How well does Smart.Format perform?

Even with all its features, SmartFormat is efficient and has amazing performance. It has several features that make it as fast as possible.

  • Fast Parser: The parsing engine is written from scratch to maximize speed and efficiency.

  • Extension System: You can easily select the set of "extensions" that are used in formatting, and unused extensions can be removed. Multiple formatters can be created, each with a specific set of extensions. For example, if you only use the plural formatting extension, you can remove the reflection extension to increase performance.

  • FormatWithCache: SmartFormat even has a FormatWithCache method that caches parsing results, resulting in the fastest performance possible! Extensions can also take advantage of the cache if they need to.

  • IOutput: SmartFormat uses a custom interface for output, meaning that the results could be directly output to any stream without having to build intermediate strings.

Performance Comparisons

Compared to String.Format

Due to its ability to cache and output directly to streams, in some scenarios Smart.Format can actually outperform String.Format!

For example, a lengthy email template would benefit greatly from the FormatWithCache method and could easily outperform String.Format by about 25%.

Even without caching, the basic Smart.Format method takes only about 50% longer than String.Format on the same format string.

Compared to other "Named Placeholder" methods

There is a collection of other "Named Placeholder" methods that you can read about on [[Phil Haack's Blog|http://haacked.com/archive/2009/01/14/named-formats-redux.aspx]]. These implementations were created by some people you might have heard of, including [[Phil Haack|http://www.haacked.com/]], [[Scott Hanselman|http://www.hanselman.com/blog/]], [[James Newton-King|http://james.newtonking.com/]], [[Oskar Austegard|http://mo.notono.us/]], and Henri Wiechers.

You can [[download the source code|http://research.microsoft.com/en-us/projects/pex/namedstringformatsolution.zip]] from [[Phil Haack's Blog|http://haacked.com/archive/2009/01/14/named-formats-redux.aspx]] or now even as a sample from [[Microsoft's Pex website|http://research.microsoft.com/en-us/downloads/d2279651-851f-4d7a-bf05-16fd7eb26559/default.aspx]].

While these methods all have good performance, Smart.Format and Smart.FormatWithCache are actually the fastest of them all, beating even Henri's method by a small fraction!

Modify the performance tests as follows:

                MeasureFormatTime("Hanselformat", () => format.HanselFormat(o));
                MeasureFormatTime("OskarFormat", () => format.OskarFormat(o));
                MeasureFormatTime("JamesFormat", () => format.JamesFormat(o));
                MeasureFormatTime("HenriFormat", () => format.HenriFormat(o));
                MeasureFormatTime("HaackFormat", () => format.HaackFormat(o));
                // New Smart.Format tests:
                MeasureFormatTime("SmartFormat", () => format.SmartFormat(o));
                SmartFormat.Core.FormatCache cache = null;
                MeasureFormatTime("CacheFormat", () => format.SmartFormat(ref cache, o));

Here are my results. They represent the average of running the test 5 times:

HanselFormat took 0.26340 ms
OskarFormat took 0.32200 ms
JamesFormat took 0.19280 ms
HenriFormat took 0.13960 ms   - 3rd fastest
HaackFormat took 0.15880 ms
SmartFormat took 0.13700 ms   - 2nd fastest
CacheFormat took 0.12780 ms   - fastest!

As you can see, the performance of Smart.Format is wonderful and should compete with any other implementation.