Code Analyzer

The Code Analyzer package should be based on the reflection component as a high level API for handling language elements. This way it leverages the internal parser of the PHP interpreter which can be assumed to be one of the best parsers for the language.

Design description

The requirement of being fault tolerant has a major influence on the design of the classes. Since the source files have to be loaded to employ the reflection component, some kind of a sandbox environment is needed to ensure that errors in the input files which stop the script execution do not affect the Code Analyzer classes during execution.

A simple way to achieve this is to start the analysis of the files in a separate PHP interpreter process. If an error occurs only this child process stops, but the Code Analyzer is able to report or simply ignore the error and to continue with the next file.

ezcCodeAnalyzerClassLoader

This class provides methods to recursively include all files that contain PHP code from a given directory and all its subdirectories. Any output of the included code will be suppressed and files are only loaded if they do not contain any syntax errors. This fault tolerance is achieved by creating a new child PHP process and performing a syntax check before loading the file into the parent PHP process.

ezcCodeAnalyzer.php

The Class ezcCodeAnalyzer implements different analyses which can be started either separately using one of the summarization methods or all together by calling a central collector method.

ezcCodeAnalyzerFileDetails

Class ezcCodeAnalyzer uses this class which is actually an ezcBaseStruct as data structure for some of the details of a given file. All data retrieval operations which include guessing the MIME type, counting the lines of code, and retrieving the file size are performed during object creation.

Algorithms

The static call graph of the CodeAnalyzer class gives an impression of the collaboration between the methods. In some methods recursion is used for traversing hierarchical directory and class structures but most of the methods are not very complex. They simply collect statistics while leveraging the Reflection component.

Data structures

The Class Loader needs no properties because the code loaded is stored in PHP's internal data structures. The Code Analyzer uses associative arrays, Reflection objects, and instances of ezcCodeAnalyzerFileDetails to store the statistical data.

Fig. 1.   A graph showing the calling structure of ezcCodeAnalyzer