#include <array.h>
Inheritance diagram for PAbstractArray:
Public Member Functions | |
Construction | |
| PAbstractArray (PINDEX elementSizeInBytes, PINDEX initialSize=0) | |
Create a new dynamic array of initalSize elements of elementSizeInBytes bytes each. | |
| PAbstractArray (PINDEX elementSizeInBytes, const void *buffer, PINDEX bufferSizeInElements, PBoolean dynamicAllocation) | |
Create a new dynamic array of bufferSizeInElements elements of elementSizeInBytes bytes each. | |
Overrides from class PObject | |
| virtual void | PrintOn (ostream &strm) const |
| Output the contents of the object to the stream. | |
| virtual void | ReadFrom (istream &strm) |
| Input the contents of the object from the stream. | |
| virtual Comparison | Compare (const PObject &obj) const |
| Get the relative rank of the two arrays. | |
Overrides from class PContainer | |
| virtual PBoolean | SetSize (PINDEX newSize) |
| Set the size of the array in elements. | |
New functions for class | |
| void | Attach (const void *buffer, PINDEX bufferSize) |
| Attach a pointer to a static block to the base array type. | |
| void * | GetPointer (PINDEX minSize=1) |
| Get a pointer to the internal array and assure that it is of at least the specified size. | |
| PBoolean | Concatenate (const PAbstractArray &array) |
| Concatenate one array to the end of this array. | |
Protected Member Functions | |
| PBoolean | InternalSetSize (PINDEX newSize, PBoolean force) |
| virtual void | PrintElementOn (ostream &stream, PINDEX index) const |
| virtual void | ReadElementFrom (istream &stream, PINDEX index) |
Protected Attributes | |
| PINDEX | elementSize |
| Size of an element in bytes. | |
| char * | theArray |
| Pointer to the allocated block of memory. | |
| PBoolean | allocatedDynamically |
| Flag indicating the array was allocated on the heap. | |
These can be anything from individual bytes to large structures. Note that that does not include class objects that require construction or destruction. Elements in this array will not execute the contructors or destructors of objects.
An abstract array consists of a linear block of memory sufficient to hold PContainer::GetSize() elements of elementSize bytes each. The memory block itself will automatically be resized when required and freed when no more references to it are present.
The PAbstractArray class would very rarely be descended from directly by the user. The PBASEARRAY macro would normally be used to create a class and any new classes descended from that. That will instantiate the template based on PBaseArray or directly declare and define a class (using inline functions) if templates are not being used.
The PBaseArray class or PBASEARRAY macro will define the correctly typed operators for pointer access (operator const T *) and subscript access (operator[]).
| PAbstractArray::PAbstractArray | ( | PINDEX | elementSizeInBytes, | |
| PINDEX | initialSize = 0 | |||
| ) |
Create a new dynamic array of initalSize elements of elementSizeInBytes bytes each.
The array memory is initialised to zeros.
If the initial size is zero then no memory is allocated. Note that the internal pointer is set to NULL, not to a pointer to zero bytes of memory. This can be an important distinction when the pointer is obtained via an operator created in the PBASEARRAY macro.
| elementSizeInBytes | Size of each element in the array. This must be > 0 or the constructor will assert. |
| initialSize | Number of elements to allocate initially. |
| PAbstractArray::PAbstractArray | ( | PINDEX | elementSizeInBytes, | |
| const void * | buffer, | |||
| PINDEX | bufferSizeInElements, | |||
| PBoolean | dynamicAllocation | |||
| ) |
Create a new dynamic array of bufferSizeInElements elements of elementSizeInBytes bytes each.
The contents of the memory pointed to by buffer is then used to initialise the newly allocated array.
If the initial size is zero then no memory is allocated. Note that the internal pointer is set to NULL, not to a pointer to zero bytes of memory. This can be an important distinction when the pointer is obtained via an operator created in the PBASEARRAY macro.
If the dynamicAllocation parameter is false then the pointer is used directly by the container. It will not be copied to a dynamically allocated buffer. If the SetSize() function is used to change the size of the buffer, the object will be converted to a dynamic form with the contents of the static buffer copied to the allocated buffer.
| elementSizeInBytes | Size of each element in the array. This must be > 0 or the constructor will assert. |
| buffer | Pointer to an array of elements. |
| bufferSizeInElements | Number of elements pointed to by buffer. |
| dynamicAllocation | Buffer is copied and dynamically allocated. |
| void PAbstractArray::Attach | ( | const void * | buffer, | |
| PINDEX | bufferSize | |||
| ) |
Attach a pointer to a static block to the base array type.
The pointer is used directly and will not be copied to a dynamically allocated buffer. If the SetSize() function is used to change the size of the buffer, the object will be converted to a dynamic form with the contents of the static buffer copied to the allocated buffer.
Any dynamically allocated buffer will be freed.
| buffer | Pointer to an array of elements. |
| bufferSize | Number of elements pointed to by buffer. |
Reimplemented in PBitArray.
| virtual Comparison PAbstractArray::Compare | ( | const PObject & | obj | ) | const [virtual] |
Get the relative rank of the two arrays.
The following algorithm is employed for the comparison:
EqualTo if the two array memory blocks are identical in length and contents. LessThan if the array length is less than the obj parameters array length. GreaterThan if the array length is greater than the obj parameters array length.
EqualTo for same, LessThan for obj logically less than the object and GreaterThan for obj logically greater than the object. | obj |
Other PAbstractArray to compare against. |
Reimplemented from PObject.
Reimplemented in PString.
| PBoolean PAbstractArray::Concatenate | ( | const PAbstractArray & | array | ) |
Concatenate one array to the end of this array.
This function will allocate a new array large enough for the existing contents and the contents of the parameter. The parameters contents is then copied to the end of the existing array.
Note this does nothing and returns false if the target array is not dynamically allocated, or if the two arrays are of base elements of different sizes.
true if the memory allocation succeeded. | array | Array to concatenate. |
| void* PAbstractArray::GetPointer | ( | PINDEX | minSize = 1 |
) |
Get a pointer to the internal array and assure that it is of at least the specified size.
This is useful when the array contents are being set by some external or system function eg file read.
It is unsafe to assume that the pointer is valid for very long after return from this function. The array may be resized or otherwise changed and the pointer returned invalidated. It should be used for simple calls to atomic functions, or very careful examination of the program logic must be performed.
| minSize | Minimum size the array must be. |
Reimplemented in PBaseArray< T >, PBitArray, PBaseArray< PObject * >, PBaseArray< berval * >, and PBaseArray< char * >.
| virtual void PAbstractArray::PrintElementOn | ( | ostream & | stream, | |
| PINDEX | index | |||
| ) | const [protected, virtual] |
Reimplemented in PBaseArray< T >, PBaseArray< PObject * >, PBaseArray< berval * >, and PBaseArray< char * >.
| virtual void PAbstractArray::PrintOn | ( | ostream & | strm | ) | const [virtual] |
Output the contents of the object to the stream.
The exact output is dependent on the exact semantics of the descendent class. This is primarily used by the standard operator<< function.
The default behaviour is to print the class name.
Reimplemented from PObject.
Reimplemented in PCharArray, PString, PASN_Stream, and PGloballyUniqueID.
| virtual void PAbstractArray::ReadElementFrom | ( | istream & | stream, | |
| PINDEX | index | |||
| ) | [protected, virtual] |
Reimplemented in PScalarArray< T >.
| virtual void PAbstractArray::ReadFrom | ( | istream & | strm | ) | [virtual] |
Input the contents of the object from the stream.
The exact input is dependent on the exact semantics of the descendent class. This is primarily used by the standard operator>> function.
The default behaviour is to do nothing.
Reimplemented from PObject.
Reimplemented in PCharArray, PString, and PGloballyUniqueID.
| virtual PBoolean PAbstractArray::SetSize | ( | PINDEX | newSize | ) | [virtual] |
Set the size of the array in elements.
A new array may be allocated to accomodate the new number of elements. If the array increases in size then the new bytes are initialised to zero. If the array is made smaller then the data beyond the new size is lost.
true if the memory for the array was allocated successfully. | newSize | New size of the array in elements. |
Implements PContainer.
PBoolean PAbstractArray::allocatedDynamically [protected] |
Flag indicating the array was allocated on the heap.
PINDEX PAbstractArray::elementSize [protected] |
Size of an element in bytes.
char* PAbstractArray::theArray [protected] |
Pointer to the allocated block of memory.
1.4.7