Class LoanableCollection
Defined in File LoanableCollection.hpp
Inheritance Relationships
Derived Types
public eprosima::fastdds::dds::LoanableTypedCollection< T, std::true_type >(Template Class LoanableTypedCollection)public eprosima::fastdds::dds::LoanableTypedCollection< T, _NonConstEnabler >(Template Class LoanableTypedCollection)public eprosima::fastdds::dds::UserAllocatedSequence(Struct UserAllocatedSequence)
Class Documentation
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class LoanableCollection
A collection of generic opaque pointers that can receive the buffer from outside (loan).
This is an abstract class. See LoanableSequence for details.
Subclassed by eprosima::fastdds::dds::LoanableTypedCollection< T, std::true_type >, eprosima::fastdds::dds::LoanableTypedCollection< T, _NonConstEnabler >, eprosima::fastdds::dds::UserAllocatedSequence
Public Functions
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inline const element_type *buffer() const
Get the pointer to the elements buffer.
The returned value may be nullptr if maximum() is 0. Otherwise it is guaranteed that up to maximum() elements can be accessed.
- Returns
the pointer to the elements buffer.
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inline bool has_ownership() const
Get the ownership flag.
- Returns
whether the collection has ownership of the buffer.
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inline size_type maximum() const
Get the maximum number of elements currently allocated.
- Returns
the maximum number of elements currently allocated.
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inline size_type length() const
Get the number of elements currently accessible.
- Returns
the number of elements currently accessible.
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inline bool length(size_type new_length)
Set the number of elements currently accessible.
This method tells the collection that a certain number of elements should be accessible. If the new length is greater than the current maximum() the collection should allocate space for the new elements. If this is the case and the collection does not own the buffer (i.e. has_ownership() is false) then no allocation will be performed, the length will remain unchanged, and false will be returned.
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inline bool loan(element_type *buffer, size_type new_maximum, size_type new_length)
Loan a buffer to the collection.
- Parameters
buffer – [in] pointer to the buffer to be loaned.
new_maximum – [in] number of allocated elements in buffer.
new_length – [in] number of accessible elements in buffer.
- Pre
(has_ownership() == false) || (maximum() == 0)
- Pre
new_maximum > 0
- Pre
new_maximum >= new_length
- Pre
buffer != nullptr
- Returns
false if preconditions are not met.
- Returns
true if operation succeeds.
- Post
buffer() == buffer
- Post
has_ownership() == false
- Post
maximum() == new_maximum
- Post
length() == new_length
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inline element_type *unloan(size_type &maximum, size_type &length)
Remove the loan from the collection.
- Parameters
maximum – [out] number of allocated elements on the returned buffer.
length – [out] number of accessible elements on the returned buffer.
- Pre
has_ownership() == false
- Returns
nullptr if preconditions are not met.
- Returns
pointer to the previously loaned buffer of elements.
- Post
buffer() == nullptr
- Post
has_ownership() == true
- Post
length() == 0
- Post
maximum() == 0
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inline element_type *unloan()
Remove the loan from the collection.
- Pre
has_ownership() == false
- Returns
nullptr if preconditions are not met.
- Returns
pointer to the previously loaned buffer of elements.
- Post
buffer() == nullptr
- Post
has_ownership() == true
- Post
length() == 0
- Post
maximum() == 0
Protected Functions
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LoanableCollection() = default
Default constructor.
Creates the loanable collection with no data.
- Post
buffer() == nullptr
- Post
has_ownership() == true
- Post
length() == 0
- Post
maximum() == 0
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inline const element_type *buffer() const