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Module contains external API of the evitaDB.
/*
*
* _ _ ____ ____
* _____ _(_) |_ __ _| _ \| __ )
* / _ \ \ / / | __/ _` | | | | _ \
* | __/\ V /| | || (_| | |_| | |_) |
* \___| \_/ |_|\__\__,_|____/|____/
*
* Copyright (c) 2023-2024
*
* Licensed under the Business Source License, Version 1.1 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://github.com/FgForrest/evitaDB/blob/master/LICENSE
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.evitadb.utils;
import lombok.AccessLevel;
import lombok.Getter;
import lombok.NoArgsConstructor;
import lombok.RequiredArgsConstructor;
import javax.annotation.Nonnull;
import javax.annotation.Nullable;
import java.lang.reflect.Array;
import java.util.AbstractList;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.List;
import java.util.Objects;
import java.util.Random;
import java.util.function.IntBinaryOperator;
import java.util.function.IntFunction;
import java.util.function.ToIntBiFunction;
import java.util.function.ToIntFunction;
import java.util.function.UnaryOperator;
/**
* String utils contains base method for working with Array operations.
* We know these functions are available in Apache Commons, but we try to keep our transitive dependencies as low as
* possible, so we rather went through duplication of the code.
*
* @author Jan Novotný ([email protected]), FG Forrest a.s. (c) 2021
*/
@NoArgsConstructor(access = AccessLevel.PRIVATE)
public class ArrayUtils {
/**
* Returns true if array is either null or has no items in it
*
* @param array to check
* @return true if empty
*/
public static boolean isEmpty(@Nullable Object[] array) {
return array == null || array.length == 0;
}
/**
* Returns true if array is either null or has no items in it
*
* @param array to check
* @return true if empty
*/
public static boolean isEmpty(@Nullable int[] array) {
return array == null || array.length == 0;
}
/**
* Returns true if array is either null or has no items in it
*
* @param array to check
* @return true if empty
*/
public static boolean isEmpty(@Nullable long[] array) {
return array == null || array.length == 0;
}
/**
* Searches a range of the specified array of object for the specified value using the binary search algorithm.
* The range must be sorted (as by the {@link Arrays#sort(Object[])} method) prior to making this call. If it
* is not sorted, the results are undefined. If the range contains multiple elements with the specified value,
* there is no guarantee which one will be found.
*
* @param a the array to be searched
* @param b the value that should be compared
* @param comparator that envelopes the value to be searched for and returns negative integer for lesser values and
* positive integer for greater values when comparing passed value with the input one
* @return index of the search key, if it is contained in the array within the specified range;
* otherwise, (-(insertion point) - 1). The insertion point is defined as the point at
* which the key would be inserted into the array: the index of the first element in the range greater than the key,
* or {@code toIndex} if all elements in the range are less than the specified key.
* Note that this guarantees that the return value will be >= 0 if and only if the key is found.
* @throws IllegalArgumentException if {@code fromIndex > toIndex}
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0 or toIndex > a.length}
*/
public static int binarySearch(@Nonnull T[] a, @Nonnull U b, @Nonnull ToIntBiFunction comparator) {
return binarySearch(a, b, 0, a.length, comparator);
}
/**
* Searches a range of the specified array of object for the specified value using the binary search algorithm.
* The range must be sorted (as by the {@link Arrays#sort(Object[])} method) prior to making this call. If it
* is not sorted, the results are undefined. If the range contains multiple elements with the specified value,
* there is no guarantee which one will be found.
*
* @param a the array to be searched
* @param a the item to be looked up
* @param fromIndex the index of the first element (inclusive) to be
* searched
* @param toIndex the index of the last element (exclusive) to be searched
* @param comparator that envelopes the value to be searched for and returns negative integer for lesser values and
* positive integer for greater values when comparing passed value with the input one
* @return index of the search key, if it is contained in the array within the specified range;
* otherwise, (-(insertion point) - 1). The insertion point is defined as the point at
* which the key would be inserted into the array: the index of the first element in the range greater than the key,
* or {@code toIndex} if all elements in the range are less than the specified key.
* Note that this guarantees that the return value will be >= 0 if and only if the key is found.
* @throws IllegalArgumentException if {@code fromIndex > toIndex}
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0 or toIndex > a.length}
*/
public static int binarySearch(@Nonnull T[] a, @Nonnull U b, int fromIndex, int toIndex, @Nonnull ToIntBiFunction comparator) {
if (fromIndex > toIndex) {
throw new IllegalArgumentException(
"fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")");
}
if (fromIndex < 0) {
throw new ArrayIndexOutOfBoundsException(fromIndex);
}
if (toIndex > a.length) {
throw new ArrayIndexOutOfBoundsException(toIndex);
}
int low = fromIndex;
int high = toIndex - 1;
while (low <= high) {
int mid = (low + high) >>> 1;
T midVal = a[mid];
final int comparisonResult = comparator.applyAsInt(midVal, b);
if (comparisonResult < 0)
low = mid + 1;
else if (comparisonResult > 0)
high = mid - 1;
else
return mid; // key found
}
return -(low + 1); // key not found.
}
/**
* Searches a range of the specified array of object for the specified value using the binary search algorithm.
* The range must be sorted (as by the {@link Arrays#sort(Object[])} method) prior to making this call. If it
* is not sorted, the results are undefined. If the range contains multiple elements with the specified value,
* there is no guarantee which one will be found.
*
* @param valueSupplier that extracts particular value for passed index
* @param b the value that should be compared
* @param totalCount the total number of elements in the searched data structure
* @param comparator that envelopes the value to be searched for and returns negative integer for lesser values and
* positive integer for greater values when comparing passed value with the input one
* @return index of the search key, if it is contained in the array within the specified range;
* otherwise, (-(insertion point) - 1). The insertion point is defined as the point at
* which the key would be inserted into the array: the index of the first element in the range greater than the key,
* or {@code toIndex} if all elements in the range are less than the specified key.
* Note that this guarantees that the return value will be >= 0 if and only if the key is found.
* @throws IllegalArgumentException if {@code fromIndex > toIndex}
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0 or toIndex > a.length}
*/
public static int binarySearch(@Nonnull IntFunction valueSupplier, @Nonnull U b, int totalCount, @Nonnull ToIntBiFunction comparator) {
return binarySearch(valueSupplier, b, 0, totalCount, totalCount, comparator);
}
/**
* Searches a range of the specified array of object for the specified value using the binary search algorithm.
* The range must be sorted (as by the {@link Arrays#sort(Object[])} method) prior to making this call. If it
* is not sorted, the results are undefined. If the range contains multiple elements with the specified value,
* there is no guarantee which one will be found.
*
* @param valueSupplier that extracts particular value for passed index
* @param b the value that should be compared
* @param fromIndex the index of the first element (inclusive) to be
* searched
* @param toIndex the index of the last element (exclusive) to be searched
* @param totalCount the total number of elements in the searched data structure
* @param comparator that envelopes the value to be searched for and returns negative integer for lesser values and
* positive integer for greater values when comparing passed value with the input one
* @return index of the search key, if it is contained in the array within the specified range;
* otherwise, (-(insertion point) - 1). The insertion point is defined as the point at
* which the key would be inserted into the array: the index of the first element in the range greater than the key,
* or {@code toIndex} if all elements in the range are less than the specified key.
* Note that this guarantees that the return value will be >= 0 if and only if the key is found.
* @throws IllegalArgumentException if {@code fromIndex > toIndex}
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0 or toIndex > a.length}
*/
public static int binarySearch(@Nonnull IntFunction valueSupplier, @Nonnull U b, int fromIndex, int toIndex, int totalCount, @Nonnull ToIntBiFunction comparator) {
if (fromIndex > toIndex) {
throw new IllegalArgumentException(
"fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")");
}
if (fromIndex < 0) {
throw new ArrayIndexOutOfBoundsException(fromIndex);
}
if (toIndex > totalCount) {
throw new ArrayIndexOutOfBoundsException(toIndex);
}
int low = fromIndex;
int high = toIndex - 1;
while (low <= high) {
int mid = (low + high) >>> 1;
T midVal = valueSupplier.apply(mid);
final int comparisonResult = comparator.applyAsInt(midVal, b);
if (comparisonResult < 0)
low = mid + 1;
else if (comparisonResult > 0)
high = mid - 1;
else
return mid; // key found
}
return -(low + 1); // key not found.
}
/**
* This variant of binary search allows duplicate records in terms of {@link Comparator} returning zero for multiple
* elements of the array. In that sense the binary search scans array to the beginning until it discovers first
* element which returns negative number for the {@link Comparator} or reaches the beginning (and in such case it
* returns first element of the array).
*
* Searches a range of the specified array of object for the specified value using the binary search algorithm.
* The range must be sorted (as by the {@link Arrays#sort(Object[])} method) prior to making this call. If it
* is not sorted, the results are undefined. If the range contains multiple elements with the specified value,
* there is no guarantee which one will be found.
*
* @param a the array to be searched
* @param b the value that should be compared
* @param comparator that envelopes the value to be searched for and returns negative integer for lesser values and
* positive integer for greater values when comparing passed value with the input one
* @return index of the search key, if it is contained in the array within the specified range;
* otherwise, (-(insertion point) - 1). The insertion point is defined as the point at
* which the key would be inserted into the array: the index of the first element in the range greater than the key,
* or {@code toIndex} if all elements in the range are less than the specified key.
* Note that this guarantees that the return value will be >= 0 if and only if the key is found.
* @throws IllegalArgumentException if {@code fromIndex > toIndex}
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0 or toIndex > a.length}
*/
public static int binarySearchWithDuplicates(@Nonnull T[] a, @Nonnull U b, @Nonnull ToIntBiFunction comparator) {
return binarySearchWithDuplicates(a, b, 0, a.length, comparator);
}
/**
* This variant of binary search allows duplicate records in terms of {@link Comparator} returning zero for multiple
* elements of the array. In that sense the binary search scans array to the beginning until it discovers first
* element which returns negative number for the {@link Comparator} or reaches the beginning (and in such case it
* returns first element of the array).
*
* Searches a range of the specified array of object for the specified value using the binary search algorithm.
* The range must be sorted (as by the {@link Arrays#sort(Object[])} method) prior to making this call. If it
* is not sorted, the results are undefined. If the range contains multiple elements with the specified value,
* there is no guarantee which one will be found.
*
* @param a the array to be searched
* @param a the item to be looked up
* @param fromIndex the index of the first element (inclusive) to be
* searched
* @param toIndex the index of the last element (exclusive) to be searched
* @param comparator that envelopes the value to be searched for and returns negative integer for lesser values and
* positive integer for greater values when comparing passed value with the input one
* @return index of the search key, if it is contained in the array within the specified range;
* otherwise, (-(insertion point) - 1). The insertion point is defined as the point at
* which the key would be inserted into the array: the index of the first element in the range greater than the key,
* or {@code toIndex} if all elements in the range are less than the specified key.
* Note that this guarantees that the return value will be >= 0 if and only if the key is found.
* @throws IllegalArgumentException if {@code fromIndex > toIndex}
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0 or toIndex > a.length}
*/
public static int binarySearchWithDuplicates(@Nonnull T[] a, @Nonnull U b, int fromIndex, int toIndex, @Nonnull ToIntBiFunction comparator) {
int index = binarySearch(a, b, fromIndex, toIndex, comparator);
while (index > 0 && comparator.applyAsInt(a[index - 1], b) == 0) {
index--;
}
return index;
}
/**
* Searches a range of the specified array of object for the specified value using the binary search algorithm.
* The range must be sorted (as by the {@link Arrays#sort(Object[])} method) prior to making this call. If it
* is not sorted, the results are undefined. If the range contains multiple elements with the specified value,
* there is no guarantee which one will be found.
*
* @param a the array to be searched
* @param b the value that should be compared
* @param comparator that envelopes the value to be searched for and returns negative integer for lesser values and
* positive integer for greater values when comparing passed value with the input one
* @return index of the search key, if it is contained in the array within the specified range;
* otherwise, (-(insertion point) - 1). The insertion point is defined as the point at
* which the key would be inserted into the array: the index of the first element in the range greater than the key,
* or {@code toIndex} if all elements in the range are less than the specified key.
* Note that this guarantees that the return value will be >= 0 if and only if the key is found.
* @throws IllegalArgumentException if {@code fromIndex > toIndex}
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0 or toIndex > a.length}
*/
public static int binarySearch(@Nonnull int[] a, int b, @Nonnull IntBinaryOperator comparator) {
return binarySearch(a, b, 0, a.length, comparator);
}
/**
* Searches a range of the specified array of object for the specified value using the binary search algorithm.
* The range must be sorted (as by the {@link Arrays#sort(Object[])} method) prior to making this call. If it
* is not sorted, the results are undefined. If the range contains multiple elements with the specified value,
* there is no guarantee which one will be found.
*
* @param a the array to be searched
* @param a the item to be looked up
* @param fromIndex the index of the first element (inclusive) to be
* searched
* @param toIndex the index of the last element (exclusive) to be searched
* @param comparator that envelopes the value to be searched for and returns negative integer for lesser values and
* positive integer for greater values when comparing passed value with the input one
* @return index of the search key, if it is contained in the array within the specified range;
* otherwise, (-(insertion point) - 1). The insertion point is defined as the point at
* which the key would be inserted into the array: the index of the first element in the range greater than the key,
* or {@code toIndex} if all elements in the range are less than the specified key.
* Note that this guarantees that the return value will be >= 0 if and only if the key is found.
* @throws IllegalArgumentException if {@code fromIndex > toIndex}
* @throws ArrayIndexOutOfBoundsException if {@code fromIndex < 0 or toIndex > a.length}
*/
public static int binarySearch(@Nonnull int[] a, int b, int fromIndex, int toIndex, @Nonnull IntBinaryOperator comparator) {
if (fromIndex > toIndex) {
throw new IllegalArgumentException(
"fromIndex(" + fromIndex + ") > toIndex(" + toIndex + ")");
}
if (fromIndex < 0) {
throw new ArrayIndexOutOfBoundsException(fromIndex);
}
if (toIndex > a.length) {
throw new ArrayIndexOutOfBoundsException(toIndex);
}
int low = fromIndex;
int high = toIndex - 1;
while (low <= high) {
int mid = (low + high) >>> 1;
int midVal = a[mid];
final int comparisonResult = comparator.applyAsInt(midVal, b);
if (comparisonResult < 0)
low = mid + 1;
else if (comparisonResult > 0)
high = mid - 1;
else
return mid; // key found
}
return -(low + 1); // key not found.
}
/**
* Method computes insertion point of an arbitrary record into the ordered array.
* Result object contains information about the position and whether the record is already in the array.
*/
public static > InsertionPosition computeInsertPositionOfObjInOrderedArray(@Nonnull T[] a, @Nonnull U b, @Nonnull ToIntBiFunction comparator) {
final int index = binarySearch(a, b, comparator);
if (index >= 0) {
return new InsertionPosition(index, true);
} else {
return new InsertionPosition(-1 * (index) - 1, false);
}
}
/**
* Inserts new integer to the sorted array on proper place and returns new expanded array.
* Integer is inserted only when array doesn't yet contain the record.
*/
@Nonnull
public static int[] insertIntIntoOrderedArray(int recId, @Nonnull int[] recordIds) {
final InsertionPosition position = computeInsertPositionOfIntInOrderedArray(recId, recordIds);
return position.alreadyPresent() ? recordIds : insertIntIntoArrayOnIndex(recId, recordIds, position.position());
}
/**
* Inserts new integer to the sorted array on proper place and returns new expanded array.
* Integer is inserted only when array doesn't yet contain the record.
* Method uses comparator to locate the proper position in the array so that other than natural int ordering can
* be used for the binary search algorithm that precedes the insertion.
*/
@Nonnull
public static int[] insertIntIntoOrderedArray(int recId, @Nonnull int[] recordIds, @Nonnull IntBinaryOperator comparator) {
final InsertionPosition position = computeInsertPositionOfIntInOrderedArray(recId, recordIds, comparator);
return position.alreadyPresent() ? recordIds : insertIntIntoArrayOnIndex(recId, recordIds, position.position());
}
/**
* Inserts new integer to the array on target position.
*/
@Nonnull
public static int[] insertIntIntoArrayOnIndex(int recId, @Nonnull int[] recordIds, int position) {
int len = recordIds.length;
final int targetSize = len + 1;
int[] newElements = new int[targetSize];
System.arraycopy(recordIds, 0, newElements, 0, position);
System.arraycopy(recordIds, position, newElements, position + 1, recordIds.length - position);
newElements[position] = recId;
return newElements;
}
/**
* Removes integer from ordered array and shrinks it.
*/
@Nonnull
public static int[] removeIntFromOrderedArray(int recId, @Nonnull int[] recordIds) {
int len = recordIds.length;
final int index = Arrays.binarySearch(recordIds, recId);
if (index >= 0) {
final int targetSize = len - 1;
int[] newElements = new int[targetSize];
System.arraycopy(recordIds, 0, newElements, 0, index);
System.arraycopy(recordIds, index + 1, newElements, index, recordIds.length - index - 1);
return newElements;
} else {
// recId not found in array
return recordIds;
}
}
/**
* Removes integer from array on specified index and shrinks it.
*/
@Nonnull
public static int[] removeIntFromArrayOnIndex(@Nonnull int[] recordIds, int index) {
int len = recordIds.length;
final int targetSize = len - 1;
int[] newElements = new int[targetSize];
System.arraycopy(recordIds, 0, newElements, 0, index);
System.arraycopy(recordIds, index + 1, newElements, index, recordIds.length - index - 1);
return newElements;
}
/**
* Removes integer from array on specified index and shrinks it.
*/
@Nonnull
public static int[] removeRangeFromArray(@Nonnull int[] recordIds, int startIndex, int endIndex) {
int len = recordIds.length;
final int targetSize = len - (endIndex - startIndex);
int[] newElements = new int[targetSize];
System.arraycopy(recordIds, 0, newElements, 0, startIndex);
System.arraycopy(recordIds, endIndex, newElements, startIndex, recordIds.length - endIndex);
return newElements;
}
/**
* Inserts new long to the sorted array on proper place and returns new expanded array.
* Long is inserted only when array doesn't yet contain the record.
*/
@Nonnull
public static long[] insertLongIntoOrderedArray(long recId, @Nonnull long[] recordIds) {
final InsertionPosition position = computeInsertPositionOfLongInOrderedArray(recId, recordIds);
return position.alreadyPresent() ? recordIds : insertLongIntoArrayOnIndex(recId, recordIds, position.position());
}
/**
* Inserts new integer to the array on target position.
*/
@Nonnull
public static long[] insertLongIntoArrayOnIndex(long recId, @Nonnull long[] recordIds, int position) {
int len = recordIds.length;
final int targetSize = len + 1;
long[] newElements = new long[targetSize];
System.arraycopy(recordIds, 0, newElements, 0, position);
System.arraycopy(recordIds, position, newElements, position + 1, recordIds.length - position);
newElements[position] = recId;
return newElements;
}
/**
* Removes integer from ordered array and shrinks it.
*/
@Nonnull
public static long[] removeLongFromOrderedArray(long recId, @Nonnull long[] recordIds) {
final int len = recordIds.length;
final int index = Arrays.binarySearch(recordIds, recId);
if (index >= 0) {
final int targetSize = len - 1;
long[] newElements = new long[targetSize];
System.arraycopy(recordIds, 0, newElements, 0, index);
System.arraycopy(recordIds, index + 1, newElements, index, recordIds.length - index - 1);
return newElements;
} else {
// recId not found in array
return recordIds;
}
}
/**
* Removes integer from array on specified index and shrinks it.
*/
@Nonnull
public static long[] removeLongFromArrayOnIndex(@Nonnull long[] recordIds, int index) {
final int len = recordIds.length;
final int targetSize = len - 1;
long[] newElements = new long[targetSize];
System.arraycopy(recordIds, 0, newElements, 0, index);
System.arraycopy(recordIds, index + 1, newElements, index, recordIds.length - index - 1);
return newElements;
}
/**
* Inserts any arbitrary record into the ordered array and returns enlarged array.
* Record is inserted only when array doesn't yet contain the record.
*/
@Nonnull
public static > T[] insertRecordIntoOrderedArray(@Nonnull T recId, @Nonnull T[] recordIds) {
final int index = Arrays.binarySearch(recordIds, recId);
if (index >= 0) {
return recordIds;
} else {
return insertRecordIntoArray(recId, recordIds, -1 * (index) - 1);
}
}
/**
* Inserts new record to the sorted array on proper place determined by comparator and returns new expanded array.
* Integer is inserted only when array doesn't yet contain the record.
*/
@Nonnull
public static T[] insertRecordIntoOrderedArray(@Nonnull T b, @Nonnull T[] a, @Nonnull Comparator comparator) {
final int index = binarySearch(a, b, comparator::compare);
if (index < 0) {
return insertRecordIntoArray(b, a, -1 * (index) - 1);
} else {
return a;
}
}
/**
* Inserts any arbitrary record into the ordered array and returns enlarged array.
* Record is inserted only when array doesn't yet contain the record.
*
* @param newItem item template with key, that should be inserted into an array
* @param mutator used to mutate existing or create new item to be placed on target position
*/
@Nonnull
public static > T[] insertRecordIntoOrderedArray(@Nonnull T newItem, @Nonnull UnaryOperator mutator, @Nonnull T[] records) {
final InsertionPosition position = computeInsertPositionOfObjInOrderedArray(newItem, records);
final int posIndex = position.position();
if (position.alreadyPresent()) {
// mutate existing record and return array untouched
records[posIndex] = mutator.apply(records[posIndex]);
return records;
} else {
// create new item using mutator and return array with new item inserted to appropriate position
return insertRecordIntoArray(mutator.apply(null), records, posIndex);
}
}
/**
* Inserts any arbitrary record into the array on specific position.
*/
@Nonnull
public static T[] insertRecordIntoArray(@Nonnull T recId, @Nonnull T[] recordIds, int position) {
int len = recordIds.length;
final int targetSize = len + 1;
@SuppressWarnings("unchecked")
T[] newElements = (T[]) Array.newInstance(recordIds.getClass().getComponentType(), targetSize);
System.arraycopy(recordIds, 0, newElements, 0, position);
System.arraycopy(recordIds, position, newElements, position + 1, recordIds.length - position);
newElements[position] = recId;
return newElements;
}
/**
* Removes arbitrary record from ordered array and shrinks it.
*/
@Nonnull
public static > T[] removeRecordFromOrderedArray(@Nonnull T recId, @Nonnull T[] recordIds) {
int len = recordIds.length;
final int index = Arrays.binarySearch(recordIds, recId);
if (index >= 0) {
final int targetSize = len - 1;
@SuppressWarnings("unchecked")
T[] newElements = (T[]) Array.newInstance(recId.getClass(), targetSize);
System.arraycopy(recordIds, 0, newElements, 0, index);
System.arraycopy(recordIds, index + 1, newElements, index, recordIds.length - index - 1);
return newElements;
} else {
// recId not found in array
return recordIds;
}
}
/**
* Removes existing record from the sorted array on proper place determined by comparator and returns new expanded array.
* Integer is removed only when array doesn't yet contain the record.
*/
@Nonnull
public static T[] removeRecordFromOrderedArray(@Nonnull T b, @Nonnull T[] a, @Nonnull Comparator comparator) {
final int index = binarySearch(a, b, comparator::compare);
if (index >= 0) {
return removeRecordFromArrayOnIndex(a, index);
} else {
return a;
}
}
/**
* Removes arbitrary record from array on specified index and shrinks it.
*/
@Nonnull
public static T[] removeRecordFromArrayOnIndex(@Nonnull T[] recordIds, int index) {
int len = recordIds.length;
final int targetSize = len - 1;
@SuppressWarnings("unchecked")
T[] newElements = (T[]) Array.newInstance(recordIds.getClass().getComponentType(), targetSize);
System.arraycopy(recordIds, 0, newElements, 0, index);
System.arraycopy(recordIds, index + 1, newElements, index, recordIds.length - index - 1);
return newElements;
}
/**
* Method computes index of an integer in the unordered array.
*/
public static int indexOf(int recId, @Nonnull int[] recordIds) {
for (int i = 0; i < recordIds.length; i++) {
if (recId == recordIds[i]) {
return i;
}
}
return -1;
}
/**
* Method computes index of a value in the unordered array.
*
* @return -1 if the value was not found or is null
*/
public static int indexOf(@Nullable T value, @Nonnull T[] values) {
for (int i = 0; i < values.length; i++) {
if (Objects.equals(value, values[i])) {
return i;
}
}
return -1;
}
/**
* Method computes insertion point of an integer into the ordered array.
* Result object contains information about the position and whether the integer is already in the array.
*/
@Nonnull
public static InsertionPosition computeInsertPositionOfIntInOrderedArray(int recId, @Nonnull int[] recordIds) {
final int index = Arrays.binarySearch(recordIds, recId);
if (index >= 0) {
return new InsertionPosition(index, true);
} else {
return new InsertionPosition(-1 * (index) - 1, false);
}
}
/**
* Method computes insertion point of an integer into the ordered array.
* Result object contains information about the position and whether the integer is already in the array.
* Method uses comparator to locate the proper position in the array so that other than natural int ordering can
* be used for the binary search algorithm.
*/
@Nonnull
public static InsertionPosition computeInsertPositionOfIntInOrderedArray(int recId, @Nonnull int[] recordIds, @Nonnull IntBinaryOperator comparator) {
final int index = ArrayUtils.binarySearch(recordIds, recId, comparator);
if (index >= 0) {
return new InsertionPosition(index, true);
} else {
return new InsertionPosition(-1 * (index) - 1, false);
}
}
/**
* Method computes insertion point of a long into the ordered array.
* Result object contains information about the position and whether the long is already in the array.
*/
@Nonnull
public static InsertionPosition computeInsertPositionOfLongInOrderedArray(long recId, @Nonnull long[] recordIds) {
final int index = Arrays.binarySearch(recordIds, recId);
if (index >= 0) {
return new InsertionPosition(index, true);
} else {
return new InsertionPosition(-1 * (index) - 1, false);
}
}
/**
* Method computes insertion point of an arbitrary record into the ordered array.
* Result object contains information about the position and whether the record is already in the array.
*/
@Nonnull
public static > InsertionPosition computeInsertPositionOfObjInOrderedArray(@Nonnull T recId, @Nonnull T[] recordIds) {
final int index = Arrays.binarySearch(recordIds, recId);
if (index >= 0) {
return new InsertionPosition(index, true);
} else {
return new InsertionPosition(-1 * (index) - 1, false);
}
}
/**
* Method computes insertion point of an arbitrary record into the ordered array.
* Result object contains information about the position and whether the record is already in the array.
*/
@Nonnull
public static > InsertionPosition computeInsertPositionOfObjInOrderedArray(@Nonnull T recId, @Nonnull T[] recordIds, @Nonnull Comparator comparator) {
final int index = Arrays.binarySearch(recordIds, recId, comparator);
if (index >= 0) {
return new InsertionPosition(index, true);
} else {
return new InsertionPosition(-1 * (index) - 1, false);
}
}
/**
* Returns TRUE if ALL subSet items are part of superSet items.
*/
public static boolean contains(@Nonnull T[] superSet, @Nonnull T[] subSet) {
for (T subSetItem : subSet) {
if (!contains(superSet, subSetItem)) {
return false;
}
}
return true;
}
/**
* Returns TRUE if item is part of superSet items.
*/
public static boolean contains(@Nonnull T[] superSet, @Nonnull T item) {
for (T superSetItem : superSet) {
if (item.equals(superSetItem)) {
return true;
}
}
return false;
}
/**
* Returns TRUE if item is part of superSet items.
*/
public static boolean contains(@Nonnull int[] superSet, int item) {
for (int superSetItem : superSet) {
if (item == superSetItem) {
return true;
}
}
return false;
}
/**
* Reverses contents of the array - i.e. first element becomes the last element of the array.
* Modifies contents of the passed array.
*/
public static void reverse(@Nonnull Object[] array) {
int i = 0;
int j = array.length - 1;
Object tmp;
while (j > i) {
tmp = array[j];
array[j] = array[i];
array[i] = tmp;
j--;
i++;
}
}
/**
* Reverses contents of the array - i.e. first element becomes the last element of the array.
* Doesn't modify contents of the passed array - instead crates and returns new.
*/
@Nonnull
public static int[] reverse(@Nonnull int[] array) {
final int[] result = new int[array.length];
System.arraycopy(array, 0, result, 0, array.length);
int i = 0;
int j = result.length - 1;
int tmp;
while (j > i) {
tmp = result[j];
result[j] = result[i];
result[i] = tmp;
j--;
i++;
}
return result;
}
/**
* Reverses contents of the array - i.e. first element becomes the last element of the array.
* Modifies contents of the passed array.
*/
public static void reverseInPlace(@Nonnull int[] array) {
int i = 0;
int j = array.length - 1;
int tmp;
while (j > i) {
tmp = array[j];
array[j] = array[i];
array[i] = tmp;
j--;
i++;
}
}
/**
* Sorts second array by the natural ordering of first array. Contents of the first are not changed, but the contents
* of the second array are changed.
*/
public static void sortSecondAlongFirstArray(@Nonnull int[] first, @Nonnull int[] second) {
Assert.isTrue(first.length == second.length, "Both arrays must have same length!");
// now sort positions according to recordId value - this will change ordered positions to unordered ones
final IntArrayWrapper wrapper = new IntArrayWrapper(second);
wrapper.sort(Comparator.comparing(o -> first[o]));
}
/**
* Sorts second array by the natural ordering of first array. Contents of the first nor second array are changed.
* Third array is created in the process and sorted contents of the second array are returned in this new third
* array as the output of the method.
*/
@Nonnull
public static > int[] computeSortedSecondAlongFirstArray(@Nonnull T[] first, @Nonnull int[] second) {
Assert.isTrue(first.length == second.length, "Both arrays must have same length!");
return computeSortedSecondAlongFirstArray(Comparator.comparing(o -> first[o]), second);
}
/**
* Sorts array by the Comparator passed in first argument. Contents of the array are not changed.
* Second array is created in the process and sorted contents of the array are returned in this new second array
* as the output of the method.
*/
@Nonnull
public static int[] computeSortedSecondAlongFirstArray(@Nonnull Comparator comparator, @Nonnull int[] array) {
// clone original array
int[] sortedRecordIds = new int[array.length];
System.arraycopy(array, 0, sortedRecordIds, 0, array.length);
// now sort positions according to recordId value - this will change ordered positions to unordered ones
final IntArrayWrapper wrapper = new IntArrayWrapper(sortedRecordIds);
wrapper.sort(comparator);
// withdraw sorted ids
return wrapper.getElements();
}
/**
* Sorts array by the Comparator passed in first argument. Contents of the array are changed.
*/
public static void sortArray(@Nonnull Comparator comparator, @Nonnull int[] array) {
// now sort positions according to recordId value - this will change ordered positions to unordered ones
final IntArrayWrapper wrapper = new IntArrayWrapper(array);
wrapper.sort(comparator);
}
/**
* Sorts array by the Comparator passed in first argument. Contents of the array are changed.
*/
public static void sortArray(@Nonnull Comparator comparator, @Nonnull T[] array) {
// now sort positions according to recordId value - this will change ordered positions to unordered ones
final ArrayWrapper wrapper = new ArrayWrapper<>(array);
wrapper.sort(comparator);
}
/**
* This method will merge all passed arrays into one. All values from all arrays will be combined one after another.
* Result array is not sorted.
*/
@Nonnull
public static T[] mergeArrays(@Nonnull T[]... array) {
if (array.length == 0) {
throw new IllegalArgumentException("Empty argument is not allowed!");
}
int resultSize = 0;
for (T[] arrayItem : array) {
resultSize = resultSize + arrayItem.length;
}
int offset = 0;
@SuppressWarnings({"unchecked"})
T[] result = (T[]) Array.newInstance(array[0].getClass().getComponentType(), resultSize);
for (T[] configItem : array) {
System.arraycopy(configItem, 0, result, offset, configItem.length);
offset = offset + configItem.length;
}
return result;
}
/**
* This method will merge all passed arrays into one. All values from all arrays will be combined one after another.
* Result array is not sorted.
*/
@Nonnull
public static int[] mergeArrays(@Nonnull int[]... array) {
if (array.length == 0) {
throw new IllegalArgumentException("Empty argument is not allowed!");
}
int resultSize = 0;
for (int[] configItem : array) {
resultSize = resultSize + configItem.length;
}
int offset = 0;
int[] result = (int[]) Array.newInstance(array[0].getClass().getComponentType(), resultSize);
for (int[] configItem : array) {
System.arraycopy(configItem, 0, result, offset, configItem.length);
offset = offset + configItem.length;
}
return result;
}
/**
* This method will shuffle elements in array in random order. The passed array gets modified.
*/
public static void shuffleArray(@Nonnull Random rnd, @Nonnull Object[] array) {
for (int i = array.length - 1; i > 0; i--) {
int index = rnd.nextInt(i + 1);
Object a = array[index];
array[index] = array[i];
array[i] = a;
}
}
/**
* This method will shuffle elements in array in random order. The passed array gets modified.
*/
public static void shuffleArray(@Nonnull Random rnd, @Nonnull int[] array, int maximalCountOfShuffledElements) {
int shuffled = 0;
for (int i = 0; i < array.length && shuffled < maximalCountOfShuffledElements; i++) {
int sourceIndex = rnd.nextInt(array.length);
int targetIndex = i + rnd.nextInt(array.length / maximalCountOfShuffledElements);
if (sourceIndex != targetIndex && targetIndex < array.length) {
int a = array[targetIndex];
array[targetIndex] = array[sourceIndex];
array[sourceIndex] = a;
i = targetIndex;
shuffled++;
}
}
}
/**
* Extracts sub-array of `items` array starting on `startIndex` (incluting), up to `endIndex` (exclusive) and
* returns it as an {@link ArrayList}.
*/
@Nonnull
public static List asList(@Nonnull T[] items, int startIndex, int endIndex) {
final int size = Math.min(items.length, endIndex - startIndex);
final ArrayList result = new ArrayList<>(size);
for (int i = 0; i < size; i++) {
result.add(items[startIndex + i]);
}
return result;
}
/**
* Returns copy of sub-array of `items`, cast to `targetType` starting on `startIndex` (incluting), up
* to `endIndex` (exclusive).
*/
@Nonnull
public static T[] copyOf(@Nonnull Object[] items, @Nonnull Class targetType, int startIndex, int endIndex) {
final int size = Math.min(items.length, endIndex - startIndex);
@SuppressWarnings("unchecked") final T[] result = (T[]) Array.newInstance(targetType, size);
for (int i = 0; i < size; i++) {
//noinspection unchecked
result[i] = (T) items[startIndex + i];
}
return result;
}
/**
* Method sorts `arrayToSort` along the position of the same number in the `sortedArray`. The `arrayToSort` is
* expected to be as subset of the `sortedArray`, but it may contain unknown numbers which will be placed at
* the end of the list. Method modifies contents of the `arrayToSort` and returns index of last "sorted" item
* in that array.
*/
public static int sortAlong(@Nonnull int[] sortedArray, @Nonnull int[] arrayToSort) {
final int lastIndex = arrayToSort.length - 1;
final int[] positions = new int[arrayToSort.length];
Arrays.fill(positions, -1);
int itemsLocalized = 0;
for (int i = 0; i < sortedArray.length && itemsLocalized < arrayToSort.length; i++) {
final int number = sortedArray[i];
if (number >= arrayToSort[0] && number <= arrayToSort[lastIndex]) {
final int indexInArrayToSort = Arrays.binarySearch(arrayToSort, number);
if (indexInArrayToSort >= 0 && positions[indexInArrayToSort] == -1) {
positions[indexInArrayToSort] = itemsLocalized++;
}
}
}
final int[] copyOfSource = Arrays.copyOf(arrayToSort, arrayToSort.length);
int unknownNumbers = 0;
for (int i = 0; i < copyOfSource.length; i++) {
if (positions[i] >= 0) {
arrayToSort[positions[i]] = copyOfSource[i];
} else {
arrayToSort[itemsLocalized + unknownNumbers++] = copyOfSource[i];
}
}
return arrayToSort.length - unknownNumbers;
}
/**
* Method sorts `arrayToSort` along the position of the same number in the `sortedArray`. The `arrayToSort` is
* expected to be as subset of the `sortedArray`, but it may contain unknown numbers which will be placed at
* the end of the list. No input argument content is modified, method returns a new array on as its result.
*
* The method is a copy of {@link #sortAlong(int[], int[])} method allowing to sort complex object which
* can produce the numbers using `extractor` function.
*/
@Nonnull
public static T[] sortAlong(@Nonnull int[] sortedArray, @Nonnull T[] arrayToSort, @Nonnull ToIntFunction extractor) {
final int first = extractor.applyAsInt(arrayToSort[0]);
final int last = extractor.applyAsInt(arrayToSort[arrayToSort.length - 1]);
final int[] positions = new int[arrayToSort.length];
Arrays.fill(positions, -1);
int itemsLocalized = 0;
for (int i = 0; i < sortedArray.length && itemsLocalized < arrayToSort.length; i++) {
final int number = sortedArray[i];
if (number >= first && number <= last) {
final int indexInArrayToSort = binarySearch(
arrayToSort,
number,
(t, integer) -> Integer.compare(extractor.applyAsInt(t), integer));
if (indexInArrayToSort >= 0) {
positions[indexInArrayToSort] = itemsLocalized++;
}
}
}
@SuppressWarnings("unchecked") final T[] result = (T[]) Array.newInstance(arrayToSort.getClass().getComponentType(), arrayToSort.length);
int unknownNumbers = 0;
for (int i = 0; i < arrayToSort.length; i++) {
if (positions[i] >= 0) {
result[positions[i]] = arrayToSort[i];
} else {
result[itemsLocalized + unknownNumbers++] = arrayToSort[i];
}
}
return result;
}
/**
* Compares two objects for equality.
* This method checks if the specified objects are both arrays (regardles of whether of primitive types or objects)
* and whether they're equal or not.
*
* @param a the first object to be compared
* @param a2 the second object to be compared
* @return true if the objects are equal, false otherwise
*/
public static boolean equals(@Nullable Object a, @Nullable Object a2) {
if (a == a2) {
return true;
}
if (a == null || a2 == null) {
return false;
}
if (!a.getClass().isArray() || !a2.getClass().isArray()) {
return false;
}
int length = Array.getLength(a);
if (Array.getLength(a2) != length) {
return false;
}
for (int i = 0; i < length; i++) {
if (!Objects.equals(Array.get(a, i), Array.get(a2, i))) {
return false;
}
}
return true;
}
/**
* Computes the hash code for the specified object. This method handles both arrays and non-array objects.
*
* @param a the object for which to compute the hash code
* @return the hash code value for the specified object
*/
public static int hashCode(@Nullable Object a) {
if (a == null) {
return 0;
}
int result = 1;
if (a.getClass().isArray()) {
final int length = Array.getLength(a);
for (int i = 0; i < length; i++) {
final Object element = Array.get(a, i);
result = 31 * result + (element == null ? 0 : element.hashCode());
}
return result;
} else {
return a.hashCode();
}
}
/**
* Simple DTO object for passing information about the record lookup in the ordered array.
*
* @param position Position where the looked up object:
* - currently is (when alreadyPresent=true)
* - should potentially be (when alreadyPresent=false)
* @param alreadyPresent Holds true if looked up object was found already present in the array.
*/
public record InsertionPosition(int position, boolean alreadyPresent) {
}
/**
* Internal helper class that is used to sort array A by comparator that uses array B. This cannot be easily done
* by other way than mimicking list to get advantage of {@link java.util.AbstractList#sort(Comparator)} function
* that accepts external comparator.
*/
@RequiredArgsConstructor
private static class IntArrayWrapper extends AbstractList {
@Getter private final int[] elements;
@Override
public Integer get(int index) {
return elements[index];
}
@Override
public Integer set(int index, Integer element) {
int v = elements[index];
elements[index] = element;
return v;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
if (!super.equals(o)) return false;
IntArrayWrapper integers = (IntArrayWrapper) o;
return Arrays.equals(elements, integers.elements);
}
@Override
public int hashCode() {
int result = super.hashCode();
result = 31 * result + Arrays.hashCode(elements);
return result;
}
@Override
public int size() {
return elements.length;
}
}
/**
* Internal helper class that is used to sort array A by comparator that uses array B. This cannot be easily done
* by other way than mimicking list to get advantage of {@link java.util.AbstractList#sort(Comparator)} function
* that accepts external comparator.
*/
@RequiredArgsConstructor
private static class ArrayWrapper extends AbstractList {
@Getter private final T[] elements;
@Override
public T get(int index) {
return elements[index];
}
@Override
public T set(int index, T element) {
T v = elements[index];
elements[index] = element;
return v;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
if (!super.equals(o)) return false;
//noinspection unchecked
ArrayWrapper otherElements = (ArrayWrapper) o;
return Arrays.equals(elements, otherElements.elements);
}
@Override
public int hashCode() {
int result = super.hashCode();
result = 31 * result + Arrays.hashCode(elements);
return result;
}
@Override
public int size() {
return elements.length;
}
}
}
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