Class AbstractBlockIntegerList
- java.lang.Object
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- com.mckoi.util.AbstractBlockIntegerList
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- All Implemented Interfaces:
IntegerListInterface
- Direct Known Subclasses:
BlockIntegerList
public abstract class AbstractBlockIntegerList extends java.lang.Object implements IntegerListInterface
An implementation of a list of integer values that are stored across an array of blocks. This allows for quicker insertion and deletion of integer values, including other memory saving benefits.The class works as follows;
- The list can contain any number of 'int' values.
- Each value is stored within a block of int's. A block is of finite size.
- When a block becomes full, int values are moved around until enough space is free. This may be by inserting a new block or by shifting information from one block to another.
- When a block becomes empty, it is removed.
NOTE: The following methods are NOT optimal: get(pos), add(val, pos), remove(pos)
Specifically, they slow as 'pos' nears the end of large lists.
This type of structure is very fast for large sorted lists where values can be inserted at any position within the list. Care needs to be taken for lists where values are inserted and removed constantly, because fragmentation of the list blocks can occur. For example, adding 60,000 random entries followed by removing 50,000 random entries will result in many only partially filled blocks. Since each block takes a constant amount of memory, this may not be acceptable.
- Author:
- Tobias Downer
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Field Summary
Fields Modifier and Type Field Description protected java.util.ArrayList
block_list
The list of blocks (objects in this list are of type 'IntegerListBlockInterface'.
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Constructor Summary
Constructors Constructor Description AbstractBlockIntegerList()
Constructs the list.AbstractBlockIntegerList(IntegerListBlockInterface[] blocks)
Constructs the list from the given set of initial blocks.AbstractBlockIntegerList(IntegerListInterface i_list)
Copies the information from the given BlockIntegerList into a new object and performs a deep clone of the information in this container.AbstractBlockIntegerList(IntegerVector ivec)
Constructs the list by copying the contents from an IntegerVector.
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Method Summary
All Methods Static Methods Instance Methods Abstract Methods Concrete Methods Modifier and Type Method Description void
add(int val)
Adds an int to the end of the list.void
add(int val, int pos)
Adds an int at the given position in the list.void
checkSorted(IndexComparator c)
static void
checkSorted(IntegerIterator iterator, IndexComparator c)
boolean
contains(int val)
Assuming the list is sorted, this performs a binary search and returns true if the value is found, otherwise returns false.boolean
contains(java.lang.Object key, IndexComparator c)
Assuming the list is sorted, this performs a binary search and returns true if the value is found, otherwise returns false.protected void
deleteListBlock(IntegerListBlockInterface list_block)
Called when the class decides this ListBlock is no longer needed.int
get(int pos)
Returns the int at the given position in the list.void
insertSort(int val)
Inserts plain 'int' values into the list in sorted order.void
insertSort(java.lang.Object key, int val, IndexComparator c)
Inserts the key/index pair into the list at the correct sorted position (determine by the IndexComparator).boolean
isImmutable()
Returns true if this interface is immutable.IntegerIterator
iterator()
Returns an IntegerIterator that will walk from the start to the end this list.IntegerIterator
iterator(int start_offset, int end_offset)
Returns an IntegerIterator that will walk from the start offset (inclusive) to the end offset (inclusive) of this list.protected abstract IntegerListBlockInterface
newListBlock()
Creates a new ListBlock for the given implementation.int
remove(int pos)
Removes an int from the given position in the list.protected int
removeFromBlock(int block_index, IntegerListBlockInterface block, int position)
Removes the value from the given position in the specified block.boolean
removeSort(int val)
Removes a plain 'int' value from the sorted position in the list only if it's already in the list.int
removeSort(java.lang.Object key, int val, IndexComparator c)
Removes the key/val pair from the list by first searching for it, and then removing it from the list.int
searchFirst(java.lang.Object key, IndexComparator c)
Returns the index of the first value in this set that equals the given value.int
searchLast(java.lang.Object key, IndexComparator c)
Returns the index of the last value in this set that equals the given value.void
setImmutable()
Sets the list as immutable (we aren't allowed to change the contents).int
size()
The number of integers that are in the list.java.lang.String
toString()
boolean
uniqueInsertSort(int val)
Inserts plain 'int' value into the sorted position in the list only if it isn't already in the list.
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Constructor Detail
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AbstractBlockIntegerList
public AbstractBlockIntegerList()
Constructs the list.
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AbstractBlockIntegerList
public AbstractBlockIntegerList(IntegerListBlockInterface[] blocks)
Constructs the list from the given set of initial blocks.
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AbstractBlockIntegerList
public AbstractBlockIntegerList(IntegerVector ivec)
Constructs the list by copying the contents from an IntegerVector.
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AbstractBlockIntegerList
public AbstractBlockIntegerList(IntegerListInterface i_list)
Copies the information from the given BlockIntegerList into a new object and performs a deep clone of the information in this container.
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Method Detail
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newListBlock
protected abstract IntegerListBlockInterface newListBlock()
Creates a new ListBlock for the given implementation.
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deleteListBlock
protected void deleteListBlock(IntegerListBlockInterface list_block)
Called when the class decides this ListBlock is no longer needed. Provided as an event for derived classes to intercept.
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removeFromBlock
protected final int removeFromBlock(int block_index, IntegerListBlockInterface block, int position)
Removes the value from the given position in the specified block. It returns the value that used to be at that position.
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setImmutable
public final void setImmutable()
Sets the list as immutable (we aren't allowed to change the contents).- Specified by:
setImmutable
in interfaceIntegerListInterface
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isImmutable
public final boolean isImmutable()
Returns true if this interface is immutable.- Specified by:
isImmutable
in interfaceIntegerListInterface
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size
public final int size()
The number of integers that are in the list.- Specified by:
size
in interfaceIntegerListInterface
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get
public final int get(int pos)
Returns the int at the given position in the list. NOTE: This is not a very fast routine. Certainly a lot slower than IntegerVector intAt.- Specified by:
get
in interfaceIntegerListInterface
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add
public final void add(int val, int pos)
Adds an int at the given position in the list.- Specified by:
add
in interfaceIntegerListInterface
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add
public final void add(int val)
Adds an int to the end of the list.- Specified by:
add
in interfaceIntegerListInterface
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remove
public final int remove(int pos)
Removes an int from the given position in the list. Returns the value that used to be at that position.- Specified by:
remove
in interfaceIntegerListInterface
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contains
public final boolean contains(int val)
Assuming the list is sorted, this performs a binary search and returns true if the value is found, otherwise returns false.We must supply a 'IndexComparator' for how the list is sorted.
- Specified by:
contains
in interfaceIntegerListInterface
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insertSort
public final void insertSort(int val)
Inserts plain 'int' values into the list in sorted order.- Specified by:
insertSort
in interfaceIntegerListInterface
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uniqueInsertSort
public final boolean uniqueInsertSort(int val)
Inserts plain 'int' value into the sorted position in the list only if it isn't already in the list. If the value is inserted it returns true, otherwise if the value wasn't inserted because it's already in the list, it returns false.- Specified by:
uniqueInsertSort
in interfaceIntegerListInterface
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removeSort
public final boolean removeSort(int val)
Removes a plain 'int' value from the sorted position in the list only if it's already in the list. If the value is removed it returns true, otherwise if the value wasn't removed because it couldn't be found in the list, it returns false.- Specified by:
removeSort
in interfaceIntegerListInterface
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contains
public final boolean contains(java.lang.Object key, IndexComparator c)
Assuming the list is sorted, this performs a binary search and returns true if the value is found, otherwise returns false.We must supply a 'IndexComparator' for how the list is sorted.
- Specified by:
contains
in interfaceIntegerListInterface
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insertSort
public final void insertSort(java.lang.Object key, int val, IndexComparator c)
Inserts the key/index pair into the list at the correct sorted position (determine by the IndexComparator). If the list already contains identical key then the value is put on the end of the set. This way, the sort is stable (the order of identical elements does not change).- Specified by:
insertSort
in interfaceIntegerListInterface
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removeSort
public final int removeSort(java.lang.Object key, int val, IndexComparator c)
Removes the key/val pair from the list by first searching for it, and then removing it from the list.NOTE: There will be a list scan (bad performance) for the erronious case when the key/val pair is not present in the list.
- Specified by:
removeSort
in interfaceIntegerListInterface
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searchLast
public final int searchLast(java.lang.Object key, IndexComparator c)
Returns the index of the last value in this set that equals the given value.- Specified by:
searchLast
in interfaceIntegerListInterface
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searchFirst
public final int searchFirst(java.lang.Object key, IndexComparator c)
Returns the index of the first value in this set that equals the given value.- Specified by:
searchFirst
in interfaceIntegerListInterface
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iterator
public IntegerIterator iterator(int start_offset, int end_offset)
Returns an IntegerIterator that will walk from the start offset (inclusive) to the end offset (inclusive) of this list.This iterator supports the 'remove' method.
- Specified by:
iterator
in interfaceIntegerListInterface
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iterator
public IntegerIterator iterator()
Returns an IntegerIterator that will walk from the start to the end this list.This iterator supports the 'remove' method.
- Specified by:
iterator
in interfaceIntegerListInterface
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toString
public java.lang.String toString()
- Overrides:
toString
in classjava.lang.Object
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checkSorted
public void checkSorted(IndexComparator c)
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checkSorted
public static void checkSorted(IntegerIterator iterator, IndexComparator c)
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