add Blob URL store

components/script/blob_url_store.rs

@@ -0,0 +1,59 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#![allow(dead_code)]
+
+use dom::bindings::js::JS;
+use dom::blob::Blob;
+use origin::Origin;
+use std::collections::HashMap;
+use uuid::Uuid;
+
+#[must_root]
+#[derive(JSTraceable, HeapSizeOf)]
+struct EntryPair(Origin, JS<Blob>);
+
+// HACK: to work around the HeapSizeOf of Uuid
+#[derive(PartialEq, HeapSizeOf, Eq, Hash, JSTraceable)]
+struct BlobUrlId(#[ignore_heap_size_of = "defined in uuid"] Uuid);
+
+#[must_root]
+#[derive(JSTraceable, HeapSizeOf)]
+pub struct BlobURLStore {
+    entries: HashMap<BlobUrlId, EntryPair>,
+}
+
+pub enum BlobURLStoreError {
+    InvalidKey,
+    InvalidOrigin,
+}
+
+impl BlobURLStore {
+    pub fn new() -> BlobURLStore {
+        BlobURLStore {
+            entries: HashMap::new(),
+        }
+    }
+
+    pub fn request(&self, id: Uuid, origin: &Origin) -> Result<&Blob, BlobURLStoreError> {
+        match self.entries.get(&BlobUrlId(id)) {
+            Some(ref pair) => {
+                if pair.0.same_origin(origin) {
+                    Ok(&pair.1)
+                } else {
+                    Err(BlobURLStoreError::InvalidOrigin)
+                }
+            }
+            None => Err(BlobURLStoreError::InvalidKey)
+        }
+    }
+
+    pub fn add_entry(&mut self, id: Uuid, origin: Origin, blob: &Blob) {
+        self.entries.insert(BlobUrlId(id), EntryPair(origin, JS::from_ref(blob)));
+    }
+
+    pub fn delete_entry(&mut self, id: Uuid) {
+        self.entries.remove(&BlobUrlId(id));
+    }
+}