Config$Key.unescapeName() performance optimizations

[brian-maulding]

Environment Details

• Helidon Version: 3.x and 4.x
• Helidon SE and MP
• JDK version: 21
• OS: Linux
• Docker version (if applicable):

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Problem Description

Profiles of an application that frequently queries Config data shows significant time in io.helidon.config.Config$Key.unescapeName(). String.replaceAll() is used for simple string replacement (no regex) resulting in Pattern compilation and regex evaluation:

escapedName.replaceAll("~1", ".")
                    .replaceAll("~0", "~")

Using String.replace() will improve performance:

escapedName.replace("~1", ".")
                    .replace("~0", "~")

[tomas-langer]

This is correct, there is no need to use regular expression here, a simple string lookup is sufficient.