Optimizing a cache of compiled expressions by removing variability

Abstract

Approaches presented herein enable optimization of a cache of compiled XML Path Language (XPath) expressions by removing variability from XPath expressions. More specifically, XPath expressions are identified that are the same but for one or more hardcoded values. These hardcoded values are identified and replaced in an identified XPath expression with an identifier to form a cache optimized XPath expression that lacks the hardcoded value variability of the identified XPath expressions. This cache optimized XPath expression is inserted into a cache optimized function that receives the hardcoded value as arguments and assigns the received hardcoded value to the identifier in the cache optimized XPath expression. The identified XPath expressions are then rewritten as calls to the cache optimized function or to another function wrapping the cache optimized function. Therefore, only the cache optimized XPath expression, instead of several of the identified XPath expressions, is stored in the XPath expression cache.