Class SimpleNIOBuffer
- All Implemented Interfaces:
AutoCloseable
,BufferProtocol
,PyBUF
,PyBuffer
java.nio.ByteBuffer
of one-byte items.-
Nested Class Summary
Nested classes/interfaces inherited from interface org.python.core.PyBuffer
PyBuffer.Pointer
-
Field Summary
Fields inherited from interface org.python.core.PyBUF
ANY_CONTIGUOUS, AS_ARRAY, C_CONTIGUOUS, CONTIG, CONTIG_RO, CONTIGUITY, F_CONTIGUOUS, FORMAT, FULL, FULL_RO, INDIRECT, IS_C_CONTIGUOUS, IS_F_CONTIGUOUS, MAX_NDIM, NAVIGATION, ND, RECORDS, RECORDS_RO, SIMPLE, STRIDED, STRIDED_RO, STRIDES, WRITABLE
-
Constructor Summary
ConstructorDescriptionSimpleNIOBuffer
(int flags, BufferProtocol obj, ByteBuffer storage) Provide an instance ofSimpleNIOBuffer
, on the entirety of aByteBuffer
, meeting the consumer's expectations as expressed in theflags
argument, which is checked against the capabilities of the buffer type.SimpleNIOBuffer
(int flags, BufferProtocol obj, ByteBuffer storage, int index0, int size) Provide an instance ofSimpleNIOBuffer
, on a slice of aByteBuffer
, meeting the consumer's expectations as expressed in theflags
argument, which is checked against the capabilities of the buffer type. -
Method Summary
Modifier and TypeMethodDescriptionfinal int
byteIndex
(int index) Convert an item index (for a one-dimensional buffer) to an absolute byte index in the storage shared by the exporter.getBufferSlice
(int flags, int start, int count) Equivalent toPyBuffer.getBufferSlice(int, int, int, int)
with stride 1.getBufferSlice
(int flags, int start, int count, int stride) Get aPyBuffer
that represents a slice of the current one described in terms of a start index, number of items to include in the slice, and the stride in the current buffer.int
getLen()
The total number of bytes represented by the view, which will be the product of the elements of theshape
array, and the item size in bytes.Methods inherited from class org.python.core.buffer.BaseNIOBuffer
byteIndex, copyFrom, copyTo, copyTo, getBuf
Methods inherited from class org.python.core.buffer.Base1DBuffer
isContiguous
Methods inherited from class org.python.core.buffer.BaseBuffer
byteAt, byteAt, close, copyFrom, copyTo, getBuffer, getBufferAgain, getFormat, getItemsize, getNdim, getNIOByteBuffer, getObj, getPointer, getPointer, getShape, getStrides, getSuboffsets, hasArray, intAt, intAt, isReadonly, isReleased, release, storeAt, storeAt, toString
-
Constructor Details
-
SimpleNIOBuffer
public SimpleNIOBuffer(int flags, BufferProtocol obj, ByteBuffer storage, int index0, int size) throws PyException, ArrayIndexOutOfBoundsException, NullPointerException Provide an instance ofSimpleNIOBuffer
, on a slice of aByteBuffer
, meeting the consumer's expectations as expressed in theflags
argument, which is checked against the capabilities of the buffer type. No reference will be kept to theByteBuffer
passed in. (It is duplicated.)- Parameters:
flags
- consumer requirementsobj
- exporting object (ornull
)storage
- theByteBuffer
wrapping the exported object stateindex0
- offset where the data starts in that buffer (item[0])size
- the number of bytes occupied- Throws:
NullPointerException
- ifstorage
is nullArrayIndexOutOfBoundsException
- ifindex0
andsize
are inconsistent withstorage.length
PyException
-BufferError
when expectations do not correspond with the type
-
SimpleNIOBuffer
public SimpleNIOBuffer(int flags, BufferProtocol obj, ByteBuffer storage) throws PyException, NullPointerException Provide an instance ofSimpleNIOBuffer
, on the entirety of aByteBuffer
, meeting the consumer's expectations as expressed in theflags
argument, which is checked against the capabilities of the buffer type. No reference will be kept to theByteBuffer
passed in. (It is duplicated.)- Parameters:
flags
- consumer requirementsobj
- exporting object (ornull
)storage
- theByteBuffer
wrapping the exported object state- Throws:
NullPointerException
- ifstorage
is nullPyException
-BufferError
when expectations do not correspond with the type
-
-
Method Details
-
getLen
public int getLen()The total number of bytes represented by the view, which will be the product of the elements of theshape
array, and the item size in bytes.SimpleNIOBuffer
provides an implementation optimised for contiguous bytes in one-dimension.- Specified by:
getLen
in interfacePyBUF
- Overrides:
getLen
in classBase1DBuffer
- Returns:
- the total number of bytes represented.
-
byteIndex
Description copied from interface:PyBuffer
Convert an item index (for a one-dimensional buffer) to an absolute byte index in the storage shared by the exporter. The storage exported as aPyBuffer
is a linearly-indexed sequence of bytes, although it may not actually be a heap-allocated Javabyte[]
object. The purpose of this method is to allow the exporter to define the relationship between the item index (as used inPyBuffer.byteAt(int)
) and the byte-index (as used with theByteBuffer
returned byPyBuffer.getNIOByteBuffer()
). SeePyBuffer.byteIndex(int[])
for discussion of the multi-dimensional case.- Specified by:
byteIndex
in interfacePyBuffer
- Overrides:
byteIndex
in classBaseBuffer
- Parameters:
index
- item-index from consumer- Returns:
- corresponding byte-index in actual storage
- Throws:
IndexOutOfBoundsException
-
getBufferSlice
Description copied from interface:PyBuffer
Equivalent toPyBuffer.getBufferSlice(int, int, int, int)
with stride 1.- Specified by:
getBufferSlice
in interfacePyBuffer
- Overrides:
getBufferSlice
in classBaseBuffer
- Parameters:
flags
- specifying features demanded and the navigational capabilities of the consumerstart
- index in the current buffercount
- number of items in the required slice- Returns:
- a buffer representing the slice
-
getBufferSlice
Get aPyBuffer
that represents a slice of the current one described in terms of a start index, number of items to include in the slice, and the stride in the current buffer. A consumer that obtains aPyBuffer
withgetBufferSlice
must release it withPyBuffer.release()
just as if it had been obtained withPyBuffer.getBuffer(int)
Suppose that x(i) denotes the ith element of the current buffer, that is, the byte retrieved by
this.byteAt(i)
or the unit indicated bythis.getPointer(i)
. A request for a slice wherestart
= s,count
= N andstride
= m, results in a buffer y such that y(k) = x(s+km) where k=0..(N-1). In Python terms, this is the slice x[s : s+(N-1)m+1 : m] (if m>0) or the slice x[s : s+(N-1)m-1 : m] (if m<0). Implementations should check that this range is entirely within the current buffer.In a simple buffer backed by a contiguous byte array, the result is a strided PyBuffer on the same storage but where the offset is adjusted by s and the stride is as supplied. If the current buffer is already strided and/or has an item size larger than single bytes, the new
start
index,count
andstride
will be translated from the arguments given, through this buffer's stride and item size. The caller always expressesstart
andstrides
in terms of the abstract view of this buffer.SimpleNIOBuffer
provides an implementation for slicing contiguous bytes in one dimension. In that case, x(i) = u(r+i) for i = 0..L-1 where u is the underlying buffer, and r and L are the start and count with which x was created from u. Thus y(k) = u(r+s+km), that is, the composite offset is r+s and the stride is m.- Parameters:
flags
- specifying features demanded and the navigational capabilities of the consumerstart
- index in the current buffercount
- number of items in the required slicestride
- index-distance in the current buffer between consecutive items in the slice- Returns:
- a buffer representing the slice
-