url,buffer: implement URL.createObjectURL

Signed-off-by: James M Snell <jasnell@gmail.com>

PR-URL: https://github.com/nodejs/node/pull/39693
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Bradley Farias <bradley.meck@gmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>

2 files changed, 61 insertions, 0 deletions

diff --git a/doc/api/buffer.md b/doc/api/buffer.md
index 7106d5c6b36..f419be1181a 100644
--- a/doc/api/buffer.md
+++ b/doc/api/buffer.md
@@ -4952,6 +4952,20 @@ added: v3.0.0
 
 An alias for [`buffer.constants.MAX_STRING_LENGTH`][].
 
+### `buffer.resolveObjectURL(id)`
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+* `id` {string} A `'blob:nodedata:...` URL string returned by a prior call to
+  `URL.createObjectURL()`.
+* Returns: {Blob}
+
+Resolves a `'blob:nodedata:...'` an associated {Blob} object registered using
+a prior call to `URL.createObjectURL()`.
+
 ### `buffer.transcode(source, fromEnc, toEnc)`
 <!-- YAML
 added: v7.1.0
diff --git a/doc/api/url.md b/doc/api/url.md
index 725084523df..d4b212f515d 100644
--- a/doc/api/url.md
+++ b/doc/api/url.md
@@ -608,6 +608,53 @@ console.log(JSON.stringify(myURLs));
 // Prints ["https://www.example.com/","https://test.example.org/"]
 ```
 
+#### `URL.createObjectURL(blob)`
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+* `blob` {Blob}
+* Returns: {string}
+
+Creates a `'blob:nodedata:...'` URL string that represents the given {Blob}
+object and can be used to retrieve the `Blob` later.
+
+```js
+const {
+  Blob,
+  resolveObjectURL,
+} = require('buffer');
+
+const blob = new Blob(['hello']);
+const id = URL.createObjectURL(blob);
+
+// later...
+
+const otherBlob = resolveObjectURL(id);
+console.log(otherBlob.size);
+```
+
+The data stored by the registered {Blob} will be retained in memory until
+`URL.revokeObjectURL()` is called to remove it.
+
+`Blob` objects are registered within the current thread. If using Worker
+Threads, `Blob` objects registered within one Worker will not be available
+to other workers or the main thread.
+
+#### `URL.revokeObjectURL(id)`
+<!-- YAML
+added: REPLACEME
+-->
+
+> Stability: 1 - Experimental
+
+* `id` {string} A `'blob:nodedata:...` URL string returned by a prior call to
+  `URL.createObjectURL()`.
+
+Removes the stored {Blob} identified by the given ID.
+
 ### Class: `URLSearchParams`
 <!-- YAML
 added: