Memory Allocation Optimization

[aryasoni98]

Problem

Memory allocation patterns can be optimized to reduce allocations and improve performance.

Current State

• Map allocations without pre-allocation (15 instances)
• Slice append operations without capacity hints (19 instances)
• String concatenation could use strings.Builder
• Potential memory leaks in long-running processes

Acceptance Criteria

• Maps pre-allocated with known capacity
• Slices pre-allocated with capacity hints
• String operations optimized
• 20% reduction in memory allocations

Tasks

Map Pre-allocation

• Pre-allocate maps with known capacity

  // Before
  activeKeys := make(map[string]struct{})
  
  // After
  activeKeys := make(map[string]struct{}, len(wip))

• Files to optimize:

  • pkg/workqueue/dispatcher/dispatcher.go
  • pkg/githubreconciler/client.go
  • pkg/workqueue/gcs/gcs.go

Slice Pre-allocation

• Pre-allocate slices with capacity hints

  // Before
  var results []string
  
  // After
  results := make([]string, 0, expectedSize)

• Files to optimize:

  • pkg/workqueue/conformance/conformance.go
  • pkg/workqueue/gcs/gcs.go
  • pkg/httpmetrics/transport.go

String Operations Optimization

• Use strings.Builder for complex concatenations

  // Before
  result := prefix + " " + suffix
  
  // After
  var builder strings.Builder
  builder.Grow(len(prefix) + len(suffix) + 1)
  builder.WriteString(prefix)
  builder.WriteString(" ")
  builder.WriteString(suffix)
  result := builder.String()

• Files to optimize:

  • pkg/githubreconciler/reconciler.go
  • pkg/workqueue/gcs/gcs.go
  • pkg/httpmetrics/transport.go

Memory Leak Prevention

• Review long-running processes for memory leaks
• Add proper cleanup in defer statements
• Review goroutine lifecycle management
• Add memory monitoring

Performance Benchmarks

• Add benchmarks for optimized functions

  func BenchmarkMapAllocation(b *testing.B) {
      // Benchmark map allocation patterns
  }
  
  func BenchmarkSliceAllocation(b *testing.B) {
      // Benchmark slice allocation patterns
  }
  
  func BenchmarkStringOperations(b *testing.B) {
      // Benchmark string operations
  }

Success Metrics

• Target: 20% reduction in memory allocations
• Measurement: go test -bench=. -benchmem
• Monitoring: Memory profiling with pprof