bundles/org.apache.jasper.glassfish/src/org/apache/jasper/compiler/JspReader.java
private int registerSourceFile(String file) {
        if (sourceFiles.contains(file))
            return -1;
	sourceFiles.add(file);
	this.size++;
	return sourceFiles.size() - 1;
    }
private int registerSourceFile(String file) {
        if (sourceFiles.contains(file))
            return -1;
	sourceFiles.add(file);
	this.size++;
	return sourceFiles.size() - 1;
    }
Register a new source file.
This method is used to implement file inclusion. Each included file
gets a unique identifier (which is the index in the array of source
files).

@return The index of the now registered file.