57 lines
1.3 KiB
Go
57 lines
1.3 KiB
Go
package memory
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import (
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"github.com/google/cadvisor/info"
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)
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// A circular buffer for ContainerStats.
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type StatsBuffer struct {
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buffer []info.ContainerStats
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size int
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index int
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}
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// Returns a new thread-compatible StatsBuffer.
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func NewStatsBuffer(size int) *StatsBuffer {
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return &StatsBuffer{
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buffer: make([]info.ContainerStats, size),
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size: 0,
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index: size - 1,
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}
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}
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// Adds an element to the start of the buffer (removing one from the end if necessary).
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func (self *StatsBuffer) Add(item *info.ContainerStats) {
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if self.size < len(self.buffer) {
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self.size++
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}
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self.index = (self.index + 1) % len(self.buffer)
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self.buffer[self.index] = *item
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}
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// Returns the first N elements in the buffer. If N > size of buffer, size of buffer elements are returned.
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func (self *StatsBuffer) FirstN(n int) []*info.ContainerStats {
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// Cap n at the number of elements we have.
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if n > self.size {
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n = self.size
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}
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// index points to the latest element, get n before that one (keeping in mind we may have gone through 0).
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start := self.index - (n - 1)
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if start < 0 {
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start += len(self.buffer)
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}
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// Copy the elements.
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res := make([]*info.ContainerStats, n)
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for i := 0; i < n; i++ {
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index := (start + i) % len(self.buffer)
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res[i] = &self.buffer[index]
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}
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return res
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}
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func (self *StatsBuffer) Size() int {
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return self.size
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}
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