Add getRaw method to Batch API (#488)

* add batch.getRaw method for raw block data

* return block if no encryption is present

* unsolo test

* add raw flag to batch and hypercore get

* break up if statements

Author: chm-diederichs

index.js

@@ -875,6 +875,8 @@ module.exports = class Hypercore extends EventEmitter {
     let block = await req
     if (!block) return null
 
+    if (opts && opts.raw) return block
+
     if (this.encryption && (!opts || opts.decrypt !== false)) {
       // Copy the block as it might be shared with other sessions.
       block = b4a.from(block)

lib/batch.js

@@ -170,12 +170,19 @@ module.exports = class HypercoreBatch extends EventEmitter {
     throw BLOCK_NOT_AVAILABLE()
   }
 
-  async get (index, opts) {
+  async get (index, opts = {}) {
     if (this.opened === false) await this.opening
     if (this.closing) throw SESSION_CLOSED()
 
     const length = this._sessionLength
-    if (index < length) return this.session.get(index, { ...opts, tree: this._sessionBatch })
+
+    if (index < length) {
+      return this.session.get(index, { ...opts, tree: this._sessionBatch })
+    }
+
+    if (opts && opts.raw) {
+      return this._appendsActual[index - length] || null
+    }
 
     const buffer = this._appends[index - length] || null
     if (!buffer) throw BLOCK_NOT_AVAILABLE()

test/batch.js

@@ -643,3 +643,43 @@ test('clear', async function (t) {
 
   t.is(b2.length, 1, 'reset the batch')
 })
+
+test('copy from with encrypted batch', async function (t) {
+  const encryptionKey = b4a.alloc(32, 2)
+
+  const core = await create({ encryptionKey })
+
+  const blocks = 290
+
+  const b = core.batch({ autoClose: false })
+
+  for (let i = 0; i < blocks; i++) {
+    await b.append('block' + i)
+  }
+
+  await b.flush({ keyPair: null })
+
+  t.is(core.length, 0)
+  t.is(b._sessionLength, blocks)
+
+  const manifest = {
+    prologue: {
+      length: b._sessionLength,
+      hash: b.createTreeBatch().hash()
+    },
+    encryptionKey
+  }
+
+  const clone = await create({
+    manifest,
+    encryptionKey
+  })
+
+  const tree = clone.core.tree.batch()
+
+  for (let i = 0; i < blocks; i++) {
+    await tree.append(await b.get(i, { raw: true }))
+  }
+
+  t.alike(tree.hash(), manifest.prologue.hash)
+})