Performance Optimization¶
Understanding how to optimize error handling is crucial for maintaining high-performance applications. While error handling is essential, it shouldn't become a bottleneck in your application. Let's explore how ewrap helps you achieve efficient error handling and learn about optimization strategies.
Understanding Error Handling Performance¶
When we talk about performance in error handling, we need to consider several aspects:
- Memory allocation and garbage collection impact
- CPU overhead from stack trace capture
- Concurrency and contention in high-throughput scenarios
- The cost of error formatting and logging
- The impact of error wrapping chains
Let's explore how ewrap addresses each of these concerns and how you can optimize your error handling.
Memory Management¶
One of the most significant performance impacts in error handling comes from memory allocations. ewrap uses several strategies to minimize this impact:
Object Pooling¶
The Error Group pool is a prime example of how we can reduce memory pressure:
// Create a pool with an appropriate size for your use case
pool := ewrap.NewErrorGroupPool(4)
func processItems(items []Item) error {
// Get an error group from the pool
eg := pool.Get()
defer eg.Release() // Return to pool when done
for _, item := range items {
if err := processItem(item); err != nil {
eg.Add(err)
}
}
return eg.Error()
}
This approach is particularly effective because:
- It reduces garbage collection pressure
- It minimizes memory fragmentation
- It provides predictable memory usage patterns
Pre-allocation Strategies¶
When dealing with metadata or formatting, pre-allocation can significantly improve performance:
// Pre-allocate slices with expected capacity
func buildErrorContext(err error, expectedFields int) map[string]interface{} {
// Allocate map with expected size to avoid resizing
context := make(map[string]interface{}, expectedFields)
if wrappedErr, ok := err.(*ewrap.Error); ok {
// Pre-allocate string builder with reasonable capacity
var builder strings.Builder
builder.Grow(256) // Reserve space for typical error message
// Build context efficiently
builder.WriteString("Error occurred in ")
builder.WriteString(wrappedErr.Operation())
context["message"] = builder.String()
// Add other fields...
}
return context
}
Stack Trace Optimization¶
Stack traces are expensive to capture, so ewrap implements several optimizations:
Lazy Stack Capture¶
type lazyStack struct {
pcs []uintptr
frames runtime.Frames
once sync.Once
}
func (ls *lazyStack) Frames() runtime.Frames {
ls.once.Do(func() {
if ls.frames == nil {
ls.frames = runtime.CallersFrames(ls.pcs)
}
})
return ls.frames
}
Stack Filtering¶
We filter out unnecessary frames to reduce memory usage and improve readability:
func filterStack(stack []runtime.Frame) []runtime.Frame {
filtered := make([]runtime.Frame, 0, len(stack))
for _, frame := range stack {
if shouldIncludeFrame(frame) {
filtered = append(filtered, frame)
}
}
return filtered
}
func shouldIncludeFrame(frame runtime.Frame) bool {
// Skip runtime frames
if strings.Contains(frame.File, "runtime/") {
return false
}
// Skip ewrap internal frames
if strings.Contains(frame.File, "ewrap/errors.go") {
return false
}
return true
}
Concurrency Optimization¶
In high-concurrency scenarios, efficient error handling becomes even more critical:
Lock-Free Operations¶
Where possible, ewrap uses atomic operations instead of locks:
type AtomicCounter struct {
value int64
}
func (c *AtomicCounter) Increment() {
atomic.AddInt64(&c.value, 1)
}
func (c *AtomicCounter) Get() int64 {
return atomic.LoadInt64(&c.value)
}
Minimizing Lock Contention¶
When locks are necessary, we minimize their scope:
func (eg *ErrorGroup) Add(err error) {
if err == nil {
return
}
// Prepare the error outside the lock
wrappedErr := prepareError(err)
// Minimize critical section
eg.mu.Lock()
eg.errors = append(eg.errors, wrappedErr)
eg.mu.Unlock()
}
Formatting Performance¶
Error formatting can be expensive, especially for JSON/YAML conversion. Here's how to optimize it:
Cached Formatting¶
For frequently accessed formats:
type CachedError struct {
err *ewrap.Error
jsonCache atomic.Value
yamlCache atomic.Value
cacheTimeout time.Duration
}
func (ce *CachedError) ToJSON() (string, error) {
if cached := ce.jsonCache.Load(); cached != nil {
cacheEntry := cached.(*formatCacheEntry)
if !cacheEntry.isExpired() {
return cacheEntry.data, nil
}
}
// Format and cache the result
json, err := ce.err.ToJSON()
if err != nil {
return "", err
}
ce.jsonCache.Store(&formatCacheEntry{
data: json,
expires: time.Now().Add(ce.cacheTimeout),
})
return json, nil
}
Efficient Buffer Usage¶
When formatting errors:
// Pool of buffers for formatting
var bufferPool = sync.Pool{
New: func() interface{} {
return new(bytes.Buffer)
},
}
func formatError(err *ewrap.Error) string {
buf := bufferPool.Get().(*bytes.Buffer)
defer func() {
buf.Reset()
bufferPool.Put(buf)
}()
// Use buffer for formatting
buf.WriteString("Error: ")
buf.WriteString(err.Error())
buf.WriteString("\nStack:\n")
buf.WriteString(err.Stack())
return buf.String()
}
Performance Monitoring¶
To ensure your error handling remains efficient, implement monitoring:
type ErrorMetrics struct {
creationTime metrics.Histogram
wrappingTime metrics.Histogram
stackDepth metrics.Histogram
allocationSize metrics.Histogram
}
func TrackErrorMetrics(err error, metrics *ErrorMetrics) {
if wrappedErr, ok := err.(*ewrap.Error); ok {
metrics.stackDepth.Observe(float64(len(wrappedErr.Stack())))
// Track other metrics...
}
}
Best Practices for Performance¶
1. Pool Appropriately¶
Choose pool sizes based on your application's characteristics:
func initializePools(config Config) {
// Size pools based on expected concurrent operations
errorGroupPool := ewrap.NewErrorGroupPool(config.MaxConcurrentOperations)
// Size buffer pools based on expected error volume
bufferPool := sync.Pool{
New: func() interface{} {
return bytes.NewBuffer(make([]byte, 0, config.AverageErrorSize))
},
}
}
2. Minimize Allocations¶
Be mindful of unnecessary allocations:
// Good - reuse error types for common cases
var (
ErrNotFound = ewrap.New("resource not found",
ewrap.WithErrorType(ErrorTypeNotFound))
ErrUnauthorized = ewrap.New("unauthorized access",
ewrap.WithErrorType(ErrorTypePermission))
)
// Avoid - creating new errors for common cases
if !exists {
return ewrap.New("resource not found") // Creates new error each time
}
3. Profile and Monitor¶
Regularly profile your error handling:
func TestErrorPerformance(t *testing.T) {
if testing.Short() {
t.Skip("skipping performance test in short mode")
}
// Profile creation
b.Run("ErrorCreation", func(b *testing.B) {
b.ResetTimer()
for i := 0; i < b.N; i++ {
_ = ewrap.New("test error")
}
})
// Profile wrapping
b.Run("ErrorWrapping", func(b *testing.B) {
baseErr := errors.New("base error")
b.ResetTimer()
for i := 0; i < b.N; i++ {
_ = ewrap.Wrap(baseErr, "wrapped error")
}
})
}