/*
* Copyright (c) 2018 Pantheon Technologies, s.r.o. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/epl-v10.html
*/
package org.opendaylight.yangtools.yang.binding;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.base.Verify.verify;
import static java.util.Objects.requireNonNull;
import com.google.common.base.MoreObjects.ToStringHelper;
import com.google.common.base.VerifyException;
import com.google.common.collect.ImmutableList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
import java.util.regex.Pattern;
import org.eclipse.jdt.annotation.NonNull;
import org.eclipse.jdt.annotation.Nullable;
/**
* Helper methods for generated binding code. This class concentrates useful primitives generated code may call
* to perform specific shared functions. This allows for generated classes to be leaner. Methods in this class follows
* general API stability requirements of the Binding Specification.
*
* @author Robert Varga
*/
public final class CodeHelpers {
private CodeHelpers() {
// Hidden
}
/**
* Require that an a value-related expression is true.
*
* @param expression Expression to evaluate
* @param value Value being validated
* @param options Valid value options checked
* @throws IllegalArgumentException if expression is false
*/
public static void validValue(final boolean expression, final Object value, final String options) {
checkArgument(expression, "expected one of: %s \n%but was: %s", options, value);
}
/**
* Require an argument being received. This is similar to {@link java.util.Objects#requireNonNull(Object)}, but
* throws an IllegalArgumentException.
*
*
* Implementation note: we expect argName to be a string literal or a constant, so that it's non-nullness can be
* quickly discovered for a call site (where we are going to be inlined).
*
* @param value Value itself
* @param name Symbolic name
* @return non-null value
* @throws IllegalArgumentException if value is null
* @throws NullPointerException if name is null
*/
// FIXME: another advantage is that it is JDT-annotated, but we could live without that. At some point we should
// schedule a big ISE-to-NPE conversion and just use Objects.requireNonNull() instead.
public static @NonNull T nonNullValue(@Nullable final T value, final @NonNull String name) {
requireNonNull(name);
checkArgument(value != null, "%s must not be null", name);
return value;
}
/**
* A shortcut for {@code Objects.requireNonNull(value, "Supplied value may not be null")}.
*
* @param value Value itself
* @throws NullPointerException if value is null
*/
public static void requireValue(@Nullable final Object value) {
requireNonNull(value, "Supplied value may not be null");
}
/**
* Append a named value to a ToStringHelper. If the value is null, this method does nothing.
*
* @param helper Helper to append to
* @param name Name of the value
* @param value Value to append
* @throws NullPointerException if the name or helper is null
*/
public static void appendValue(final ToStringHelper helper, final @NonNull String name,
final @Nullable Object value) {
if (value != null) {
helper.add(name, value);
}
}
/**
* Append a named value to a ToStringHelper. If the value is null, this method does nothing.
*
* @param helper Helper to append to
* @param name Name of the value
* @param value Value to append
* @throws NullPointerException if the name or helper is null
*/
public static void appendValue(final ToStringHelper helper, final String name, final byte[] value) {
if (value != null) {
helper.add(name, Arrays.toString(value));
}
}
/**
* Compile a list of pattern regular expressions and return them as an array. The list must hold at least two
* expressions.
*
* @param patterns Patterns to compile
* @return Compiled patterns in an array
* @throws NullPointerException if the list or any of its elements is null
* @throws VerifyException if the list has fewer than two elements
*/
public static @NonNull Pattern[] compilePatterns(final @NonNull List patterns) {
final int size = patterns.size();
verify(size > 1, "Patterns has to have at least 2 elements");
final @NonNull Pattern[] result = new Pattern[size];
for (int i = 0; i < size; ++i) {
result[i] = Pattern.compile(patterns.get(i));
}
return result;
}
/**
* Check whether a specified string value matches a specified pattern. This method handles the distinction between
* modeled XSD expression and enforcement {@link Pattern} which may reflect negation.
*
* @param value Value to be checked.
* @param pattern Enforcement pattern
* @param regex Source regular expression, as defined in YANG model
* @throws IllegalArgumentException if the value does not match the pattern
* @throws NullPointerException if any of the arguments are null
*/
public static void checkPattern(final String value, final Pattern pattern, final String regex) {
if (!pattern.matcher(value).matches()) {
final String match = RegexPatterns.isNegatedPattern(pattern) ? "matches forbidden"
: "does not match required";
throw new IllegalArgumentException("Supplied value \"" + value + "\" " + match + " pattern \""
+ regex + "\"");
}
}
/**
* Check whether a specified string value matches specified patterns. This method handles the distinction between
* modeled XSD expression and enforcement {@link Pattern} which may reflect negation.
*
* @param value Value to be checked.
* @param patterns Enforcement patterns
* @param regexes Source regular expression, as defined in YANG model. Size and order must match patterns.
* @throws IllegalArgumentException if the value does not match the pattern
* @throws NullPointerException if any of the arguments are null
* @throws VerifyException if the size of patterns and regexes does not match
*/
public static void checkPattern(final String value, final Pattern[] patterns, final String[] regexes) {
verify(patterns.length == regexes.length, "Patterns and regular expression lengths have to match");
for (int i = 0; i < patterns.length; ++i) {
checkPattern(value, patterns[i], regexes[i]);
}
}
/**
* Throw an IllegalArgument exception describing a length violation.
*
* @param expected String describing expected lengths
* @param actual Actual observed object
* @throws IllegalArgumentException always
*/
public static void throwInvalidLength(final String expected, final Object actual) {
throw new IllegalArgumentException("Invalid length: " + actual + ", expected: " + expected + ".");
}
/**
* Throw an IllegalArgument exception describing a length violation.
*
* @param expected String describing expected lengths
* @param actual Actual observed byte array
* @throws IllegalArgumentException always
*/
public static void throwInvalidLength(final String expected, final byte[] actual) {
throwInvalidLength(expected, Arrays.toString(actual));
}
/**
* Throw an IllegalArgument exception describing a range violation.
*
* @param expected String describing expected ranges
* @param actual Actual observed object
* @throws IllegalArgumentException always
*/
public static void throwInvalidRange(final String expected, final Object actual) {
throw new IllegalArgumentException("Invalid range: " + actual + ", expected: " + expected + ".");
}
/**
* Throw an IllegalArgument exception describing a range violation.
*
* @param expected String describing expected ranges
* @param actual Actual observed value
* @throws IllegalArgumentException always
*/
public static void throwInvalidRange(final String expected, final int actual) {
// Not a code duplication: provides faster string concat via StringBuilder.append(int)
throw new IllegalArgumentException("Invalid range: " + actual + ", expected: " + expected + ".");
}
/**
* Throw an IllegalArgument exception describing a range violation.
*
* @param expected String describing expected ranges
* @param actual Actual observed value
* @throws IllegalArgumentException always
*/
public static void throwInvalidRange(final String expected, final long actual) {
// Not a code duplication: provides faster string concat via StringBuilder.append(long)
throw new IllegalArgumentException("Invalid range: " + actual + ", expected: " + expected + ".");
}
/**
* Throw an IllegalArgument exception describing a range violation.
*
* @param expected Objects describing expected ranges
* @param actual Actual observed byte array
* @throws IllegalArgumentException always
*/
public static void throwInvalidRange(final Object[] expected, final Object actual) {
throwInvalidRange(Arrays.toString(expected), actual);
}
/**
* Check whether specified List is null and if so return an immutable list instead. This method supports
* non-null default getter methods.
*
* @param input input list, may be null
* @return Input list or an empty list.
*/
public static @NonNull List nonnull(final @Nullable List input) {
return input != null ? input : ImmutableList.of();
}
/**
* Return hash code of a single-property wrapper class. Since the wrapper is not null, we really want to discern
* this object being present, hence {@link Objects#hashCode()} is not really useful we would end up with {@code 0}
* for both non-present and present-with-null objects.
*
* @param obj Internal object to hash
* @return Wrapper object hash code
*/
public static int wrapperHashCode(final @Nullable Object obj) {
return wrapHashCode(Objects.hashCode(obj));
}
/**
* Return hash code of a single-property wrapper class. Since the wrapper is not null, we really want to discern
* this object being present, hence {@link Arrays#hashCode()} is not really useful we would end up with {@code 0}
* for both non-present and present-with-null objects.
*
* @param obj Internal object to hash
* @return Wrapper object hash code
*/
public static int wrapperHashCode(final byte @Nullable[] obj) {
return wrapHashCode(Arrays.hashCode(obj));
}
/**
* The constant '31' is the result of folding this code:
*
* final int prime = 31;
* int result = 1;
* result = result * prime + Objects.hashCode(obj);
* return result;
*
* when hashCode is returned as 0, such as due to obj being null or its hashCode being 0.
*
* @param hash Wrapped object hash
* @return Wrapper object hash
*/
private static int wrapHashCode(final int hash) {
return hash == 0 ? 31 : hash;
}
}