AdGuardHome/internal/aghalg/ringbuffer.go

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Pull request 2020: AG-26236-ring-buffer Squashed commit of the following: commit 4b9cc9ddf52739fc5f918babedc99ac7ac0e2415 Merge: a6259ed57 39aeaf891 Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Tue Oct 3 20:39:58 2023 +0300 Merge branch 'master' into AG-26236-ring-buffer commit a6259ed5758156e4110ee3ea6a49760d2880ade3 Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Tue Oct 3 20:30:20 2023 +0300 querylog: imp code commit 40f9f7cd5a1cff22bcb858020f2cfa9be8399671 Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Tue Oct 3 20:11:49 2023 +0300 querylog: fix typo commit 1aabbadcb5fcbe6a95945c5bd1455b956b85a8d0 Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Tue Oct 3 20:05:22 2023 +0300 querylog: imp err msg commit 02913d35b43e190e42765823ccfcdd332839e984 Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Tue Oct 3 19:37:47 2023 +0300 aghalg: imp tests commit 98a7909088d2a65b78afa9fa3113545c94429e65 Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Tue Oct 3 19:23:10 2023 +0300 all: imp tests commit e147804eeafe89e5020cd917784eef3ff2b310d0 Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Tue Oct 3 18:49:49 2023 +0300 all: imp code commit 5f21f2f63b7bce89f2bc79c97c7350cd693c956b Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Tue Oct 3 14:39:43 2023 +0300 all: add tests commit 35a45c7dc5d5961f6987da7c69249c56e54e97f5 Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Mon Oct 2 17:43:09 2023 +0300 all: imp code commit 21e51fcbe411258eaf830825df9d05b7ddcc187a Author: Stanislav Chzhen <s.chzhen@adguard.com> Date: Fri Sep 29 18:21:00 2023 +0300 all: add ring buffer
2023-10-03 18:50:43 +01:00
package aghalg
import (
"github.com/AdguardTeam/golibs/errors"
)
// RingBuffer is the implementation of ring buffer data structure.
type RingBuffer[T any] struct {
buf []T
cur int
full bool
}
// NewRingBuffer initializes the new instance of ring buffer. size must be
// greater or equal to zero.
func NewRingBuffer[T any](size int) (rb *RingBuffer[T]) {
if size < 0 {
panic(errors.Error("ring buffer: size must be greater or equal to zero"))
}
return &RingBuffer[T]{
buf: make([]T, size),
}
}
// Append appends an element to the buffer.
func (rb *RingBuffer[T]) Append(e T) {
if len(rb.buf) == 0 {
return
}
rb.buf[rb.cur] = e
rb.cur = (rb.cur + 1) % cap(rb.buf)
if rb.cur == 0 {
rb.full = true
}
}
// Range calls cb for each element of the buffer. If cb returns false it stops.
func (rb *RingBuffer[T]) Range(cb func(T) (cont bool)) {
before, after := rb.splitCur()
for _, e := range before {
if !cb(e) {
return
}
}
for _, e := range after {
if !cb(e) {
return
}
}
}
// ReverseRange calls cb for each element of the buffer in reverse order. If
// cb returns false it stops.
func (rb *RingBuffer[T]) ReverseRange(cb func(T) (cont bool)) {
before, after := rb.splitCur()
for i := len(after) - 1; i >= 0; i-- {
if !cb(after[i]) {
return
}
}
for i := len(before) - 1; i >= 0; i-- {
if !cb(before[i]) {
return
}
}
}
// splitCur splits the buffer in two, before and after current position in
// chronological order. If buffer is not full, after is nil.
func (rb *RingBuffer[T]) splitCur() (before, after []T) {
if len(rb.buf) == 0 {
return nil, nil
}
cur := rb.cur
if !rb.full {
return rb.buf[:cur], nil
}
return rb.buf[cur:], rb.buf[:cur]
}
// Len returns a length of the buffer.
func (rb *RingBuffer[T]) Len() (l int) {
if !rb.full {
return rb.cur
}
return cap(rb.buf)
}
// Clear clears the buffer.
func (rb *RingBuffer[T]) Clear() {
rb.full = false
rb.cur = 0
}