feat(messaging-streams): manually deepen all six stream utility modules

- chunker: framed seq chunks, reassemble, setChunkSize
- multiplex: closeAll, getStream, per-stream byte counters
- backpressure: low/high water marks, bufferedBytes
- tee: branchBytes, removeBranch, depth guard
- transform: pipeTo and outbound backpressure
- resume-token: labeled checkpoints, clearTokens, bytesFromOffset
- Update category README and chunker tests

Co-authored-by: Cursor <[email protected]>

messaging-streams/hyper-p2p-stream-tee/index.js

@@ -8,24 +8,40 @@ class HyperP2PStreamTee extends EventEmitter {
   constructor (opts = {}) {
     super()
     this._branches = new Map()
-    this._stats = { written: 0, branches: 0 }
+    this._stats = { written: 0, branches: 0, dropped: 0 }
+    this.maxBranchDepth = opts.maxBranchDepth ?? 10000
   }
 
   addBranch (name) {
     if (!name) throw new Error('branch name required')
-    const branch = { name, chunks: [] }
+    const branch = { name, chunks: [], bytes: 0 }
     this._branches.set(name, branch)
     this._stats.branches++
-    return () => this._branches.delete(name)
+    this.emit('branch-added', { name })
+    return () => this.removeBranch(name)
+  }
+
+  removeBranch (name) {
+    return this._branches.delete(name)
   }
 
   write (chunk) {
     if (chunk == null) throw new Error('chunk required')
     const buf = typeof chunk === 'string' ? b4a.from(chunk) : chunk
-    for (const branch of this._branches.values()) branch.chunks.push(buf)
+    const size = buf.length || buf.byteLength || 0
+    let n = 0
+    for (const branch of this._branches.values()) {
+      if (branch.chunks.length >= this.maxBranchDepth) {
+        this._stats.dropped++
+        continue
+      }
+      branch.chunks.push(buf)
+      branch.bytes += size
+      n++
+    }
     this._stats.written++
     this.emit('data', buf)
-    return true
+    return n > 0
   }
 
   readBranch (name) {
@@ -38,14 +54,24 @@ class HyperP2PStreamTee extends EventEmitter {
     return b ? b.chunks.length : 0
   }
 
-  listBranches () { return [...this._branches.keys()] }
+  branchBytes (name) {
+    const b = this._branches.get(name)
+    return b ? b.bytes : 0
+  }
 
-  hasBranch (name) { return this._branches.has(name) }
+  listBranches () {
+    return [...this._branches.keys()]
+  }
+
+  hasBranch (name) {
+    return this._branches.has(name)
+  }
 
   drainBranch (name) {
     const b = this._branches.get(name)
     if (!b) return []
     const out = b.chunks.splice(0, b.chunks.length)
+    b.bytes = 0
     return out
   }
 
@@ -59,8 +85,14 @@ class HyperP2PStreamTee extends EventEmitter {
     return { ...this._stats, branchCount: this._branches.size, protocol: PROTOCOL }
   }
 
-  async ready () { return this }
-  async close () { this._branches.clear() }
+  async ready () {
+    return this
+  }
+
+  async close () {
+    this._branches.clear()
+    this.emit('closed')
+  }
 }
 
 module.exports = { HyperP2PStreamTee, PROTOCOL }