transports.rb in buildr-0.22.0

- old
+ new

@@ -1,5 +1,6 @@
+require "cgi"
 require "net/http"
 require "net/ssh"
 require "net/sftp"
 require "uri"
 require "uri/sftp"
@@ -112,13 +113,13 @@
         @base_path = @uri.path || "/"
         @base_path += "/" unless @base_path[-1] == ?/
         @options = options || {}
       end
 
-      # Downloads a file from the specified path, relative to the
-      # server URI. Downloads to either the target file, or by
-      # calling the block with each chunk of the file.
+      # Downloads a file from the specified path, relative to the server URI.
+      # Downloads to either the target file, or by calling the block with each
+      # chunk of the file. Returns the file's modified timestamp, or now.
       #
       # For example:
       #   Transports.perform("http://server/libs") do |http|
       #     http.download("my_project/test.jar", "test.jar")
       #     http.download("my_project/readme") { |text| $stdout.write text }
@@ -270,20 +271,28 @@
         super
         @http = Net::HTTP.start(@uri.host, @uri.port)
       end
 
       def download(path, target = nil, &block)
-        puts "Requesting #{path} from #{@uri}" if Rake.application.options.trace
-        @http.request_get(@base_path + path) do |response|
+        puts "Requesting #{@uri}/#{path} " if Rake.application.options.trace
+        last_modified = File.stat(target).mtime.utc if target && File.exist?(target)
+        headers = {}
+        headers["If-Modified-Since"] = CGI.rfc1123_date(last_modified) if last_modified
+        @http.request_get(@base_path + path, headers) do |response|
           case response
+          when Net::HTTPNotModified
+            # No modification, nothing to do.
+            puts "Not modified since last download" if Rake.application.options.trace
+
           when Net::HTTPRedirection
             # Try to download from the new URI, handle relative redirects.
-            puts "Redirected" if Rake.application.options.trace
-            Transports.download(@uri + URI.parse(response["location"]), target, @options)
+            puts "Redirected to #{response['Location']}" if Rake.application.options.trace
+            last_modified = Transports.download(@uri + URI.parse(response["location"]), target, @options)
 
           when Net::HTTPOK
             puts "Downloading #{@uri}/#{path}" if verbose
+            last_modified = Time.parse(response["Last-Modified"] || "")
             with_progress_bar path.split("/").last, response.content_length do |progress|
               with_digests(@options[:digests]) do |digester|
 
                 download = proc do |write|
                   # Read the body of the page and write it out.
@@ -309,11 +318,12 @@
                   # worse than not having a file at all, so download to temporary
                   # file and then move over.
                   temp = Tempfile.new(File.basename(target))
                   download[ proc { |chunk| temp.write chunk } ]
                   temp.close
-                  File.move temp.path, target if target
+                  File.move temp.path, target
+                  File.utime last_modified, last_modified, target
                 else
                   download[ block ]
                 end
 
               end
@@ -322,9 +332,10 @@
             raise NotFound
           else
             fail "Failed to download #{@uri}/#{path}: #{response.message}"
           end
         end
+        last_modified
       end
 
       def close()
         @http.finish
         @http = nil