refactor: object API write methods now return CIDs

BREAKING CHANGE: Object API refactor.

Object API methods that write DAG nodes now return a CID instead of a DAG node. Affected methods:

* `ipfs.object.new`
* `ipfs.object.patch.addLink`
* `ipfs.object.patch.appendData`
* `ipfs.object.patch.rmLink`
* `ipfs.object.patch.setData`
* `ipfs.object.put`

Example:

```js
// Before
const dagNode = await ipfs.object.new()
```

```js
// After
const cid = await ipfs.object.new() // now returns a CID
const dagNode = await ipfs.object.get(cid) // fetch the DAG node that was created
```

IMPORTANT: `DAGNode` instances, which are part of the IPLD dag-pb format have been refactored.

These instances no longer have `multihash`, `cid` or `serialized` properties.

This effects the following API methods that return these types of objects:

* `ipfs.object.get`
* `ipfs.dag.get`

See ipld/js-ipld-dag-pb#99 for more information.

License: MIT
Signed-off-by: Alan Shaw <[email protected]>

src/object/addLink.js

@@ -1,11 +1,10 @@
 'use strict'
 
 const promisify = require('promisify-es6')
+const CID = require('cids')
 const cleanMultihash = require('../utils/clean-multihash')
 
 module.exports = (send) => {
-  const objectGet = require('./get')(send)
-
   return promisify((multihash, dLink, opts, callback) => {
     if (typeof opts === 'function') {
       callback = opts
@@ -32,7 +31,7 @@ module.exports = (send) => {
       if (err) {
         return callback(err)
       }
-      objectGet(result.Hash, { enc: 'base58' }, callback)
+      callback(null, new CID(result.Hash))
     })
   })
 }

src/object/appendData.js

@@ -2,11 +2,11 @@
 
 const promisify = require('promisify-es6')
 const once = require('once')
+const CID = require('cids')
 const cleanMultihash = require('../utils/clean-multihash')
 const SendOneFile = require('../utils/send-one-file')
 
 module.exports = (send) => {
-  const objectGet = require('./get')(send)
   const sendOneFile = SendOneFile(send, 'object/patch/append-data')
 
   return promisify((multihash, data, opts, _callback) => {
@@ -30,7 +30,7 @@ module.exports = (send) => {
         return callback(err)
       }
 
-      objectGet(result.Hash, { enc: 'base58' }, callback)
+      callback(null, new CID(result.Hash))
     })
   })
 }

src/object/new.js

@@ -1,9 +1,7 @@
 'use strict'
 
 const promisify = require('promisify-es6')
-const dagPB = require('ipld-dag-pb')
-const DAGNode = dagPB.DAGNode
-const Unixfs = require('ipfs-unixfs')
+const CID = require('cids')
 
 module.exports = (send) => {
   return promisify((template, callback) => {
@@ -19,24 +17,7 @@ module.exports = (send) => {
         return callback(err)
       }
 
-      let data
-
-      if (template) {
-        if (template !== 'unixfs-dir') {
-          return callback(new Error('unkown template: ' + template))
-        }
-        data = (new Unixfs('directory')).marshal()
-      } else {
-        data = Buffer.alloc(0)
-      }
-
-      DAGNode.create(data, (err, node) => {
-        if (err) {
-          return callback(err)
-        }
-
-        callback(null, node)
-      })
+      callback(null, new CID(result.Hash))
     })
   })
 }

src/object/put.js

@@ -1,14 +1,9 @@
 'use strict'
 
 const promisify = require('promisify-es6')
-const dagPB = require('ipld-dag-pb')
-const DAGNode = dagPB.DAGNode
-const LRU = require('lru-cache')
-const lruOptions = {
-  max: 128
-}
+const CID = require('cids')
+const { DAGNode } = require('ipld-dag-pb')
 
-const cache = LRU(lruOptions)
 const SendOneFile = require('../utils/send-one-file')
 const once = require('once')
 
@@ -72,49 +67,7 @@ module.exports = (send) => {
         return callback(err) // early
       }
 
-      if (Buffer.isBuffer(obj)) {
-        if (!options.enc) {
-          obj = { Data: obj, Links: [] }
-        } else if (options.enc === 'json') {
-          obj = JSON.parse(obj.toString())
-        }
-      }
-
-      let node
-
-      if (DAGNode.isDAGNode(obj)) {
-        node = obj
-      } else if (options.enc === 'protobuf') {
-        dagPB.util.deserialize(obj, (err, _node) => {
-          if (err) {
-            return callback(err)
-          }
-          node = _node
-          next()
-        })
-        return
-      } else {
-        DAGNode.create(Buffer.from(obj.Data), obj.Links, (err, _node) => {
-          if (err) {
-            return callback(err)
-          }
-          node = _node
-          next()
-        })
-        return
-      }
-      next()
-
-      function next () {
-        dagPB.util.cid(node, (err, cid) => {
-          if (err) {
-            return callback(err)
-          }
-
-          cache.set(cid.toBaseEncodedString(), node)
-          callback(null, node)
-        })
-      }
+      callback(null, new CID(result.Hash))
     })
   })
 }

src/object/rmLink.js

@@ -1,11 +1,10 @@
 'use strict'
 
 const promisify = require('promisify-es6')
+const CID = require('cids')
 const cleanMultihash = require('../utils/clean-multihash')
 
 module.exports = (send) => {
-  const objectGet = require('./get')(send)
-
   return promisify((multihash, dLink, opts, callback) => {
     if (typeof opts === 'function') {
       callback = opts
@@ -31,7 +30,7 @@ module.exports = (send) => {
       if (err) {
         return callback(err)
       }
-      objectGet(result.Hash, { enc: 'base58' }, callback)
+      callback(null, new CID(result.Hash))
     })
   })
 }

src/object/setData.js

@@ -2,11 +2,11 @@
 
 const promisify = require('promisify-es6')
 const once = require('once')
+const CID = require('cids')
 const cleanMultihash = require('../utils/clean-multihash')
 const SendOneFile = require('../utils/send-one-file')
 
 module.exports = (send) => {
-  const objectGet = require('./get')(send)
   const sendOneFile = SendOneFile(send, 'object/patch/set-data')
 
   return promisify((multihash, data, opts, _callback) => {
@@ -29,7 +29,7 @@ module.exports = (send) => {
       if (err) {
         return callback(err)
       }
-      objectGet(result.Hash, { enc: 'base58' }, callback)
+      callback(null, new CID(result.Hash))
     })
   })
 }