diff --git a/src/org/thoughtcrime/securesms/util/LinkedBlockingLifoQueue.java b/src/org/thoughtcrime/securesms/util/LinkedBlockingLifoQueue.java index cad838ee22..c7cd36b853 100644 --- a/src/org/thoughtcrime/securesms/util/LinkedBlockingLifoQueue.java +++ b/src/org/thoughtcrime/securesms/util/LinkedBlockingLifoQueue.java @@ -1,5 +1,7 @@ package org.thoughtcrime.securesms.util; +import org.thoughtcrime.securesms.util.deque.LinkedBlockingDeque; + public class LinkedBlockingLifoQueue extends LinkedBlockingDeque { @Override public void put(E runnable) throws InterruptedException { diff --git a/src/org/thoughtcrime/securesms/util/deque/BlockingDeque.java b/src/org/thoughtcrime/securesms/util/deque/BlockingDeque.java new file mode 100644 index 0000000000..a486fbd7ce --- /dev/null +++ b/src/org/thoughtcrime/securesms/util/deque/BlockingDeque.java @@ -0,0 +1,616 @@ +/* + * Written by Doug Lea with assistance from members of JCP JSR-166 + * Expert Group and released to the public domain, as explained at + * http://creativecommons.org/licenses/publicdomain + */ + +package org.thoughtcrime.securesms.util.deque; +import java.util.Iterator; +import java.util.NoSuchElementException; +import java.util.concurrent.BlockingQueue; +import java.util.concurrent.TimeUnit; + +/** + * A {@link Deque} that additionally supports blocking operations that wait + * for the deque to become non-empty when retrieving an element, and wait for + * space to become available in the deque when storing an element. + * + *

BlockingDeque methods come in four forms, with different ways + * of handling operations that cannot be satisfied immediately, but may be + * satisfied at some point in the future: + * one throws an exception, the second returns a special value (either + * null or false, depending on the operation), the third + * blocks the current thread indefinitely until the operation can succeed, + * and the fourth blocks for only a given maximum time limit before giving + * up. These methods are summarized in the following table: + * + *

+ * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
First Element (Head)
Throws exceptionSpecial valueBlocksTimes out
Insert{@link #addFirst addFirst(e)}{@link #offerFirst offerFirst(e)}{@link #putFirst putFirst(e)}{@link #offerFirst offerFirst(e, time, unit)}
Remove{@link #removeFirst removeFirst()}{@link #pollFirst pollFirst()}{@link #takeFirst takeFirst()}{@link #pollFirst(long, TimeUnit) pollFirst(time, unit)}
Examine{@link #getFirst getFirst()}{@link #peekFirst peekFirst()}not applicablenot applicable
Last Element (Tail)
Throws exceptionSpecial valueBlocksTimes out
Insert{@link #addLast addLast(e)}{@link #offerLast offerLast(e)}{@link #putLast putLast(e)}{@link #offerLast offerLast(e, time, unit)}
Remove{@link #removeLast() removeLast()}{@link #pollLast() pollLast()}{@link #takeLast takeLast()}{@link #pollLast(long, TimeUnit) pollLast(time, unit)}
Examine{@link #getLast getLast()}{@link #peekLast peekLast()}not applicablenot applicable
+ * + *

Like any {@link BlockingQueue}, a BlockingDeque is thread safe, + * does not permit null elements, and may (or may not) be + * capacity-constrained. + * + *

A BlockingDeque implementation may be used directly as a FIFO + * BlockingQueue. The methods inherited from the + * BlockingQueue interface are precisely equivalent to + * BlockingDeque methods as indicated in the following table: + * + *

+ * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
BlockingQueue Method Equivalent BlockingDeque Method
Insert
{@link #add add(e)}{@link #addLast addLast(e)}
{@link #offer offer(e)}{@link #offerLast offerLast(e)}
{@link #put put(e)}{@link #putLast putLast(e)}
{@link #offer offer(e, time, unit)}{@link #offerLast offerLast(e, time, unit)}
Remove
{@link #remove() remove()}{@link #removeFirst() removeFirst()}
{@link #poll() poll()}{@link #pollFirst() pollFirst()}
{@link #take() take()}{@link #takeFirst() takeFirst()}
{@link #poll(long, TimeUnit) poll(time, unit)}{@link #pollFirst(long, TimeUnit) pollFirst(time, unit)}
Examine
{@link #element() element()}{@link #getFirst() getFirst()}
{@link #peek() peek()}{@link #peekFirst() peekFirst()}
+ * + *

Memory consistency effects: As with other concurrent + * collections, actions in a thread prior to placing an object into a + * {@code BlockingDeque} + * happen-before + * actions subsequent to the access or removal of that element from + * the {@code BlockingDeque} in another thread. + * + *

This interface is a member of the + * + * Java Collections Framework. + * + * @since 1.6 + * @author Doug Lea + * @param the type of elements held in this collection + */ +public interface BlockingDeque extends BlockingQueue, Deque { + /* + * We have "diamond" multiple interface inheritance here, and that + * introduces ambiguities. Methods might end up with different + * specs depending on the branch chosen by javadoc. Thus a lot of + * methods specs here are copied from superinterfaces. + */ + + /** + * Inserts the specified element at the front of this deque if it is + * possible to do so immediately without violating capacity restrictions, + * throwing an IllegalStateException if no space is currently + * available. When using a capacity-restricted deque, it is generally + * preferable to use {@link #offerFirst offerFirst}. + * + * @param e the element to add + * @throws IllegalStateException {@inheritDoc} + * @throws ClassCastException {@inheritDoc} + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException {@inheritDoc} + */ + void addFirst(E e); + + /** + * Inserts the specified element at the end of this deque if it is + * possible to do so immediately without violating capacity restrictions, + * throwing an IllegalStateException if no space is currently + * available. When using a capacity-restricted deque, it is generally + * preferable to use {@link #offerLast offerLast}. + * + * @param e the element to add + * @throws IllegalStateException {@inheritDoc} + * @throws ClassCastException {@inheritDoc} + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException {@inheritDoc} + */ + void addLast(E e); + + /** + * Inserts the specified element at the front of this deque if it is + * possible to do so immediately without violating capacity restrictions, + * returning true upon success and false if no space is + * currently available. + * When using a capacity-restricted deque, this method is generally + * preferable to the {@link #addFirst addFirst} method, which can + * fail to insert an element only by throwing an exception. + * + * @param e the element to add + * @throws ClassCastException {@inheritDoc} + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException {@inheritDoc} + */ + boolean offerFirst(E e); + + /** + * Inserts the specified element at the end of this deque if it is + * possible to do so immediately without violating capacity restrictions, + * returning true upon success and false if no space is + * currently available. + * When using a capacity-restricted deque, this method is generally + * preferable to the {@link #addLast addLast} method, which can + * fail to insert an element only by throwing an exception. + * + * @param e the element to add + * @throws ClassCastException {@inheritDoc} + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException {@inheritDoc} + */ + boolean offerLast(E e); + + /** + * Inserts the specified element at the front of this deque, + * waiting if necessary for space to become available. + * + * @param e the element to add + * @throws InterruptedException if interrupted while waiting + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + void putFirst(E e) throws InterruptedException; + + /** + * Inserts the specified element at the end of this deque, + * waiting if necessary for space to become available. + * + * @param e the element to add + * @throws InterruptedException if interrupted while waiting + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + void putLast(E e) throws InterruptedException; + + /** + * Inserts the specified element at the front of this deque, + * waiting up to the specified wait time if necessary for space to + * become available. + * + * @param e the element to add + * @param timeout how long to wait before giving up, in units of + * unit + * @param unit a TimeUnit determining how to interpret the + * timeout parameter + * @return true if successful, or false if + * the specified waiting time elapses before space is available + * @throws InterruptedException if interrupted while waiting + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + boolean offerFirst(E e, long timeout, TimeUnit unit) + throws InterruptedException; + + /** + * Inserts the specified element at the end of this deque, + * waiting up to the specified wait time if necessary for space to + * become available. + * + * @param e the element to add + * @param timeout how long to wait before giving up, in units of + * unit + * @param unit a TimeUnit determining how to interpret the + * timeout parameter + * @return true if successful, or false if + * the specified waiting time elapses before space is available + * @throws InterruptedException if interrupted while waiting + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + boolean offerLast(E e, long timeout, TimeUnit unit) + throws InterruptedException; + + /** + * Retrieves and removes the first element of this deque, waiting + * if necessary until an element becomes available. + * + * @return the head of this deque + * @throws InterruptedException if interrupted while waiting + */ + E takeFirst() throws InterruptedException; + + /** + * Retrieves and removes the last element of this deque, waiting + * if necessary until an element becomes available. + * + * @return the tail of this deque + * @throws InterruptedException if interrupted while waiting + */ + E takeLast() throws InterruptedException; + + /** + * Retrieves and removes the first element of this deque, waiting + * up to the specified wait time if necessary for an element to + * become available. + * + * @param timeout how long to wait before giving up, in units of + * unit + * @param unit a TimeUnit determining how to interpret the + * timeout parameter + * @return the head of this deque, or null if the specified + * waiting time elapses before an element is available + * @throws InterruptedException if interrupted while waiting + */ + E pollFirst(long timeout, TimeUnit unit) + throws InterruptedException; + + /** + * Retrieves and removes the last element of this deque, waiting + * up to the specified wait time if necessary for an element to + * become available. + * + * @param timeout how long to wait before giving up, in units of + * unit + * @param unit a TimeUnit determining how to interpret the + * timeout parameter + * @return the tail of this deque, or null if the specified + * waiting time elapses before an element is available + * @throws InterruptedException if interrupted while waiting + */ + E pollLast(long timeout, TimeUnit unit) + throws InterruptedException; + + /** + * Removes the first occurrence of the specified element from this deque. + * If the deque does not contain the element, it is unchanged. + * More formally, removes the first element e such that + * o.equals(e) (if such an element exists). + * Returns true if this deque contained the specified element + * (or equivalently, if this deque changed as a result of the call). + * + * @param o element to be removed from this deque, if present + * @return true if an element was removed as a result of this call + * @throws ClassCastException if the class of the specified element + * is incompatible with this deque (optional) + * @throws NullPointerException if the specified element is null (optional) + */ + boolean removeFirstOccurrence(Object o); + + /** + * Removes the last occurrence of the specified element from this deque. + * If the deque does not contain the element, it is unchanged. + * More formally, removes the last element e such that + * o.equals(e) (if such an element exists). + * Returns true if this deque contained the specified element + * (or equivalently, if this deque changed as a result of the call). + * + * @param o element to be removed from this deque, if present + * @return true if an element was removed as a result of this call + * @throws ClassCastException if the class of the specified element + * is incompatible with this deque (optional) + * @throws NullPointerException if the specified element is null (optional) + */ + boolean removeLastOccurrence(Object o); + + // *** BlockingQueue methods *** + + /** + * Inserts the specified element into the queue represented by this deque + * (in other words, at the tail of this deque) if it is possible to do so + * immediately without violating capacity restrictions, returning + * true upon success and throwing an + * IllegalStateException if no space is currently available. + * When using a capacity-restricted deque, it is generally preferable to + * use {@link #offer offer}. + * + *

This method is equivalent to {@link #addLast addLast}. + * + * @param e the element to add + * @throws IllegalStateException {@inheritDoc} + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + boolean add(E e); + + /** + * Inserts the specified element into the queue represented by this deque + * (in other words, at the tail of this deque) if it is possible to do so + * immediately without violating capacity restrictions, returning + * true upon success and false if no space is currently + * available. When using a capacity-restricted deque, this method is + * generally preferable to the {@link #add} method, which can fail to + * insert an element only by throwing an exception. + * + *

This method is equivalent to {@link #offerLast offerLast}. + * + * @param e the element to add + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + boolean offer(E e); + + /** + * Inserts the specified element into the queue represented by this deque + * (in other words, at the tail of this deque), waiting if necessary for + * space to become available. + * + *

This method is equivalent to {@link #putLast putLast}. + * + * @param e the element to add + * @throws InterruptedException {@inheritDoc} + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + void put(E e) throws InterruptedException; + + /** + * Inserts the specified element into the queue represented by this deque + * (in other words, at the tail of this deque), waiting up to the + * specified wait time if necessary for space to become available. + * + *

This method is equivalent to + * {@link #offerLast offerLast}. + * + * @param e the element to add + * @return true if the element was added to this deque, else + * false + * @throws InterruptedException {@inheritDoc} + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + boolean offer(E e, long timeout, TimeUnit unit) + throws InterruptedException; + + /** + * Retrieves and removes the head of the queue represented by this deque + * (in other words, the first element of this deque). + * This method differs from {@link #poll poll} only in that it + * throws an exception if this deque is empty. + * + *

This method is equivalent to {@link #removeFirst() removeFirst}. + * + * @return the head of the queue represented by this deque + * @throws NoSuchElementException if this deque is empty + */ + E remove(); + + /** + * Retrieves and removes the head of the queue represented by this deque + * (in other words, the first element of this deque), or returns + * null if this deque is empty. + * + *

This method is equivalent to {@link #pollFirst()}. + * + * @return the head of this deque, or null if this deque is empty + */ + E poll(); + + /** + * Retrieves and removes the head of the queue represented by this deque + * (in other words, the first element of this deque), waiting if + * necessary until an element becomes available. + * + *

This method is equivalent to {@link #takeFirst() takeFirst}. + * + * @return the head of this deque + * @throws InterruptedException if interrupted while waiting + */ + E take() throws InterruptedException; + + /** + * Retrieves and removes the head of the queue represented by this deque + * (in other words, the first element of this deque), waiting up to the + * specified wait time if necessary for an element to become available. + * + *

This method is equivalent to + * {@link #pollFirst(long,TimeUnit) pollFirst}. + * + * @return the head of this deque, or null if the + * specified waiting time elapses before an element is available + * @throws InterruptedException if interrupted while waiting + */ + E poll(long timeout, TimeUnit unit) + throws InterruptedException; + + /** + * Retrieves, but does not remove, the head of the queue represented by + * this deque (in other words, the first element of this deque). + * This method differs from {@link #peek peek} only in that it throws an + * exception if this deque is empty. + * + *

This method is equivalent to {@link #getFirst() getFirst}. + * + * @return the head of this deque + * @throws NoSuchElementException if this deque is empty + */ + E element(); + + /** + * Retrieves, but does not remove, the head of the queue represented by + * this deque (in other words, the first element of this deque), or + * returns null if this deque is empty. + * + *

This method is equivalent to {@link #peekFirst() peekFirst}. + * + * @return the head of this deque, or null if this deque is empty + */ + E peek(); + + /** + * Removes the first occurrence of the specified element from this deque. + * If the deque does not contain the element, it is unchanged. + * More formally, removes the first element e such that + * o.equals(e) (if such an element exists). + * Returns true if this deque contained the specified element + * (or equivalently, if this deque changed as a result of the call). + * + *

This method is equivalent to + * {@link #removeFirstOccurrence removeFirstOccurrence}. + * + * @param o element to be removed from this deque, if present + * @return true if this deque changed as a result of the call + * @throws ClassCastException if the class of the specified element + * is incompatible with this deque (optional) + * @throws NullPointerException if the specified element is null (optional) + */ + boolean remove(Object o); + + /** + * Returns true if this deque contains the specified element. + * More formally, returns true if and only if this deque contains + * at least one element e such that o.equals(e). + * + * @param o object to be checked for containment in this deque + * @return true if this deque contains the specified element + * @throws ClassCastException if the class of the specified element + * is incompatible with this deque (optional) + * @throws NullPointerException if the specified element is null (optional) + */ + public boolean contains(Object o); + + /** + * Returns the number of elements in this deque. + * + * @return the number of elements in this deque + */ + public int size(); + + /** + * Returns an iterator over the elements in this deque in proper sequence. + * The elements will be returned in order from first (head) to last (tail). + * + * @return an iterator over the elements in this deque in proper sequence + */ + Iterator iterator(); + + // *** Stack methods *** + + /** + * Pushes an element onto the stack represented by this deque. In other + * words, inserts the element at the front of this deque unless it would + * violate capacity restrictions. + * + *

This method is equivalent to {@link #addFirst addFirst}. + * + * @throws IllegalStateException {@inheritDoc} + * @throws ClassCastException {@inheritDoc} + * @throws NullPointerException if the specified element is null + * @throws IllegalArgumentException {@inheritDoc} + */ + void push(E e); +} diff --git a/src/org/thoughtcrime/securesms/util/deque/Deque.java b/src/org/thoughtcrime/securesms/util/deque/Deque.java new file mode 100644 index 0000000000..c260941c98 --- /dev/null +++ b/src/org/thoughtcrime/securesms/util/deque/Deque.java @@ -0,0 +1,555 @@ +/* + * Written by Doug Lea and Josh Bloch with assistance from members of + * JCP JSR-166 Expert Group and released to the public domain, as explained + * at http://creativecommons.org/licenses/publicdomain + */ + +package org.thoughtcrime.securesms.util.deque; + +import java.util.Collection; +import java.util.Iterator; +import java.util.List; +import java.util.NoSuchElementException; +import java.util.Queue; +import java.util.Stack; + +// BEGIN android-note +// removed link to collections framework docs +// changed {@link #offer(Object)} to {@link #offer} to satisfy DroidDoc +// END android-note + +/** + * A linear collection that supports element insertion and removal at + * both ends. The name deque is short for "double ended queue" + * and is usually pronounced "deck". Most Deque + * implementations place no fixed limits on the number of elements + * they may contain, but this interface supports capacity-restricted + * deques as well as those with no fixed size limit. + * + *

This interface defines methods to access the elements at both + * ends of the deque. Methods are provided to insert, remove, and + * examine the element. Each of these methods exists in two forms: + * one throws an exception if the operation fails, the other returns a + * special value (either null or false, depending on + * the operation). The latter form of the insert operation is + * designed specifically for use with capacity-restricted + * Deque implementations; in most implementations, insert + * operations cannot fail. + * + *

The twelve methods described above are summarized in the + * following table: + * + *

+ * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
First Element (Head) Last Element (Tail)
Throws exceptionSpecial valueThrows exceptionSpecial value
Insert{@link #addFirst addFirst(e)}{@link #offerFirst offerFirst(e)}{@link #addLast addLast(e)}{@link #offerLast offerLast(e)}
Remove{@link #removeFirst removeFirst()}{@link #pollFirst pollFirst()}{@link #removeLast removeLast()}{@link #pollLast pollLast()}
Examine{@link #getFirst getFirst()}{@link #peekFirst peekFirst()}{@link #getLast getLast()}{@link #peekLast peekLast()}
+ * + *

This interface extends the {@link Queue} interface. When a deque is + * used as a queue, FIFO (First-In-First-Out) behavior results. Elements are + * added at the end of the deque and removed from the beginning. The methods + * inherited from the Queue interface are precisely equivalent to + * Deque methods as indicated in the following table: + * + *

+ * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
Queue Method Equivalent Deque Method
{@link java.util.Queue#add add(e)}{@link #addLast addLast(e)}
{@link java.util.Queue#offer offer(e)}{@link #offerLast offerLast(e)}
{@link java.util.Queue#remove remove()}{@link #removeFirst removeFirst()}
{@link java.util.Queue#poll poll()}{@link #pollFirst pollFirst()}
{@link java.util.Queue#element element()}{@link #getFirst getFirst()}
{@link java.util.Queue#peek peek()}{@link #peek peekFirst()}
+ * + *

Deques can also be used as LIFO (Last-In-First-Out) stacks. This + * interface should be used in preference to the legacy {@link Stack} class. + * When a deque is used as a stack, elements are pushed and popped from the + * beginning of the deque. Stack methods are precisely equivalent to + * Deque methods as indicated in the table below: + * + *

+ * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + * + *
Stack Method Equivalent Deque Method
{@link #push push(e)}{@link #addFirst addFirst(e)}
{@link #pop pop()}{@link #removeFirst removeFirst()}
{@link #peek peek()}{@link #peekFirst peekFirst()}
+ * + *

Note that the {@link #peek peek} method works equally well when + * a deque is used as a queue or a stack; in either case, elements are + * drawn from the beginning of the deque. + * + *

This interface provides two methods to remove interior + * elements, {@link #removeFirstOccurrence removeFirstOccurrence} and + * {@link #removeLastOccurrence removeLastOccurrence}. + * + *

Unlike the {@link List} interface, this interface does not + * provide support for indexed access to elements. + * + *

While Deque implementations are not strictly required + * to prohibit the insertion of null elements, they are strongly + * encouraged to do so. Users of any Deque implementations + * that do allow null elements are strongly encouraged not to + * take advantage of the ability to insert nulls. This is so because + * null is used as a special return value by various methods + * to indicated that the deque is empty. + * + *

Deque implementations generally do not define + * element-based versions of the equals and hashCode + * methods, but instead inherit the identity-based versions from class + * Object. + * + * @author Doug Lea + * @author Josh Bloch + * @since 1.6 + * @param the type of elements held in this collection + */ + +public interface Deque extends Queue { + /** + * Inserts the specified element at the front of this deque if it is + * possible to do so immediately without violating capacity restrictions. + * When using a capacity-restricted deque, it is generally preferable to + * use method {@link #offerFirst}. + * + * @param e the element to add + * @throws IllegalStateException if the element cannot be added at this + * time due to capacity restrictions + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + void addFirst(E e); + + /** + * Inserts the specified element at the end of this deque if it is + * possible to do so immediately without violating capacity restrictions. + * When using a capacity-restricted deque, it is generally preferable to + * use method {@link #offerLast}. + * + *

This method is equivalent to {@link #add}. + * + * @param e the element to add + * @throws IllegalStateException if the element cannot be added at this + * time due to capacity restrictions + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + void addLast(E e); + + /** + * Inserts the specified element at the front of this deque unless it would + * violate capacity restrictions. When using a capacity-restricted deque, + * this method is generally preferable to the {@link #addFirst} method, + * which can fail to insert an element only by throwing an exception. + * + * @param e the element to add + * @return true if the element was added to this deque, else + * false + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + boolean offerFirst(E e); + + /** + * Inserts the specified element at the end of this deque unless it would + * violate capacity restrictions. When using a capacity-restricted deque, + * this method is generally preferable to the {@link #addLast} method, + * which can fail to insert an element only by throwing an exception. + * + * @param e the element to add + * @return true if the element was added to this deque, else + * false + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + boolean offerLast(E e); + + /** + * Retrieves and removes the first element of this deque. This method + * differs from {@link #pollFirst pollFirst} only in that it throws an + * exception if this deque is empty. + * + * @return the head of this deque + * @throws NoSuchElementException if this deque is empty + */ + E removeFirst(); + + /** + * Retrieves and removes the last element of this deque. This method + * differs from {@link #pollLast pollLast} only in that it throws an + * exception if this deque is empty. + * + * @return the tail of this deque + * @throws NoSuchElementException if this deque is empty + */ + E removeLast(); + + /** + * Retrieves and removes the first element of this deque, + * or returns null if this deque is empty. + * + * @return the head of this deque, or null if this deque is empty + */ + E pollFirst(); + + /** + * Retrieves and removes the last element of this deque, + * or returns null if this deque is empty. + * + * @return the tail of this deque, or null if this deque is empty + */ + E pollLast(); + + /** + * Retrieves, but does not remove, the first element of this deque. + * + * This method differs from {@link #peekFirst peekFirst} only in that it + * throws an exception if this deque is empty. + * + * @return the head of this deque + * @throws NoSuchElementException if this deque is empty + */ + E getFirst(); + + /** + * Retrieves, but does not remove, the last element of this deque. + * This method differs from {@link #peekLast peekLast} only in that it + * throws an exception if this deque is empty. + * + * @return the tail of this deque + * @throws NoSuchElementException if this deque is empty + */ + E getLast(); + + /** + * Retrieves, but does not remove, the first element of this deque, + * or returns null if this deque is empty. + * + * @return the head of this deque, or null if this deque is empty + */ + E peekFirst(); + + /** + * Retrieves, but does not remove, the last element of this deque, + * or returns null if this deque is empty. + * + * @return the tail of this deque, or null if this deque is empty + */ + E peekLast(); + + /** + * Removes the first occurrence of the specified element from this deque. + * If the deque does not contain the element, it is unchanged. + * More formally, removes the first element e such that + * (o==null ? e==null : o.equals(e)) + * (if such an element exists). + * Returns true if this deque contained the specified element + * (or equivalently, if this deque changed as a result of the call). + * + * @param o element to be removed from this deque, if present + * @return true if an element was removed as a result of this call + * @throws ClassCastException if the class of the specified element + * is incompatible with this deque (optional) + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements (optional) + */ + boolean removeFirstOccurrence(Object o); + + /** + * Removes the last occurrence of the specified element from this deque. + * If the deque does not contain the element, it is unchanged. + * More formally, removes the last element e such that + * (o==null ? e==null : o.equals(e)) + * (if such an element exists). + * Returns true if this deque contained the specified element + * (or equivalently, if this deque changed as a result of the call). + * + * @param o element to be removed from this deque, if present + * @return true if an element was removed as a result of this call + * @throws ClassCastException if the class of the specified element + * is incompatible with this deque (optional) + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements (optional) + */ + boolean removeLastOccurrence(Object o); + + // *** Queue methods *** + + /** + * Inserts the specified element into the queue represented by this deque + * (in other words, at the tail of this deque) if it is possible to do so + * immediately without violating capacity restrictions, returning + * true upon success and throwing an + * IllegalStateException if no space is currently available. + * When using a capacity-restricted deque, it is generally preferable to + * use {@link #offer offer}. + * + *

This method is equivalent to {@link #addLast}. + * + * @param e the element to add + * @return true (as specified by {@link Collection#add}) + * @throws IllegalStateException if the element cannot be added at this + * time due to capacity restrictions + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + boolean add(E e); + + /** + * Inserts the specified element into the queue represented by this deque + * (in other words, at the tail of this deque) if it is possible to do so + * immediately without violating capacity restrictions, returning + * true upon success and false if no space is currently + * available. When using a capacity-restricted deque, this method is + * generally preferable to the {@link #add} method, which can fail to + * insert an element only by throwing an exception. + * + *

This method is equivalent to {@link #offerLast}. + * + * @param e the element to add + * @return true if the element was added to this deque, else + * false + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + boolean offer(E e); + + /** + * Retrieves and removes the head of the queue represented by this deque + * (in other words, the first element of this deque). + * This method differs from {@link #poll poll} only in that it throws an + * exception if this deque is empty. + * + *

This method is equivalent to {@link #removeFirst()}. + * + * @return the head of the queue represented by this deque + * @throws NoSuchElementException if this deque is empty + */ + E remove(); + + /** + * Retrieves and removes the head of the queue represented by this deque + * (in other words, the first element of this deque), or returns + * null if this deque is empty. + * + *

This method is equivalent to {@link #pollFirst()}. + * + * @return the first element of this deque, or null if + * this deque is empty + */ + E poll(); + + /** + * Retrieves, but does not remove, the head of the queue represented by + * this deque (in other words, the first element of this deque). + * This method differs from {@link #peek peek} only in that it throws an + * exception if this deque is empty. + * + *

This method is equivalent to {@link #getFirst()}. + * + * @return the head of the queue represented by this deque + * @throws NoSuchElementException if this deque is empty + */ + E element(); + + /** + * Retrieves, but does not remove, the head of the queue represented by + * this deque (in other words, the first element of this deque), or + * returns null if this deque is empty. + * + *

This method is equivalent to {@link #peekFirst()}. + * + * @return the head of the queue represented by this deque, or + * null if this deque is empty + */ + E peek(); + + + // *** Stack methods *** + + /** + * Pushes an element onto the stack represented by this deque (in other + * words, at the head of this deque) if it is possible to do so + * immediately without violating capacity restrictions, returning + * true upon success and throwing an + * IllegalStateException if no space is currently available. + * + *

This method is equivalent to {@link #addFirst}. + * + * @param e the element to push + * @throws IllegalStateException if the element cannot be added at this + * time due to capacity restrictions + * @throws ClassCastException if the class of the specified element + * prevents it from being added to this deque + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements + * @throws IllegalArgumentException if some property of the specified + * element prevents it from being added to this deque + */ + void push(E e); + + /** + * Pops an element from the stack represented by this deque. In other + * words, removes and returns the first element of this deque. + * + *

This method is equivalent to {@link #removeFirst()}. + * + * @return the element at the front of this deque (which is the top + * of the stack represented by this deque) + * @throws NoSuchElementException if this deque is empty + */ + E pop(); + + + // *** Collection methods *** + + /** + * Removes the first occurrence of the specified element from this deque. + * If the deque does not contain the element, it is unchanged. + * More formally, removes the first element e such that + * (o==null ? e==null : o.equals(e)) + * (if such an element exists). + * Returns true if this deque contained the specified element + * (or equivalently, if this deque changed as a result of the call). + * + *

This method is equivalent to {@link #removeFirstOccurrence}. + * + * @param o element to be removed from this deque, if present + * @return true if an element was removed as a result of this call + * @throws ClassCastException if the class of the specified element + * is incompatible with this deque (optional) + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements (optional) + */ + boolean remove(Object o); + + /** + * Returns true if this deque contains the specified element. + * More formally, returns true if and only if this deque contains + * at least one element e such that + * (o==null ? e==null : o.equals(e)). + * + * @param o element whose presence in this deque is to be tested + * @return true if this deque contains the specified element + * @throws ClassCastException if the type of the specified element + * is incompatible with this deque (optional) + * @throws NullPointerException if the specified element is null and this + * deque does not permit null elements (optional) + */ + boolean contains(Object o); + + /** + * Returns the number of elements in this deque. + * + * @return the number of elements in this deque + */ + public int size(); + + /** + * Returns an iterator over the elements in this deque in proper sequence. + * The elements will be returned in order from first (head) to last (tail). + * + * @return an iterator over the elements in this deque in proper sequence + */ + Iterator iterator(); + + /** + * Returns an iterator over the elements in this deque in reverse + * sequential order. The elements will be returned in order from + * last (tail) to first (head). + * + * @return an iterator over the elements in this deque in reverse + * sequence + */ + Iterator descendingIterator(); + +} diff --git a/src/org/thoughtcrime/securesms/util/LinkedBlockingDeque.java b/src/org/thoughtcrime/securesms/util/deque/LinkedBlockingDeque.java similarity index 99% rename from src/org/thoughtcrime/securesms/util/LinkedBlockingDeque.java rename to src/org/thoughtcrime/securesms/util/deque/LinkedBlockingDeque.java index 921b3937c3..de006ea58a 100644 --- a/src/org/thoughtcrime/securesms/util/LinkedBlockingDeque.java +++ b/src/org/thoughtcrime/securesms/util/deque/LinkedBlockingDeque.java @@ -9,13 +9,12 @@ * it here for backwards compatibility. */ -package org.thoughtcrime.securesms.util; +package org.thoughtcrime.securesms.util.deque; import java.util.AbstractQueue; import java.util.Collection; import java.util.Iterator; import java.util.NoSuchElementException; -import java.util.concurrent.BlockingDeque; import java.util.concurrent.TimeUnit; import java.util.concurrent.locks.Condition; import java.util.concurrent.locks.ReentrantLock;