build: DTail fork — benchmarks, PGO tooling, Makefile, docker

Squashed development of the build/benchmark/profiling tooling:

- Turbo-vs-normal and per-tool benchmark harnesses under benchmarks/ (with dated
  baseline and result artifacts preserved), plus MapReduce/SSH/network suites.
- Profile-Guided Optimization workflow (internal/tools/pgo lives with the code):
  Makefile targets (make pgo / pgo-quick / build-pgo), profile generation with
  non-zero-sample and representativeness guards.
- Makefile targets for build, test (unit + integration), lint, vet, benchmarking
  and profiling; docker config updates.
- .gitignore hardened against pgo profiles and accidental integration-test
  debug/output dumps.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

1 files changed, 69 insertions, 0 deletions

diff --git a/benchmarks/benchmark_test.go b/benchmarks/benchmark_test.go
new file mode 100644
index 0000000..baa53fc
--- /dev/null
+++ b/benchmarks/benchmark_test.go
@@ -0,0 +1,69 @@
+package benchmarks
+
+import (
+	"fmt"
+	"os"
+	"testing"
+)
+
+// TestMain sets up and tears down the benchmark environment
+func TestMain(m *testing.M) {
+	// Clean up any leftover files before starting
+	if err := CleanupBenchmarkFiles(""); err != nil {
+		fmt.Fprintf(os.Stderr, "Warning: failed to cleanup old files: %v\n", err)
+	}
+	
+	// Run tests/benchmarks
+	code := m.Run()
+	
+	// Clean up after benchmarks unless asked to keep files
+	if os.Getenv("DTAIL_BENCH_KEEP_FILES") != "true" {
+		if err := CleanupBenchmarkFiles(""); err != nil {
+			fmt.Fprintf(os.Stderr, "Warning: failed to cleanup files: %v\n", err)
+		}
+	}
+	
+	os.Exit(code)
+}
+
+// BenchmarkAll runs a representative subset of all benchmarks
+func BenchmarkAll(b *testing.B) {
+	b.Run("DCat", func(b *testing.B) {
+		BenchmarkDCatSimple(b)
+	})
+	
+	b.Run("DGrep", func(b *testing.B) {
+		BenchmarkDGrepSimplePattern(b)
+	})
+	
+	b.Run("DMap", func(b *testing.B) {
+		BenchmarkDMapSimpleAggregation(b)
+	})
+}
+
+// BenchmarkQuick runs only quick benchmarks with small files
+func BenchmarkQuick(b *testing.B) {
+	// Set quick mode
+	oldQuick := os.Getenv("DTAIL_BENCH_QUICK")
+	os.Setenv("DTAIL_BENCH_QUICK", "true")
+	defer func() {
+		if oldQuick == "" {
+			os.Unsetenv("DTAIL_BENCH_QUICK")
+		} else {
+			os.Setenv("DTAIL_BENCH_QUICK", oldQuick)
+		}
+	}()
+	
+	// Set small files only
+	oldSizes := os.Getenv("DTAIL_BENCH_SIZES")
+	os.Setenv("DTAIL_BENCH_SIZES", "small")
+	defer func() {
+		if oldSizes == "" {
+			os.Unsetenv("DTAIL_BENCH_SIZES")
+		} else {
+			os.Setenv("DTAIL_BENCH_SIZES", oldSizes)
+		}
+	}()
+	
+	BenchmarkAll(b)
+}
\ No newline at end of file