public static Whitelist loadFromResourceFiles()

in modules/lang-painless/spi/src/main/java/org/elasticsearch/painless/spi/WhitelistLoader.java [143:496]


    public static Whitelist loadFromResourceFiles(Class<?> owner, Map<String, WhitelistAnnotationParser> parsers, String... filepaths) {
        List<WhitelistClass> whitelistClasses = new ArrayList<>();
        List<WhitelistMethod> whitelistStatics = new ArrayList<>();
        List<WhitelistClassBinding> whitelistClassBindings = new ArrayList<>();

        // Execute a single pass through the whitelist text files. This will gather all the
        // constructors, methods, augmented methods, and fields for each whitelisted class.
        for (String filepath : filepaths) {
            String line;
            int number = -1;

            try (
                LineNumberReader reader = new LineNumberReader(
                    new InputStreamReader(getResourceAsStream(owner, filepath), StandardCharsets.UTF_8)
                )
            ) {

                String parseType = null;
                String whitelistClassOrigin = null;
                String javaClassName = null;
                List<WhitelistConstructor> whitelistConstructors = null;
                List<WhitelistMethod> whitelistMethods = null;
                List<WhitelistField> whitelistFields = null;
                List<Object> classAnnotations = null;

                while ((line = reader.readLine()) != null) {
                    number = reader.getLineNumber();
                    line = line.trim();

                    // Skip any lines that are either blank or comments.
                    if (line.length() == 0 || line.charAt(0) == '#') {
                        continue;
                    }

                    // Handle a new class by resetting all the variables necessary to construct a new WhitelistClass for the whitelist.
                    // Expects the following format: 'class' ID annotations? '{' '\n'
                    if (line.startsWith("class ")) {
                        // Ensure the final token of the line is '{'.
                        if (line.endsWith("{") == false) {
                            throw new IllegalArgumentException(
                                "invalid class definition: failed to parse class opening bracket [" + line + "]"
                            );
                        }

                        if (parseType != null) {
                            throw new IllegalArgumentException("invalid definition: cannot embed class definition [" + line + "]");
                        }

                        // Parse the Java class name and annotations if they exist.
                        int annotationIndex = line.indexOf('@');

                        if (annotationIndex == -1) {
                            annotationIndex = line.length() - 1;
                            classAnnotations = Collections.emptyList();
                        } else {
                            classAnnotations = parseWhitelistAnnotations(parsers, line.substring(annotationIndex, line.length() - 1));
                        }

                        parseType = "class";
                        whitelistClassOrigin = "[" + filepath + "]:[" + number + "]";
                        javaClassName = line.substring(5, annotationIndex).trim();

                        // Reset all the constructors, methods, and fields to support a new class.
                        whitelistConstructors = new ArrayList<>();
                        whitelistMethods = new ArrayList<>();
                        whitelistFields = new ArrayList<>();
                    } else if (line.startsWith("static_import ")) {
                        // Ensure the final token of the line is '{'.
                        if (line.endsWith("{") == false) {
                            throw new IllegalArgumentException(
                                "invalid static import definition: failed to parse static import opening bracket [" + line + "]"
                            );
                        }

                        if (parseType != null) {
                            throw new IllegalArgumentException("invalid definition: cannot embed static import definition [" + line + "]");
                        }

                        parseType = "static_import";

                        // Handle the end of a definition and reset all previously gathered values.
                        // Expects the following format: '}' '\n'
                    } else if (line.equals("}")) {
                        if (parseType == null) {
                            throw new IllegalArgumentException("invalid definition: extraneous closing bracket");
                        }

                        // Create a new WhitelistClass with all the previously gathered constructors, methods,
                        // augmented methods, and fields, and add it to the list of whitelisted classes.
                        if ("class".equals(parseType)) {
                            whitelistClasses.add(
                                new WhitelistClass(
                                    whitelistClassOrigin,
                                    javaClassName,
                                    whitelistConstructors,
                                    whitelistMethods,
                                    whitelistFields,
                                    classAnnotations
                                )
                            );

                            whitelistClassOrigin = null;
                            javaClassName = null;
                            whitelistConstructors = null;
                            whitelistMethods = null;
                            whitelistFields = null;
                            classAnnotations = null;
                        }

                        // Reset the parseType.
                        parseType = null;

                        // Handle static import definition types.
                        // Expects the following format: ID ID '(' ( ID ( ',' ID )* )? ')' ( 'from_class' | 'bound_to' ) ID annotations?
                        // '\n'
                    } else if ("static_import".equals(parseType)) {
                        // Mark the origin of this parsable object.
                        String origin = "[" + filepath + "]:[" + number + "]";

                        // Parse the tokens prior to the method parameters.
                        int parameterStartIndex = line.indexOf('(');

                        if (parameterStartIndex == -1) {
                            throw new IllegalArgumentException(
                                "illegal static import definition: start of method parameters not found [" + line + "]"
                            );
                        }

                        String[] tokens = line.substring(0, parameterStartIndex).trim().split("\\s+");

                        String methodName;

                        // Based on the number of tokens, look up the Java method name.
                        if (tokens.length == 2) {
                            methodName = tokens[1];
                        } else {
                            throw new IllegalArgumentException("invalid method definition: unexpected format [" + line + "]");
                        }

                        String returnCanonicalTypeName = tokens[0];

                        // Parse the method parameters.
                        int parameterEndIndex = line.indexOf(')');

                        if (parameterEndIndex == -1) {
                            throw new IllegalArgumentException(
                                "illegal static import definition: end of method parameters not found [" + line + "]"
                            );
                        }

                        String[] canonicalTypeNameParameters = line.substring(parameterStartIndex + 1, parameterEndIndex)
                            .replaceAll("\\s+", "")
                            .split(",");

                        // Handle the case for a method with no parameters.
                        if ("".equals(canonicalTypeNameParameters[0])) {
                            canonicalTypeNameParameters = new String[0];
                        }

                        // Parse the annotations if they exist.
                        List<Object> annotations;
                        int annotationIndex = line.indexOf('@');

                        if (annotationIndex == -1) {
                            annotationIndex = line.length();
                            annotations = Collections.emptyList();
                        } else {
                            annotations = parseWhitelistAnnotations(parsers, line.substring(annotationIndex));
                        }

                        // Parse the static import type and class.
                        tokens = line.substring(parameterEndIndex + 1, annotationIndex).trim().split("\\s+");

                        String staticImportType;
                        String targetJavaClassName;

                        // Based on the number of tokens, look up the type and class.
                        if (tokens.length == 2) {
                            staticImportType = tokens[0];
                            targetJavaClassName = tokens[1];
                        } else {
                            throw new IllegalArgumentException("invalid static import definition: unexpected format [" + line + "]");
                        }

                        // Add a static import method or binding depending on the static import type.
                        if ("from_class".equals(staticImportType)) {
                            whitelistStatics.add(
                                new WhitelistMethod(
                                    origin,
                                    targetJavaClassName,
                                    methodName,
                                    returnCanonicalTypeName,
                                    Arrays.asList(canonicalTypeNameParameters),
                                    annotations
                                )
                            );
                        } else if ("bound_to".equals(staticImportType)) {
                            whitelistClassBindings.add(
                                new WhitelistClassBinding(
                                    origin,
                                    targetJavaClassName,
                                    methodName,
                                    returnCanonicalTypeName,
                                    List.of(canonicalTypeNameParameters),
                                    annotations
                                )
                            );
                        } else {
                            throw new IllegalArgumentException(
                                "invalid static import definition: "
                                    + "unexpected static import type ["
                                    + staticImportType
                                    + "] ["
                                    + line
                                    + "]"
                            );
                        }

                        // Handle class definition types.
                    } else if ("class".equals(parseType)) {
                        // Mark the origin of this parsable object.
                        String origin = "[" + filepath + "]:[" + number + "]";

                        // Handle the case for a constructor definition.
                        // Expects the following format: '(' ( ID ( ',' ID )* )? ')' annotations? '\n'
                        if (line.startsWith("(")) {
                            // Parse the constructor parameters.
                            int parameterEndIndex = line.indexOf(')');

                            if (parameterEndIndex == -1) {
                                throw new IllegalArgumentException(
                                    "illegal constructor definition: end of constructor parameters not found [" + line + "]"
                                );
                            }

                            String[] canonicalTypeNameParameters = line.substring(1, parameterEndIndex).replaceAll("\\s+", "").split(",");

                            // Handle the case for a constructor with no parameters.
                            if ("".equals(canonicalTypeNameParameters[0])) {
                                canonicalTypeNameParameters = new String[0];
                            }

                            // Parse the annotations if they exist.
                            List<Object> annotations;
                            int annotationIndex = line.indexOf('@');
                            annotations = annotationIndex == -1
                                ? Collections.emptyList()
                                : parseWhitelistAnnotations(parsers, line.substring(annotationIndex));

                            whitelistConstructors.add(new WhitelistConstructor(origin, List.of(canonicalTypeNameParameters), annotations));

                            // Handle the case for a method or augmented method definition.
                            // Expects the following format: ID ID? ID '(' ( ID ( ',' ID )* )? ')' annotations? '\n'
                        } else if (line.contains("(")) {
                            // Parse the tokens prior to the method parameters.
                            int parameterStartIndex = line.indexOf('(');
                            String[] tokens = line.substring(0, parameterStartIndex).trim().split("\\s+");

                            String methodName;
                            String javaAugmentedClassName;

                            // Based on the number of tokens, look up the Java method name and if provided the Java augmented class.
                            if (tokens.length == 2) {
                                methodName = tokens[1];
                                javaAugmentedClassName = null;
                            } else if (tokens.length == 3) {
                                methodName = tokens[2];
                                javaAugmentedClassName = tokens[1];
                            } else {
                                throw new IllegalArgumentException("invalid method definition: unexpected format [" + line + "]");
                            }

                            String returnCanonicalTypeName = tokens[0];

                            // Parse the method parameters.
                            int parameterEndIndex = line.indexOf(')');

                            if (parameterEndIndex == -1) {
                                throw new IllegalArgumentException(
                                    "illegal static import definition: end of method parameters not found [" + line + "]"
                                );
                            }

                            String[] canonicalTypeNameParameters = line.substring(parameterStartIndex + 1, parameterEndIndex)
                                .replaceAll("\\s+", "")
                                .split(",");

                            // Handle the case for a method with no parameters.
                            if ("".equals(canonicalTypeNameParameters[0])) {
                                canonicalTypeNameParameters = new String[0];
                            }

                            // Parse the annotations if they exist.
                            List<Object> annotations;
                            int annotationIndex = line.indexOf('@');
                            annotations = annotationIndex == -1
                                ? Collections.emptyList()
                                : parseWhitelistAnnotations(parsers, line.substring(annotationIndex));

                            whitelistMethods.add(
                                new WhitelistMethod(
                                    origin,
                                    javaAugmentedClassName,
                                    methodName,
                                    returnCanonicalTypeName,
                                    Arrays.asList(canonicalTypeNameParameters),
                                    annotations
                                )
                            );

                            // Handle the case for a field definition.
                            // Expects the following format: ID ID annotations? '\n'
                        } else {
                            // Parse the annotations if they exist.
                            List<Object> annotations;
                            int annotationIndex = line.indexOf('@');

                            if (annotationIndex == -1) {
                                annotationIndex = line.length();
                                annotations = Collections.emptyList();
                            } else {
                                annotations = parseWhitelistAnnotations(parsers, line.substring(annotationIndex));
                            }

                            // Parse the field tokens.
                            String[] tokens = line.substring(0, annotationIndex).split("\\s+");

                            // Ensure the correct number of tokens.
                            if (tokens.length != 2) {
                                throw new IllegalArgumentException("invalid field definition: unexpected format [" + line + "]");
                            }

                            whitelistFields.add(new WhitelistField(origin, tokens[1], tokens[0], annotations));
                        }
                    } else {
                        throw new IllegalArgumentException("invalid definition: unable to parse line [" + line + "]");
                    }
                }

                // Ensure all classes end with a '}' token before the end of the file.
                if (javaClassName != null) {
                    throw new IllegalArgumentException("invalid definition: expected closing bracket");
                }
            } catch (ResourceNotFoundException e) {
                throw e; // rethrow
            } catch (Exception exception) {
                throw new RuntimeException("error in [" + filepath + "] at line [" + number + "]", exception);
            }
        }

        ClassLoader loader = owner.getClassLoader();

        return new Whitelist(loader, whitelistClasses, whitelistStatics, whitelistClassBindings, Collections.emptyList());
    }