def fetch_http uri, last_modified = nil, head = false, depth = 0
fetch_type = head ? Net::HTTP::Head : Net::HTTP::Get
response = request uri, fetch_type, last_modified
case response
when Net::HTTPOK, Net::HTTPNotModified then
head ? response : response.body
when Net::HTTPMovedPermanently, Net::HTTPFound, Net::HTTPSeeOther,
Net::HTTPTemporaryRedirect then
raise FetchError.new('too many redirects', uri) if depth > 10
location = URI.parse response['Location']
fetch_http(location, last_modified, head, depth + 1)
else
raise FetchError.new("bad response #{response.message} #{response.code}", uri)
end
end