use std::cell::RefCell;
use std::collections::HashMap;
use std::fmt::Debug;
use std::rc::Rc;
use std::sync::Arc;
use async_trait::async_trait;
use deno_core::op2;
use deno_core::parking_lot::Mutex;
use deno_core::url::Url;
use deno_core::JsBuffer;
use deno_core::OpState;
use deno_core::ToJsBuffer;
use serde::Deserialize;
use serde::Serialize;
use uuid::Uuid;
#[derive(Debug, thiserror::Error)]
pub enum BlobError {
#[error("Blob part not found")]
BlobPartNotFound,
#[error("start + len can not be larger than blob part size")]
SizeLargerThanBlobPart,
#[error("Blob URLs are not supported in this context")]
BlobURLsNotSupported,
#[error(transparent)]
Url(#[from] deno_core::url::ParseError),
}
use crate::Location;
pub type PartMap = HashMap<Uuid, Arc<dyn BlobPart + Send + Sync>>;
#[derive(Default, Debug)]
pub struct BlobStore {
parts: Mutex<PartMap>,
object_urls: Mutex<HashMap<Url, Arc<Blob>>>,
}
impl BlobStore {
pub fn insert_part(&self, part: Arc<dyn BlobPart + Send + Sync>) -> Uuid {
let id = Uuid::new_v4();
let mut parts = self.parts.lock();
parts.insert(id, part);
id
}
pub fn get_part(&self, id: &Uuid) -> Option<Arc<dyn BlobPart + Send + Sync>> {
let parts = self.parts.lock();
let part = parts.get(id);
part.cloned()
}
pub fn remove_part(
&self,
id: &Uuid,
) -> Option<Arc<dyn BlobPart + Send + Sync>> {
let mut parts = self.parts.lock();
parts.remove(id)
}
pub fn get_object_url(&self, mut url: Url) -> Option<Arc<Blob>> {
let blob_store = self.object_urls.lock();
url.set_fragment(None);
blob_store.get(&url).cloned()
}
pub fn insert_object_url(
&self,
blob: Blob,
maybe_location: Option<Url>,
) -> Url {
let origin = if let Some(location) = maybe_location {
location.origin().ascii_serialization()
} else {
"null".to_string()
};
let id = Uuid::new_v4();
let url = Url::parse(&format!("blob:{origin}/{id}")).unwrap();
let mut blob_store = self.object_urls.lock();
blob_store.insert(url.clone(), Arc::new(blob));
url
}
pub fn remove_object_url(&self, url: &Url) {
let mut blob_store = self.object_urls.lock();
blob_store.remove(url);
}
pub fn clear(&self) {
self.parts.lock().clear();
self.object_urls.lock().clear();
}
}
#[derive(Debug)]
pub struct Blob {
pub media_type: String,
pub parts: Vec<Arc<dyn BlobPart + Send + Sync>>,
}
impl Blob {
pub async fn read_all(&self) -> Vec<u8> {
let size = self.size();
let mut bytes = Vec::with_capacity(size);
for part in &self.parts {
let chunk = part.read().await;
bytes.extend_from_slice(chunk);
}
assert_eq!(bytes.len(), size);
bytes
}
fn size(&self) -> usize {
let mut total = 0;
for part in &self.parts {
total += part.size()
}
total
}
}
#[async_trait]
pub trait BlobPart: Debug {
async fn read(&self) -> &[u8];
fn size(&self) -> usize;
}
#[derive(Debug)]
pub struct InMemoryBlobPart(Vec<u8>);
impl From<Vec<u8>> for InMemoryBlobPart {
fn from(vec: Vec<u8>) -> Self {
Self(vec)
}
}
#[async_trait]
impl BlobPart for InMemoryBlobPart {
async fn read(&self) -> &[u8] {
&self.0
}
fn size(&self) -> usize {
self.0.len()
}
}
#[derive(Debug)]
pub struct SlicedBlobPart {
part: Arc<dyn BlobPart + Send + Sync>,
start: usize,
len: usize,
}
#[async_trait]
impl BlobPart for SlicedBlobPart {
async fn read(&self) -> &[u8] {
let original = self.part.read().await;
&original[self.start..self.start + self.len]
}
fn size(&self) -> usize {
self.len
}
}
#[op2]
#[serde]
pub fn op_blob_create_part(
state: &mut OpState,
#[buffer] data: JsBuffer,
) -> Uuid {
let blob_store = state.borrow::<Arc<BlobStore>>();
let part = InMemoryBlobPart(data.to_vec());
blob_store.insert_part(Arc::new(part))
}
#[derive(Deserialize)]
#[serde(rename_all = "camelCase")]
pub struct SliceOptions {
start: usize,
len: usize,
}
#[op2]
#[serde]
pub fn op_blob_slice_part(
state: &mut OpState,
#[serde] id: Uuid,
#[serde] options: SliceOptions,
) -> Result<Uuid, BlobError> {
let blob_store = state.borrow::<Arc<BlobStore>>();
let part = blob_store
.get_part(&id)
.ok_or(BlobError::BlobPartNotFound)?;
let SliceOptions { start, len } = options;
let size = part.size();
if start + len > size {
return Err(BlobError::SizeLargerThanBlobPart);
}
let sliced_part = SlicedBlobPart { part, start, len };
let id = blob_store.insert_part(Arc::new(sliced_part));
Ok(id)
}
#[op2(async)]
#[serde]
pub async fn op_blob_read_part(
state: Rc<RefCell<OpState>>,
#[serde] id: Uuid,
) -> Result<ToJsBuffer, BlobError> {
let part = {
let state = state.borrow();
let blob_store = state.borrow::<Arc<BlobStore>>();
blob_store.get_part(&id)
}
.ok_or(BlobError::BlobPartNotFound)?;
let buf = part.read().await;
Ok(ToJsBuffer::from(buf.to_vec()))
}
#[op2]
pub fn op_blob_remove_part(state: &mut OpState, #[serde] id: Uuid) {
let blob_store = state.borrow::<Arc<BlobStore>>();
blob_store.remove_part(&id);
}
#[op2]
#[string]
pub fn op_blob_create_object_url(
state: &mut OpState,
#[string] media_type: String,
#[serde] part_ids: Vec<Uuid>,
) -> Result<String, BlobError> {
let mut parts = Vec::with_capacity(part_ids.len());
let blob_store = state.borrow::<Arc<BlobStore>>();
for part_id in part_ids {
let part = blob_store
.get_part(&part_id)
.ok_or(BlobError::BlobPartNotFound)?;
parts.push(part);
}
let blob = Blob { media_type, parts };
let maybe_location = state.try_borrow::<Location>();
let blob_store = state.borrow::<Arc<BlobStore>>();
let url = blob_store
.insert_object_url(blob, maybe_location.map(|location| location.0.clone()));
Ok(url.to_string())
}
#[op2(fast)]
pub fn op_blob_revoke_object_url(
state: &mut OpState,
#[string] url: &str,
) -> Result<(), BlobError> {
let url = Url::parse(url)?;
let blob_store = state.borrow::<Arc<BlobStore>>();
blob_store.remove_object_url(&url);
Ok(())
}
#[derive(Serialize)]
pub struct ReturnBlob {
pub media_type: String,
pub parts: Vec<ReturnBlobPart>,
}
#[derive(Serialize)]
pub struct ReturnBlobPart {
pub uuid: Uuid,
pub size: usize,
}
#[op2]
#[serde]
pub fn op_blob_from_object_url(
state: &mut OpState,
#[string] url: String,
) -> Result<Option<ReturnBlob>, BlobError> {
let url = Url::parse(&url)?;
if url.scheme() != "blob" {
return Ok(None);
}
let blob_store = state
.try_borrow::<Arc<BlobStore>>()
.ok_or(BlobError::BlobURLsNotSupported)?;
if let Some(blob) = blob_store.get_object_url(url) {
let parts = blob
.parts
.iter()
.map(|part| ReturnBlobPart {
uuid: blob_store.insert_part(part.clone()),
size: part.size(),
})
.collect();
Ok(Some(ReturnBlob {
media_type: blob.media_type.clone(),
parts,
}))
} else {
Ok(None)
}
}