feat: allow updating pin metadata (#647)

Adds a `setMetadata` method to the pins interface to allow updating
pin metadata, also a `.get` method to retrieve data for a specific
pin.

packages/interface/src/pins.ts

@@ -40,14 +40,14 @@ export interface IsPinnedOptions extends AbortOptions {
 
 export interface Pins {
   /**
-   * Pin a block in the blockstore. It will not be deleted
-   * when garbage collection is run.
+   * Pin a block in the blockstore. It will not be deleted when garbage
+   * collection is run.
    */
   add(cid: CID, options?: AddOptions): AsyncGenerator<CID, void, undefined>
 
   /**
-   * Unpin the block that corresponds to the passed CID. The block will
-   * be deleted when garbage collection is run.
+   * Unpin the block that corresponds to the passed CID. The block will be
+   * deleted when garbage collection is run.
    */
   rm(cid: CID, options?: RmOptions): AsyncGenerator<CID, void, undefined>
 
@@ -56,8 +56,19 @@ export interface Pins {
    */
   ls(options?: LsOptions): AsyncGenerator<Pin, void, undefined>
 
+  /**
+   * If the CID is pinned, return details of the pin, otherwise throw an error
+   */
+  get(cid: CID, options?: AbortOptions): Promise<Pin>
+
   /**
    * Return true if the passed CID is pinned
    */
   isPinned(cid: CID, options?: IsPinnedOptions): Promise<boolean>
+
+  /**
+   * If the CID is pinned, update the metadata associated with the pin,
+   * otherwise throw an error
+   */
+  setMetadata(cid: CID, metadata: Record<string, string | number | boolean> | undefined, options?: AbortOptions): Promise<void>
 }

packages/utils/src/pins.ts

@@ -221,4 +221,21 @@ export class PinsImpl implements Pins {
 
     return this.datastore.has(blockKey, options)
   }
+
+  async get (cid: CID, options?: AbortOptions): Promise<Pin> {
+    const pinKey = toDSKey(cid)
+    const buf = await this.datastore.get(pinKey, options)
+
+    return cborg.decode(buf)
+  }
+
+  async setMetadata (cid: CID, metadata: Record<string, string | number | boolean> | undefined, options?: AbortOptions): Promise<void> {
+    const pinKey = toDSKey(cid)
+    const buf = await this.datastore.get(pinKey, options)
+    const pin: DatastorePin = cborg.decode(buf)
+
+    pin.metadata = metadata ?? {}
+
+    await this.datastore.put(pinKey, cborg.encode(pin), options)
+  }
 }

packages/utils/test/pins.spec.ts

@@ -37,6 +37,39 @@ describe('pins', () => {
     await expect(helia.pins.isPinned(cidV0)).to.eventually.be.true('did not pin v0 CID')
   })
 
+  it('gets a pin', async () => {
+    const cid = await createAndPutBlock(raw.code, Uint8Array.from([0, 1, 2, 3]), helia.blockstore)
+
+    await drain(helia.pins.add(cid))
+
+    const pin = await helia.pins.get(cid)
+
+    expect(pin).to.have.property('depth', Infinity)
+    expect(pin).to.have.deep.property('metadata', {})
+  })
+
+  it('updates metadata for a pin', async () => {
+    const cid = await createAndPutBlock(raw.code, Uint8Array.from([0, 1, 2, 3]), helia.blockstore)
+
+    await drain(helia.pins.add(cid))
+
+    const pin = await helia.pins.get(cid)
+
+    expect(pin).to.have.deep.property('metadata', {})
+
+    const newMetadata = {
+      foo: 'bar',
+      baz: true,
+      qux: 5
+    }
+
+    await helia.pins.setMetadata(cid, newMetadata)
+
+    const updatedPin = await helia.pins.get(cid)
+
+    expect(updatedPin).to.have.deep.property('metadata', newMetadata)
+  })
+
   it('pins a block with progress events', async () => {
     const cidV1 = await createAndPutBlock(raw.code, Uint8Array.from([0, 1, 2, 3]), helia.blockstore)