).
• s3.listObjects(bucket_name).
• s3.putObject(bucket_name, key_name, new File(file_path)).
• s3.getObject(bucket_name, key_name).
• s3.deleteObject(bucket_name, summary.getKey()).
• s3.deleteObjects(deleteObjectRequest).
• s3.copyObject(from_bucket, object_key, to_bucket, object_key).

Waiting on Headers Support from Server-Side

This PR is waiting on headers support from the server-side which are integral to supporting some of thebucket-operations the have currently been added to the Java SDK

[dekobon]

I just noticed that in MantaClient:418, the *bucket methods are under the section:

    /* ======================================================================
     * Object Access
     * ====================================================================== */

That doesn't seem to harmonize with the existing code well.

Additionally, the string in the rawPath validation on MantaClient:441 doesn't make sense:

    public boolean createBucket(final String rawPath, final MantaHttpHeaders rawHeaders)
            throws IOException {
        Validate.notBlank(rawPath, "CREATE bucket must not be empty nor null");

You are validating rawPath. How would that message be helpful to a user of the SDK to understand that the path provided was in an invalid format?

In MantaClient:534, this catch is confusing:

            } catch (ConnectionPoolTimeoutException e) {
                LOG.debug("{} for deleting bucket {}", e.getMessage(), path);
            } catch (IOException e) {
                throw new UncheckedIOException(e);
            }

1. Why do you not bubble up an error for the timeout exception? In this case, the operation never completed successfully. What behavior were you expecting to happen as a user of the SDK?
2. The log message {} for deleting bucket {} doesn't quite make sense.
3. Why are you wrapping an IOException in an UncheckedIOException that is specified in the deleteBucket method signature?

[dekobon]

In ConfigContext:87:

Use MantaClient.SEPARATOR rather than hardcoding a slash:

    /**
     * @return String of buckets directory based on Manta username.
     */
    default String getMantaBucketsDirectory() {
        return deriveHomeDirectoryFromUser(getMantaUser()) + "/buckets";
    }

[indianwhocodes]

544 is yet to be ready for review as we are still undergoing some implementation discussions. Nevertheless, cleanup of this PR is required at many places and suggestions are most welcome.