Add support for :writedata/:file options -- write body directly to a file

lib/ethon/curls/options.rb

@@ -57,6 +57,9 @@ def set_option(option, value, handle, type = :easy)
           s = value.to_s unless value.nil?
           value = FFI::MemoryPointer.new(:char, s.bytesize)
           value.put_bytes(0, s)
+        when :file
+          func=:ffipointer
+          # We expect that easy is passing us a FILE *
         when :string_escape_null
           func=:string
           value=Util.escape_zero_byte(value) unless value.nil?
@@ -126,7 +129,8 @@ def set_option(option, value, handle, type = :easy)
         :ffipointer => :objectpoint, # FFI::Pointer
         :curl_slist => :objectpoint,
         :buffer => :objectpoint, # A memory buffer of size defined in the options
-        :dontuse_object => :objectpoint, # An object we don't support (e.g. FILE*)
+        :dontuse_object => :objectpoint, # An object we don't support
+        :file => :objectpoint,
         :cbdata => :objectpoint,
         :callback => :functionpoint,
         :debug_callback => :functionpoint,
@@ -227,7 +231,7 @@ def #{type.to_s.downcase}_options(rt=nil)
       option :easy, :wildcardmatch, :bool, 197
       ## CALLBACK OPTIONS
       option :easy, :writefunction, :callback, 11
-      option :easy, :file, :cbdata, 1
+      option :easy, :file, :file, 1
       option_alias :easy, :file, :writedata
       option :easy, :readfunction, :callback, 12
       option :easy, :infile, :cbdata, 9

lib/ethon/easy.rb

@@ -10,6 +10,7 @@
 require 'ethon/easy/response_callbacks'
 require 'ethon/easy/debug_info'
 require 'ethon/easy/mirror'
+require 'ethon/easy/files'
 
 module Ethon
 
@@ -39,6 +40,7 @@ class Easy
     include Ethon::Easy::Http
     include Ethon::Easy::Operations
     include Ethon::Easy::ResponseCallbacks
+    include Ethon::Easy::Files
 
     # Returns the curl return code.
     #
@@ -216,7 +218,7 @@ class Easy
     def initialize(options = {})
       Curl.init
       set_attributes(options)
-      set_callbacks
+      set_callbacks(options)
     end
 
     # Set given options.
@@ -231,6 +233,10 @@ def initialize(options = {})
     # @see initialize
     def set_attributes(options)
       options.each_pair do |key, value|
+        if key == :file || key == :writedata
+          # TODO: modes other than 'w+'
+          value = open_file(value, 'w+')
+        end
         method = "#{key}="
         unless respond_to?(method)
           raise Errors::InvalidOption.new(key)
@@ -252,6 +258,7 @@ def reset
       @on_body = nil
       @procs = nil
       @mirror = nil
+      close_all_files
       Curl.easy_reset(handle)
       set_callbacks
     end

lib/ethon/easy/callbacks.rb

@@ -18,11 +18,18 @@ def self.included(base)
       #
       # @example Set callbacks.
       #   easy.set_callbacks
-      def set_callbacks
-        Curl.set_option(:writefunction, body_write_callback, handle)
+      def set_callbacks(options = {})
+        if options[:file].nil? && options[:writedata].nil?
+          Curl.set_option(:writefunction, body_write_callback, handle)
+          @response_body = ""
+        else
+          # If we are writing to a file, set writefuntion to NULL
+          Curl.set_option(:writefunction, nil, handle)
+          @response_body = nil
+        end
         Curl.set_option(:headerfunction, header_write_callback, handle)
         Curl.set_option(:debugfunction, debug_callback, handle)
-        @response_body = ""
+        on_complete { close_all_files }
         @response_headers = ""
         @headers_called = false
         @debug_info = Ethon::Easy::DebugInfo.new

lib/ethon/easy/files.rb

@@ -0,0 +1,18 @@
+module Ethon
+  class Easy
+    # This module contains logic for managing open files on an easy instance
+    module Files
+      def open_file(path, mode)
+        @open_files ||= []
+        fh = Libc.ffi_fopen(path, mode)
+        @open_files << fh
+        fh
+      end
+
+      def close_all_files
+        @open_files.each {|fh| Libc.ffi_fclose(fh)} unless @open_files.nil?
+        @open_files = []
+      end
+    end
+  end
+end

lib/ethon/libc.rb

@@ -12,9 +12,22 @@ def self.windows?
       Gem.win_platform?
     end
 
+    def self.ffi_fclose(fh)
+      retv = fclose(fh)
+      fail SystemCallError.new(FFI.errno) unless retv == 0
+    end
+
+    def self.ffi_fopen(path, mode)
+      fh = fopen(path, mode)
+      fail SystemCallError.new(FFI.errno), path if fh == nil
+      return fh
+    end
+
     unless windows?
       attach_function :getdtablesize, [], :int
       attach_function :free, [:pointer], :void
+      attach_function :fopen, [:string, :string], :pointer
+      attach_function :fclose, [:pointer], :int
     end
   end
 end

spec/ethon/easy/callbacks_spec.rb

@@ -12,6 +12,13 @@
       easy.set_callbacks
     end
 
+    [:file, :writedata].each do |file_opt|
+      it "sets @response_body to null if file passed" do
+        easy.set_callbacks({file_opt => '/some/file'})
+        expect(easy.instance_variable_get(:@response_body)).to be_nil
+      end
+    end
+
     it "resets @response_body" do
       easy.set_callbacks
       expect(easy.instance_variable_get(:@response_body)).to eq("")

spec/ethon/easy/files_spec.rb

@@ -0,0 +1,30 @@
+require 'spec_helper'
+
+describe Ethon::Easy::Files do
+  let!(:easy) { Ethon::Easy.new }
+
+  describe "#open_file" do
+    path, mode = '/i/am/no/file', 'w'
+
+    before do
+      expect(Ethon::Libc).to receive(:ffi_fopen).with(path, mode)
+    end
+
+    it "calls ffi_fopen" do
+      easy.open_file(path, mode)
+    end
+
+    it "tracks the open files in @open_files" do
+      easy.open_file(path, mode)
+      expect(easy.instance_variable_get(:@open_files).count).to eq(1)
+    end
+  end
+
+  describe "#close_all_files" do
+    it "calls ffi_fclose on all open files" do
+      easy.instance_variable_set(:@open_files, [nil])
+      expect(Ethon::Libc).to receive(:ffi_fclose).exactly(1).times
+      easy.close_all_files
+    end
+  end
+end

spec/ethon/easy/response_callbacks_spec.rb

@@ -11,22 +11,24 @@
 
       context "when no block given" do
         it "returns @#{callback_type}" do
-          expect(easy.send("#{callback_type}")).to eq([])
+          expect(easy.send("#{callback_type}")).to be_kind_of(Array)
         end
       end
 
       context "when block given" do
         it "stores" do
+          orig_size = easy.send(callback_type).count
           easy.send(callback_type) { p 1 }
-          expect(easy.instance_variable_get("@#{callback_type}").size).to eq(1)
+          expect(easy.instance_variable_get("@#{callback_type}").size).to eq(orig_size + 1)
         end
       end
 
       context "when multiple blocks given" do
         it "stores" do
+          orig_size = easy.send(callback_type).count
           easy.send(callback_type) { p 1 }
           easy.send(callback_type) { p 2 }
-          expect(easy.instance_variable_get("@#{callback_type}").size).to eq(2)
+          expect(easy.instance_variable_get("@#{callback_type}").size).to eq(orig_size + 2)
         end
       end
     end

spec/ethon/easy_spec.rb

@@ -53,6 +53,16 @@
           expect{ easy.set_attributes({:fubar => 1}) }.to raise_error(Ethon::Errors::InvalidOption)
         end
       end
+
+      context "when file passed" do
+        it "opens the file" do
+          [:file, :writedata].each do |file_opt|
+            path = '/i/am/not/a/file'
+            expect(easy).to receive(:open_file).with(path, 'w+')
+            easy.set_attributes({file_opt => path})
+          end
+        end
+      end
     end
   end
 
@@ -75,9 +85,10 @@
     end
 
     it "resets on_complete" do
+      orig_size = easy.on_complete.count
       easy.on_complete { p 1 }
       easy.reset
-      expect(easy.on_complete).to be_empty
+      expect(easy.on_complete.count).to eq(orig_size)
     end
 
     it "resets on_headers" do
@@ -86,6 +97,11 @@
       expect(easy.on_headers).to be_empty
     end
 
+    it "closes files" do
+      easy.reset
+      expect(easy.instance_variable_get(:@open_files)).to eq([])
+    end
+
     it "resets on_body" do
       easy.on_body { p 1 }
       easy.reset