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Class: Bundler::CompactIndexClient::Updater

Relationships & Source Files
Namespace Children
Exceptions:
Inherits: Object
Defined in: lib/bundler/compact_index_client/updater.rb

Class Method Summary

Instance Method Summary

Constructor Details

.new(fetcher) ⇒ Updater

[ GitHub ]

  
# File 'lib/bundler/compact_index_client/updater.rb', line 12

def initialize(fetcher)
  @fetcher = fetcher
end

Instance Method Details

#append(remote_path, local_path, etag_path) (private)

[ GitHub ]

  
# File 'lib/bundler/compact_index_client/updater.rb', line 26

def append(remote_path, local_path, etag_path)
  return false unless local_path.file? && local_path.size.nonzero?

  CacheFile.copy(local_path) do |file|
    etag = etag_path.read.tap(&:chomp!) if etag_path.file?
    etag ||= generate_etag(etag_path, file) # Remove this after 2.5.0 has been out for a while.

    # Subtract a byte to ensure the range won't be empty.
    # Avoids 416 (Range Not Satisfiable) responses.
    response = @fetcher.call(remote_path, request_headers(etag, file.size - 1))
    break true if response.is_a?(Gem::Net::HTTPNotModified)

    file.digests = parse_digests(response)
    # server may ignore Range and return the full response
    if response.is_a?(Gem::Net::HTTPPartialContent)
      break false unless file.append(response.body.byteslice(1..-1))
    else
      file.write(response.body)
    end
    CacheFile.write(etag_path, etag_from_response(response))
    true
  end
end

#byte_sequence(value) (private)

Unwrap surrounding colons (byte sequence) The wrapping characters must be matched or we return nil. Also handles quotes because right now rubygems.org sends them.

[ GitHub ]

  
# File 'lib/bundler/compact_index_client/updater.rb', line 108

def byte_sequence(value)
  return if value.delete_prefix!(":") && !value.delete_suffix!(":")
  return if value.delete_prefix!('"') && !value.delete_suffix!('"')
  value
end

#etag_for_request(etag_path) (private)

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# File 'lib/bundler/compact_index_client/updater.rb', line 66

def etag_for_request(etag_path)
  etag_path.read.tap(&:chomp!) if etag_path.file?
end

#etag_from_response(response) (private)

[ GitHub ]

  
# File 'lib/bundler/compact_index_client/updater.rb', line 80

def etag_from_response(response)
  return unless response["ETag"]
  etag = response["ETag"].delete_prefix("W/")
  return if etag.delete_prefix!('"') && !etag.delete_suffix!('"')
  etag
end

#generate_etag(etag_path, file) (private)

When first releasing this opaque etag feature, we want to generate the old MD5 etag based on the content of the file. After that it will always use the saved opaque etag. This transparently saves existing users with good caches from updating a bunch of files. Remove this behavior after 2.5.0 has been out for a while.

[ GitHub ]

  
# File 'lib/bundler/compact_index_client/updater.rb', line 74

def generate_etag(etag_path, file)
  etag = file.md5.hexdigest
  CacheFile.write(etag_path, etag)
  etag
end

#parse_digests(response) (private)

Unwraps and returns a Hash of digest algorithms and base64 values according to RFC 8941 Structured Field Values for HTTP. www.rfc-editor.org/rfc/rfc8941#name-parsing-a-byte-sequence Ignores unsupported algorithms.

[ GitHub ]

  
# File 'lib/bundler/compact_index_client/updater.rb', line 91

def parse_digests(response)
  return unless header = response["Repr-Digest"] || response["Digest"]
  digests = {}
  header.split(",") do |param|
    algorithm, value = param.split("=", 2)
    algorithm.strip!
    algorithm.downcase!
    next unless SUPPORTED_DIGESTS.key?(algorithm)
    next unless value = byte_sequence(value)
    digests[algorithm] = value
  end
  digests.empty? ? nil : digests
end

#replace(remote_path, local_path, etag_path) (private)

request without range header to get the full file or a 304 Not Modified

[ GitHub ]

  
# File 'lib/bundler/compact_index_client/updater.rb', line 51

def replace(remote_path, local_path, etag_path)
  etag = etag_path.read.tap(&:chomp!) if etag_path.file?
  response = @fetcher.call(remote_path, request_headers(etag))
  return true if response.is_a?(Gem::Net::HTTPNotModified)
  CacheFile.write(local_path, response.body, parse_digests(response))
  CacheFile.write(etag_path, etag_from_response(response))
end

#request_headers(etag, range_start = nil) (private)

[ GitHub ]

  
# File 'lib/bundler/compact_index_client/updater.rb', line 59

def request_headers(etag, range_start = nil)
  headers = {}
  headers["Range"] = "bytes=#{range_start}-" if range_start
  headers["If-None-Match"] = %("#{etag}") if etag
  headers
end

#update(remote_path, local_path, etag_path)

[ GitHub ]

  
# File 'lib/bundler/compact_index_client/updater.rb', line 16

def update(remote_path, local_path, etag_path)
  append(remote_path, local_path, etag_path) || replace(remote_path, local_path, etag_path)
rescue CacheFile::DigestMismatchError => e
  raise MismatchedChecksumError.new(remote_path, e.message)
rescue Zlib::GzipFile::Error
  raise Bundler::HTTPError
end