Benchmarking different ways of creating presigned S3 URLs

url_gen_benchmark.rb

# A local domain ActiveRecord, Asset#file is a shrine attachment
asset = Asset.last

# load outside of benchmarking
asset.file
s3_object = asset.file.storage.object(asset.file.id)

ITERATIONS = (ENV['ITERATIONS'] || "1200").to_i

$stderr.puts "#{ITERATIONS} iterations\n\n"


def naive_public_url(shrine_file)
  "https://#{["#{shrine_file.storage.bucket.name}.s3.amazonaws.com", *shrine_file.storage.prefix, shrine_file.id].join('/')}"
end

if naive_public_url(asset.file) != asset.file.url(public: true)
  raise "naive_public_url implementation does not pass:\n\n#{naive_public_url(asset.file)}\n#{asset.file.url(public: true)}"
end

# URI.escape may do exactly what we need without requiring splitting on "/", but
# it's sadly deprecated when it really ought not to be
def naive_with_uri_escape_escaping(shrine_file)
  # because URI.escape does NOT escape `/`, we don't need to split it, which is what
  # actually saves us the time.
  path = URI.escape(shrine_file.id)

  "https://#{["#{shrine_file.storage.bucket.name}.s3.amazonaws.com", *shrine_file.storage.prefix, shrine_file.id].join('/')}"
end
if naive_with_uri_escape_escaping(asset.file) != asset.file.url(public: true)
  raise "naive_with_uri_escape_escaping implementation does not pass:\n\n#{naive_with_uri_escape_escaping(asset.file)}\n#{asset.file.url(public: true)}"
end


# Re-use a Presigner to see if it gets us any speed -- hope it's thread-safe?
AWS_CLIENT = asset.file.storage.client
S3_PRESIGNER = Aws::S3::Presigner.new(client: AWS_CLIENT)
def reused_sdk_presigner(shrine_file)
  bucket_name = shrine_file.storage.bucket.name
  s3_key = [*shrine_file.storage.prefix, shrine_file.id].join("/")

  S3_PRESIGNER.presigned_url(
    :get_object,
    bucket: bucket_name,
    key: s3_key
  )
end
if reused_sdk_presigner(asset.file) != asset.file.url(public: false)
  raise "reused_sdk_presigner implementation does not pass:\n\n#{reused_sdk_presigner(asset.file)}\n#{asset.file.url(public: false)}"
end


AWS_SIG4_SIGNER = Aws::Sigv4::Signer.new(
  service: 's3',
  region: AWS_CLIENT.config.region,
  credentials_provider: AWS_CLIENT.config.credentials,
  unsigned_headers: Aws::S3::Presigner::BLACKLISTED_HEADERS,
  uri_escape_path: false
)

def direct_aws_sig4_signer(url)
  AWS_SIG4_SIGNER.presign_url(
            http_method: "GET",
            url: url,
            headers: {},
            body_digest: 'UNSIGNED-PAYLOAD',
            expires_in: 900, # seconds
            time: nil
  ).to_s
end
if direct_aws_sig4_signer(naive_public_url(asset.file)) != asset.file.url(public: false)
  raise "direct_aws_sig4_signer implementation does not pass:\n\n#{direct_aws_sig4_signer(asset.file)}\n#{asset.file.url(public: false)}"
end

def inline_direct_aws_sig4_signer(url)
  signer = Aws::Sigv4::Signer.new(
    service: 's3',
    region: AWS_CLIENT.config.region,
    credentials_provider: AWS_CLIENT.config.credentials,
    unsigned_headers: Aws::S3::Presigner::BLACKLISTED_HEADERS,
    uri_escape_path: false
  )

  signer.presign_url(
            http_method: "GET",
            url: url,
            headers: {},
            body_digest: 'UNSIGNED-PAYLOAD',
            expires_in: 900, # seconds
            time: nil
  ).to_s
end


Benchmark.bmbm do |x|

  x.report("sdk public_url") do
    ITERATIONS.times do
      s3_object.public_url
    end
  end

  x.report("naive S3 public url") do
    # May not always properly escape chars that need to be escaped in uris? Not sure, may be fine.
    ITERATIONS.times do
      naive_public_url(asset.file)
    end
  end

  x.report("naive S3 public url with URI.escape") do
    ITERATIONS.times do
      naive_with_uri_escape_escaping(asset.file)
    end
  end


  x.report("sdk presigned_url") do
    ITERATIONS.times do
      s3_object.presigned_url(:get)
    end
  end


  x.report("re-use instantiated SDK Presigner") do
    ITERATIONS.times do
      reused_sdk_presigner(asset.file)
    end
  end

  x.report("use inline instantiated Aws::Sigv4::Signer directly for presigned url (with escaping)") do
    ITERATIONS.times do
      inline_direct_aws_sig4_signer(naive_with_uri_escape_escaping(asset.file))
    end
  end

  x.report("Re-use Aws::Sigv4::Signer for presigned url (with escaping)") do
    ITERATIONS.times do
      direct_aws_sig4_signer(naive_with_uri_escape_escaping(asset.file))
    end
  end

  x.report("Re-use Aws::Sigv4::Signer for presigned url (without escaping)") do
    ITERATIONS.times do
      direct_aws_sig4_signer(naive_public_url(asset.file))
    end
  end


end