Memory (datasketches-memory-java8 2.2.0 API)

All Superinterfaces:

BaseState

All Known Subinterfaces:

WritableMemory
```
public interface Memory
extends BaseState
```
Defines the read-only API for offset access to a resource.

Author:

Lee Rhodes

Field Summary
- Fields inherited from interface org.apache.datasketches.memory.BaseState
  defaultMemReqSvr

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Default Methods
Modifier and Type	Method and Description
`default Buffer`	`asBuffer()` Returns a new Buffer view of this object.
`Buffer`	`asBuffer(ByteOrder byteOrder)` Returns a new Buffer view of this object, with the given byte order.
`int`	`compareTo(long thisOffsetBytes, long thisLengthBytes, Memory that, long thatOffsetBytes, long thatLengthBytes)` Compares the bytes of this Memory to that Memory.
`void`	`copyTo(long srcOffsetBytes, WritableMemory destination, long dstOffsetBytes, long lengthBytes)` Copies bytes from a source range of this Memory to a destination range of the given Memory with the same semantics when copying between overlapping ranges of bytes as method `System.arraycopy(Object, int, Object, int, int)` has.
`boolean`	`getBoolean(long offsetBytes)` Gets the boolean value at the given offset
`void`	`getBooleanArray(long offsetBytes, boolean[] dstArray, int dstOffsetBooleans, int lengthBooleans)` Gets the boolean array at the given offset
`byte`	`getByte(long offsetBytes)` Gets the byte value at the given offset
`void`	`getByteArray(long offsetBytes, byte[] dstArray, int dstOffsetBytes, int lengthBytes)` Gets the byte array at the given offset
`char`	`getChar(long offsetBytes)` Gets the char value at the given offset
`void`	`getCharArray(long offsetBytes, char[] dstArray, int dstOffsetChars, int lengthChars)` Gets the char array at the given offset
`int`	`getCharsFromUtf8(long offsetBytes, int utf8LengthBytes, Appendable dst)` Gets UTF-8 encoded bytes from this Memory, starting at offsetBytes to a length of utf8LengthBytes, decodes them into characters and appends them to the given Appendable.
`int`	`getCharsFromUtf8(long offsetBytes, int utf8LengthBytes, StringBuilder dst)` Gets UTF-8 encoded bytes from this Memory, starting at offsetBytes to a length of utf8LengthBytes, decodes them into characters and appends them to the given StringBuilder.
`double`	`getDouble(long offsetBytes)` Gets the double value at the given offset
`void`	`getDoubleArray(long offsetBytes, double[] dstArray, int dstOffsetDoubles, int lengthDoubles)` Gets the double array at the given offset
`float`	`getFloat(long offsetBytes)` Gets the float value at the given offset
`void`	`getFloatArray(long offsetBytes, float[] dstArray, int dstOffsetFloats, int lengthFloats)` Gets the float array at the given offset
`int`	`getInt(long offsetBytes)` Gets the int value at the given offset
`void`	`getIntArray(long offsetBytes, int[] dstArray, int dstOffsetInts, int lengthInts)` Gets the int array at the given offset
`long`	`getLong(long offsetBytes)` Gets the long value at the given offset
`void`	`getLongArray(long offsetBytes, long[] dstArray, int dstOffsetLongs, int lengthLongs)` Gets the long array at the given offset
`short`	`getShort(long offsetBytes)` Gets the short value at the given offset
`void`	`getShortArray(long offsetBytes, short[] dstArray, int dstOffsetShorts, int lengthShorts)` Gets the short array at the given offset
`static MapHandle`	`map(File file)` Maps the entire given file into native-ordered Memory for read operations Calling this method is equivalent to calling `map(file, 0, file.length(), ByteOrder.nativeOrder())`.
`static MapHandle`	`map(File file, long fileOffsetBytes, long capacityBytes, ByteOrder byteOrder)` Maps the specified portion of the given file into Memory for read operations.
`default Memory`	`region(long offsetBytes, long capacityBytes)` A region is a read-only view of this object.
`Memory`	`region(long offsetBytes, long capacityBytes, ByteOrder byteOrder)` A region is a read-only view of this object.
`static Memory`	`wrap(boolean[] array)` Wraps the given primitive array for read operations assuming native byte order.
`static Memory`	`wrap(byte[] array)` Wraps the given primitive array for read operations assuming native byte order.
`static Memory`	`wrap(byte[] array, ByteOrder byteOrder)` Wraps the given primitive array for read operations with the given byte order.
`static Memory`	`wrap(byte[] array, int offsetBytes, int lengthBytes, ByteOrder byteOrder)` Wraps the given primitive array for read operations with the given byte order.
`static Memory`	`wrap(ByteBuffer byteBuffer)` Accesses the given ByteBuffer for read-only operations.
`static Memory`	`wrap(ByteBuffer byteBuffer, ByteOrder byteOrder)` Accesses the given ByteBuffer for read-only operations.
`static Memory`	`wrap(char[] array)` Wraps the given primitive array for read operations assuming native byte order.
`static Memory`	`wrap(double[] array)` Wraps the given primitive array for read operations assuming native byte order.
`static Memory`	`wrap(float[] array)` Wraps the given primitive array for read operations assuming native byte order.
`static Memory`	`wrap(int[] array)` Wraps the given primitive array for read operations assuming native byte order.
`static Memory`	`wrap(long[] array)` Wraps the given primitive array for read operations assuming native byte order.
`static Memory`	`wrap(short[] array)` Wraps the given primitive array for read operations assuming native byte order.
`void`	`writeTo(long offsetBytes, long lengthBytes, WritableByteChannel out)` Writes bytes from a source range of this Memory to the given `WritableByteChannel`.

Methods inherited from interface org.apache.datasketches.memory.BaseState
checkValidAndBounds, equals, equalTo, getByteBuffer, getCapacity, getCumulativeOffset, getCumulativeOffset, getCurrentDirectMemoryAllocated, getCurrentDirectMemoryAllocations, getCurrentDirectMemoryMapAllocated, getCurrentDirectMemoryMapAllocations, getRegionOffset, getRegionOffset, getTypeByteOrder, hasArray, hasByteBuffer, hashCode, isByteOrderCompatible, isDirect, isReadOnly, isSameResource, isValid, toHexString, xxHash64, xxHash64

- Method Detail
  - wrap
```
static Memory wrap(ByteBuffer byteBuffer)
```
    Accesses the given ByteBuffer for read-only operations. The returned Memory object has the same byte order, as the given ByteBuffer.
    
    Parameters:
    
    byteBuffer - the given ByteBuffer. It must be non-null and with capacity ≥ 0.
    
    Returns:
    
    a new Memory for read-only operations on the given ByteBuffer.
  - wrap
```
static Memory wrap(ByteBuffer byteBuffer,
                   ByteOrder byteOrder)
```
    Accesses the given ByteBuffer for read-only operations. The returned Memory object has the given byte order, ignoring the byte order of the given ByteBuffer for future reads and writes.
    
    Parameters:
    
    byteBuffer - the given ByteBuffer. It must be non-null and with capacity ≥ 0.
    
    byteOrder - the byte order to be used. It must be non-null.
    
    Returns:
    
    a new Memory for read-only operations on the given ByteBuffer.
  - map
```
static MapHandle map(File file)
```
    Maps the entire given file into native-ordered Memory for read operations Calling this method is equivalent to calling map(file, 0, file.length(), ByteOrder.nativeOrder()).
    
    Parameters:
    
    file - the given file to map. It must be non-null, length ≥ 0, and readable.
    
    Returns:
    
    MapHandle for managing the mapped memory. Please read Javadocs for Handle.
  - map
```
static MapHandle map(File file,
                     long fileOffsetBytes,
                     long capacityBytes,
                     ByteOrder byteOrder)
```
    Maps the specified portion of the given file into Memory for read operations.
    
    Parameters:
    
    file - the given file to map. It must be non-null and readable.
    
    fileOffsetBytes - the position in the given file in bytes. It must not be negative.
    
    capacityBytes - the size of the mapped memory. It must not be negative.
    
    byteOrder - the byte order to be used for the mapped memory. It must be non-null.
    
    Returns:
    
    MapHandle for managing the mapped memory. Please read Javadocs for Handle.
  - region
```
default Memory region(long offsetBytes,
                      long capacityBytes)
```
    A region is a read-only view of this object.
    - Returned object's origin = this object's origin + offsetBytes
    - Returned object's capacity = capacityBytes
    Parameters:
    
    offsetBytes - the starting offset with respect to the origin of this Memory. It must be ≥ 0.
    
    capacityBytes - the capacity of the region in bytes. It must be ≥ 0.
    
    Returns:
    
    a new Memory representing the defined region based on the given offsetBytes and capacityBytes.
  - region
```
Memory region(long offsetBytes,
              long capacityBytes,
              ByteOrder byteOrder)
```
    A region is a read-only view of this object.
    - Returned object's origin = this object's origin + offsetBytes
    - Returned object's capacity = capacityBytes
    - Returned object's byte order = byteOrder
    Parameters:
    
    offsetBytes - the starting offset with respect to the origin of this Memory. It must be ≥ 0.
    
    capacityBytes - the capacity of the region in bytes. It must be ≥ 0.
    
    byteOrder - the given byte order. It must be non-null.
    
    Returns:
    
    a new Memory representing the defined region based on the given offsetBytes, capacityBytes and byteOrder.
  - asBuffer
```
default Buffer asBuffer()
```
    Returns a new Buffer view of this object.
    - Returned object's origin = this object's origin
    - Returned object's start = 0
    - Returned object's position = 0
    - Returned object's end = this object's capacity
    - Returned object's capacity = this object's capacity
    - Returned object's start, position and end are mutable
    Returns:
    
    a new Buffer
  - asBuffer
```
Buffer asBuffer(ByteOrder byteOrder)
```
    Returns a new Buffer view of this object, with the given byte order.
    - Returned object's origin = this object's origin
    - Returned object's start = 0
    - Returned object's position = 0
    - Returned object's end = this object's capacity
    - Returned object's capacity = this object's capacity
    - Returned object's start, position and end are mutable
    Parameters:
    
    byteOrder - the given byte order
    
    Returns:
    
    a new Buffer with the given byteOrder.
  - wrap
```
static Memory wrap(byte[] array)
```
    Wraps the given primitive array for read operations assuming native byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    Returns:
    
    a new Memory for read operations
  - wrap
```
static Memory wrap(byte[] array,
                   ByteOrder byteOrder)
```
    Wraps the given primitive array for read operations with the given byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    byteOrder - the byte order to be used
    
    Returns:
    
    a new Memory for read operations
  - wrap
```
static Memory wrap(byte[] array,
                   int offsetBytes,
                   int lengthBytes,
                   ByteOrder byteOrder)
```
    Wraps the given primitive array for read operations with the given byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    offsetBytes - the byte offset into the given array
    
    lengthBytes - the number of bytes to include from the given array
    
    byteOrder - the byte order to be used
    
    Returns:
    
    a new Memory for read operations
  - wrap
```
static Memory wrap(boolean[] array)
```
    Wraps the given primitive array for read operations assuming native byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    Returns:
    
    a new Memory for read operations
  - wrap
```
static Memory wrap(char[] array)
```
    Wraps the given primitive array for read operations assuming native byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    Returns:
    
    a new Memory for read operations
  - wrap
```
static Memory wrap(short[] array)
```
    Wraps the given primitive array for read operations assuming native byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    Returns:
    
    a new Memory for read operations
  - wrap
```
static Memory wrap(int[] array)
```
    Wraps the given primitive array for read operations assuming native byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    Returns:
    
    a new Memory for read operations
  - wrap
```
static Memory wrap(long[] array)
```
    Wraps the given primitive array for read operations assuming native byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    Returns:
    
    a new Memory for read operations
  - wrap
```
static Memory wrap(float[] array)
```
    Wraps the given primitive array for read operations assuming native byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    Returns:
    
    a new Memory for read operations
  - wrap
```
static Memory wrap(double[] array)
```
    Wraps the given primitive array for read operations assuming native byte order.
    
    Parameters:
    
    array - the given primitive array.
    
    Returns:
    
    a new Memory for read operations
  - getBoolean
```
boolean getBoolean(long offsetBytes)
```
    Gets the boolean value at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    Returns:
    
    the boolean at the given offset
  - getBooleanArray
```
void getBooleanArray(long offsetBytes,
                     boolean[] dstArray,
                     int dstOffsetBooleans,
                     int lengthBooleans)
```
    Gets the boolean array at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    dstArray - The preallocated destination array.
    
    dstOffsetBooleans - offset in array units
    
    lengthBooleans - number of array units to transfer
  - getByte
```
byte getByte(long offsetBytes)
```
    Gets the byte value at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    Returns:
    
    the byte at the given offset
  - getByteArray
```
void getByteArray(long offsetBytes,
                  byte[] dstArray,
                  int dstOffsetBytes,
                  int lengthBytes)
```
    Gets the byte array at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    dstArray - The preallocated destination array.
    
    dstOffsetBytes - offset in array units
    
    lengthBytes - number of array units to transfer
  - getChar
```
char getChar(long offsetBytes)
```
    Gets the char value at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    Returns:
    
    the char at the given offset
  - getCharArray
```
void getCharArray(long offsetBytes,
                  char[] dstArray,
                  int dstOffsetChars,
                  int lengthChars)
```
    Gets the char array at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    dstArray - The preallocated destination array.
    
    dstOffsetChars - offset in array units
    
    lengthChars - number of array units to transfer
  - getCharsFromUtf8
```
int getCharsFromUtf8(long offsetBytes,
                     int utf8LengthBytes,
                     Appendable dst)
              throws IOException,
                     Utf8CodingException
```
    Gets UTF-8 encoded bytes from this Memory, starting at offsetBytes to a length of utf8LengthBytes, decodes them into characters and appends them to the given Appendable. This is specifically designed to reduce the production of intermediate objects (garbage), thus significantly reducing pressure on the JVM Garbage Collector.
    
    Parameters:
    
    offsetBytes - offset bytes relative to the Memory start
    
    utf8LengthBytes - the number of encoded UTF-8 bytes to decode. It is assumed that the caller has the correct number of utf8 bytes required to decode the number of characters to be appended to dst. Characters outside the ASCII range can require 2, 3 or 4 bytes per character to decode.
    
    dst - the destination Appendable to append the decoded characters to.
    
    Returns:
    
    the number of characters decoded
    
    Throws:
    
    IOException - if dst.append() throws IOException
    
    Utf8CodingException - in case of malformed or illegal UTF-8 input
  - getCharsFromUtf8
```
int getCharsFromUtf8(long offsetBytes,
                     int utf8LengthBytes,
                     StringBuilder dst)
              throws Utf8CodingException
```
    Gets UTF-8 encoded bytes from this Memory, starting at offsetBytes to a length of utf8LengthBytes, decodes them into characters and appends them to the given StringBuilder. This method does *not* reset the length of the destination StringBuilder before appending characters to it. This is specifically designed to reduce the production of intermediate objects (garbage), thus significantly reducing pressure on the JVM Garbage Collector.
    
    Parameters:
    
    offsetBytes - offset bytes relative to the Memory start
    
    utf8LengthBytes - the number of encoded UTF-8 bytes to decode. It is assumed that the caller has the correct number of utf8 bytes required to decode the number of characters to be appended to dst. Characters outside the ASCII range can require 2, 3 or 4 bytes per character to decode.
    
    dst - the destination StringBuilder to append decoded characters to.
    
    Returns:
    
    the number of characters decoded.
    
    Throws:
    
    Utf8CodingException - in case of malformed or illegal UTF-8 input
  - getDouble
```
double getDouble(long offsetBytes)
```
    Gets the double value at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    Returns:
    
    the double at the given offset
  - getDoubleArray
```
void getDoubleArray(long offsetBytes,
                    double[] dstArray,
                    int dstOffsetDoubles,
                    int lengthDoubles)
```
    Gets the double array at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    dstArray - The preallocated destination array.
    
    dstOffsetDoubles - offset in array units
    
    lengthDoubles - number of array units to transfer
  - getFloat
```
float getFloat(long offsetBytes)
```
    Gets the float value at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    Returns:
    
    the float at the given offset
  - getFloatArray
```
void getFloatArray(long offsetBytes,
                   float[] dstArray,
                   int dstOffsetFloats,
                   int lengthFloats)
```
    Gets the float array at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    dstArray - The preallocated destination array.
    
    dstOffsetFloats - offset in array units
    
    lengthFloats - number of array units to transfer
  - getInt
```
int getInt(long offsetBytes)
```
    Gets the int value at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    Returns:
    
    the int at the given offset
  - getIntArray
```
void getIntArray(long offsetBytes,
                 int[] dstArray,
                 int dstOffsetInts,
                 int lengthInts)
```
    Gets the int array at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    dstArray - The preallocated destination array.
    
    dstOffsetInts - offset in array units
    
    lengthInts - number of array units to transfer
  - getLong
```
long getLong(long offsetBytes)
```
    Gets the long value at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    Returns:
    
    the long at the given offset
  - getLongArray
```
void getLongArray(long offsetBytes,
                  long[] dstArray,
                  int dstOffsetLongs,
                  int lengthLongs)
```
    Gets the long array at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    dstArray - The preallocated destination array.
    
    dstOffsetLongs - offset in array units
    
    lengthLongs - number of array units to transfer
  - getShort
```
short getShort(long offsetBytes)
```
    Gets the short value at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    Returns:
    
    the short at the given offset
  - getShortArray
```
void getShortArray(long offsetBytes,
                   short[] dstArray,
                   int dstOffsetShorts,
                   int lengthShorts)
```
    Gets the short array at the given offset
    
    Parameters:
    
    offsetBytes - offset bytes relative to this Memory start
    
    dstArray - The preallocated destination array.
    
    dstOffsetShorts - offset in array units
    
    lengthShorts - number of array units to transfer
  - compareTo
```
int compareTo(long thisOffsetBytes,
              long thisLengthBytes,
              Memory that,
              long thatOffsetBytes,
              long thatLengthBytes)
```
    Compares the bytes of this Memory to that Memory. Returns (this < that) ? (some negative value) : (this > that) ? (some positive value) : 0;. If all bytes are equal up to the shorter of the two lengths, the shorter length is considered to be less than the other.
    
    Parameters:
    
    thisOffsetBytes - the starting offset for this Memory
    
    thisLengthBytes - the length of the region to compare from this Memory
    
    that - the other Memory to compare with
    
    thatOffsetBytes - the starting offset for that Memory
    
    thatLengthBytes - the length of the region to compare from that Memory
    
    Returns:
    
    (this < that) ? (some negative value) : (this > that) ? (some positive value) : 0;
  - copyTo
```
void copyTo(long srcOffsetBytes,
            WritableMemory destination,
            long dstOffsetBytes,
            long lengthBytes)
```
    Copies bytes from a source range of this Memory to a destination range of the given Memory with the same semantics when copying between overlapping ranges of bytes as method System.arraycopy(Object, int, Object, int, int) has. However, if the source and the destination ranges are exactly the same, this method throws IllegalArgumentException, because it should never be needed in real-world scenarios and therefore indicates a bug.
    
    Parameters:
    
    srcOffsetBytes - the source offset for this Memory
    
    destination - the destination Memory, which may not be Read-Only.
    
    dstOffsetBytes - the destination offset
    
    lengthBytes - the number of bytes to copy
  - writeTo
```
void writeTo(long offsetBytes,
             long lengthBytes,
             WritableByteChannel out)
      throws IOException
```
    Writes bytes from a source range of this Memory to the given WritableByteChannel.
    
    Parameters:
    
    offsetBytes - the source offset for this Memory
    
    lengthBytes - the number of bytes to copy
    
    out - the destination WritableByteChannel
    
    Throws:
    
    IOException - may occur while writing to the WritableByteChannel

Interface Memory

Field Summary

Fields inherited from interface org.apache.datasketches.memory.BaseState

Method Summary

Methods inherited from interface org.apache.datasketches.memory.BaseState

Method Detail

wrap

wrap

map

map

region

region

asBuffer

asBuffer

wrap

wrap

wrap

wrap

wrap

wrap

wrap

wrap

wrap

wrap

getBoolean

getBooleanArray

getByte

getByteArray

getChar

getCharArray

getCharsFromUtf8

getCharsFromUtf8

getDouble

getDoubleArray

getFloat

getFloatArray

getInt

getIntArray

getLong

getLongArray

getShort

getShortArray

compareTo

copyTo

writeTo