bool PurgeableVector::reservePurgeableCapacity(size_t capacity, PurgeableAllocationStrategy allocationStrategy)
{
ASSERT(m_isPurgeable);
if (m_discardable && m_discardableCapacity >= capacity) {
ASSERT(!m_vector.capacity());
return true;
}
if (capacity < minimumDiscardableAllocationSize)
return false;
if (allocationStrategy == UseExponentialGrowth)
capacity = adjustPurgeableCapacity(capacity);
scoped_ptr<base::DiscardableMemory> discardable =
base::DiscardableMemoryAllocator::GetInstance()->AllocateLockedDiscardableMemory(capacity);
ASSERT(discardable);
m_discardableCapacity = capacity;
// Copy the data that was either in the previous purgeable buffer or in the vector to the new
// purgeable buffer.
if (m_discardable) {
memcpy(discardable->data(), m_discardable->data(), m_discardableSize);
} else {
memcpy(discardable->data(), m_vector.data(), m_vector.size());
m_discardableSize = m_vector.size();
m_vector.clear();
}
m_discardable = std::move(discardable);
ASSERT(!m_vector.capacity());
return true;
}
bool PurgeableVector::reservePurgeableCapacity(size_t capacity, PurgeableAllocationStrategy allocationStrategy)
{
ASSERT(m_isPurgeable);
if (m_discardable && m_discardableCapacity >= capacity) {
ASSERT(!m_vector.capacity());
return true;
}
if (capacity < minimumDiscardableAllocationSize)
return false;
if (allocationStrategy == UseExponentialGrowth)
capacity = adjustPurgeableCapacity(capacity);
OwnPtr<WebDiscardableMemory> discardable = adoptPtr(
Platform::current()->allocateAndLockDiscardableMemory(capacity));
if (!discardable) {
// Discardable memory is not supported.
m_isPurgeable = false;
return false;
}
m_discardableCapacity = capacity;
// Copy the data that was either in the previous purgeable buffer or in the vector to the new
// purgeable buffer.
if (m_discardable) {
memcpy(discardable->data(), m_discardable->data(), m_discardableSize);
} else {
memcpy(discardable->data(), m_vector.data(), m_vector.size());
m_discardableSize = m_vector.size();
m_vector.clear();
}
m_discardable.swap(discardable);
ASSERT(!m_vector.capacity());
return true;
}
