weichen
45f21e84c7
Add typed jevdecide HTTP client (circuit, metrics) and coordinator DecideAssist wiring behind JEV_DECIDE_MODE (default off). Offline eval and synthetic soak evidence gate realtime/profile before assist rollout.
91 lines
1.8 KiB
Go
91 lines
1.8 KiB
Go
package jevdecide
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import (
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"sync"
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"time"
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)
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const (
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defaultFailThreshold = 5
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defaultOpenFor = 60 * time.Second
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)
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// CircuitBreaker opens after consecutive failures and half-opens after a cool-down.
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type CircuitBreaker struct {
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mu sync.Mutex
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failures int
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failThreshold int
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openUntil time.Time
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openFor time.Duration
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now func() time.Time
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}
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// NewCircuitBreaker builds a breaker with the given thresholds.
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func NewCircuitBreaker(failThreshold int, openFor time.Duration) *CircuitBreaker {
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if failThreshold <= 0 {
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failThreshold = defaultFailThreshold
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}
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if openFor <= 0 {
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openFor = defaultOpenFor
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}
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return &CircuitBreaker{
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failThreshold: failThreshold,
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openFor: openFor,
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now: time.Now,
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}
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}
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// Allow reports whether a call may proceed.
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func (c *CircuitBreaker) Allow() bool {
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if c == nil {
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return true
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}
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c.mu.Lock()
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defer c.mu.Unlock()
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if c.openUntil.IsZero() {
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return true
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}
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if c.now().After(c.openUntil) {
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// half-open: allow one probe
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c.openUntil = time.Time{}
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c.failures = c.failThreshold - 1
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return true
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}
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return false
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}
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// RecordSuccess resets the breaker.
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func (c *CircuitBreaker) RecordSuccess() {
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if c == nil {
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return
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}
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c.mu.Lock()
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defer c.mu.Unlock()
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c.failures = 0
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c.openUntil = time.Time{}
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}
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// RecordFailure increments consecutive failures and may open the circuit.
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func (c *CircuitBreaker) RecordFailure() {
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if c == nil {
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return
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}
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c.mu.Lock()
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defer c.mu.Unlock()
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c.failures++
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if c.failures >= c.failThreshold {
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c.openUntil = c.now().Add(c.openFor)
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c.failures = 0
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}
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}
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// Open reports whether the circuit is currently open (for tests/metrics).
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func (c *CircuitBreaker) Open() bool {
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if c == nil {
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return false
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}
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c.mu.Lock()
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defer c.mu.Unlock()
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return !c.openUntil.IsZero() && c.now().Before(c.openUntil)
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}
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