evict 0.3.1

Page eviction policies: LRU, LRU-k, LIRS, SLRU etc
Documentation 
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use crate::FrameId;

/// Page eviction strategy error.
#[derive(Debug, PartialEq, thiserror::Error)]
pub enum EvictError<F: FrameId> {
    /// Invalid frame id.
    #[error("Invalid frame id: {0}")]
    InvalidFrameId(F),

    /// Trying to remove pinned frame.
    #[error("Trying to remove pinned frame: {0}")]
    PinnedFrameRemoval(F),

    /// Cannot add any more pages to the frame replacer.
    #[error("Frame replacer is full")]
    FrameReplacerFull,

    /// Invalid sequence number.
    #[error("Invalid timestamp")]
    InvalidTimestamp,

    /// No free frames available.
    #[error("No free frames available (nor in free list nor in frame replacer)")]
    NoFramesAvailable,

    /// Sequence generator arrived at maximum value.
    #[error("Sequence generator exhausted")]
    SequenceExhausted,
}

/// Cache eviction policy result type.
pub type EvictResult<T, F> = Result<T, EvictError<F>>;