mirror of https://github.com/deavmi/niknaks
782 lines
18 KiB
D
782 lines
18 KiB
D
/**
|
|
* Container types
|
|
*
|
|
* Authors: Tristan Brice Velloza Kildaire (deavmi)
|
|
*/
|
|
module niknaks.containers;
|
|
|
|
import core.sync.mutex : Mutex;
|
|
import std.datetime : Duration, dur;
|
|
import std.datetime.stopwatch : StopWatch, AutoStart;
|
|
import core.thread : Thread;
|
|
import core.sync.condition : Condition;
|
|
import std.functional : toDelegate;
|
|
|
|
version(unittest)
|
|
{
|
|
import std.stdio : writeln;
|
|
}
|
|
|
|
/**
|
|
* Represents an entry of
|
|
* some value of type `V`
|
|
*
|
|
* Associated with this
|
|
* is a timer used to
|
|
* check against for
|
|
* expiration
|
|
*/
|
|
private template Entry(V)
|
|
{
|
|
/**
|
|
* The entry type
|
|
*/
|
|
public struct Entry
|
|
{
|
|
private V value;
|
|
private StopWatch timer;
|
|
|
|
@disable
|
|
private this();
|
|
|
|
/**
|
|
* Creates a new entry
|
|
* with the given value
|
|
*
|
|
* Params:
|
|
* value = the value
|
|
*/
|
|
public this(V value)
|
|
{
|
|
setValue(value);
|
|
timer = StopWatch(AutoStart.yes);
|
|
}
|
|
|
|
/**
|
|
* Sets the value of this
|
|
* entry
|
|
*
|
|
* Params:
|
|
* value = the value
|
|
*/
|
|
public void setValue(V value)
|
|
{
|
|
this.value = value;
|
|
}
|
|
|
|
/**
|
|
* Returns the value associated
|
|
* with this entry
|
|
*
|
|
* Returns: the value
|
|
*/
|
|
public V getValue()
|
|
{
|
|
return this.value;
|
|
}
|
|
|
|
/**
|
|
* Resets the timer back
|
|
* to zero
|
|
*/
|
|
public void bump()
|
|
{
|
|
timer.reset();
|
|
}
|
|
|
|
/**
|
|
* Gets the time elapsed
|
|
* since this entry was
|
|
* instantiated
|
|
*
|
|
* Returns: the elapsed
|
|
* time
|
|
*/
|
|
public Duration getElapsedTime()
|
|
{
|
|
return timer.peek();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* A `CacheMap` with a key type of `K`
|
|
* and value type of `V`
|
|
*/
|
|
public template CacheMap(K, V)
|
|
{
|
|
/**
|
|
* A replacement function which takes
|
|
* in the key of type `K` and returns
|
|
* a value of type `V`
|
|
*
|
|
* This is the delegate-based variant
|
|
*/
|
|
public alias ReplacementDelegate = V delegate(K);
|
|
|
|
/**
|
|
* A replacement function which takes
|
|
* in the key of type `K` and returns
|
|
* a value of type `V`
|
|
*
|
|
* This is the function-based variant
|
|
*/
|
|
public alias ReplacementFunction = V function(K);
|
|
|
|
/**
|
|
* A caching map which when queried
|
|
* for a key which does not exist yet
|
|
* will call a so-called replacement
|
|
* function which produces a result
|
|
* which will be stored at that key's
|
|
* location
|
|
*
|
|
* After this process a timer is started,
|
|
* and periodically entries are checked
|
|
* for timeouts, if they have timed out
|
|
* then they are removed and the process
|
|
* begins again.
|
|
*
|
|
* Accessing an entry will reset its
|
|
* timer ONLY if it has not yet expired
|
|
* however accessing an entry which
|
|
* has expired causing an on-demand
|
|
* replacement function call, just not
|
|
* a removal in between
|
|
*/
|
|
public class CacheMap
|
|
{
|
|
private Entry!(V)[K] map;
|
|
private Mutex lock;
|
|
private Duration expirationTime;
|
|
private ReplacementDelegate replFunc;
|
|
|
|
private Thread checker;
|
|
private bool isRunning;
|
|
private Condition condVar;
|
|
private Duration sweepInterval;
|
|
|
|
/**
|
|
* Constructs a new cache map with the
|
|
* given replacement delegate and the
|
|
* expiration deadline.
|
|
*
|
|
* Params:
|
|
* replFunc = the replacement delegate
|
|
* expirationTime = the expiration
|
|
* deadline
|
|
* sweepInterval = the interval at
|
|
* which the sweeper thread should
|
|
* run at to check for expired entries
|
|
*/
|
|
this(ReplacementDelegate replFunc, Duration expirationTime = dur!("seconds")(10), Duration sweepInterval = dur!("seconds")(10))
|
|
{
|
|
this.replFunc = replFunc;
|
|
this.lock = new Mutex();
|
|
this.expirationTime = expirationTime;
|
|
|
|
this.sweepInterval = sweepInterval;
|
|
this.condVar = new Condition(this.lock);
|
|
this.checker = new Thread(&checkerFunc);
|
|
this.isRunning = true;
|
|
this.checker.start();
|
|
|
|
}
|
|
|
|
/**
|
|
* Constructs a new cache map with the
|
|
* given replacement function and the
|
|
* expiration deadline.
|
|
*
|
|
* Params:
|
|
* replFunc = the replacement function
|
|
* expirationTime = the expiration
|
|
* deadline
|
|
* sweepInterval = the interval at
|
|
* which the sweeper thread should
|
|
* run at to check for expired entries
|
|
*/
|
|
this(ReplacementFunction replFunc, Duration expirationTime = dur!("seconds")(10), Duration sweepInterval = dur!("seconds")(10))
|
|
{
|
|
this(toDelegate(replFunc), expirationTime, sweepInterval);
|
|
}
|
|
|
|
/**
|
|
* Creates an entry for the given
|
|
* key by creating the `Entry`
|
|
* at the key and then setting
|
|
* that entry's value with the
|
|
* replacement function
|
|
*
|
|
* Params:
|
|
* key = the key
|
|
* Returns: the value set
|
|
*/
|
|
private V makeKey(K key)
|
|
{
|
|
// Lock the mutex
|
|
this.lock.lock();
|
|
|
|
// On exit
|
|
scope(exit)
|
|
{
|
|
// Unlock the mutex
|
|
this.lock.unlock();
|
|
}
|
|
|
|
// Run the replacement function for this key
|
|
V newValue = replFunc(key);
|
|
|
|
// Create a new entry with this value
|
|
Entry!(V) newEntry = Entry!(V)(newValue);
|
|
|
|
// Save this entry into the hashmap
|
|
this.map[key] = newEntry;
|
|
|
|
return newValue;
|
|
}
|
|
|
|
/**
|
|
* Called to update an existing
|
|
* `Entry` (already present) in
|
|
* the map. This will run the
|
|
* replacement function and update
|
|
* the value present.
|
|
*
|
|
* Params:
|
|
* key = the key
|
|
* Returns: the value set
|
|
*/
|
|
private V updateKey(K key)
|
|
{
|
|
// Lock the mutex
|
|
this.lock.lock();
|
|
|
|
// On exit
|
|
scope(exit)
|
|
{
|
|
// Unlock the mutex
|
|
this.lock.unlock();
|
|
}
|
|
|
|
// Run the replacement function for this key
|
|
V newValue = replFunc(key);
|
|
|
|
// Update the value saved at this key's entry
|
|
this.map[key].setValue(newValue);
|
|
|
|
return newValue;
|
|
}
|
|
|
|
/**
|
|
* Check's a specific key for expiration,
|
|
* and if expired then refreshes it if
|
|
* not it leaves it alone.
|
|
*
|
|
* Returns the key's value
|
|
*
|
|
* Params:
|
|
* key = the key to check
|
|
* Returns: the key's value
|
|
*/
|
|
private V expirationCheck(K key)
|
|
{
|
|
// Lock the mutex
|
|
this.lock.lock();
|
|
|
|
// On exit
|
|
scope(exit)
|
|
{
|
|
// Unlock the mutex
|
|
this.lock.unlock();
|
|
}
|
|
|
|
// Obtain the entry at this key
|
|
Entry!(V)* entry = key in this.map;
|
|
|
|
// If the key exists
|
|
if(entry != null)
|
|
{
|
|
// If this entry expired, run the refresher
|
|
if(entry.getElapsedTime() >= this.expirationTime)
|
|
{
|
|
version(unittest) { writeln("Expired entry for key '", key, "', refreshing"); }
|
|
|
|
updateKey(key);
|
|
}
|
|
// Else, if not, then bump the entry
|
|
else
|
|
{
|
|
entry.bump();
|
|
}
|
|
}
|
|
// If it does not exist (then make it)
|
|
else
|
|
{
|
|
version(unittest) { writeln("Hello there, we must MAKE key as it does not exist"); }
|
|
makeKey(key);
|
|
version(unittest) { writeln("fic"); }
|
|
}
|
|
|
|
return this.map[key].getValue();
|
|
}
|
|
|
|
/**
|
|
* Gets the value of
|
|
* the entry at the
|
|
* provided key
|
|
*
|
|
* This may or may not
|
|
* call the replication
|
|
* function
|
|
*
|
|
* Params:
|
|
* key = the key to
|
|
* lookup by
|
|
*
|
|
* Returns: the value
|
|
*/
|
|
public V get(K key)
|
|
{
|
|
// Lock the mutex
|
|
this.lock.lock();
|
|
|
|
// On exit
|
|
scope(exit)
|
|
{
|
|
// Unlock the mutex
|
|
this.lock.unlock();
|
|
}
|
|
|
|
// The key's value
|
|
V keyValue;
|
|
|
|
// On access expiration check
|
|
keyValue = expirationCheck(key);
|
|
|
|
return keyValue;
|
|
}
|
|
|
|
/**
|
|
* Removes the given key
|
|
* returning whether or
|
|
* not it was a success
|
|
*
|
|
* Params:
|
|
* key = the key to
|
|
* remove
|
|
* Returns: `true` if the
|
|
* key existed, `false`
|
|
* otherwise
|
|
*/
|
|
public bool removeKey(K key)
|
|
{
|
|
// Lock the mutex
|
|
this.lock.lock();
|
|
|
|
// On exit
|
|
scope(exit)
|
|
{
|
|
// Unlock the mutex
|
|
this.lock.unlock();
|
|
}
|
|
|
|
// Remove the key
|
|
return this.map.remove(key);
|
|
}
|
|
|
|
/**
|
|
* Runs at the latest every
|
|
* `expirationTime` ticks
|
|
* and checks the entire
|
|
* map for expired
|
|
* entries
|
|
*/
|
|
private void checkerFunc()
|
|
{
|
|
while(this.isRunning)
|
|
{
|
|
// Lock the mutex
|
|
this.lock.lock();
|
|
|
|
// On loop exit
|
|
scope(exit)
|
|
{
|
|
// Unlock the mutex
|
|
this.lock.unlock();
|
|
}
|
|
|
|
// Sleep until sweep interval
|
|
this.condVar.wait(this.sweepInterval);
|
|
|
|
// Run the expiration check
|
|
K[] marked;
|
|
foreach(K curKey; this.map.keys())
|
|
{
|
|
Entry!(V) curEntry = this.map[curKey];
|
|
|
|
// If entry has expired mark it for removal
|
|
if(curEntry.getElapsedTime() >= this.expirationTime)
|
|
{
|
|
version(unittest) { writeln("Marked entry '", curEntry, "' for removal"); }
|
|
marked ~= curKey;
|
|
}
|
|
}
|
|
|
|
foreach(K curKey; marked)
|
|
{
|
|
Entry!(V) curEntry = this.map[curKey];
|
|
|
|
version(unittest) { writeln("Removing entry '", curEntry, "'..."); }
|
|
this.map.remove(curKey);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Wakes up the checker
|
|
* immediately such that
|
|
* it can perform a cycle
|
|
* over the map and check
|
|
* for expired entries
|
|
*/
|
|
private void doLiveCheck()
|
|
{
|
|
// Lock the mutex
|
|
this.lock.lock();
|
|
|
|
// Signal wake up
|
|
this.condVar.notify();
|
|
|
|
// Unlock the mutex
|
|
this.lock.unlock();
|
|
}
|
|
|
|
/**
|
|
* On destruction, set
|
|
* the running status
|
|
* to `false`, then
|
|
* wake up the checker
|
|
* and wait for it to
|
|
* exit
|
|
*/
|
|
~this()
|
|
{
|
|
version(unittest)
|
|
{
|
|
writeln("Dtor running");
|
|
|
|
scope(exit)
|
|
{
|
|
writeln("Dtor running [done]");
|
|
}
|
|
}
|
|
|
|
// Set run state to false
|
|
this.isRunning = false;
|
|
|
|
// Signal to stop
|
|
doLiveCheck();
|
|
|
|
// Wait for it to stop
|
|
this.checker.join();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Tests the usage of the `CacheMap` type
|
|
* along with the expiration of entries
|
|
* mechanism
|
|
*/
|
|
unittest
|
|
{
|
|
int i = 0;
|
|
int getVal(string)
|
|
{
|
|
i++;
|
|
return i;
|
|
}
|
|
|
|
// Create a CacheMap with 10 second expiration and 10 second sweeping interval
|
|
CacheMap!(string, int) map = new CacheMap!(string, int)(&getVal, dur!("seconds")(10));
|
|
|
|
// Get the value
|
|
int tValue = map.get("Tristan");
|
|
assert(tValue == 1);
|
|
|
|
// Get the value (should still be cached)
|
|
tValue = map.get("Tristan");
|
|
assert(tValue == 1);
|
|
|
|
// Wait for expiry (by sweeping thread)
|
|
Thread.sleep(dur!("seconds")(11));
|
|
|
|
// Should call replacement function
|
|
tValue = map.get("Tristan");
|
|
assert(tValue == 2);
|
|
|
|
// Wait for expiry (by sweeping thread)
|
|
writeln("Sleeping now 11 secs");
|
|
Thread.sleep(dur!("seconds")(11));
|
|
|
|
// Destroy the map (such that it ends the sweeper)
|
|
destroy(map);
|
|
}
|
|
|
|
/**
|
|
* Creates a `CacheMap` which tests out
|
|
* the on-access expiration checking of
|
|
* entries by accessing an entry faster
|
|
* then the sweep interval and by
|
|
* having an expiration interval below
|
|
* the aforementioned interval
|
|
*/
|
|
unittest
|
|
{
|
|
int i = 0;
|
|
int getVal(string)
|
|
{
|
|
i++;
|
|
return i;
|
|
}
|
|
|
|
// Create a CacheMap with 5 second expiration and 10 second sweeping interval
|
|
CacheMap!(string, int) map = new CacheMap!(string, int)(&getVal, dur!("seconds")(5), dur!("seconds")(10));
|
|
|
|
// Get the value
|
|
int tValue = map.get("Tristan");
|
|
assert(tValue == 1);
|
|
|
|
// Wait for 5 seconds (the entry should then be expired by then for on-access check)
|
|
Thread.sleep(dur!("seconds")(5));
|
|
|
|
// Get the value (should have replacement function run)
|
|
tValue = map.get("Tristan");
|
|
assert(tValue == 2);
|
|
|
|
// Destroy the map (such that it ends the sweeper
|
|
destroy(map);
|
|
}
|
|
|
|
/**
|
|
* Tests the usage of the `CacheMap`,
|
|
* specifically the explicit key
|
|
* removal method
|
|
*/
|
|
unittest
|
|
{
|
|
int i = 0;
|
|
int getVal(string)
|
|
{
|
|
i++;
|
|
return i;
|
|
}
|
|
|
|
// Create a CacheMap with 10 second expiration and 10 second sweeping interval
|
|
CacheMap!(string, int) map = new CacheMap!(string, int)(&getVal, dur!("seconds")(10), dur!("seconds")(10));
|
|
|
|
// Get the value
|
|
int tValue = map.get("Tristan");
|
|
assert(tValue == 1);
|
|
|
|
// Remove the key
|
|
assert(map.removeKey("Tristan"));
|
|
|
|
// Get the value
|
|
tValue = map.get("Tristan");
|
|
assert(tValue == 2);
|
|
|
|
// Destroy the map (such that it ends the sweeper
|
|
destroy(map);
|
|
}
|
|
|
|
// TODO: make delegate kak
|
|
// public interface InclusionStratergy(T)
|
|
// {
|
|
// public bool include(T item);
|
|
// }
|
|
|
|
// private class AlwaysStrat(T) : InclusionStratergy
|
|
// {
|
|
// public override bool include(T item)
|
|
// {
|
|
// return true;
|
|
// }
|
|
// }
|
|
|
|
public template Always(T)
|
|
{
|
|
public bool Always(Tree!(T) treeNode)
|
|
{
|
|
version(unittest)
|
|
{
|
|
import std.stdio : writeln;
|
|
writeln("Strat for: ", treeNode);
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
|
|
public template Nothing(T)
|
|
{
|
|
public void Nothing(Tree!(T) treeNode)
|
|
{
|
|
|
|
}
|
|
}
|
|
|
|
public template InclusionStratergy(T)
|
|
{
|
|
public alias InclusionStratergy = bool delegate(Tree!(T) item);
|
|
}
|
|
|
|
// Called prior to visitation?
|
|
public template TouchStratergy(T)
|
|
{
|
|
public alias TouchStratergy = void delegate(Tree!(T) item);
|
|
}
|
|
|
|
import std.string : format;
|
|
|
|
// TODO: Technically this is a graph
|
|
public class Tree(T)
|
|
{
|
|
private T value;
|
|
private Tree!(T)[] children;
|
|
|
|
this(T value)
|
|
{
|
|
this.value = value;
|
|
}
|
|
|
|
public void appendValue(T value)
|
|
{
|
|
|
|
}
|
|
|
|
public void appendNode(Tree!(T) node)
|
|
{
|
|
this.children ~= node;
|
|
}
|
|
|
|
public T[] dfs
|
|
(
|
|
InclusionStratergy!(T) strat = toDelegate(&Always!(T)),
|
|
TouchStratergy!(T) touch = toDelegate(&Nothing!(T))
|
|
)
|
|
{
|
|
T[] collected;
|
|
foreach(Tree!(T) child; this.children)
|
|
{
|
|
if(strat(child))
|
|
{
|
|
// Touch
|
|
touch(child);
|
|
|
|
// Visit
|
|
collected ~= child.dfs(strat);
|
|
}
|
|
}
|
|
|
|
if(strat(this))
|
|
{
|
|
// Touch
|
|
touch(this);
|
|
|
|
// "Visit"
|
|
collected ~= this.value;
|
|
}
|
|
|
|
return collected;
|
|
}
|
|
|
|
public override string toString()
|
|
{
|
|
return format("TreeNode [val: %s]", this.value);
|
|
}
|
|
}
|
|
|
|
|
|
version(unittest)
|
|
{
|
|
import std.functional : toDelegate;
|
|
import std.stdio : writeln;
|
|
|
|
private void DebugTouch(T)(Tree!(T) node)
|
|
{
|
|
writeln("Touching tree node ", node);
|
|
}
|
|
}
|
|
|
|
unittest
|
|
{
|
|
Tree!(string) treeOfStrings = new Tree!(string)("Top");
|
|
|
|
Tree!(string) subtree_1 = new Tree!(string)("1");
|
|
Tree!(string) subtree_2 = new Tree!(string)("2");
|
|
Tree!(string) subtree_3 = new Tree!(string)("3");
|
|
|
|
treeOfStrings.appendNode(subtree_1);
|
|
treeOfStrings.appendNode(subtree_2);
|
|
treeOfStrings.appendNode(subtree_3);
|
|
|
|
|
|
InclusionStratergy!(string) strat = toDelegate(&Always!(string));
|
|
TouchStratergy!(string) touch = toDelegate(&DebugTouch!(string));
|
|
|
|
string[] result = treeOfStrings.dfs(strat, touch);
|
|
writeln("dfs: ", result);
|
|
}
|
|
|
|
public class VisitationTree(T) : Tree!(T)
|
|
{
|
|
private bool visisted;
|
|
|
|
this(T value)
|
|
{
|
|
super(value);
|
|
}
|
|
|
|
public T[] linearize()
|
|
{
|
|
return dfs(toDelegate(&_shouldVisit), toDelegate(&_touch));
|
|
}
|
|
|
|
private static bool _shouldVisit(Tree!(T) tnode)
|
|
{
|
|
VisitationTree!(T) vnode = cast(VisitationTree!(T))tnode;
|
|
return vnode && !vnode.isVisited();
|
|
}
|
|
|
|
private static void _touch(Tree!(T) tnode)
|
|
{
|
|
VisitationTree!(T) vnode = cast(VisitationTree!(T))tnode;
|
|
if(vnode)
|
|
{
|
|
vnode.mark();
|
|
}
|
|
}
|
|
|
|
private void mark()
|
|
{
|
|
this.visisted = true;
|
|
}
|
|
|
|
private bool isVisited()
|
|
{
|
|
return this.visisted;
|
|
}
|
|
}
|
|
|
|
unittest
|
|
{
|
|
VisitationTree!(string) root = new VisitationTree!(string)("root");
|
|
|
|
VisitationTree!(string) thing = new VisitationTree!(string)("subtree");
|
|
root.appendNode(thing);
|
|
thing.appendNode(root);
|
|
|
|
writeln(root.linearize());
|
|
|
|
} |