Fix #741 Added list objects v2 api support

[Ankk98]

Fix #741

AWS S3 ListObjectsV2 is the recommended API for listing objects in S3 buckets. It provides better performance and more efficient pagination compared to the original ListObjects API.

Added support for v2 API without integration with list related functionalities, that will be added in the next PR.

Usage

Basic ListObjectsV2 API Call

# Initialize storage connection
storage = Fog::Storage.new(provider: 'AWS', region: 'us-east-1')

# Basic ListObjectsV2 call
response = storage.list_objects_v2("my-bucket")
objects = response.body['Contents']
key_count = response.body['KeyCount']

ListObjectsV2 with Parameters

# List with prefix
response = storage.list_objects_v2("my-bucket", 'prefix' => 'photos/')

# List with max-keys limit
response = storage.list_objects_v2("my-bucket", 'max-keys' => 1000)

# List starting after a specific key
response = storage.list_objects_v2("my-bucket", 'start-after' => 'photos/2023/')

# List with delimiter for directory-like behavior
response = storage.list_objects_v2("my-bucket", 'delimiter' => '/')

# Include owner information
response = storage.list_objects_v2("my-bucket", 'fetch-owner' => true)

# Combine multiple parameters
response = storage.list_objects_v2("my-bucket", {
  'prefix' => 'uploads/',
  'max-keys' => 100,
  'delimiter' => '/',
  'start-after' => 'uploads/2023/'
})

Pagination with Continuation Token

# Get first page
first_page = storage.list_objects_v2("my-bucket", 'max-keys' => 1000)

if first_page.body['IsTruncated']
  # Get next page using continuation token
  next_page = storage.list_objects_v2("my-bucket", {
    'continuation-token' => first_page.body['NextContinuationToken']
  })
end

Complete Pagination Example

def list_all_objects(storage, bucket_name, options = {})
  all_objects = []
  continuation_token = nil
  
  loop do
    request_options = options.dup
    request_options['continuation-token'] = continuation_token if continuation_token
    
    response = storage.list_objects_v2(bucket_name, request_options)
    all_objects.concat(response.body['Contents'] || [])
    
    break unless response.body['IsTruncated']
    continuation_token = response.body['NextContinuationToken']
  end
  
  all_objects
end

# Usage
all_objects = list_all_objects(storage, "my-bucket", {
  'prefix' => 'photos/',
  'max-keys' => 1000
})

Testing

Run the tests:

rake test

[geemus]

LGTM, thanks! Apologies it took me so long to get to it.