fix: identity blockstore should wrap child (#303)

Allow passing a child blockstore to an identity blockstore.

Author: achingbrain

packages/blockstore-core/package.json

@@ -110,6 +110,7 @@
   "devDependencies": {
     "aegir": "^42.2.3",
     "interface-blockstore-tests": "^6.0.0",
+    "it-all": "^3.0.4",
     "uint8arrays": "^5.0.2"
   }
 }

packages/blockstore-core/src/identity.ts

@@ -1,34 +1,72 @@
 import { BaseBlockstore } from './base.js'
-import * as Errors from './errors.js'
-import type { Pair } from 'interface-blockstore'
-import type { Await, AwaitIterable } from 'interface-store'
+import { Errors } from './index.js'
+import type { Blockstore, Pair } from 'interface-blockstore'
+import type { AbortOptions, Await, AwaitIterable } from 'interface-store'
 import type { CID } from 'multiformats/cid'
 
 // https://github.com/multiformats/multicodec/blob/d06fc6194710e8909bac64273c43f16b56ca4c34/table.csv#L2
 const IDENTITY_CODEC = 0x00
 
 export class IdentityBlockstore extends BaseBlockstore {
-  put (key: CID): CID {
-    return key
+  private readonly child?: Blockstore
+
+  constructor (child?: Blockstore) {
+    super()
+
+    this.child = child
+  }
+
+  put (key: CID, block: Uint8Array): Await<CID> {
+    if (key.multihash.code === IDENTITY_CODEC) {
+      return key
+    }
+
+    if (this.child == null) {
+      return key
+    }
+
+    return this.child.put(key, block)
   }
 
   get (key: CID): Await<Uint8Array> {
-    if (key.code === IDENTITY_CODEC) {
+    if (key.multihash.code === IDENTITY_CODEC) {
       return key.multihash.digest
     }
 
-    throw Errors.notFoundError()
+    if (this.child == null) {
+      throw Errors.notFoundError()
+    }
+
+    return this.child.get(key)
   }
 
-  has (key: CID): boolean {
-    return key.code === IDENTITY_CODEC
+  has (key: CID): Await<boolean> {
+    if (key.multihash.code === IDENTITY_CODEC) {
+      return true
+    }
+
+    if (this.child == null) {
+      return false
+    }
+
+    return this.child.has(key)
   }
 
-  delete (): void {
+  delete (key: CID): Await<void> {
+    if (key.code === IDENTITY_CODEC) {
+      return
+    }
 
+    if (this.child != null) {
+      return this.child.delete(key)
+    }
   }
 
-  * getAll (): AwaitIterable<Pair> {
+  getAll (options?: AbortOptions): AwaitIterable<Pair> {
+    if (this.child != null) {
+      return this.child.getAll(options)
+    }
 
+    return []
   }
 }

packages/blockstore-core/test/identity.spec.ts

@@ -1,19 +1,23 @@
 /* eslint-env mocha */
 
 import { expect } from 'aegir/chai'
+import all from 'it-all'
 import drain from 'it-drain'
 import { CID } from 'multiformats/cid'
 import * as raw from 'multiformats/codecs/raw'
 import { identity } from 'multiformats/hashes/identity'
 import { sha256 } from 'multiformats/hashes/sha2'
 import { IdentityBlockstore } from '../src/identity.js'
+import { MemoryBlockstore } from '../src/memory.js'
 import type { Blockstore } from 'interface-blockstore'
 
 describe('identity', () => {
   let blockstore: Blockstore
+  let child: Blockstore
 
   beforeEach(() => {
     blockstore = new IdentityBlockstore()
+    child = new MemoryBlockstore()
   })
 
   it('has an identity CID', () => {
@@ -56,4 +60,70 @@ describe('identity', () => {
 
     expect(blockstore.has(cid)).to.be.true()
   })
+
+  it('puts CIDs to child', async () => {
+    const block = Uint8Array.from([0, 1, 2, 3, 4])
+    const multihash = await sha256.digest(block)
+    const cid = CID.createV1(raw.code, multihash)
+
+    blockstore = new IdentityBlockstore(child)
+
+    await blockstore.put(cid, block)
+    expect(child.has(cid)).to.be.true()
+    expect(child.get(cid)).to.equalBytes(block)
+  })
+
+  it('gets CIDs from child', async () => {
+    const block = Uint8Array.from([0, 1, 2, 3, 4])
+    const multihash = await sha256.digest(block)
+    const cid = CID.createV1(raw.code, multihash)
+
+    await child.put(cid, block)
+
+    blockstore = new IdentityBlockstore(child)
+    expect(blockstore.has(cid)).to.be.true()
+    expect(blockstore.get(cid)).to.equalBytes(block)
+  })
+
+  it('has CIDs from child', async () => {
+    const block = Uint8Array.from([0, 1, 2, 3, 4])
+    const multihash = await sha256.digest(block)
+    const cid = CID.createV1(raw.code, multihash)
+
+    await child.put(cid, block)
+
+    blockstore = new IdentityBlockstore(child)
+    expect(blockstore.has(cid)).to.be.true()
+  })
+
+  it('deletes CIDs from child', async () => {
+    const block = Uint8Array.from([0, 1, 2, 3, 4])
+    const multihash = await sha256.digest(block)
+    const cid = CID.createV1(raw.code, multihash)
+
+    await child.put(cid, block)
+
+    blockstore = new IdentityBlockstore(child)
+    expect(blockstore.has(cid)).to.be.true()
+
+    await blockstore.delete(cid)
+
+    expect(blockstore.has(cid)).to.be.false()
+  })
+
+  it('gets all pairs from child', async () => {
+    const block = Uint8Array.from([0, 1, 2, 3, 4])
+    const multihash = await sha256.digest(block)
+    const cid = CID.createV1(raw.code, multihash)
+
+    await child.put(cid, block)
+
+    blockstore = new IdentityBlockstore(child)
+    expect(blockstore.has(cid)).to.be.true()
+
+    const result = await all(blockstore.getAll())
+
+    expect(result).to.have.lengthOf(1)
+    expect(result[0].cid.toString()).to.equal(cid.toString())
+  })
 })