/// <summary>
/// Searches the hash map and returns the area element for the given pointer.
/// </summary>
/// <param name="pointer"></param>
/// <returns></returns>
private HeapAreaElement GetAreaElement(long pointer)
{
lock (this) {
// Find the pointer in the hash
int hash_pos = (int)(pointer % area_map.Length);
HeapAreaElement prev = null;
HeapAreaElement element = area_map[hash_pos];
// Search for this pointer
while (element != null && element.Id != pointer)
{
prev = element;
element = element.next_hash_element;
}
// If not found
if (element == null)
{
throw new IOException("Pointer " + pointer + " is invalid.");
}
// Move the element to the start of the list.
if (prev != null)
{
prev.next_hash_element = element.next_hash_element;
element.next_hash_element = area_map[hash_pos];
area_map[hash_pos] = element;
}
// Return the element
return(element);
}
}
/// <inheritdoc/>
public void DeleteArea(long pointer)
{
lock (this) {
// Find the pointer in the hash
int hash_pos = (int)(pointer % area_map.Length);
HeapAreaElement prev = null;
HeapAreaElement element = area_map[hash_pos];
// Search for this pointer
while (element != null && element.Id != pointer)
{
prev = element;
element = element.next_hash_element;
}
// If not found
if (element == null)
{
throw new IOException("Pointer " + pointer + " is invalid.");
}
// Remove
if (prev == null)
{
area_map[hash_pos] = element.next_hash_element;
}
else
{
prev.next_hash_element = element.next_hash_element;
}
// Garbage collector should do the rest...
}
}
/// <inheritdoc/>
public IAreaWriter CreateArea(long size)
{
if (size > Int32.MaxValue)
{
throw new IOException("'size' is too large.");
}
lock (this) {
// Generate a unique id for this area.
long id = unique_id_key;
++unique_id_key;
// Create the element.
HeapAreaElement element = new HeapAreaElement(id, (int)size);
// The position in the hash map
int hash_pos = (int)(id % area_map.Length);
// Add to the chain
element.next_hash_element = area_map[hash_pos];
// Set the element in the chain
area_map[hash_pos] = element;
// And return the object
return(element.GetAreaWriter());
}
}
/// <inheritdoc/>
public IAreaWriter CreateArea(long size)
{
if (size > Int32.MaxValue) {
throw new IOException("'size' is too large.");
}
lock (this) {
// Generate a unique id for this area.
long id = unique_id_key;
++unique_id_key;
// Create the element.
HeapAreaElement element = new HeapAreaElement(id, (int)size);
// The position in the hash map
int hash_pos = (int)(id % area_map.Length);
// Add to the chain
element.next_hash_element = area_map[hash_pos];
// Set the element in the chain
area_map[hash_pos] = element;
// And return the object
return element.GetAreaWriter();
}
}
