Files
tanya/source/tanya/memory/allocator.d
2017-01-07 09:30:42 +01:00

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2.9 KiB
D

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
/**
* Copyright: Eugene Wissner 2016.
* License: $(LINK2 https://www.mozilla.org/en-US/MPL/2.0/,
* Mozilla Public License, v. 2.0).
* Authors: $(LINK2 mailto:info@caraus.de, Eugene Wissner)
*/
module tanya.memory.allocator;
/**
* Abstract class implementing a basic allocator.
*/
interface Allocator
{
/**
* Returns: Alignment offered.
*/
@property uint alignment() const shared pure nothrow @safe @nogc;
/**
* Allocates $(D_PARAM size) bytes of memory.
*
* Params:
* size = Amount of memory to allocate.
*
* Returns: Pointer to the new allocated memory.
*/
void[] allocate(in size_t size) shared nothrow @nogc;
/**
* Deallocates a memory block.
*
* Params:
* p = A pointer to the memory block to be freed.
*
* Returns: Whether the deallocation was successful.
*/
bool deallocate(void[] p) shared nothrow @nogc;
/**
* Increases or decreases the size of a memory block.
*
* Params:
* p = A pointer to the memory block.
* size = Size of the reallocated block.
*
* Returns: Pointer to the allocated memory.
*/
bool reallocate(ref void[] p, in size_t size) shared nothrow @nogc;
/**
* Expands a memory block in place.
*
* Params:
* p = A pointer to the memory block.
* size = Size of the reallocated block.
*
* Returns: $(D_KEYWORD true) if successful, $(D_KEYWORD false) otherwise.
*/
bool expand(ref void[] p, in size_t size) shared nothrow @nogc;
}
/**
* The mixin generates common methods for classes and structs using
* allocators. It provides a protected member, constructor and a read-only property,
* that checks if an allocator was already set and sets it to the default
* one, if not (useful for structs which don't have a default constructor).
*/
mixin template DefaultAllocator()
{
/// Allocator.
protected shared Allocator allocator_;
/**
* Params:
* allocator = The allocator should be used.
*/
this(shared Allocator allocator)
in
{
assert(allocator !is null);
}
body
{
this.allocator_ = allocator;
}
/**
* This property checks if the allocator was set in the constructor
* and sets it to the default one, if not.
*
* Returns: Used allocator.
*
* Postcondition: $(D_INLINECODE allocator_ !is null)
*/
protected @property shared(Allocator) allocator() nothrow @safe @nogc
out (allocator)
{
assert(allocator !is null);
}
body
{
if (allocator_ is null)
{
allocator_ = defaultAllocator;
}
return allocator_;
}
/// Ditto.
@property shared(Allocator) allocator() const nothrow @trusted @nogc
out (allocator)
{
assert(allocator !is null);
}
body
{
if (allocator_ is null)
{
return defaultAllocator;
}
return cast(shared Allocator) allocator_;
}
}