feat: decode with coreDiscoveryId or coreDiscoveryKey

Allow decode to work when a coreDiscoveryId is
passed, instead of coreDiscoveryKey to match an
upstream change in the multi-core-indexer to use
coreDiscoveryId rather than coreDiscoveryKey. This
reduces a round-trip conversion from buffer to
string, and will also facilitate sending entries
between threads when we run indexing in a separate
worker thread.

src/decode.ts

@@ -25,7 +25,7 @@ import cenc from 'compact-encoding'
 import { DATA_TYPE_ID_BYTES, SCHEMA_VERSION_BYTES } from './constants.js'
 import {
   ExhaustivenessError,
-  VersionIdObject,
+  VersionObject,
   getOwn,
   getProtoTypeName,
 } from './lib/utils.js'
@@ -42,12 +42,9 @@ for (const [schemaName, dataTypeId] of Object.entries(dataTypeIds) as Array<
  * Decode a Buffer as an object validated against the corresponding schema
  *
  * @param buf Buffer to be decoded
- * @param versionObj public key (coreKey) of the core where this block is stored, and the index of the block in the core.
+ * @param versionObj discovery key or discovery id of the core where this block is stored, and the index of the block in the core.
  * */
-export function decode(
-  buf: Buffer,
-  versionObj: VersionIdObject
-): MapeoDocDecode {
+export function decode(buf: Buffer, versionObj: VersionObject): MapeoDocDecode {
   const schemaDef = decodeBlockPrefix(buf)
 
   const encodedMsg = buf.subarray(

src/index.ts

@@ -6,7 +6,9 @@ export {
   getVersionId,
   parseVersionId,
   valueOf,
-  type VersionIdObject,
+  /** Deprecated: rename VersionIdObject to VersionObject */
+  type VersionObject as VersionIdObject,
+  type VersionObject,
 } from './lib/utils.js'
 
 export * from './schema/index.js'

src/lib/decode-conversions.ts

@@ -39,14 +39,14 @@ import {
   assert,
   ExhaustivenessError,
   getVersionId,
-  VersionIdObject,
+  VersionObject,
 } from './utils.js'
 
 /** Function type for converting a protobuf type of any version for a particular
  * schema name, and returning the most recent JSONSchema type */
 type ConvertFunction<TSchemaName extends SchemaName> = (
   message: Extract<ProtoTypesWithSchemaInfo, { schemaName: TSchemaName }>,
-  versionObj: VersionIdObject
+  versionObj: VersionObject
 ) => FilterBySchemaName<MapeoDocDecode, TSchemaName>
 
 function ensure(
@@ -465,7 +465,7 @@ function convertTagPrimitive({
 
 function convertCommon(
   common: ProtoTypesWithSchemaInfo['common'],
-  versionObj: VersionIdObject
+  versionObj: VersionObject
 ): Omit<MapeoCommon, 'schemaName'> {
   if (
     !common ||

src/lib/utils.ts

@@ -37,28 +37,48 @@ function capitalize<T extends string>(str: T): Capitalize<T> {
   return (str.charAt(0).toUpperCase() + str.slice(1)) as any
 }
 
-export type VersionIdObject = {
+export type VersionObject = VersionDiscoveryKeyObject | VersionDiscoveryIdObject
+
+export type VersionDiscoveryKeyObject = {
   coreDiscoveryKey: Buffer
   index: number
 }
 
+export type VersionDiscoveryIdObject = {
+  coreDiscoveryId: string
+  index: number
+}
+
+export const VERSION_ID_SEPARATOR = '/'
+
 /**
- * Get a string versionId from a core key and index in that core. A versionId
- * uniquely identifies a record in the underlying Hypercore storage used by
- * Mapeo
+ * Get a string versionId from a core discovery key or discovery id and index in
+ * that core. A versionId uniquely identifies a record in the underlying
+ * Hypercore storage used by Mapeo
  * @param versionIdObject
  * @returns versionId string
  */
-export function getVersionId({ coreDiscoveryKey, index }: VersionIdObject) {
-  assert(
-    coreDiscoveryKey.byteLength >= 32,
-    'version ID core discovery key must be have at least 32 bytes'
-  )
+export function getVersionId(versionIdObject: VersionObject) {
+  const { index } = versionIdObject
   assert(
     Number.isSafeInteger(index) && index >= 0,
     'version ID index must be a non-negative integer'
   )
-  return coreDiscoveryKey.toString('hex') + '/' + index
+  let discoveryId
+  if ('coreDiscoveryId' in versionIdObject) {
+    discoveryId = versionIdObject.coreDiscoveryId
+    assert(
+      discoveryId.length > 0,
+      'version ID core discovery id must be non-empty string'
+    )
+  } else {
+    assert(
+      versionIdObject.coreDiscoveryKey.byteLength >= 32,
+      'version ID core discovery key must be have at least 32 bytes'
+    )
+    discoveryId = versionIdObject.coreDiscoveryKey.toString('hex')
+  }
+  return discoveryId + VERSION_ID_SEPARATOR + index
 }
 
 /**
@@ -68,8 +88,8 @@ export function getVersionId({ coreDiscoveryKey, index }: VersionIdObject) {
  * @param versionId hex-encoded 32-byte core key and index in the core, separated with `/`
  * @returns coreKey as a Buffer and index in the core
  */
-export function parseVersionId(versionId: string): VersionIdObject {
-  const items = versionId.split('/')
+export function parseVersionId(versionId: string): VersionDiscoveryKeyObject {
+  const items = versionId.split(VERSION_ID_SEPARATOR)
   if (!items[0] || !items[1]) throw new Error('Invalid versionId')
   const coreDiscoveryKey = Buffer.from(items[0], 'hex')
   if (coreDiscoveryKey.length !== 32) throw new Error('Invalid versionId')

test/index.test.js

@@ -6,7 +6,6 @@ import {
   encode,
   decode,
   decodeBlockPrefix,
-  parseVersionId,
   validate,
   valueOf,
 } from '../dist/index.js'
@@ -20,6 +19,7 @@ import {
   badDocs,
 } from './fixtures/index.js'
 import { cachedValues } from './fixtures/cached.js'
+import { VERSION_ID_SEPARATOR } from '../dist/lib/utils.js'
 
 /** @import { SchemaName } from '../dist/types.js' */
 
@@ -341,3 +341,8 @@ function removeBlockPrefix(buf) {
   const blockPrefix = encodeBlockPrefix(decodeBlockPrefix(buf))
   return buf.slice(blockPrefix.byteLength)
 }
+
+function parseVersionId(versionId) {
+  const [coreDiscoveryId, index] = versionId.split(VERSION_ID_SEPARATOR)
+  return { coreDiscoveryId, index: Number.parseInt(index) }
+}