1 files changed, 231 insertions, 0 deletions
diff --git a/internal/benchutil/eventmix.go b/internal/benchutil/eventmix.go
new file mode 100644
index 0000000..1057c0e
--- /dev/null
+++ b/internal/benchutil/eventmix.go
@@ -0,0 +1,231 @@
+package benchutil
+
+import (
+	"fmt"
+	"math/rand"
+	"syscall"
+
+	"ior/internal/types"
+)
+
+const (
+	defaultMixSeed    int64  = 1
+	defaultStreamTime uint64 = 1
+	defaultBasePid    uint32 = 1000
+	defaultBaseTid    uint32 = 2000
+	defaultBaseFd     int32  = 64
+)
+
+type MixEvent uint8
+
+const (
+	MixRead MixEvent = iota + 1
+	MixWrite
+	MixOpen
+	MixClose
+	MixStat
+	MixSync
+	MixFsync
+	MixAccess
+	MixMkdir
+	MixUnlink
+	MixRename
+	MixLink
+	MixFcntl
+	MixDup3
+	MixOpenByHandleAt
+)
+
+type MixEntry struct {
+	Event  MixEvent
+	Weight int
+}
+
+type EventMix struct {
+	Entries []MixEntry
+	Seed    int64
+}
+
+var ReadHeavy = EventMix{
+	Entries: []MixEntry{
+		{Event: MixRead, Weight: 30},
+		{Event: MixWrite, Weight: 30},
+		{Event: MixOpen, Weight: 10},
+		{Event: MixClose, Weight: 10},
+		{Event: MixStat, Weight: 10},
+		{Event: MixSync, Weight: 10},
+	},
+	Seed: defaultMixSeed,
+}
+
+var WriteHeavy = EventMix{
+	Entries: []MixEntry{
+		{Event: MixWrite, Weight: 40},
+		{Event: MixFsync, Weight: 20},
+		{Event: MixRead, Weight: 15},
+		{Event: MixOpen, Weight: 5},
+		{Event: MixClose, Weight: 5},
+		{Event: MixStat, Weight: 15},
+	},
+	Seed: defaultMixSeed,
+}
+
+var MetadataHeavy = EventMix{
+	Entries: []MixEntry{
+		{Event: MixStat, Weight: 15},
+		{Event: MixAccess, Weight: 15},
+		{Event: MixOpen, Weight: 12},
+		{Event: MixClose, Weight: 13},
+		{Event: MixMkdir, Weight: 10},
+		{Event: MixUnlink, Weight: 10},
+		{Event: MixRename, Weight: 8},
+		{Event: MixLink, Weight: 7},
+		{Event: MixRead, Weight: 5},
+		{Event: MixWrite, Weight: 5},
+	},
+	Seed: defaultMixSeed,
+}
+
+var DiverseAllTypes = EventMix{
+	Entries: []MixEntry{
+		{Event: MixOpen, Weight: 1},
+		{Event: MixRead, Weight: 1},
+		{Event: MixSync, Weight: 1},
+		{Event: MixStat, Weight: 1},
+		{Event: MixRename, Weight: 1},
+		{Event: MixFcntl, Weight: 1},
+		{Event: MixDup3, Weight: 1},
+		{Event: MixOpenByHandleAt, Weight: 1},
+		{Event: MixClose, Weight: 1},
+	},
+	Seed: defaultMixSeed,
+}
+
+func (m EventMix) GenerateStream(gen EventGenerator, n, numThreads int) [][]byte {
+	if n <= 0 {
+		return nil
+	}
+
+	threadCount := numThreads
+	if threadCount < 1 {
+		threadCount = 1
+	}
+
+	entries := m.activeEntries()
+	totalWeight := sumWeights(entries)
+	rng := rand.New(rand.NewSource(m.seed()))
+
+	stream := make([][]byte, 0, n*2)
+	nextTime := defaultStreamTime
+	for i := 0; i < n; i++ {
+		threadIdx := i % threadCount
+		pid := defaultBasePid + uint32(threadIdx)
+		tid := defaultBaseTid + uint32(threadIdx)
+		fd := fdFor(threadIdx, i)
+		event := choose(entries, totalWeight, rng)
+		enter, exit := event.pair(gen, nextTime, pid, tid, fd, i)
+		stream = append(stream, enter, exit)
+		nextTime += gen.pairDelta() + 1
+	}
+
+	return stream
+}
+
+func choose(entries []MixEntry, totalWeight int, rng *rand.Rand) MixEvent {
+	if totalWeight <= 0 {
+		return MixRead
+	}
+
+	roll := rng.Intn(totalWeight)
+	for _, entry := range entries {
+		if entry.Weight <= 0 {
+			continue
+		}
+		if roll < entry.Weight {
+			return entry.Event
+		}
+		roll -= entry.Weight
+	}
+	return entries[len(entries)-1].Event
+}
+
+func fdFor(threadIdx, seq int) int32 {
+	return defaultBaseFd + int32(threadIdx*100+seq%100)
+}
+
+func (m EventMix) activeEntries() []MixEntry {
+	active := make([]MixEntry, 0, len(m.Entries))
+	for _, entry := range m.Entries {
+		if entry.Weight > 0 {
+			active = append(active, entry)
+		}
+	}
+	if len(active) == 0 {
+		return DiverseAllTypes.Entries
+	}
+	return active
+}
+
+func (m EventMix) seed() int64 {
+	if m.Seed == 0 {
+		return defaultMixSeed
+	}
+	return m.Seed
+}
+
+func sumWeights(entries []MixEntry) int {
+	total := 0
+	for _, entry := range entries {
+		total += entry.Weight
+	}
+	return total
+}
+
+func (e MixEvent) pair(gen EventGenerator, time uint64, pid, tid uint32, fd int32, seq int) ([]byte, []byte) {
+	switch e {
+	case MixRead:
+		return gen.FdPair(time, pid, tid, fd, types.SYS_ENTER_READ, types.SYS_EXIT_READ, 128)
+	case MixWrite:
+		return gen.FdPair(time, pid, tid, fd, types.SYS_ENTER_WRITE, types.SYS_EXIT_WRITE, 256)
+	case MixOpen:
+		return gen.OpenPair(time, pid, tid)
+	case MixClose:
+		_, enter := gen.EnterFdEvent(time, pid, tid, fd, types.SYS_ENTER_CLOSE)
+		_, exit := gen.ExitFdEvent(time+gen.pairDelta(), pid, tid, fd, types.SYS_EXIT_CLOSE)
+		return enter, exit
+	case MixStat:
+		path := fmt.Sprintf("/tmp/ior-stat-%d-%d", tid, seq)
+		return gen.PathPair(time, pid, tid, path, types.SYS_ENTER_NEWSTAT, types.SYS_EXIT_NEWSTAT, 0)
+	case MixSync:
+		return gen.NullPair(time, pid, tid, types.SYS_ENTER_SYNC, types.SYS_EXIT_SYNC)
+	case MixFsync:
+		return gen.FdPair(time, pid, tid, fd, types.SYS_ENTER_FSYNC, types.SYS_EXIT_FSYNC, 0)
+	case MixAccess:
+		path := fmt.Sprintf("/tmp/ior-access-%d-%d", tid, seq)
+		return gen.PathPair(time, pid, tid, path, types.SYS_ENTER_ACCESS, types.SYS_EXIT_ACCESS, 0)
+	case MixMkdir:
+		path := fmt.Sprintf("/tmp/ior-mkdir-%d-%d", tid, seq)
+		return gen.PathPair(time, pid, tid, path, types.SYS_ENTER_MKDIR, types.SYS_EXIT_MKDIR, 0)
+	case MixUnlink:
+		path := fmt.Sprintf("/tmp/ior-unlink-%d-%d", tid, seq)
+		return gen.PathPair(time, pid, tid, path, types.SYS_ENTER_UNLINK, types.SYS_EXIT_UNLINK, 0)
+	case MixRename:
+		oldname := fmt.Sprintf("/tmp/ior-old-%d-%d", tid, seq)
+		newname := fmt.Sprintf("/tmp/ior-new-%d-%d", tid, seq)
+		return gen.NamePair(time, pid, tid, oldname, newname, types.SYS_ENTER_RENAME, types.SYS_EXIT_RENAME, 0)
+	case MixLink:
+		oldname := fmt.Sprintf("/tmp/ior-link-old-%d-%d", tid, seq)
+		newname := fmt.Sprintf("/tmp/ior-link-new-%d-%d", tid, seq)
+		return gen.NamePair(time, pid, tid, oldname, newname, types.SYS_ENTER_LINK, types.SYS_EXIT_LINK, 0)
+	case MixFcntl:
+		return gen.FcntlPair(time, pid, tid, uint32(fd), syscall.F_SETFL, syscall.O_NONBLOCK, types.SYS_EXIT_FCNTL, 0)
+	case MixDup3:
+		return gen.Dup3Pair(time, pid, tid, fd, syscall.O_CLOEXEC, types.SYS_EXIT_DUP3, int64(fd+1))
+	case MixOpenByHandleAt:
+		_, enter := gen.EnterOpenByHandleAtEvent(time, pid, tid, syscall.O_RDWR)
+		_, exit := gen.ExitRetEvent(time+gen.pairDelta(), pid, tid, types.SYS_EXIT_OPEN_BY_HANDLE_AT, int64(fd))
+		return enter, exit
+	default:
+		return gen.NullPair(time, pid, tid, types.SYS_ENTER_SYNC, types.SYS_EXIT_SYNC)
+	}
+}