Creating a bucket (#48)

* Spec for creating a bucket
* fix english
* Address comments

index.bs

@@ -14,6 +14,14 @@ Abstract: The Storage Buckets API provides a way for sites to organize locally s
 Markup Shorthands: css no, markdown yes
 </pre>
 
+<pre class=anchors>
+spec: storage; urlPrefix: https://storage.spec.whatwg.org/
+    type: dfn
+        text: mode; url: bucket-mode
+        text: storage bucket; url: storage-bucket
+        text: storage key; url: storage-key
+</pre>
+
 <h2 id="storage-bucket-manager">The {{StorageBucketManager}} interface</h2>
 
 <xmp class="idl">
@@ -54,6 +62,70 @@ dictionary StorageBucketOptions {
 
 <h3 id="storage-bucket-open">Creating a bucket</h3>
 
+<div algorithm>
+
+  The <dfn method for="StorageBucketManager">open(|name|, |options|)</dfn> method steps are:
+
+  1. Let |environment| be [=/this=]'s [=/relevant settings object=].
+
+  1. Let |storageKey| be the result of running [=obtain a storage key=] given |environment|.
+
+  1. If |storageKey| is failure, then [=exception/throw=] a "{{SecurityError}}" {{DOMException}} and abort these steps.
+
+  1. Let |p| be [=a new promise=].
+
+  1. Run the following steps [=in parallel=]:
+
+      1. Let |r| be the result of running [=open a bucket=] with |storageKey|, |name|, and |options|.
+
+      1. If |r| is failure, then [=reject=] |p| with a {{TypeError}} and abort these steps.
+
+      1. [=/Resolve=] |p| with |r|.
+
+  1. Return |p|.
+
+</div>
+
+<div algorithm>
+
+ To <dfn>open a bucket</dfn> for a |storageKey| given a bucket |name| and optional |options|, run the following steps:
+
+ 1. If |name| contain any character that is not [=ASCII lower alpha=], [=ASCII digit=], U+005F (_), or U+002D(-), then return failure.
+
+ 1. If |name| [=string/length=] is 0 or exceeds 64, then return failure.
+
+ 1. If |name| begins with U+005F (_) or U+002D(-), then return failure.
+
+ 1. Let |persisted| be false.
+
+ 1. If |options|["{{StorageBucketOptions/persisted}}"] is true, then:
+
+     1. Let |permission| be the result of [=/requesting permission to use=] "<code>persistent-storage</code>".
+
+     1. If |permission| is "{{PermissionState/granted}}", then set |persisted| to true.
+
+ 1. Let |quota| be |options|["{{StorageBucketOptions/quota}}"] if it exists; otherwise undefined.
+
+ 1. Let |expires| be |options|["{{StorageBucketOptions/expires}}"] if it exists; otherwise undefined.
+
+ 1. Let |bucket| be the [=/storage bucket=] named |name| in |storageKey| or null otherwise.
+
+ 1. If |bucket| is null, then:
+
+     1. Let |bucket| be a new [=/storage bucket=] with name |name|
+
+     1. Set |bucket|'s [=bucket durability|durability=] to |options|["{{StorageBucketOptions/durability}}"] if it exists.
+
+ 1. If |persisted| is true, set |bucket|'s [=/mode=] to "<code>persistent</code>".
+
+ 1. Set |bucket|'s [=bucket quota|quota=] to |quota|.
+
+ 1. Set |bucket|'s [=bucket expiration|expiration=] to |expires|.
+
+ 1. Return |bucket|.
+
+</div>
+
 When not null, {{StorageBucketOptions/durability}} is a hint to the user agent
 specifying the desired {{StorageBucket/durability}}. The user agent MAY
 create a new {{StorageBucket}} with this [=bucket durability=]. The user agent
@@ -85,6 +157,14 @@ interface StorageBucket {
 };
 </xmp>
 
+A {{StorageBucket}} has a <dfn>bucket quota</dfn>, a number-or-null, initially null.
+Specifies the upper limit of usage which can be used by the bucket. The user agent MAY further limit
+the realized storage space.
+
+A {{StorageBucket}} has a <dfn>bucket expiration</dfn>, a timestamp-or-null, initially null.
+Specifies the upper limit of a bucket lifetime. The user agent MAY clear buckets whose [=/mode=] is
+"<code>best-effort</code>" before the specified timestamp when faced with storage pressure.
+
 <h3 id="storage-bucket-durability">Durability</h3>
 
 A {{StorageBucket}} has a <dfn>bucket durability</dfn>. This reflects whether the user agent