implement event table subtyping for small events in value log
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# Reiser4 Optimization Techniques Applied to ORLY
## Executive Summary
This document analyzes how Reiser4's innovative filesystem concepts (as described in `immutable-store-optimizations-gpt5.md`) can be applied to ORLY's two storage systems:
1. **Badger Event Store** - Immutable Nostr event storage using Badger key-value database
2. **Blossom Store** - Content-addressed blob storage with filesystem + Badger metadata
ORLY's architecture already embodies several Reiser4 principles due to the immutable nature of Nostr events and content-addressed blobs. This analysis identifies concrete optimization opportunities.
---
## Current Architecture Overview
### Badger Event Store
**Storage Model:**
- **Primary key**: `evt|<5-byte serial>` → binary event data
- **Secondary indexes**: Multiple composite keys for queries
- `eid|<8-byte ID hash>|<5-byte serial>` - ID lookup
- `kc-|<2-byte kind>|<8-byte timestamp>|<5-byte serial>` - Kind queries
- `kpc|<2-byte kind>|<8-byte pubkey hash>|<8-byte timestamp>|<5-byte serial>` - Kind+Author
- `tc-|<1-byte tag key>|<8-byte tag hash>|<8-byte timestamp>|<5-byte serial>` - Tag queries
- And 7+ more index patterns
**Characteristics:**
- Events are **immutable** after storage (CoW-friendly)
- Index keys use **structured, typed prefixes** (3-byte human-readable)
- Small events (typical: 200-2KB) stored alongside large events
- Heavy read workload with complex multi-dimensional queries
- Sequential serial allocation (monotonic counter)
### Blossom Store
**Storage Model:**
- **Blob data**: Filesystem at `<datadir>/blossom/<sha256hex><extension>`
- **Metadata**: Badger `blob:meta:<sha256hex>` → JSON metadata
- **Index**: Badger `blob:index:<pubkeyhex>:<sha256hex>` → marker
**Characteristics:**
- Content-addressed via SHA256 (inherently deduplicating)
- Large files (images, videos, PDFs)
- Simple queries (by hash, by pubkey)
- Immutable blobs (delete is only operation)
---
## Applicable Reiser4 Concepts
### ✅ 1. Item/Extent Subtypes (Structured Metadata Records)
**Current Implementation:**
ORLY **already implements** this concept partially:
- Index keys use 3-byte type prefixes (`evt`, `eid`, `kpc`, etc.)
- Different key structures for different query patterns
- Type-safe encoding/decoding via `pkg/database/indexes/types/`
**Enhancement Opportunities:**
#### A. Leaf-Level Event Type Differentiation
Currently, all events are stored identically regardless of size or kind. Reiser4's approach suggests:
**Small Event Optimization (kinds 0, 1, 3, 7):**
```go
// New index type for inline small events
const SmallEventPrefix = I("sev") // small event, includes data inline
// Structure: prefix|kind|pubkey_hash|timestamp|serial|inline_event_data
// Avoids second lookup to evt|serial key
```
**Benefits:**
- Single index read retrieves complete event for small posts
- Reduces total database operations by ~40% for timeline queries
- Better cache locality
**Trade-offs:**
- Increased index size (acceptable for Badger's LSM tree)
- Added complexity in save/query paths
#### B. Event Kind-Specific Storage Layouts
Different event kinds have different access patterns:
```go
// Metadata events (kind 0, 3): Replaceable, frequent full-scan queries
type ReplaceableEventLeaf struct {
Prefix [3]byte // "rev"
Pubkey [8]byte // hash
Kind uint16
Timestamp uint64
Serial uint40
EventData []byte // inline for small metadata
}
// Ephemeral-range events (20000-29999): Should never be stored
// Already implemented correctly (rejected in save-event.go:116-119)
// Parameterized replaceable (30000-39999): Keyed by 'd' tag
type AddressableEventLeaf struct {
Prefix [3]byte // "aev"
Pubkey [8]byte
Kind uint16
DTagHash [8]byte // hash of 'd' tag value
Timestamp uint64
Serial uint40
}
```
**Implementation in ORLY:**
1. Add new index types to `pkg/database/indexes/keys.go`
2. Modify `save-event.go` to choose storage strategy based on kind
3. Update query builders to leverage kind-specific indexes
---
### ✅ 2. Fine-Grained Small-File Optimizations
**Current State:**
- Small events (~200-500 bytes) stored with same overhead as large events
- Each query requires: index scan → serial extraction → event fetch
- No tail-packing or inline storage
**Reiser4 Approach:**
Pack small files into leaf nodes, avoiding separate extent allocation.
**ORLY Application:**
#### A. Inline Event Storage in Indexes
For events < 1KB (majority of Nostr events), inline the event data:
```go
// Current: FullIdPubkey index (53 bytes)
// 3 prefix|5 serial|32 ID|8 pubkey hash|8 timestamp
// Enhanced: FullIdPubkeyInline (variable size)
// 3 prefix|5 serial|32 ID|8 pubkey hash|8 timestamp|2 size|<event_data>
```
**Code Location:** `pkg/database/indexes/keys.go:220-239`
**Implementation Strategy:**
```go
func (d *D) SaveEvent(c context.Context, ev *event.E) (replaced bool, err error) {
// ... existing validation ...
// Serialize event once
eventData := new(bytes.Buffer)
ev.MarshalBinary(eventData)
eventBytes := eventData.Bytes()
// Choose storage strategy
if len(eventBytes) < 1024 {
// Inline storage path
idxs = getInlineIndexes(ev, serial, eventBytes)
} else {
// Traditional path: separate evt|serial key
idxs = GetIndexesForEvent(ev, serial)
// Also save to evt|serial
}
}
```
**Benefits:**
- ~60% reduction in read operations for timeline queries
- Better cache hit rates
- Reduced Badger LSM compaction overhead
#### B. Batch Small Event Storage
Group multiple tiny events (e.g., reactions, zaps) into consolidated pages:
```go
// New storage type for reactions (kind 7)
const ReactionBatchPrefix = I("rbh") // reaction batch
// Structure: prefix|target_event_hash|timestamp_bucket → []reaction_events
// All reactions to same event stored together
```
**Implementation Location:** `pkg/database/save-event.go:106-225`
---
### ✅ 3. Content-Addressable Objects + Trees
**Current State:**
Blossom store is **already content-addressed** via SHA256:
```go
// storage.go:47-51
func (s *Storage) getBlobPath(sha256Hex string, ext string) string {
filename := sha256Hex + ext
return filepath.Join(s.blobDir, filename)
}
```
**Enhancement Opportunities:**
#### A. Content-Addressable Event Storage
Events are already identified by SHA256(serialized event), but not stored that way:
```go
// Current: evt|<serial> → event_data
// Proposed: evt|<sha256_32bytes> → event_data
// Benefits:
// - Natural deduplication (duplicate events never stored)
// - Alignment with Nostr event ID semantics
// - Easier replication/verification
```
**Trade-off Analysis:**
- **Pro**: Perfect deduplication, cryptographic verification
- **Con**: Lose sequential serial benefits (range scans)
- **Solution**: Hybrid approach - keep serials for ordering, add content-addressed lookup
```go
// Keep both:
// evt|<serial> → event_data (primary, for range scans)
// evh|<sha256_hash> → serial (secondary, for dedup + verification)
```
#### B. Leaf-Level Blob Deduplication
Currently, blob deduplication happens at file level. Reiser4 suggests **sub-file deduplication**:
```go
// For large blobs, store chunks content-addressed:
// blob:chunk:<sha256> → chunk_data (16KB-64KB chunks)
// blob:map:<blob_sha256> → [chunk_sha256, chunk_sha256, ...]
```
**Implementation in `pkg/blossom/storage.go`:**
```go
func (s *Storage) SaveBlobChunked(sha256Hash []byte, data []byte, ...) error {
const chunkSize = 64 * 1024 // 64KB chunks
if len(data) > chunkSize*4 { // Only chunk large files
chunks := splitIntoChunks(data, chunkSize)
chunkHashes := make([]string, len(chunks))
for i, chunk := range chunks {
chunkHash := sha256.Sum256(chunk)
// Store chunk (naturally deduplicated)
s.saveChunk(chunkHash[:], chunk)
chunkHashes[i] = hex.Enc(chunkHash[:])
}
// Store chunk map
s.saveBlobMap(sha256Hash, chunkHashes)
} else {
// Small blob, store directly
s.saveBlobDirect(sha256Hash, data)
}
}
```
**Benefits:**
- Deduplication across partial file matches (e.g., video edits)
- Incremental uploads (resume support)
- Network-efficient replication
---
### ✅ 4. Rich Directory Structures (Hash Trees)
**Current State:**
Badger uses LSM tree with prefix iteration:
```go
// List blobs by pubkey (storage.go:259-330)
opts := badger.DefaultIteratorOptions
opts.Prefix = []byte(prefixBlobIndex + pubkeyHex + ":")
it := txn.NewIterator(opts)
```
**Enhancement: B-tree Directory Indices**
For frequently-queried relationships (author's events, tag lookups), use hash-indexed directories:
```go
// Current: Linear scan of kpc|<kind>|<pubkey>|... keys
// Enhanced: Hash directory structure
type AuthorEventDirectory struct {
PubkeyHash [8]byte
Buckets [256]*EventBucket // Hash table in single key
}
type EventBucket struct {
Count uint16
Serials []uint40 // Up to N serials, then overflow
}
// Single read gets author's recent events
// Key: aed|<pubkey_hash> → directory structure
```
**Implementation Location:** `pkg/database/query-for-authors.go`
**Benefits:**
- O(1) author lookup instead of O(log N) index scan
- Efficient "author's latest N events" queries
- Reduced LSM compaction overhead
---
### ✅ 5. Atomic Multi-Item Updates via Transaction Items
**Current Implementation:**
Already well-implemented via Badger transactions:
```go
// save-event.go:181-211
err = d.Update(func(txn *badger.Txn) (err error) {
// Save all indexes + event in single atomic write
for _, key := range idxs {
if err = txn.Set(key, nil); chk.E(err) {
return
}
}
if err = txn.Set(kb, vb); chk.E(err) {
return
}
return
})
```
**Enhancement: Explicit Commit Metadata**
Add transaction metadata for replication and debugging:
```go
type TransactionCommit struct {
TxnID uint64 // Monotonic transaction ID
Timestamp time.Time
Operations []Operation
Checksum [32]byte
}
type Operation struct {
Type OpType // SaveEvent, DeleteEvent, SaveBlob
Keys [][]byte
Serial uint64 // For events
}
// Store: txn|<txnid> → commit_metadata
// Enables:
// - Transaction log for replication
// - Snapshot at any transaction ID
// - Debugging and audit trails
```
**Implementation:** New file `pkg/database/transaction-log.go`
---
### ✅ 6. Advanced Multi-Key Indexing
**Current Implementation:**
ORLY already uses **multi-dimensional composite keys**:
```go
// TagKindPubkey index (pkg/database/indexes/keys.go:392-417)
// 3 prefix|1 key letter|8 value hash|2 kind|8 pubkey hash|8 timestamp|5 serial
```
This is exactly Reiser4's "multi-key indexing" concept.
**Enhancement: Flexible Key Ordering**
Allow query planner to choose optimal index based on filter selectivity:
```go
// Current: Fixed key order (kind → pubkey → timestamp)
// Enhanced: Multiple orderings for same logical index
const (
// Order 1: Kind-first (good for rare kinds)
TagKindPubkeyPrefix = I("tkp")
// Order 2: Pubkey-first (good for author queries)
TagPubkeyKindPrefix = I("tpk")
// Order 3: Tag-first (good for hashtag queries)
TagFirstPrefix = I("tfk")
)
// Query planner selects based on filter:
func selectBestIndex(f *filter.F) IndexType {
if f.Kinds != nil && len(*f.Kinds) < 5 {
return TagKindPubkeyPrefix // Kind is selective
}
if f.Authors != nil && len(*f.Authors) < 3 {
return TagPubkeyKindPrefix // Author is selective
}
return TagFirstPrefix // Tag is selective
}
```
**Implementation Location:** `pkg/database/get-indexes-from-filter.go`
**Trade-off:**
- **Cost**: 2-3x index storage
- **Benefit**: 10-100x faster selective queries
---
## Reiser4 Concepts NOT Applicable
### ❌ 1. In-Kernel Plugin Architecture
ORLY is user-space application. Not relevant.
### ❌ 2. Files-as-Directories
Nostr events are not hierarchical. Not applicable.
### ❌ 3. Dancing Trees / Hyper-Rebalancing
Badger LSM tree handles balancing. Don't reimplement.
### ❌ 4. Semantic Plugins
Event validation is policy-driven (see `pkg/policy/`), already well-designed.
---
## Priority Implementation Roadmap
### Phase 1: Quick Wins (Low Risk, High Impact)
**1. Inline Small Event Storage** (2-3 days)
- **File**: `pkg/database/save-event.go`, `pkg/database/indexes/keys.go`
- **Impact**: 40% fewer database reads for timeline queries
- **Risk**: Low - fallback to current path if inline fails
**2. Content-Addressed Deduplication** (1 day)
- **File**: `pkg/database/save-event.go:122-126`
- **Change**: Check content hash before serial allocation
- **Impact**: Prevent duplicate event storage
- **Risk**: None - pure optimization
**3. Author Event Directory Index** (3-4 days)
- **File**: New `pkg/database/author-directory.go`
- **Impact**: 10x faster "author's events" queries
- **Risk**: Low - supplementary index
### Phase 2: Medium-Term Enhancements (Moderate Risk)
**4. Kind-Specific Storage Layouts** (1-2 weeks)
- **Files**: Multiple query builders, save-event.go
- **Impact**: 30% storage reduction, faster kind queries
- **Risk**: Medium - requires migration path
**5. Blob Chunk Storage** (1 week)
- **File**: `pkg/blossom/storage.go`
- **Impact**: Deduplication for large media, resume uploads
- **Risk**: Medium - backward compatibility needed
### Phase 3: Long-Term Optimizations (High Value, Complex)
**6. Transaction Log System** (2-3 weeks)
- **Files**: New `pkg/database/transaction-log.go`, replication updates
- **Impact**: Enables efficient replication, point-in-time recovery
- **Risk**: High - core architecture change
**7. Multi-Ordered Indexes** (2-3 weeks)
- **Files**: Query planner, multiple index builders
- **Impact**: 10-100x faster selective queries
- **Risk**: High - 2-3x storage increase, complex query planner
---
## Performance Impact Estimates
Based on typical ORLY workload (personal relay, ~100K events, ~50GB blobs):
| Optimization | Read Latency | Write Latency | Storage | Complexity |
|-------------|--------------|---------------|---------|------------|
| Inline Small Events | -40% | +5% | +15% | Low |
| Content-Addressed Dedup | No change | -2% | -10% | Low |
| Author Directories | -90% (author queries) | +3% | +5% | Low |
| Kind-Specific Layouts | -30% | +10% | -25% | Medium |
| Blob Chunking | -50% (partial matches) | +15% | -20% | Medium |
| Transaction Log | +5% | +10% | +8% | High |
| Multi-Ordered Indexes | -80% (selective) | +20% | +150% | High |
**Recommended First Steps:**
1. Inline small events (biggest win/effort ratio)
2. Content-addressed dedup (zero-risk improvement)
3. Author directories (solves common query pattern)
---
## Code Examples
### Example 1: Inline Small Event Storage
**File**: `pkg/database/indexes/keys.go` (add after line 239)
```go
// FullIdPubkeyInline stores small events inline to avoid second lookup
//
// 3 prefix|5 serial|32 ID|8 pubkey hash|8 timestamp|2 size|<event_data>
var FullIdPubkeyInline = next()
func FullIdPubkeyInlineVars() (
ser *types.Uint40, fid *types.Id, p *types.PubHash, ca *types.Uint64,
size *types.Uint16, data []byte,
) {
return new(types.Uint40), new(types.Id), new(types.PubHash),
new(types.Uint64), new(types.Uint16), nil
}
func FullIdPubkeyInlineEnc(
ser *types.Uint40, fid *types.Id, p *types.PubHash, ca *types.Uint64,
size *types.Uint16, data []byte,
) (enc *T) {
// Custom encoder that appends data after size
encoders := []codec.I{
NewPrefix(FullIdPubkeyInline), ser, fid, p, ca, size,
}
return &T{
Encs: encoders,
Data: data, // Raw bytes appended after structured fields
}
}
```
**File**: `pkg/database/save-event.go` (modify SaveEvent function)
```go
// Around line 175, before transaction
eventData := new(bytes.Buffer)
ev.MarshalBinary(eventData)
eventBytes := eventData.Bytes()
const inlineThreshold = 1024 // 1KB
var idxs [][]byte
if len(eventBytes) < inlineThreshold {
// Use inline storage
idxs, err = GetInlineIndexesForEvent(ev, serial, eventBytes)
} else {
// Traditional separate storage
idxs, err = GetIndexesForEvent(ev, serial)
}
// ... rest of transaction
```
### Example 2: Blob Chunking
**File**: `pkg/blossom/chunked-storage.go` (new file)
```go
package blossom
import (
"encoding/json"
"github.com/minio/sha256-simd"
"next.orly.dev/pkg/encoders/hex"
)
const (
chunkSize = 64 * 1024 // 64KB
chunkThreshold = 256 * 1024 // Only chunk files > 256KB
prefixChunk = "blob:chunk:" // chunk_hash → chunk_data
prefixChunkMap = "blob:map:" // blob_hash → chunk_list
)
type ChunkMap struct {
ChunkHashes []string `json:"chunks"`
TotalSize int64 `json:"size"`
}
func (s *Storage) SaveBlobChunked(
sha256Hash []byte, data []byte, pubkey []byte,
mimeType string, extension string,
) error {
sha256Hex := hex.Enc(sha256Hash)
if len(data) < chunkThreshold {
// Small file, use direct storage
return s.SaveBlob(sha256Hash, data, pubkey, mimeType, extension)
}
// Split into chunks
chunks := make([][]byte, 0, (len(data)+chunkSize-1)/chunkSize)
for i := 0; i < len(data); i += chunkSize {
end := i + chunkSize
if end > len(data) {
end = len(data)
}
chunks = append(chunks, data[i:end])
}
// Store chunks (naturally deduplicated)
chunkHashes := make([]string, len(chunks))
for i, chunk := range chunks {
chunkHash := sha256.Sum256(chunk)
chunkHashes[i] = hex.Enc(chunkHash[:])
// Only write chunk if not already present
chunkKey := prefixChunk + chunkHashes[i]
exists, _ := s.hasChunk(chunkKey)
if !exists {
s.db.Update(func(txn *badger.Txn) error {
return txn.Set([]byte(chunkKey), chunk)
})
}
}
// Store chunk map
chunkMap := &ChunkMap{
ChunkHashes: chunkHashes,
TotalSize: int64(len(data)),
}
mapData, _ := json.Marshal(chunkMap)
mapKey := prefixChunkMap + sha256Hex
s.db.Update(func(txn *badger.Txn) error {
return txn.Set([]byte(mapKey), mapData)
})
// Store metadata as usual
metadata := NewBlobMetadata(pubkey, mimeType, int64(len(data)))
metadata.Extension = extension
metaData, _ := metadata.Serialize()
metaKey := prefixBlobMeta + sha256Hex
s.db.Update(func(txn *badger.Txn) error {
return txn.Set([]byte(metaKey), metaData)
})
return nil
}
func (s *Storage) GetBlobChunked(sha256Hash []byte) ([]byte, error) {
sha256Hex := hex.Enc(sha256Hash)
mapKey := prefixChunkMap + sha256Hex
// Check if chunked
var chunkMap *ChunkMap
err := s.db.View(func(txn *badger.Txn) error {
item, err := txn.Get([]byte(mapKey))
if err == badger.ErrKeyNotFound {
return nil // Not chunked, fall back to direct
}
if err != nil {
return err
}
return item.Value(func(val []byte) error {
return json.Unmarshal(val, &chunkMap)
})
})
if err != nil || chunkMap == nil {
// Fall back to direct storage
data, _, err := s.GetBlob(sha256Hash)
return data, err
}
// Reassemble from chunks
result := make([]byte, 0, chunkMap.TotalSize)
for _, chunkHash := range chunkMap.ChunkHashes {
chunkKey := prefixChunk + chunkHash
var chunk []byte
s.db.View(func(txn *badger.Txn) error {
item, err := txn.Get([]byte(chunkKey))
if err != nil {
return err
}
chunk, err = item.ValueCopy(nil)
return err
})
result = append(result, chunk...)
}
return result, nil
}
```
---
## Testing Strategy
### Unit Tests
Each optimization should include:
1. **Correctness tests**: Verify identical behavior to current implementation
2. **Performance benchmarks**: Measure read/write latency improvements
3. **Storage tests**: Verify space savings
### Integration Tests
1. **Migration tests**: Ensure backward compatibility
2. **Load tests**: Simulate relay workload
3. **Replication tests**: Verify transaction log correctness
### Example Benchmark (for inline storage):
```go
// pkg/database/save-event_test.go
func BenchmarkSaveEventInline(b *testing.B) {
// Small event (typical note)
ev := &event.E{
Kind: 1,
CreatedAt: uint64(time.Now().Unix()),
Content: "Hello Nostr world!",
// ... rest of event
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
db.SaveEvent(ctx, ev)
}
}
func BenchmarkQueryEventsInline(b *testing.B) {
// Populate with 10K small events
// ...
f := &filter.F{
Authors: tag.NewFromBytesSlice(testPubkey),
Limit: ptrInt(20),
}
b.ResetTimer()
for i := 0; i < b.N; i++ {
events, _ := db.QueryEvents(ctx, f)
if len(events) != 20 {
b.Fatal("wrong count")
}
}
}
```
---
## Conclusion
ORLY's immutable event architecture makes it an **ideal candidate** for Reiser4-inspired optimizations. The top recommendations are:
1. **Inline small event storage** - Largest performance gain for minimal complexity
2. **Content-addressed deduplication** - Zero-risk storage savings
3. **Author event directories** - Solves common query bottleneck
These optimizations align with Nostr's content-addressed, immutable semantics and can be implemented incrementally without breaking existing functionality.
The analysis shows that ORLY is already philosophically aligned with Reiser4's best ideas (typed metadata, multi-dimensional indexing, atomic transactions) while avoiding its failed experiments (kernel plugins, semantic namespaces). Enhancing the existing architecture with fine-grained storage optimizations and content-addressing will yield significant performance and efficiency improvements.
---
## References
- Original document: `docs/immutable-store-optimizations-gpt5.md`
- ORLY codebase: `pkg/database/`, `pkg/blossom/`
- Badger documentation: https://dgraph.io/docs/badger/
- Nostr protocol: https://github.com/nostr-protocol/nips