At the Forge - Incremental Form Submission

A creative solution for solving Web service performance bottlenecks, or “ix-nay on the ottleneck-bay”.

The key to making all this work is shown in Listing 3, which provides the code for our XML-RPC server. We begin by reading from a simple cache of English words and their Pig Latin equivalents. Again, it seems silly to store things in this way, when it's much faster simply to write the code that handles the Pig Latin rules. If you imagine that each translation takes several seconds, you can see how things could pile up quickly.

There are several things to notice in this program. One of the first is the use of an on-disk cache to store recently processed inputs. (Please don't try to emulate the simple and foolish way in which I implemented this; I ignored locking and permission issues.) The cache itself is a simple text file containing name-value pairs. Before computing the Pig Latin translation of each item, the Web service consults the cache. If the word is in the cache, the service grabs that value and almost immediately returns the translated value.

If the word isn't in the cache, it translates the English into Pig Latin, storing the values for the next time around. Again, this ensures that we have to work hard (that is, translate the word into Pig Latin) only if it fails to appear in the cache.

If you've never programmed in Ruby before, you might be put off a bit by this line: {|word| word.to_s}.each do |word|

This tells Ruby that it should take the array named words and turn each of its elements into a string. (If the element already is a string, it is unaffected.) We then iterate over each string (word) in the array, assigning the local variable word to each element in sequence.

With Listings 1, 2 and 3 in place, you should be able to translate sentences from English into Pig Latin without too much difficulty. You enter the English words into the HTML form, the server-side program calls the Web service, and the Web service takes care of things quickly.