BufferDataSet

java.lang.Object
- org.das2.qds.AbstractDataSet
- - org.das2.qds.buffer.BufferDataSet

All Implemented Interfaces:

MutablePropertyDataSet, QDataSet, WritableDataSet

Direct Known Subclasses:

AsciiDataSet, ByteDataSet, DoubleDataSet, FloatDataSet, Int24DataSet, IntDataSet, LongDataSet, NybbleDataSet, ShortDataSet, TimeDataSet, TruncatedFloatDataSet, UByteDataSet, UInt24DataSet, UIntDataSet, UShortDataSet, VaxFloatDataSet
```
public abstract class BufferDataSet
extends AbstractDataSet
implements WritableDataSet
```
rank 1, 2, 3, and 4 datasets backed by NIO buffers. These have the advantage that data can be stored outside of the JVM, and in fact they can be backed by a huge file on disk. This code was copied from BinaryDataSource.

Field Summary

Fields
Modifier and Type	Field and Description
`protected java.nio.ByteBuffer`	`back` the array backing the data
`static java.lang.Object`	`BITS` constructor units are in bits.
`static java.lang.Object`	`BYTE` 1 byte signed byte.
`static java.lang.Object`	`BYTES` constructor units are in bytes.
`static java.lang.Object`	`DOUBLE` the data is in 8 byte doubles.
`static java.lang.Object`	`FLOAT` the data is in 4 byte floats.
`static java.lang.Object`	`INT` 4 byte signed integers.
`static java.lang.Object`	`INT24` three-byte ints.
`static java.lang.Object`	`INTEGER` 4 byte signed integers, INT is canonical but INTEGER should be accepted.
`protected static java.util.logging.Logger`	`logger`
`static java.lang.Object`	`LONG` 8 byte signed longs.
`static java.lang.Object`	`NYBBLE` four-bit unsigned ints.
`static java.lang.Object`	`SHORT` 2 byte short integer.
`static java.lang.Object`	`TRUNCATEDFLOAT` the data is in 16 bit real that has exponent like a FLOAT but mantissa precision is reduced.
`static java.lang.Object`	`UBYTE` 1 byte unsigned byte.
`static java.lang.Object`	`UINT` 4 byte unsigned integers.
`static java.lang.Object`	`UINT24` three-byte unsigned ints.
`static java.lang.Object`	`USHORT` 2 byte unsigned short.
`static java.lang.Object`	`VAX_FLOAT` VAX floats.

Fields inherited from class org.das2.qds.AbstractDataSet
properties

Fields inherited from interface org.das2.qds.QDataSet
AVERAGE_TYPE, BIN_MAX, BIN_MAX_NAME, BIN_MIN, BIN_MIN_NAME, BIN_MINUS, BIN_MINUS_NAME, BIN_PLUS, BIN_PLUS_NAME, BINS_0, BINS_1, BUNDLE_0, BUNDLE_1, BUNDLE_2, BUNDLE_3, CACHE_TAG, CADENCE, CONTEXT_0, CONTEXT_1, COORDINATE_FRAME, DEFAULT_FILL_VALUE, DELTA_MINUS, DELTA_MINUS_NAME, DELTA_PLUS, DELTA_PLUS_NAME, DEPEND_0, DEPEND_1, DEPEND_2, DEPEND_3, DEPENDNAME_0, DEPENDNAME_1, DESCRIPTION, ELEMENT_DIMENSIONS, ELEMENT_LABEL, ELEMENT_NAME, FILL_VALUE, FORMAT, JOIN_0, LABEL, LIMIT_HUGE_DATASET, MAX_HIGH_RANK, MAX_PLANE_COUNT, MAX_RANK, MAX_UNIT_BUNDLE_COUNT, METADATA, METADATA_MODEL, MIN_WAVEFORM_LENGTH, MONOTONIC, NAME, NOTES, PLANE_0, QUBE, RENDER_TYPE, SCALE_TYPE, SOURCE, START_INDEX, TITLE, TYPICAL_MAX, TYPICAL_MIN, UNITS, USER_PROPERTIES, VALID_MAX, VALID_MIN, VALUE_AVERAGE_TYPE_GEOMETRIC, VALUE_AVERAGE_TYPE_LINEAR, VALUE_AVERAGE_TYPE_MOD24, VALUE_AVERAGE_TYPE_MOD360, VALUE_AVERAGE_TYPE_MODPI, VALUE_AVERAGE_TYPE_MODTAU, VALUE_AVERAGE_TYPE_NONE, VALUE_BINS_MIN_MAX, VALUE_BINS_MIN_MAX_INCLUSIVE, VALUE_COORDINATE_FRAME_COMPLEX_NUMBER, VALUE_METADATA_MODEL_ISTP, VALUE_METADATA_MODEL_SPASE, VALUE_RENDER_TYPE_COMPOSITE_IMAGE, VALUE_RENDER_TYPE_DIGITAL, VALUE_RENDER_TYPE_EVENTS_BAR, VALUE_RENDER_TYPE_NNSPECTROGRAM, VALUE_RENDER_TYPE_SERIES, VALUE_RENDER_TYPE_TRIANGLE_MESH, VALUE_SCALE_TYPE_LINEAR, VALUE_SCALE_TYPE_LOG, VERSION, WEIGHTS

Constructor Summary

Constructors
Constructor and Description
`BufferDataSet(int rank, int reclen, int recoffs, int len0, int len1, int len2, int len3, java.lang.Object type, java.nio.ByteBuffer back)` Create a new BufferDataSet of the given type.
`BufferDataSet(int rank, int reclen, int recoffs, int len0, int len1, int len2, java.lang.Object type, java.nio.ByteBuffer back)` Create a new BufferDataSet of the given type.
`BufferDataSet(int rank, int reclen, int recoffs, java.lang.Object bitByte, int len0, int len1, int len2, int len3, java.lang.Object type, java.nio.ByteBuffer back)` Create a new BufferDataSet of the given type.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`about()` print some info about this BufferDataSet.
`void`	`append(BufferDataSet ds)` append the dataset with the same geometry but different number of records (zeroth dim) to this.
`static BufferDataSet`	`append(BufferDataSet ths, BufferDataSet ds)` append the two datasets.
`static int`	`bitCount(java.lang.Object type)`
`static int`	`byteCount(java.lang.Object type)` return the number of bytes of each type (double=8, etc).
`boolean`	`canAppend(BufferDataSet ds)` return true if the dataset can be appended.
`BufferDataSet`	`compact()` get rid of extra spaces between records.
`static BufferDataSet`	`copy(java.lang.Object type, QDataSet ds)` Copy to array of specific type.
`static BufferDataSet`	`copy(QDataSet ds)` return a copy of the data.
`static BufferDataSet`	`create(int rank, java.lang.Object type, int len0, int[] size)` create a dataset backed by the given type.
`static BufferDataSet`	`createRank0(java.lang.Object type)` create a rank 0 dataset backed by the given type.
`static BufferDataSet`	`createRank1(java.lang.Object type, int len0)` create a rank 1 dataset backed by the given type.
`static BufferDataSet`	`createRank2(java.lang.Object type, int len0, int len1)` create a rank 2 dataset backed by the given type.
`static BufferDataSet`	`createRank3(java.lang.Object type, int len0, int len1, int len2)` create a rank 3 dataset backed by the given type.
`static BufferDataSet`	`createRank4(java.lang.Object type, int len0, int len1, int len2, int len3)` create a rank 4 dataset backed by the given type.
`protected void`	`ensureWritable()` copy the data to a writable buffer if it's not already writable.
`java.lang.Class`	`getCompatibleComponentType()` return the Java type that is capable of containing elements of this dataset.
`int`	`getFieldStride()` return the number of bytes to advance for each field.
`int`	`getRecordStride()` return the number of bytes to advance for each record.
`java.lang.Object`	`getType()` return the type of this dataset, for example BufferDataSet.INT, BufferDataSet.DOUBLE, etc...
`void`	`grow(int newRecCount)` grow the internal store so that append may be used to resize the dataset.
`static java.lang.Object`	`guessBackingStore(QDataSet ds)` guess the type of the backing store, returning double.class if it cannot be determined.
`boolean`	`isCompact()` returns true if the dataset is compact, meaning that there are no gaps between records, and no byte offset.
`protected static java.util.Map<java.lang.String,java.lang.Object>`	`joinProperties(BufferDataSet ths, BufferDataSet ds)` join the properties of the two datasets.
`int`	`jvmMemory()` estimate the jvmMemory occupied by this dataset, looking at the NIO buffer to see if it is direct as has no JVM memory cost, or if it has been made into an array.
`int`	`length()` return the length of the first dimension
`int`	`length(int i)` return the length of the second dimension, for the ith element of the first dimension.
`int`	`length(int i0, int i1)` return the length of the third dimension, for the ith element of the first dimension and jth element of the second dimension.
`int`	`length(int i0, int i1, int i2)` return the length of the fourth dimension for the ith, jth and kth elements of the first three dimensions.
`static BufferDataSet`	`makeDataSet(int rank, int reclen, int recoffs, int[] qube, java.nio.ByteBuffer buf, java.lang.Object type)` Make a BufferDataSet of the given type.
`static BufferDataSet`	`makeDataSet(int rank, int reclen, int recoffs, int len0, int len1, int len2, int len3, java.nio.ByteBuffer buf, java.lang.Object type)` Make a BufferDataSet of the given type.
`static BufferDataSet`	`makeDataSetBits(int rank, int reclenbits, int recoffsbits, int len0, int len1, int len2, int len3, java.nio.ByteBuffer buf, java.lang.Object type)` support binary types that are not a multiple of 8 bits.
`static BufferDataSet`	`maybeCopy(QDataSet ds)` Copy the dataset to an BufferDataSet only if the dataset is not already an BufferDataSet.
`protected int`	`offset()` return the offset, in bytes, of the element.
`protected int`	`offset(int i0)` return the offset, in bytes, of the element.
`protected int`	`offset(int i0, int i1)` return the offset, in bytes, of the element.
`protected int`	`offset(int i0, int i1, int i2)` return the offset, in bytes, of the element.
`protected int`	`offset(int i0, int i1, int i2, int i3)` return the offset, in bytes, of the element.
`protected void`	`rangeCheck(int i0, int i1, int i2, int i3)` for internal use, verify that the indeces are all within bounds.
`int`	`rank()` returns the rank of the dataset, which is the number of indeces used to access data.
`void`	`setFieldStride(int bytes)` allow clients to override the cadence of data.
`void`	`setLength(int len0)` reset the number of records.
`void`	`setLength1(int len1)` reset the length (in fields) of each record of the rank 2 dataset.
`void`	`setRecordStride(int bytes)` allow clients to override the cadece of the records.
`static int`	`shouldAllocateDirect()` return 1 if direct allocate should be used, 0 if not.
`QDataSet`	`slice(int i)` return a dataset that is a slice of this dataset, slicing on the zeroth dimension.
`QDataSet`	`trim(int ist, int ien)` return a dataset that is a subset of this dataset.
`static java.lang.Object`	`typeFor(java.lang.Class c)` Return the type for the given class.
`abstract double`	`value()` rank 0 accessor.
`abstract double`	`value(int i0)` rank 1 accessor.
`abstract double`	`value(int i0, int i1)` rank 2 accessor.
`abstract double`	`value(int i0, int i1, int i2)` rank 3 accessor.
`abstract double`	`value(int i0, int i1, int i2, int i3)` rank 4 accessor.

Methods inherited from class org.das2.qds.AbstractDataSet
capability, checkImmutable, isImmutable, makeImmutable, property, property, putProperty, putProperty, svalue, toString

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.das2.qds.WritableDataSet
putValue, putValue, putValue, putValue, putValue

Methods inherited from interface org.das2.qds.MutablePropertyDataSet
isImmutable, makeImmutable, putProperty, putProperty

Methods inherited from interface org.das2.qds.QDataSet
capability, property, property, svalue

- Field Detail
  - logger
```
protected static final java.util.logging.Logger logger
```
  - back
```
protected java.nio.ByteBuffer back
```
    the array backing the data
  - DOUBLE
```
public static final java.lang.Object DOUBLE
```
    the data is in 8 byte doubles.
  - FLOAT
```
public static final java.lang.Object FLOAT
```
    the data is in 4 byte floats.
  - TRUNCATEDFLOAT
```
public static final java.lang.Object TRUNCATEDFLOAT
```
    the data is in 16 bit real that has exponent like a FLOAT but mantissa precision is reduced.
  - VAX_FLOAT
```
public static final java.lang.Object VAX_FLOAT
```
    VAX floats.
  - INT24
```
public static final java.lang.Object INT24
```
    three-byte ints.
  - UINT24
```
public static final java.lang.Object UINT24
```
    three-byte unsigned ints.
  - NYBBLE
```
public static final java.lang.Object NYBBLE
```
    four-bit unsigned ints.
  - LONG
```
public static final java.lang.Object LONG
```
    8 byte signed longs.
  - INT
```
public static final java.lang.Object INT
```
    4 byte signed integers.
  - INTEGER
```
public static final java.lang.Object INTEGER
```
    4 byte signed integers, INT is canonical but INTEGER should be accepted.
  - UINT
```
public static final java.lang.Object UINT
```
    4 byte unsigned integers. Note 4-byte signed ints are used to store the data which is unpacked in the value() method.
  - SHORT
```
public static final java.lang.Object SHORT
```
    2 byte short integer.
  - USHORT
```
public static final java.lang.Object USHORT
```
    2 byte unsigned short.
  - BYTE
```
public static final java.lang.Object BYTE
```
    1 byte signed byte.
  - UBYTE
```
public static final java.lang.Object UBYTE
```
    1 byte unsigned byte.
  - BYTES
```
public static final java.lang.Object BYTES
```
    constructor units are in bytes.
  - BITS
```
public static final java.lang.Object BITS
```
    constructor units are in bits.
- Constructor Detail
  - BufferDataSet
```
public BufferDataSet(int rank,
                     int reclen,
                     int recoffs,
                     int len0,
                     int len1,
                     int len2,
                     java.lang.Object type,
                     java.nio.ByteBuffer back)
```
    Create a new BufferDataSet of the given type. Simple sanity checks are made, including:
    - rank 1 dataset may not have len1>1.
    - reclen cannot be shorter than the byte length of the field type.
    - buffer must have room for the dataset
    Parameters:
    
    rank - dataset rank
    
    reclen - length in bytes of each record
    
    recoffs - byte offet of each record
    
    len0 - number of elements in the first index
    
    len1 - number of elements in the second index
    
    len2 - number of elements in the third index
    
    back - ByteBuffer containing the data, which should be at least reclen * len0 bytes long.
    
    type - BufferDataSet.INT, BufferDataSet.DOUBLE, etc...
  - BufferDataSet
```
public BufferDataSet(int rank,
                     int reclen,
                     int recoffs,
                     int len0,
                     int len1,
                     int len2,
                     int len3,
                     java.lang.Object type,
                     java.nio.ByteBuffer back)
```
    Create a new BufferDataSet of the given type. Simple sanity checks are made, including:
    - rank 1 dataset may not have len1>1.
    - reclen cannot be shorter than the byte length of the field type.
    - buffer must have room for the dataset
    Parameters:
    
    rank - dataset rank
    
    reclen - length in bytes of each record
    
    recoffs - byte offset of each record
    
    len0 - number of elements in the first index
    
    len1 - number of elements in the second index
    
    len2 - number of elements in the third index
    
    len3 - number of elements in the fourth index
    
    back - ByteBuffer containing the data, which should be at least reclen * len0 bytes long.
    
    type - BufferDataSet.INT, BufferDataSet.DOUBLE, etc...
  - BufferDataSet
```
public BufferDataSet(int rank,
                     int reclen,
                     int recoffs,
                     java.lang.Object bitByte,
                     int len0,
                     int len1,
                     int len2,
                     int len3,
                     java.lang.Object type,
                     java.nio.ByteBuffer back)
```
    Create a new BufferDataSet of the given type. Simple sanity checks are made, including:
    - rank 1 dataset may not have len1>1.
    - reclen cannot be shorter than the byte length of the field type.
    - buffer must have room for the dataset
    Parameters:
    
    rank - dataset rank
    
    reclen - length in bytes/bits of each record.
    
    recoffs - byte/bit offset of each record. For bits this must be multiple of 8.
    
    bitByte - either BufferDataSet.BYTES or BufferDataSet.BITS
    
    len0 - number of elements in the first index
    
    len1 - number of elements in the second index
    
    len2 - number of elements in the third index
    
    len3 - number of elements in the fourth index
    
    back - ByteBuffer containing the data, which should be at least reclen * len0 bytes long (when reclen is in bytes).
    
    type - BufferDataSet.INT, BufferDataSet.DOUBLE, etc...
- Method Detail
  - bitCount
```
public static int bitCount(java.lang.Object type)
```
  - byteCount
```
public static int byteCount(java.lang.Object type)
```
    return the number of bytes of each type (double=8, etc).
    
    Parameters:
    
    type - DOUBLE, FLOAT, UBYTE, TIME28, etc.
    
    Returns:
    
    8, 4, 1, etc.
    
    Throws:
    
    java.lang.IllegalArgumentException - for NYBBLE, which can only be used with bitCount.
  - makeDataSetBits
```
public static BufferDataSet makeDataSetBits(int rank,
                                            int reclenbits,
                                            int recoffsbits,
                                            int len0,
                                            int len1,
                                            int len2,
                                            int len3,
                                            java.nio.ByteBuffer buf,
                                            java.lang.Object type)
```
    support binary types that are not a multiple of 8 bits. This was added to support Nybbles, and 12-bit ints.
    
    Parameters:
    
    rank -
    
    reclenbits - number of bits per record
    
    recoffsbits - number of bits offset. Note this must be a multiple of 8, for now.
    
    len0 - number of elements in the first index
    
    len1 - number of elements in the second index
    
    len2 - number of elements in the third index
    
    len3 - number of elements in the fourth index
    
    buf - ByteBuffer containing the data, which should be at least recoffsbits/8 + reclenbits/8 * len0 bytes long.
    
    type - BufferDataSet.NYBBLE, etc
    
    Returns:
    
    BufferDataSet of the given type.
  - makeDataSet
```
public static BufferDataSet makeDataSet(int rank,
                                        int reclen,
                                        int recoffs,
                                        int len0,
                                        int len1,
                                        int len2,
                                        int len3,
                                        java.nio.ByteBuffer buf,
                                        java.lang.Object type)
```
    Make a BufferDataSet of the given type.
    
    Parameters:
    
    rank - the rank (number of indeces) of the data.
    
    reclen - length in bytes of each record. This may be longer than len1*len2*len3*byteCount(type)
    
    recoffs - byte offset of each record
    
    len0 - number of elements in the first index
    
    len1 - number of elements in the second index
    
    len2 - number of elements in the third index
    
    len3 - number of elements in the fourth index
    
    buf - ByteBuffer containing the data, which should be at least recoffs + reclen * len0 bytes long.
    
    type - BufferDataSet.INT, BufferDataSet.DOUBLE, etc...
    
    Returns:
    
    BufferDataSet of the given type.
  - makeDataSet
```
public static BufferDataSet makeDataSet(int rank,
                                        int reclen,
                                        int recoffs,
                                        int[] qube,
                                        java.nio.ByteBuffer buf,
                                        java.lang.Object type)
```
    Make a BufferDataSet of the given type.
    
    Parameters:
    
    rank - the rank (number of indeces) of the data.
    
    reclen - length in bytes of each record
    
    recoffs - byte offset of each record
    
    qube - integer array of the number of elements in each index. If rank is less than the number of elements, then ignore extra trailing elements.
    
    buf - ByteBuffer containing the data, which should be at least recoffs + reclen * len0 bytes long.
    
    type - BufferDataSet.INT, BufferDataSet.DOUBLE, etc...
    
    Returns:
    
    BufferDataSet of the given type.
  - setFieldStride
```
public void setFieldStride(int bytes)
```
    allow clients to override the cadence of data. By default, this is just the number of bytes in each field.
    
    Parameters:
    
    bytes - number of bytes between field beginnings.
  - getFieldStride
```
public int getFieldStride()
```
    return the number of bytes to advance for each field.
    
    Returns:
    
    the number of bytes to advance for each field.
  - setRecordStride
```
public void setRecordStride(int bytes)
```
    allow clients to override the cadece of the records. By default, this is the number of bytes in each record.
    
    Parameters:
    
    bytes - number of bytes between record beginnings.
  - getRecordStride
```
public int getRecordStride()
```
    return the number of bytes to advance for each record.
    
    Returns:
    
    the number of bytes to advance for each record.
  - setLength
```
public void setLength(int len0)
```
    reset the number of records.
    
    Parameters:
    
    len0 - the new number of records.
  - setLength1
```
public void setLength1(int len1)
```
    reset the length (in fields) of each record of the rank 2 dataset.
    
    Parameters:
    
    len1 - the length of each record of the rank 2 dataset.
    
    See Also:
    
    Ops.decimateBufferDataSet(org.das2.qds.buffer.BufferDataSet, int, int)
  - create
```
public static BufferDataSet create(int rank,
                                   java.lang.Object type,
                                   int len0,
                                   int[] size)
```
    create a dataset backed by the given type.
    
    Parameters:
    
    rank - the rank of the data
    
    type - DOUBLE, FLOAT, UINT, etc
    
    len0 - number of records (ignored for rank 0).
    
    size - size of each record
    
    Returns:
    
    BufferDataSet of the given type.
  - createRank0
```
public static BufferDataSet createRank0(java.lang.Object type)
```
    create a rank 0 dataset backed by the given type.
    
    Parameters:
    
    type - DOUBLE, FLOAT, UINT, etc
    
    Returns:
    
    BufferDataSet of the given type.
  - createRank1
```
public static BufferDataSet createRank1(java.lang.Object type,
                                        int len0)
```
    create a rank 1 dataset backed by the given type.
    
    Parameters:
    
    type - DOUBLE, FLOAT, UINT, etc
    
    len0 - length of the zeroth index
    
    Returns:
    
    BufferDataSet of the given type.
  - createRank2
```
public static BufferDataSet createRank2(java.lang.Object type,
                                        int len0,
                                        int len1)
```
    create a rank 2 dataset backed by the given type.
    
    Parameters:
    
    type - DOUBLE, FLOAT, UINT, etc
    
    len0 - length of the zeroth index
    
    len1 - length of the first index
    
    Returns:
    
    BufferDataSet of the given type.
  - createRank3
```
public static BufferDataSet createRank3(java.lang.Object type,
                                        int len0,
                                        int len1,
                                        int len2)
```
    create a rank 3 dataset backed by the given type.
    
    Parameters:
    
    type - DOUBLE, FLOAT, UINT, etc
    
    len0 - length of the zeroth index
    
    len1 - length of the first index
    
    len2 - length of the second index
    
    Returns:
    
    BufferDataSet of the given type.
  - createRank4
```
public static BufferDataSet createRank4(java.lang.Object type,
                                        int len0,
                                        int len1,
                                        int len2,
                                        int len3)
```
    create a rank 4 dataset backed by the given type.
    
    Parameters:
    
    type - DOUBLE, FLOAT, UINT, etc
    
    len0 - length of the zeroth index
    
    len1 - length of the first index
    
    len2 - length of the second index
    
    len3 - length of the third index
    
    Returns:
    
    BufferDataSet of the given type.
  - copy
```
public static BufferDataSet copy(QDataSet ds)
```
    return a copy of the data. If the data is a BufferDataSet, then a new BufferDataSet is used for the copy. Note this does not consider isMutable. If the dataset is not mutable, then the original data could be returned (probably).
    
    Parameters:
    
    ds - any qube dataset.
    
    Returns:
    
    a BufferDataSet copy of the dataset.
  - guessBackingStore
```
public static java.lang.Object guessBackingStore(QDataSet ds)
```
    guess the type of the backing store, returning double.class if it cannot be determined.
    
    Parameters:
    
    ds - the dataset
    
    Returns:
    
    the backing store class, one of double.class, float.class, etc.
  - maybeCopy
```
public static BufferDataSet maybeCopy(QDataSet ds)
```
    Copy the dataset to an BufferDataSet only if the dataset is not already an BufferDataSet.
    
    Parameters:
    
    ds -
    
    Returns:
    
    a BufferDataSet.
  - canAppend
```
public boolean canAppend(BufferDataSet ds)
```
    return true if the dataset can be appended. Note this assumes that the same length, etc. This just checks that we have the number of spare records in the backing store.
    
    Parameters:
    
    ds - dataset of the same rank and len1, len2, and len3.
    
    Returns:
    
    true if the dataset can be appended.
  - shouldAllocateDirect
```
public static int shouldAllocateDirect()
```
    return 1 if direct allocate should be used, 0 if not. Direct allocations are memory allocations outside of the JVM heap memory. (The internal variable has a -1 initial state, which is why this is not boolean.) This looks for 32bit Javas, and if more than 1/2 Gig is being used then it will allocate direct. This is because 32bit Javas cannot access any memory outside of 1Gig.
    
    Returns:
    
    1 or 0 if direct allocations should not be made.
    
    See Also:
    
    https://sourceforge.net/p/autoplot/bugs/1395/, http://stackoverflow.com/questions/807263/how-do-i-detect-which-kind-of-jre-is-installed-32bit-vs-64bit, "How ByteBuffer works and why Direct (Byte)Buffers are the only truly useful now"
  - append
```
public void append(BufferDataSet ds)
```
    append the dataset with the same geometry but different number of records (zeroth dim) to this. An IllegalArgumentException is thrown when there is not enough room. See grow(newRecCount). This buffer's capacity will be something like java.nio.DirectByteBuffer[pos=0 lim=6256 cap=13760] and the dataset ds's buffer will have java.nio.DirectByteBufferR[pos=0 lim=6256 cap=6256]. After this append operation, the buffer of the second will be copied into the first's: java.nio.DirectByteBuffer[pos=0 lim=12512 cap=13760]. Not thread safe--we need to go through and make it so...
    
    Parameters:
    
    ds -
    
    See Also:
    
    grow(int)
  - append
```
public static BufferDataSet append(BufferDataSet ths,
                                   BufferDataSet ds)
```
    append the two datasets. The two datasets need only have convertible units, so for example two time arrays may be appended even if their units don't have the same base. Only properties of the two datasets that do not change are preserved.
    
    Parameters:
    
    ths - rank N dataset
    
    ds - rank N dataset of the same type and geometry as ths.
    
    Returns:
    
    the dataset
  - joinProperties
```
protected static java.util.Map<java.lang.String,java.lang.Object> joinProperties(BufferDataSet ths,
                                                                                 BufferDataSet ds)
```
    join the properties of the two datasets. (for append, really...) Note MONOTONIC assumes the ds will be added after ths.
    
    Parameters:
    
    ths -
    
    ds -
    
    Returns:
    
    the two sets combined.
  - typeFor
```
public static java.lang.Object typeFor(java.lang.Class c)
```
    Return the type for the given class. Note that there is a type for each native type (Byte,Short,Float,etc), but not a class for each type. (E.g. UBYTE is unsigned byte.)
    
    Parameters:
    
    c - java class
    
    Returns:
    
    DOUBLE,FLOAT,etc.
  - copy
```
public static BufferDataSet copy(java.lang.Object type,
                                 QDataSet ds)
```
    Copy to array of specific type. For example, copy( DOUBLE, ds ) would return a copy in a DoubleDataSet.
    
    Parameters:
    
    type - the primitive type to use (e.g. double.class).
    
    ds - the data to copy.
    
    Returns:
    
    BufferDataSet of specific type.
  - grow
```
public void grow(int newRecCount)
```
    grow the internal store so that append may be used to resize the dataset. This simply grows the internal buffer, so for example length() will return the same value after.
    
    Parameters:
    
    newRecCount - the new record count, generally larger than the old rec count.
    
    See Also:
    
    append(org.das2.qds.buffer.BufferDataSet)
  - getType
```
public java.lang.Object getType()
```
    return the type of this dataset, for example BufferDataSet.INT, BufferDataSet.DOUBLE, etc...
    
    Returns:
    
    the type of this dataset.
  - rank
```
public int rank()
```
    Description copied from interface: QDataSet
    
    returns the rank of the dataset, which is the number of indeces used to access data. Only rank 0, 1, 2, 3, and 4 datasets are supported in the interface. When a dataset's rank is 5 or greater, it should implement the HighRankDataSet interface which affords a slice operation to reduce rank.
    
    Specified by:
    
    rank in interface QDataSet
    
    Specified by:
    
    rank in class AbstractDataSet
    
    Returns:
    
    the rank, or number of indeces used to access data.
  - length
```
public int length()
```
    Description copied from interface: QDataSet
    
    return the length of the first dimension
    
    Specified by:
    
    length in interface QDataSet
    
    Overrides:
    
    length in class AbstractDataSet
    
    Returns:
    
    the length of the first dimension
  - length
```
public int length(int i)
```
    Description copied from interface: QDataSet
    
    return the length of the second dimension, for the ith element of the first dimension. Note if there are zero elements in the first dimension, but this is a QUBE, then this should not throw an IndexOutOfBoundsException.
    
    Specified by:
    
    length in interface QDataSet
    
    Overrides:
    
    length in class AbstractDataSet
    
    Parameters:
    
    i - the index
    
    Returns:
    
    the length of the second dimension at index i.
  - length
```
public int length(int i0,
                  int i1)
```
    Description copied from interface: QDataSet
    
    return the length of the third dimension, for the ith element of the first dimension and jth element of the second dimension.
    
    Specified by:
    
    length in interface QDataSet
    
    Overrides:
    
    length in class AbstractDataSet
    
    Parameters:
    
    i0 - the index
    
    i1 - the index
    
    Returns:
    
    the length of the third dimension at index i.
  - length
```
public int length(int i0,
                  int i1,
                  int i2)
```
    Description copied from interface: QDataSet
    
    return the length of the fourth dimension for the ith, jth and kth elements of the first three dimensions.
    
    Specified by:
    
    length in interface QDataSet
    
    Overrides:
    
    length in class AbstractDataSet
    
    Parameters:
    
    i0 - the index
    
    i1 - the index
    
    i2 - the index
    
    Returns:
    
    the length of the fourth dimension for the ith, jth and kth elements of the first three dimensions.
  - rangeCheck
```
protected void rangeCheck(int i0,
                          int i1,
                          int i2,
                          int i3)
```
    for internal use, verify that the indeces are all within bounds.
    
    Parameters:
    
    i0 - the zeroth index.
    
    i1 - the first index
    
    i2 - the second index
    
    i3 - the third index
    
    See Also:
    
    which is used to turn on range checking.
  - offset
```
protected int offset()
```
    return the offset, in bytes, of the element.
    
    Returns:
    
    the offset, in bytes, of the element.
  - offset
```
protected int offset(int i0)
```
    return the offset, in bytes, of the element. We do not check the dataset rank, so that trim and slice may find the location of any record.
    
    Parameters:
    
    i0 -
    
    Returns:
    
    the offset, in bytes, of the element.
  - offset
```
protected int offset(int i0,
                     int i1)
```
    return the offset, in bytes, of the element.
    
    Parameters:
    
    i0 - first index
    
    i1 - second index
    
    Returns:
    
    the offset, in bytes, of the element.
  - offset
```
protected int offset(int i0,
                     int i1,
                     int i2)
```
    return the offset, in bytes, of the element.
    
    Parameters:
    
    i0 - first index
    
    i1 - second index
    
    i2 - third index
    
    Returns:
    
    the offset, in bytes, of the element.
  - offset
```
protected int offset(int i0,
                     int i1,
                     int i2,
                     int i3)
```
    return the offset, in bytes, of the element.
    
    Parameters:
    
    i0 - first index
    
    i1 - second index
    
    i2 - third index
    
    i3 - fourth index
    
    Returns:
    
    the offset, in bytes, of the element.
  - value
```
public abstract double value()
```
    Description copied from interface: QDataSet
    
    rank 0 accessor.
    
    Specified by:
    
    value in interface QDataSet
    
    Overrides:
    
    value in class AbstractDataSet
    
    Returns:
    
    the value, see the property UNITS to interpret this.
  - value
```
public abstract double value(int i0)
```
    Description copied from interface: QDataSet
    
    rank 1 accessor.
    
    Specified by:
    
    value in interface QDataSet
    
    Overrides:
    
    value in class AbstractDataSet
    
    Parameters:
    
    i0 - the index
    
    Returns:
    
    the value, see the property UNITS to interpret this.
  - value
```
public abstract double value(int i0,
                             int i1)
```
    Description copied from interface: QDataSet
    
    rank 2 accessor.
    
    Specified by:
    
    value in interface QDataSet
    
    Overrides:
    
    value in class AbstractDataSet
    
    Parameters:
    
    i0 - the index
    
    i1 - the index
    
    Returns:
    
    the value, see the property UNITS to interpret this.
  - value
```
public abstract double value(int i0,
                             int i1,
                             int i2)
```
    Description copied from interface: QDataSet
    
    rank 3 accessor.
    
    Specified by:
    
    value in interface QDataSet
    
    Overrides:
    
    value in class AbstractDataSet
    
    Parameters:
    
    i0 - the index
    
    i1 - the index
    
    i2 - the index
    
    Returns:
    
    the value, see the property UNITS to interpret this.
  - value
```
public abstract double value(int i0,
                             int i1,
                             int i2,
                             int i3)
```
    Description copied from interface: QDataSet
    
    rank 4 accessor.
    
    Specified by:
    
    value in interface QDataSet
    
    Overrides:
    
    value in class AbstractDataSet
    
    Parameters:
    
    i0 - the index
    
    i1 - the index
    
    i2 - the index
    
    i3 - the index
    
    Returns:
    
    the value, see the property UNITS to interpret this.
  - trim
```
public QDataSet trim(int ist,
                     int ien)
```
    Description copied from interface: QDataSet
    return a dataset that is a subset of this dataset. For example:
```
 
    ds= DDataSet.createRank1(100);
    QDataSet trim= ds.trim(50,60);
    assert( trim.length()==10 );
 
 
```
    Note start and end must be positive. Negative indices, referenced from the end of the dataset, are not supported here.
    Specified by:
    
    trim in interface QDataSet
    
    Overrides:
    
    trim in class AbstractDataSet
    
    Parameters:
    
    ist - the first index to be included in the new dataset.
    
    ien - the exclusive index indicating the last index.
    
    Returns:
    
    a QDataSet with the same rank but fewer elements.
  - slice
```
public QDataSet slice(int i)
```
    Description copied from interface: QDataSet
    
    return a dataset that is a slice of this dataset, slicing on the zeroth dimension. A slice will be the elements at this index, for example if this dataset is a rank 2 dataset flux(Time,Energy) then the slice of this will be a rank 1 dataset flux(Energy). The result of any slice will be a qube. Note the index must be positive. Negative indices, referenced from the end of the dataset, are not supported.
    
    Specified by:
    
    slice in interface QDataSet
    
    Overrides:
    
    slice in class AbstractDataSet
    
    Parameters:
    
    i - the index to slice at
    
    Returns:
    
    the rank n-1 QDataSet at index i.
  - ensureWritable
```
protected void ensureWritable()
```
    copy the data to a writable buffer if it's not already writable.
  - jvmMemory
```
public int jvmMemory()
```
    estimate the jvmMemory occupied by this dataset, looking at the NIO buffer to see if it is direct as has no JVM memory cost, or if it has been made into an array.
    
    Returns:
    
    the estimated number bytes that the dataSet occupies.
  - about
```
public void about()
```
    print some info about this BufferDataSet.
  - getCompatibleComponentType
```
public java.lang.Class getCompatibleComponentType()
```
    return the Java type that is capable of containing elements of this dataset. For unsigned types, the next Java class is used, for example int.class is used to store unsigned shorts.
    
    Returns:
    
    double.class, float.class, long.class, etc.
  - isCompact
```
public boolean isCompact()
```
    returns true if the dataset is compact, meaning that there are no gaps between records, and no byte offset.
    
    Returns:
    
    true if the dataset is compact
  - compact
```
public BufferDataSet compact()
```
    get rid of extra spaces between records.
    
    Returns:
    
    new BufferDataSet without gaps.

Class BufferDataSet

Field Summary

Fields inherited from class org.das2.qds.AbstractDataSet

Fields inherited from interface org.das2.qds.QDataSet

Constructor Summary

Method Summary

Methods inherited from class org.das2.qds.AbstractDataSet

Methods inherited from class java.lang.Object

Methods inherited from interface org.das2.qds.WritableDataSet

Methods inherited from interface org.das2.qds.MutablePropertyDataSet

Methods inherited from interface org.das2.qds.QDataSet

Field Detail

logger

back

DOUBLE

FLOAT

TRUNCATEDFLOAT

VAX_FLOAT

INT24

UINT24

NYBBLE

LONG

INT

INTEGER

UINT

SHORT

USHORT

BYTE

UBYTE

BYTES

BITS

Constructor Detail

BufferDataSet

BufferDataSet

BufferDataSet

Method Detail

bitCount

byteCount

makeDataSetBits

makeDataSet

makeDataSet

setFieldStride

getFieldStride

setRecordStride

getRecordStride

setLength

setLength1

create

createRank0

createRank1

createRank2

createRank3

createRank4

copy

guessBackingStore

maybeCopy

canAppend

shouldAllocateDirect

append

append

joinProperties

typeFor

copy

grow

getType

rank

length

length

length

length

rangeCheck

offset

offset

offset

offset

offset

value

value

value

value