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Allow PagedBuffer to hold non-power-of-2-sized objects

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This commit is contained in:
Josh Holtrop 2016-07-17 21:55:29 -04:00
parent cab874305f
commit 7e8b5c0b64
1 changed files with 8 additions and 15 deletions
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23
src/core/PagedBuffer.h
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@ -4,6 +4,7 @@
#include "System.h"
#include <vector>
#include <stdint.h>
#include <stdlib.h>
template <typename T>
class PagedBuffer
@ -11,14 +12,10 @@ class PagedBuffer
public:
/**
* Create a PagedBuffer.
*
* Note: sizeof(T) must be a power of 2. A single page can hold
* System::page_size / sizeof(T) entries.
*/
PagedBuffer<T>()
{
static_assert((sizeof(T) & (sizeof(T) - 1)) == 0,
"sizeof(T) must be a power of 2");
m_n_per_page = System::page_size / sizeof(T);
m_size = 0u;
}
@ -32,7 +29,7 @@ public:
const T & operator[](unsigned int index) const
{
while (index >= (m_pages.size() * n_per_page()))
while (index >= (m_pages.size() * m_n_per_page))
{
grow();
}
@ -41,7 +38,7 @@ public:
T & operator[](unsigned int index)
{
while (index >= (m_pages.size() * n_per_page()))
while (index >= (m_pages.size() * m_n_per_page))
{
grow();
}
@ -51,29 +48,25 @@ public:
size_t size() { return m_size; }
protected:
unsigned int n_per_page()
{
return System::page_size / sizeof(T);
}
unsigned int page_index(unsigned int index)
{
return index / n_per_page();
return index / m_n_per_page;
}
unsigned int index_in_page(unsigned int index)
{
return index % n_per_page();
return index % m_n_per_page;
}
void grow()
{
m_pages.push_back((T *)System::alloc_pages(1));
m_size += n_per_page();
m_size += m_n_per_page;
}
std::vector<T *> m_pages;
unsigned long m_size;
unsigned int m_n_per_page;
};
#endif