refactor(nbd-client): remove unused method and default iterator

@vates/nbd-client/index.mjs

@@ -3,7 +3,6 @@ import { Socket } from 'node:net'
 import { connect } from 'node:tls'
 import { fromCallback, pRetry, pDelay, pTimeout, pFromCallback } from 'promise-toolbox'
 import { readChunkStrict } from '@vates/read-chunk'
-import { createLogger } from '@xen-orchestra/log'
 
 import {
   INIT_PASSWD,
@@ -21,9 +20,6 @@ import {
   OPTS_MAGIC,
   NBD_CMD_DISC,
 } from './constants.mjs'
-import { Readable } from 'node:stream'
-
-const { warn } = createLogger('vates:nbd-client')
 
 // documentation is here : https://github.com/NetworkBlockDevice/nbd/blob/master/doc/proto.md
 
@@ -337,58 +333,4 @@ export default class NbdClient {
       this.#readBlockResponse()
     })
   }
-
-  async *readBlocks(indexGenerator = 2 * 1024 * 1024) {
-    // default : read all blocks
-    if (typeof indexGenerator === 'number') {
-      const exportSize = Number(this.#exportSize)
-      const chunkSize = indexGenerator
-
-      indexGenerator = function* () {
-        const nbBlocks = Math.ceil(exportSize / chunkSize)
-        for (let index = 0; index < nbBlocks; index++) {
-          yield { index, size: chunkSize }
-        }
-      }
-    }
-    const readAhead = []
-    const readAheadMaxLength = this.#readAhead
-    const makeReadBlockPromise = (index, size) => {
-      const promise = pRetry(() => this.readBlock(index, size), {
-        tries: this.#readBlockRetries,
-        onRetry: async err => {
-          warn('will retry reading block ', index, err)
-          await this.reconnect()
-        },
-      })
-      // error is handled during unshift
-      promise.catch(() => {})
-      return promise
-    }
-
-    // read all blocks, but try to keep readAheadMaxLength promise waiting ahead
-    for (const { index, size } of indexGenerator()) {
-      // stack readAheadMaxLength promises before starting to handle the results
-      if (readAhead.length === readAheadMaxLength) {
-        // any error will stop reading blocks
-        yield readAhead.shift()
-      }
-
-      readAhead.push(makeReadBlockPromise(index, size))
-    }
-    while (readAhead.length > 0) {
-      yield readAhead.shift()
-    }
-  }
-
-  stream(chunkSize) {
-    async function* iterator() {
-      for await (const chunk of this.readBlocks(chunkSize)) {
-        yield chunk
-      }
-    }
-    // create a readable stream instead of returning the iterator
-    // since iterators don't like unshift and partial reading
-    return Readable.from(iterator())
-  }
 }

@vates/nbd-client/tests/nbdclient.integ.mjs

@@ -1,4 +1,3 @@
-import NbdClient from '../index.mjs'
 import { spawn, exec } from 'node:child_process'
 import fs from 'node:fs/promises'
 import { test } from 'tap'
@@ -7,6 +6,7 @@ import { pFromCallback } from 'promise-toolbox'
 import { Socket } from 'node:net'
 import { NBD_DEFAULT_PORT } from '../constants.mjs'
 import assert from 'node:assert'
+import MultiNbdClient from '../multi.mjs'
 
 const FILE_SIZE = 10 * 1024 * 1024
 
@@ -81,7 +81,7 @@ test('it works with unsecured network', async tap => {
   const path = await createTempFile(FILE_SIZE)
 
   let nbdServer = await spawnNbdKit(path)
-  const client = new NbdClient(
+  const client = new MultiNbdClient(
     {
       address: '127.0.0.1',
       exportname: 'MY_SECRET_EXPORT',
@@ -147,17 +147,6 @@ CYu1Xn/FVPx1HoRgWc7E8wFhDcA/P3SJtfIQWHB9FzSaBflKGR4t8WCE2eE8+cTB
       nbdServer = await spawnNbdKit(path)
     }
   }
-
-  // we can reuse the conneciton to read other blocks
-  // default iterator
-  const nbdIteratorWithDefaultBlockIterator = client.readBlocks()
-  let nb = 0
-  for await (const block of nbdIteratorWithDefaultBlockIterator) {
-    nb++
-    tap.equal(block.length, 2 * 1024 * 1024)
-  }
-
-  tap.equal(nb, 5)
   assert.rejects(() => client.readBlock(100, CHUNK_SIZE))
 
   await client.disconnect()

packages/vhd-lib/createStreamNbd.js

@@ -15,7 +15,16 @@ const { fuHeader, checksumStruct } = require('./_structs')
 const assert = require('node:assert')
 
 exports.createNbdRawStream = function createRawStream(nbdClient) {
-  const stream = Readable.from(nbdClient.readBlocks(), { objectMode: false })
+  const exportSize = Number(nbdClient.exportSize)
+  const chunkSize = 2 * 1024 * 1024
+
+  const indexGenerator = function* () {
+    const nbBlocks = Math.ceil(exportSize / chunkSize)
+    for (let index = 0; index < nbBlocks; index++) {
+      yield { index, size: chunkSize }
+    }
+  }
+  const stream = Readable.from(nbdClient.readBlocks(indexGenerator), { objectMode: false })
 
   stream.on('error', () => nbdClient.disconnect())
   stream.on('end', () => nbdClient.disconnect())
@@ -26,6 +35,7 @@ exports.createNbdVhdStream = async function createVhdStream(nbdClient, sourceStr
   const bufFooter = await readChunkStrict(sourceStream, FOOTER_SIZE)
 
   const header = unpackHeader(await readChunkStrict(sourceStream, HEADER_SIZE))
+  header.tableOffset = FOOTER_SIZE + HEADER_SIZE
   // compute BAT in order
   const batSize = Math.ceil((header.maxTableEntries * 4) / SECTOR_SIZE) * SECTOR_SIZE
   await skipStrict(sourceStream, header.tableOffset - (FOOTER_SIZE + HEADER_SIZE))
@@ -47,7 +57,6 @@ exports.createNbdVhdStream = async function createVhdStream(nbdClient, sourceStr
       precLocator = offset
     }
   }
-  header.tableOffset = FOOTER_SIZE + HEADER_SIZE
   const rawHeader = fuHeader.pack(header)
   checksumStruct(rawHeader, fuHeader)