public SmoothBurstyRateLimiter(SleepingStopwatch stopwatch, double maxBurstSec)
: base(stopwatch)
{
maxBurstSeconds = maxBurstSec;
}
internal static IRateLimiter Create(double permitsPerSecond, SleepingStopwatch stopwatch)
{
return new SmoothBurstyRateLimiter(stopwatch, 1.0)
.FluidSetRate(permitsPerSecond);
}
internal static IRateLimiter Create(double permitsPerSecond, TimeSpan warmupPeriod, SleepingStopwatch stopwatch)
{
return new SmoothWarmingUpRateLimiter(stopwatch, warmupPeriod)
.FluidSetRate(permitsPerSecond);
}
public SmoothBurstyRateLimiter(SleepingStopwatch stopwatch, double maxBurstSec) : base(stopwatch)
{
maxBurstSeconds = maxBurstSec;
}
private long nextFreeTicketMicros = 0L; // Could be either in the past or future
#endregion Fields
#region Constructors
protected SmoothRateLimiter(SleepingStopwatch stopwatch)
: base(stopwatch)
{
}
private long nextFreeTicketMicros = 0L; // Could be either in the past or future
protected SmoothRateLimiter(SleepingStopwatch stopwatch) : base(stopwatch)
{
}
internal BaseRateLimiter(SleepingStopwatch stopwatch)
{
this.stopwatch = Preconditions.CheckNotNull(stopwatch);
}
public SmoothWarmingUpRateLimiter(SleepingStopwatch stopwatch, TimeSpan warmupPeriod)
: base(stopwatch)
{
warmupPeriodMicroseconds = TimeUnit.Ticks.ToMicroseconds(warmupPeriod.Ticks);
}
internal BaseRateLimiter(SleepingStopwatch stopwatch)
{
this.stopwatch = Preconditions.CheckNotNull(stopwatch);
}
public SmoothWarmingUpRateLimiter(SleepingStopwatch stopwatch, TimeSpan warmupPeriod) : base(stopwatch)
{
warmupPeriodMicroseconds = TimeUnit.Ticks.ToMicroseconds(warmupPeriod.Ticks);
}
internal static IRateLimiter Create(double permitsPerSecond, TimeSpan warmupPeriod, SleepingStopwatch stopwatch)
{
return(new SmoothWarmingUpRateLimiter(stopwatch, warmupPeriod)
.FluidSetRate(permitsPerSecond));
}
internal static IRateLimiter Create(double permitsPerSecond, SleepingStopwatch stopwatch)
{
return(new SmoothBurstyRateLimiter(stopwatch, 1.0)
.FluidSetRate(permitsPerSecond));
}
/// <summary>
/// Creates a <see cref="IRateLimiter" /> with the specified stable throughput, given as
/// "permits per second" (commonly referred to as <em>QPS</em>, queries per second), and a
/// <em>warmup period</em>, during which the <see cref="IRateLimiter" /> smoothly ramps up its rate,
/// until it reaches its maximum rate at the end of the period (as long as there are enough requests to
/// saturate it). Similarly, if the <see cref="IRateLimiter" /> is left <em>unsed</em> for a duration of
/// <paramref name="warmupPeriod" />, it will gradually return to its "cold" state,
/// i.e. it will go through the same warming up process as when it was first created.
/// </summary>
/// <remarks>
/// <para>
/// The returned <see cref="IRateLimiter" /> is intended for cases where the resource that actually
/// fulfills the requests (e.g., a remote server) needs "warmup" time, rather than
/// being immediately accessed at the stable (maximum) rate.
/// </para>
/// <para>
/// The returned <see cref="IRateLimiter" /> starts in a "cold" state (i.e. the warmup period
/// will follow), and if it is left unused for long enough, it will return to that state.
/// </para>
/// </remarks>
/// <param name="permitsPerSecond">
/// the rate of the returned <see cref="IRateLimiter" />, measured in
/// how many permits become available per second
/// </param>
/// <param name="warmupPeriod">
/// the duration of the period where the <see cref="IRateLimiter" /> ramps
/// up its rate, before reaching its stable (maximum) rate
/// </param>
/// <exception cref="ArgumentException">
/// if <paramref name="permitsPerSecond" /> is negative or zero or
/// <paramref name="warmupPeriod" /> is negative
/// </exception>
public static IRateLimiter Create(double permitsPerSecond, TimeSpan warmupPeriod)
{
Preconditions.CheckArgument(warmupPeriod >= TimeSpan.Zero, "warmupPeriod", "must not be negative %s", warmupPeriod);
return(Create(permitsPerSecond, warmupPeriod, SleepingStopwatch.CreateDefault()));
}
/// <summary>
/// Creates a <see cref="IRateLimiter" /> with the specified stable throughput, given as
/// "permits per second" (commonly referred to as <em>QPS</em>, queries per second).
/// </summary>
/// <remarks>
/// <para>
/// The returned <see cref="IRateLimiter" /> ensures that on average no more than
/// <paramref name="permitsPerSecond" /> are issued during any given second, with sustained
/// requests being smoothly spread over each second. When the incoming request rate exceeds
/// <paramref name="permitsPerSecond" /> the rate limiter will release one permit every
/// <c>(1.0 / <paramref name="permitsPerSecond" />)</c> seconds. When the rate limiter is unsed,
/// bursts of up to <paramref name="permitsPerSecond" /> permits will be allowed, with subsequent
/// requests being smoothly limited at the stable rate of <paramref name="permitsPerSecond" />.
/// </para>
/// </remarks>
/// <param name="permitsPerSecond">
/// the rate of the returned <see cref="IRateLimiter" />, measured in
/// how many permits become available per second
/// </param>
/// <exception cref="ArgumentException">if <paramref name="permitsPerSecond" /> is negative or zero</exception>
public static IRateLimiter Create(double permitsPerSecond)
{
return(Create(permitsPerSecond, SleepingStopwatch.CreateDefault()));
}