TtlCache

Ecng.Net

Keeps the answers to a remote question for as long as they are worth keeping.

Constructors

TtlCache

public TtlCache(TimeSpan ttl, TimeSpan maxAge, TimeProvider time)

ttlCache = TtlCache(ttl, maxAge, time)

Initializes a new instance of the TtlCache.

ttl: How long an answer is kept after it was last asked for.
maxAge: The oldest an answer may be, however often it is asked for.
time: The clock an answer's age is measured on.

TtlCache

public TtlCache(TimeSpan ttl, TimeSpan maxAge, TimeProvider time, IEqualityComparer<TKey> comparer)

ttlCache = TtlCache(ttl, maxAge, time, comparer)

Initializes a new instance of the TtlCache.

ttl: How long an answer is kept after it was last asked for.
maxAge: The oldest an answer may be, however often it is asked for.
time: The clock an answer's age is measured on.
comparer: How keys are compared.

Properties

Count

public int Count { get; }

value = ttlCache.Count

Gets the number of answers that have not gone stale.

HeldCount

public int HeldCount { get; }

value = ttlCache.HeldCount

Gets the number of answers held, stale ones included.

Values

public IEnumerable<TValue> Values { get; }

value = ttlCache.Values

Gets the answers held that have not gone stale.

Methods

Clear

public void Clear()

ttlCache.Clear()

Drops every answer held.

GetAsync

public ValueTask<TValue> GetAsync(TKey key, Func<TKey, CancellationToken, ValueTask<TValue>> resolve, CancellationToken cancellationToken)

result = ttlCache.GetAsync(key, resolve, cancellationToken)

Serves the answer for a key, asking when there is none to serve.

key: What the answer is looked up by.
resolve: Where the answer comes from.
cancellationToken: Cancellation token.

Returns: The answer.

GetAsync

public ValueTask<TValue> GetAsync(TKey key, Func<TKey, CancellationToken, ValueTask<TValue>> resolve, TimeSpan ttl, TimeSpan maxAge, CancellationToken cancellationToken)

result = ttlCache.GetAsync(key, resolve, ttl, maxAge, cancellationToken)

Serves the answer for a key, asking when there is none to serve, and holds what it answered for a lifetime of this call's choosing.

key: What the answer is looked up by.
resolve: Where the answer comes from.
ttl: How long this answer is served before the source is asked again.
cancellationToken: Cancellation token.

Returns: The answer.

Remove

public bool Remove(TKey key)

result = ttlCache.Remove(key)

Drops the answer held for a key, for a caller that knows it has changed.

key: What the answer is looked up by.

Returns: true if an answer was held; otherwise, false.

RemoveWhere

public int RemoveWhere(Func<TKey, bool> match)

result = ttlCache.RemoveWhere(match)

Drops every answer whose key the caller names.

match: What the keys to drop have in common.

Returns: How many were dropped.

RemoveWhere

public int RemoveWhere(Func<TKey, TValue, bool> match)

result = ttlCache.RemoveWhere(match)

Drops every answer the caller recognises by what was cached.

match: What the answers to drop have in common.

Returns: How many were dropped.

Set

public void Set(TKey key, TValue value)

ttlCache.Set(key, value)

Holds an answer for a key, for the lifetime this cache was made with.

key: What the answer is looked up by.
value: The answer.

Set

public void Set(TKey key, TValue value, TimeSpan ttl, TimeSpan maxAge)

ttlCache.Set(key, value, ttl, maxAge)

Holds an answer for a key, for a lifetime of this call's choosing.

key: What the answer is looked up by.
value: The answer.
ttl: How long it is kept after it was last asked for.
maxAge: The oldest it may be, however often it is asked for.

TryGet

public bool TryGet(TKey key, TValue value)

result = ttlCache.TryGet(key, value)

Serves the answer held for a key, for a caller that puts them there itself.

key: What the answer is looked up by.
value: The answer.

Returns: true if one is held and has not gone stale; otherwise, false.