curlffi-test.rb

require 'rubygems'
# gem 'ffi', '= 0.3.5'
require 'ffi'
require 'fileutils'

if defined?(JRUBY_VERSION)
  jsys = java.lang.System
  $stderr.puts "#{jsys.get_property('java.vm.name')} #{jsys.get_property('java.version')}"
end

module CurlFfi
  module Easy
    extend FFI::Library

    class CurlFfiError < StandardError
    end

    COTYPE_LONG          = 0
    COTYPE_OBJECTPOINT   = 10_000
    COTYPE_FUNCTIONPOINT = 20_000
    COTYPE_OFF_T         = 30_000

    # constants defined in curl.h
    CURL_GLOBAL_SSL     = (1 << 0)
    CURL_GLOBAL_WIN32   = (1 << 1)
    CURL_GLOBAL_ALL     =  (CURL_GLOBAL_SSL|CURL_GLOBAL_WIN32)
    CURL_GLOBAL_NOTHING = 0
    CURL_GLOBAL_DEFAULT = CURL_GLOBAL_ALL

    # options
    CURLOPT_FILE          = COTYPE_OBJECTPOINT   + 1
    CURLOPT_URL           = COTYPE_OBJECTPOINT   + 2
    CURLOPT_ERRORBUFFER   = COTYPE_OBJECTPOINT   + 10
    CURLOPT_WRITEFUNCTION = COTYPE_FUNCTIONPOINT + 11

    # status
    CURLE_OK            = 0

    ffi_lib "curl"

    attach_function :_global_init, :curl_global_init, [:long], :int
    attach_function :_init, :curl_easy_init, [], :pointer
    attach_function :_cleanup, :curl_easy_cleanup, [:pointer], :void
    attach_function :_setopt, :curl_easy_setopt, [:pointer, :int, :pointer], :int
    attach_function :_setoptstr, :curl_easy_setopt, [:pointer, :int, :string], :int
    attach_function :_setoptva, :curl_easy_setopt, [:pointer, :int, :varargs], :int
    attach_function :_perform, :curl_easy_perform, [:pointer], :int
    attach_function :_strerror, :curl_easy_strerror, [:int], :string

    @@global_init_done = false unless defined?(@@global_init_done)
    @@mutex = Mutex.new unless defined?(@@mutex)

    attr_reader :url

    def self.global_init!
      @@mutex.synchronize do
        return if @@global_init_done
        @@global_init_done = true
        _global_init(CURL_GLOBAL_DEFAULT)
      end
    end

    class StdIO
      extend FFI::Library

      ffi_lib 'c'

      attach_function :_fopen, :fopen, [:string, :string], :pointer
      attach_function :_fdopen, :fdopen, [:int, :string], :pointer
      attach_function :_fclose, :fclose, [:pointer], :int  
      attach_function :_fflush, :fflush, [:pointer], :int
      attach_function :_strerror, :strerror, [:int], :string
      attach_function :_printf, :printf, [:varargs], :int


      class << self
        def fopen(path, mode)
          _fopen(path, mode) or raise_errno!
        end

        def fdopen(int, str)
          _fdopen(int, str) or raise_errno!
        end

        def fclose(ptr)
          raise_errno! unless _fclose(ptr) == 0
        end

        def fflush(ptr)
          raise_errno! unless _fflush(ptr) == 0
        end

        private
          def raise_errno!
            raise SystemCallError.new(nil, FFI.errno)
          end
      end
    end

    class << self
      def download(url, path)
        fp = nil
        handle = self._init

        $stderr.puts "printing url from stdlib printf"
        StdIO._printf(:string, url)

        self._setoptstr(handle, CURLOPT_URL, url)

        self._setopt(handle, CURLOPT_WRITEFUNCTION, nil)

        fpointer = StdIO.fopen(path, 'w')

        p fpointer

        self._setopt(handle, CURLOPT_FILE, fpointer)

        if (code = self._perform(handle)) > CURLE_OK
          raise CurlFfiError, self._strerror(code)
        end

        StdIO.fflush(fpointer)

        true
      rescue Exception => e
        FileUtils.rm_f(path) rescue nil
        raise e
      ensure
        StdIO.fclose(fpointer) if fpointer
        self._cleanup(handle) if handle
      end

      private
        def raise_curl_errno!
          raise CurlFfiError, self._strerror
        end
    end
  end
end

def main
  if ARGV.empty?
    $stderr.puts "Usage: #{File.basename($0)} http://example.com/ /tmp/blah.out"
    exit 1
  end

  CurlFfi::Easy.global_init!

  url = ARGV.first
  outpath = ARGV[1]

  CurlFfi::Easy.download(url, outpath)
end

main if __FILE__ == $0

output on leopard

[20091003-02.14.14]$ jruby curlffi.rb http://www.google.com/ /tmp/blah.html
Java HotSpot(TM) 64-Bit Server VM 1.6.0_07
printing url from stdlib printf
#<Pointer address=0x7fff700d0440>
curlffi.rb:119:in `download': couldn't resolve host name (CurlFfi::Easy::CurlFfiError)
        from curlffi.rb:152:in `main'
        from curlffi.rb:155
http://www.google.com/

[20091003-02.15.30]$ uname -a
Darwin hackett 9.6.0 Darwin Kernel Version 9.6.0: Mon Nov 24 17:37:00 PST 2008; root:xnu-1228.9.59~1/RELEASE_I386 i386

slyphon@hackett:~
[20091003-02.15.33]$ jruby --version
jruby 1.3.1 (ruby 1.8.6p287) (2009-09-21 6586) (Java HotSpot(TM) 64-Bit Server VM 1.6.0_07) [x86_64-java]

slyphon@hackett:~
[20091003-02.16.15]$ $JAVA_HOME/bin/java -version
java version "1.6.0_07"
Java(TM) SE Runtime Environment (build 1.6.0_07-b06-153)
Java HotSpot(TM) 64-Bit Server VM (build 1.6.0_07-b06-57, mixed mode)

slyphon@hackett:~
[20091003-02.16.28]$ curl --version
curl 7.19.6 (i386-apple-darwin9.6.0) libcurl/7.19.6 OpenSSL/0.9.8k zlib/1.2.3
Protocols: tftp ftp telnet dict http file https ftps
Features: Largefile NTLM SSL libz