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Fix FileAPI's refcount implementation
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@izgzhen
izgzhen committed Jul 25, 2016
1 parent 81a1e28 commit 49ed453
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Showing 3 changed files with 120 additions and 91 deletions.
62 changes: 38 additions & 24 deletions components/net/filemanager_thread.rs
View file
Expand Up @@ -178,7 +178,7 @@ impl<UI: 'static + UIProvider> FileManager<UI> {
if let Ok(id) = Uuid::parse_str(&id.0) {
spawn_named("revoke blob url".to_owned(), move || {
// Since it is revocation, unset_url_validity is true
let _ = sender.send(store.dec_ref(&id, &origin, true));
let _ = sender.send(store.set_blob_url_validity(false, &id, &origin));
})
} else {
let _ = sender.send(Err(BlobURLStoreError::InvalidFileID));
Expand All @@ -189,23 +189,16 @@ impl<UI: 'static + UIProvider> FileManager<UI> {
spawn_named("dec ref".to_owned(), move || {
// Since it is simple DecRef (possibly caused by close/drop),
// unset_url_validity is false
let _ = sender.send(store.dec_ref(&id, &origin, false));
let _ = sender.send(store.dec_ref(&id, &origin));
})
} else {
let _ = sender.send(Err(BlobURLStoreError::InvalidFileID));
}
}
FileManagerThreadMsg::IncRef(id, origin) => {
if let Ok(id) = Uuid::parse_str(&id.0) {
spawn_named("inc ref".to_owned(), move || {
let _ = store.inc_ref(&id, &origin);
})
}
}
FileManagerThreadMsg::ActivateBlobURL(id, sender, origin) => {
if let Ok(id) = Uuid::parse_str(&id.0) {
spawn_named("activate blob url".to_owned(), move || {
let _ = sender.send(store.activate_blob_url(&id, &origin));
let _ = sender.send(store.set_blob_url_validity(true, &id, &origin));
});
} else {
let _ = sender.send(Err(BlobURLStoreError::InvalidFileID));
Expand Down Expand Up @@ -287,9 +280,11 @@ impl <UI: 'static + UIProvider> FileManagerStore<UI> {
file_impl: FileImpl::Sliced(parent_id, rel_pos),
refs: AtomicUsize::new(1),
// Valid here since AddSlicedURLEntry implies URL creation
// from a BlobImpl::Sliced
is_valid_url: AtomicBool::new(true),
});

// We assume that the returned id will be held by BlobImpl::File
let _ = sender.send(Ok(SelectedFileId(new_id.simple().to_string())));
}
Err(e) => {
Expand Down Expand Up @@ -475,17 +470,12 @@ impl <UI: 'static + UIProvider> FileManagerStore<UI> {
self.get_blob_buf(&id, &origin_in, RelativePos::full_range(), check_url_validity)
}

fn dec_ref(&self, id: &Uuid, origin_in: &FileOrigin,
unset_url_validity: bool) -> Result<(), BlobURLStoreError> {
fn dec_ref(&self, id: &Uuid, origin_in: &FileOrigin) -> Result<(), BlobURLStoreError> {
let (do_remove, opt_parent_id) = match self.entries.read().unwrap().get(id) {
Some(entry) => {
if *entry.origin == *origin_in {
let old_refs = entry.refs.fetch_sub(1, Ordering::Release);

if unset_url_validity {
entry.is_valid_url.store(false, Ordering::Release);
}

if old_refs > 1 {
// not the last reference, no need to touch parent
(false, None)
Expand Down Expand Up @@ -515,7 +505,7 @@ impl <UI: 'static + UIProvider> FileManagerStore<UI> {
if let Some(parent_id) = opt_parent_id {
// unset_url_validity for parent is false since we only need
// to unset the initial requesting URL
return self.dec_ref(&parent_id, origin_in, false);
return self.dec_ref(&parent_id, origin_in);
}
}

Expand Down Expand Up @@ -543,22 +533,46 @@ impl <UI: 'static + UIProvider> FileManagerStore<UI> {
}
}

fn activate_blob_url(&self, id: &Uuid, origin_in: &FileOrigin) -> Result<(), BlobURLStoreError> {
match self.entries.read().unwrap().get(id) {
fn set_blob_url_validity(&self, validity: bool, id: &Uuid,
origin_in: &FileOrigin) -> Result<(), BlobURLStoreError> {
let (do_remove, opt_parent_id, res) = match self.entries.read().unwrap().get(id) {
Some(entry) => {
if *entry.origin == *origin_in {
entry.is_valid_url.store(true, Ordering::Release);
Ok(())
entry.is_valid_url.store(validity, Ordering::Release);

if !validity {
// Check if it is the last possible reference
// since refs only accounts for blob id holders
// and store entry id holders
let zero_refs = entry.refs.load(Ordering::Acquire) == 0;

if let FileImpl::Sliced(ref parent_id, _) = entry.file_impl {
(zero_refs, Some(parent_id.clone()), Ok(()))
} else {
(zero_refs, None, Ok(()))
}
} else {
(false, None, Ok(()))
}
} else {
Err(BlobURLStoreError::InvalidOrigin)
(false, None, Err(BlobURLStoreError::InvalidOrigin))
}
}
None => Err(BlobURLStoreError::InvalidFileID)
None => (false, None, Err(BlobURLStoreError::InvalidFileID))
};

if do_remove {
atomic::fence(Ordering::Acquire);
self.remove(id);

if let Some(parent_id) = opt_parent_id {
return self.dec_ref(&parent_id, origin_in);
}
}
res
}
}


fn select_files_pref_enabled() -> bool {
PREFS.get("dom.testing.htmlinputelement.select_files.enabled")
.as_boolean().unwrap_or(false)
Expand Down
9 changes: 3 additions & 6 deletions components/net_traits/filemanager_thread.rs
View file
Expand Up @@ -139,18 +139,15 @@ pub enum FileManagerThreadMsg {
/// as part of a valid Blob URL
AddSlicedURLEntry(SelectedFileId, RelativePos, IpcSender<Result<SelectedFileId, BlobURLStoreError>>, FileOrigin),

/// Revoke Blob URL and send back the acknowledgement
RevokeBlobURL(SelectedFileId, FileOrigin, IpcSender<Result<(), BlobURLStoreError>>),

/// Decrease reference count and send back the acknowledgement
DecRef(SelectedFileId, FileOrigin, IpcSender<Result<(), BlobURLStoreError>>),

/// Increase reference count
IncRef(SelectedFileId, FileOrigin),

/// Activate an internal FileID so it becomes valid as part of a Blob URL
ActivateBlobURL(SelectedFileId, IpcSender<Result<(), BlobURLStoreError>>, FileOrigin),

/// Revoke Blob URL and send back the acknowledgement
RevokeBlobURL(SelectedFileId, FileOrigin, IpcSender<Result<(), BlobURLStoreError>>),

/// Shut down this thread
Exit,
}
Expand Down
140 changes: 79 additions & 61 deletions components/script/dom/blob.rs
View file
Expand Up @@ -18,6 +18,7 @@ use net_traits::IpcSend;
use net_traits::blob_url_store::{BlobBuf, get_blob_origin};
use net_traits::filemanager_thread::{FileManagerThreadMsg, SelectedFileId, RelativePos};
use std::cell::Cell;
use std::mem;
use std::ops::Index;
use std::path::PathBuf;
use uuid::Uuid;
Expand All @@ -26,7 +27,7 @@ use uuid::Uuid;
#[derive(JSTraceable)]
pub struct FileBlob {
id: SelectedFileId,
name: PathBuf,
name: Option<PathBuf>,
cache: DOMRefCell<Option<Vec<u8>>>,
size: u64,
}
Expand Down Expand Up @@ -57,7 +58,7 @@ impl BlobImpl {
pub fn new_from_file(file_id: SelectedFileId, name: PathBuf, size: u64) -> BlobImpl {
BlobImpl::File(FileBlob {
id: file_id,
name: name,
name: Some(name),
cache: DOMRefCell::new(None),
size: size,
})
Expand Down Expand Up @@ -98,9 +99,7 @@ impl Blob {
relativeContentType: DOMString) -> Root<Blob> {
let global = parent.global();
let blob_impl = match *parent.blob_impl.borrow() {
BlobImpl::File(ref f) => {
inc_ref_id(global.r(), f.id.clone());

BlobImpl::File(_) => {
// Create new parent node
BlobImpl::Sliced(JS::from_ref(parent), rel_pos)
}
Expand All @@ -110,13 +109,7 @@ impl Blob {
}
BlobImpl::Sliced(ref grandparent, ref old_rel_pos) => {
// Adjust the slicing position, using same parent
let new_rel_pos = old_rel_pos.slice_inner(&rel_pos);

if let BlobImpl::File(ref f) = *grandparent.blob_impl.borrow() {
inc_ref_id(global.r(), f.id.clone());
}

BlobImpl::Sliced(grandparent.clone(), new_rel_pos)
BlobImpl::Sliced(grandparent.clone(), old_rel_pos.slice_inner(&rel_pos))
}
};

Expand Down Expand Up @@ -173,71 +166,89 @@ impl Blob {
/// Get a FileID representing the Blob content,
/// used by URL.createObjectURL
pub fn get_blob_url_id(&self) -> SelectedFileId {
match *self.blob_impl.borrow() {
BlobImpl::File(ref f) => {
let global = self.global();
let origin = get_blob_origin(&global.r().get_url());
let filemanager = global.r().resource_threads().sender();
let (tx, rx) = ipc::channel().unwrap();

let _ = filemanager.send(FileManagerThreadMsg::ActivateBlobURL(f.id.clone(), tx, origin.clone()));

match rx.recv().unwrap() {
Ok(_) => f.id.clone(),
Err(_) => SelectedFileId(Uuid::new_v4().simple().to_string()) // Return a dummy id on error
}
}
BlobImpl::Memory(ref slice) => {
self.promote(slice, true)
}
let opt_sliced_parent = match *self.blob_impl.borrow() {
BlobImpl::Sliced(ref parent, ref rel_pos) => {
match *parent.blob_impl.borrow() {
BlobImpl::Sliced(_, _) => {
debug!("Sliced can't have a sliced parent");
// Return dummy id
SelectedFileId(Uuid::new_v4().simple().to_string())
}
BlobImpl::File(ref f) =>
self.create_sliced_url_id(&f.id, rel_pos),
BlobImpl::Memory(ref bytes) => {
let parent_id = parent.promote(bytes, false);
*self.blob_impl.borrow_mut() = BlobImpl::Sliced(parent.clone(), rel_pos.clone());
self.create_sliced_url_id(&parent_id, rel_pos)
}
}
Some((parent.promote(/* set_valid is */ false), rel_pos.clone(), parent.Size()))
}
_ => None
};

match opt_sliced_parent {
Some((parent_id, rel_pos, size)) => self.create_sliced_url_id(&parent_id, &rel_pos, size),
None => self.promote(/* set_valid is */ true),
}
}

/// Promite memory-based Blob to file-based,
/// The bytes in data slice will be transferred to file manager thread.
/// Promote non-Slice blob:
/// 1. Memory-based: The bytes in data slice will be transferred to file manager thread.
/// 2. File-based: Activation
/// Depending on set_valid, the returned FileID can be part of
/// valid or invalid Blob URL.
fn promote(&self, bytes: &[u8], set_valid: bool) -> SelectedFileId {
fn promote(&self, set_valid: bool) -> SelectedFileId {
let mut bytes = vec![];

match *self.blob_impl.borrow_mut() {
BlobImpl::Sliced(_, _) => {
debug!("Sliced can't have a sliced parent");
// Return dummy id
return SelectedFileId(Uuid::new_v4().simple().to_string());
}
BlobImpl::File(ref f) => {
if set_valid {
let global = self.global();
let origin = get_blob_origin(&global.r().get_url());
let filemanager = global.r().resource_threads().sender();
let (tx, rx) = ipc::channel().unwrap();

let msg = FileManagerThreadMsg::ActivateBlobURL(f.id.clone(), tx, origin.clone());
let _ = filemanager.send(msg);

match rx.recv().unwrap() {
Ok(_) => return f.id.clone(),
// Return a dummy id on error
Err(_) => return SelectedFileId(Uuid::new_v4().simple().to_string())
}
} else {
// no need to activate
return f.id.clone();
}
}
BlobImpl::Memory(ref mut bytes_in) => mem::swap(bytes_in, &mut bytes),
};

let global = self.global();
let origin = get_blob_origin(&global.r().get_url());
let filemanager = global.r().resource_threads().sender();

let blob_buf = BlobBuf {
filename: None,
type_string: self.typeString.clone(),
size: self.Size(),
size: bytes.len() as u64,
bytes: bytes.to_vec(),
};

let (tx, rx) = ipc::channel().unwrap();
let _ = filemanager.send(FileManagerThreadMsg::PromoteMemory(blob_buf, set_valid, tx, origin.clone()));

match rx.recv().unwrap() {
Ok(new_id) => SelectedFileId(new_id.0),
Ok(id) => {
let id = SelectedFileId(id.0);
*self.blob_impl.borrow_mut() = BlobImpl::File(FileBlob {
id: id.clone(),
name: None,
cache: DOMRefCell::new(Some(bytes.to_vec())),
size: bytes.len() as u64,
});
id
}
// Dummy id
Err(_) => SelectedFileId(Uuid::new_v4().simple().to_string()),
}
}

/// Get a FileID representing sliced parent-blob content
fn create_sliced_url_id(&self, parent_id: &SelectedFileId,
rel_pos: &RelativePos) -> SelectedFileId {
rel_pos: &RelativePos, parent_len: u64) -> SelectedFileId {
let global = self.global();

let origin = get_blob_origin(&global.r().get_url());
Expand All @@ -248,10 +259,25 @@ impl Blob {
rel_pos.clone(),
tx, origin.clone());
let _ = filemanager.send(msg);
let new_id = rx.recv().unwrap().unwrap();

// Return the indirect id reference
SelectedFileId(new_id.0)
match rx.recv().expect("File manager thread is down") {
Ok(new_id) => {
let new_id = SelectedFileId(new_id.0);

*self.blob_impl.borrow_mut() = BlobImpl::File(FileBlob {
id: new_id.clone(),
name: None,
cache: DOMRefCell::new(None),
size: rel_pos.to_abs_range(parent_len as usize).len() as u64,
});

// Return the indirect id reference
new_id
}
Err(_) => {
// Return dummy id
SelectedFileId(Uuid::new_v4().simple().to_string())
}
}
}

/// Cleanups at the time of destruction/closing
Expand Down Expand Up @@ -380,11 +406,3 @@ fn is_ascii_printable(string: &str) -> bool {
// https://w3c.github.io/FileAPI/#constructorBlob
string.chars().all(|c| c >= '\x20' && c <= '\x7E')
}

/// Bump the reference counter in file manager thread
fn inc_ref_id(global: GlobalRef, id: SelectedFileId) {
let file_manager = global.filemanager_thread();
let origin = get_blob_origin(&global.get_url());
let msg = FileManagerThreadMsg::IncRef(id, origin);
let _ = file_manager.send(msg);
}

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