PRBool nsVoidArray::GrowArrayBy(PRInt32 aGrowBy)
{
// We have to grow the array. Grow by kMinGrowArrayBy slots if we're
// smaller than kLinearThreshold bytes, or a power of two if we're
// larger. This is much more efficient with most memory allocators,
// especially if it's very large, or of the allocator is binned.
if (aGrowBy < kMinGrowArrayBy)
aGrowBy = kMinGrowArrayBy;
PRUint32 newCapacity = GetArraySize() + aGrowBy; // Minimum increase
PRUint32 newSize = SIZEOF_IMPL(newCapacity);
if (newSize >= (PRUint32) kLinearThreshold)
{
// newCount includes enough space for at least kMinGrowArrayBy new
// slots. Select the next power-of-two size in bytes above or
// equal to that.
// Also, limit the increase in size to about a VM page or two.
if (GetArraySize() >= kMaxGrowArrayBy)
{
newCapacity = GetArraySize() + PR_MAX(kMaxGrowArrayBy,aGrowBy);
newSize = SIZEOF_IMPL(newCapacity);
}
else
{
PR_CEILING_LOG2(newSize, newSize);
newCapacity = CAPACITYOF_IMPL(PR_BIT(newSize));
}
}
// frees old mImpl IF this succeeds
if (!SizeTo(newCapacity))
return PR_FALSE;
return PR_TRUE;
}
bool nsVoidArray::GrowArrayBy(int32_t aGrowBy)
{
// We have to grow the array. Grow by kMinGrowArrayBy slots if we're
// smaller than kLinearThreshold bytes, or a power of two if we're
// larger. This is much more efficient with most memory allocators,
// especially if it's very large, or of the allocator is binned.
if (aGrowBy < kMinGrowArrayBy)
aGrowBy = kMinGrowArrayBy;
uint32_t newCapacity = GetArraySize() + aGrowBy; // Minimum increase
uint32_t newSize = SIZEOF_IMPL(newCapacity);
if (newSize >= (uint32_t) kLinearThreshold)
{
// newCount includes enough space for at least kMinGrowArrayBy new
// slots. Select the next power-of-two size in bytes above or
// equal to that.
// Also, limit the increase in size to about a VM page or two.
if (GetArraySize() >= kMaxGrowArrayBy)
{
newCapacity = GetArraySize() + XPCOM_MAX(kMaxGrowArrayBy,aGrowBy);
newSize = SIZEOF_IMPL(newCapacity);
}
else
{
newSize = mozilla::CeilingLog2(newSize);
newCapacity = CAPACITYOF_IMPL(1u << newSize);
}
}
// frees old mImpl IF this succeeds
if (!SizeTo(newCapacity))
return false;
return true;
}
