Class: GnipApi::Adapter

Inherits:
Object
  • Object
show all
Defined in:
lib/gnip_api/adapter.rb

Overview

The interface to the world. Wraps the net adapter of choice and exposes common methods for the rest of the classes to use, abstracting details of the request/response. A note on the data: HTTParty was selected over Excon for the simple reason that Excon doesn’t handle GZip responses. HTTParty uses net/http under the hood and handles this as expected. However, for reasons I don’t know at this point, the Zlib responsible of inflating the GZip compressed data waits to fill in a buffer in order to return a decompressed chunk. You can test this on a farily busy stream and you’ll see that all chunks you receive decompressed are almsot always 16384 bytes. Additionally, the rn Gnip sends as a keep alive signal seems to be buffered further. As a result I expose 2 additional methods for consuming the stream that uses Curl instead. Curl handles the GZip data better. You can launch it in a shell and the keep alive signals are properly there. These alternatives are a bit of a cheat, but allows delegation of handling the actual connection and the GZip data.

#stream_get will work as usual, using HTTParty and Net::HTTP stuff.

#io_curl_stream will launch a subprocess and capture output with IO.popen. This method behaves similarly to #stream_get regarding the keep alive signals. However, these are returned all at once when a bigger chunk of data is sent over the stream. Still, it reads them well and can be handled.

#pty_curl_stream is different. Using the PTY features, a shell is opened and the output captured is as (in my opinion) should be. All keep-alive signals are returned when received with no wait at all.

All this will remain experimental until tested on a real environment. I recomment to use #stream_get which was already tested and works as expected.

Constant Summary collapse

GET = 
'GET'
POST = 
'POST'
DELETE = 
'DELETE'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Adapter

Returns a new instance of Adapter.

Raises:



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# File 'lib/gnip_api/adapter.rb', line 38

def initialize
  raise GnipApi::Errors::MissingCredentials unless GnipApi.credentials?
  @logger = GnipApi.config.logger
  @debug = GnipApi.config.debug
end

Instance Attribute Details

#debug ⇒ Object (readonly)

Returns the value of attribute debug.



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# File 'lib/gnip_api/adapter.rb', line 36

def debug
  @debug
end

#logger ⇒ Object (readonly)

Returns the value of attribute logger.



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# File 'lib/gnip_api/adapter.rb', line 36

def logger
  @logger
end

Instance Method Details

#delete(request) ⇒ Object 



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# File 'lib/gnip_api/adapter.rb', line 56

def delete request
  options = default_options(request)
  data = HTTParty.post request.uri, options
  create_response(request, data.code, data.body, data.headers)
end

#get(request) ⇒ Object 



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# File 'lib/gnip_api/adapter.rb', line 44

def get request
  options = default_options(request)
  data = HTTParty.get request.uri, options
  create_response(request, data.code, data.body, data.headers)
end

#io_curl_stream(request) ⇒ Object 



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# File 'lib/gnip_api/adapter.rb', line 74

def io_curl_stream request
  request.log!
  auth_header = "Authorization: Basic #{base64_auth}"
  cmd = "curl --compressed -s --header \"#{auth_header}\" \"#{request.uri}\""
  begin
    IO.popen(cmd) do |io|
      while line = io.gets.strip do
        logger.info "Keep alive received" if line == ''
        next if line == ''
        yield(line)
      end
    end
  ensure
    logger.warn "Stream closed"
  end
end

#post(request) ⇒ Object 



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# File 'lib/gnip_api/adapter.rb', line 50

def post request
  options = default_options(request)
  data = HTTParty.post request.uri, options
  create_response(request, data.code, data.body, data.headers)
end

#pty_curl_stream(request) ⇒ Object 



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# File 'lib/gnip_api/adapter.rb', line 91

def pty_curl_stream request
  request.log!
  auth_header = "Authorization: Basic #{base64_auth}"
  cmd = "curl --compressed -s --header \"#{auth_header}\" \"#{request.uri}\""
  begin
    PTY.spawn(cmd) do |stdout, stdin, pid|
      begin
        stdout.each do |line|
          logger.info "Keep alive received" if line.strip == ''
          next if line.strip == ''
          yield(line.strip)
        end
      rescue Errno::EIO
      end
    end
  rescue PTY::ChildExited
    logger.warn "Stream closed"
  end
end

#stream_get(request) ⇒ Object 



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# File 'lib/gnip_api/adapter.rb', line 62

def stream_get request
  request.log!
  begin
    HTTParty.get request.uri, :headers => request.headers, :stream_body => true, :basic_auth => auth do |data|
      yield(data)
    end
  rescue Zlib::BufError => error
    logger.error "STREAM ERROR -> #{error.class} -- #{error.message}\n" + error.backtrace.join("\n")
    raise error
  end
end