51 lines
1.4 KiB
Go
51 lines
1.4 KiB
Go
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package channeldb
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// channelCache is an in-memory cache used to improve the performance of
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// ChanUpdatesInHorizon. It caches the chan info and edge policies for a
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// particular channel.
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type channelCache struct {
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n int
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channels map[uint64]ChannelEdge
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}
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// newChannelCache creates a new channelCache with maximum capacity of n
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// channels.
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func newChannelCache(n int) *channelCache {
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return &channelCache{
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n: n,
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channels: make(map[uint64]ChannelEdge),
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}
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}
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// get returns the channel from the cache, if it exists.
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func (c *channelCache) get(chanid uint64) (ChannelEdge, bool) {
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channel, ok := c.channels[chanid]
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return channel, ok
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}
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// insert adds the entry to the channel cache. If an entry for chanid already
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// exists, it will be replaced with the new entry. If the entry doesn't exist,
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// it will be inserted to the cache, performing a random eviction if the cache
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// is at capacity.
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func (c *channelCache) insert(chanid uint64, channel ChannelEdge) {
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// If entry exists, replace it.
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if _, ok := c.channels[chanid]; ok {
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c.channels[chanid] = channel
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return
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}
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// Otherwise, evict an entry at random and insert.
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if len(c.channels) == c.n {
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for id := range c.channels {
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delete(c.channels, id)
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break
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}
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}
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c.channels[chanid] = channel
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}
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// remove deletes an edge for chanid from the cache, if it exists.
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func (c *channelCache) remove(chanid uint64) {
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delete(c.channels, chanid)
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}
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