Initial implementation of asynchronous blob url fetching

3 files changed, 171 insertions, 90 deletions

diff --git a/components/net/blob_loader.rs b/components/net/blob_loader.rs
index e6d64acc16e..50c5455808d 100644
--- a/components/net/blob_loader.rs
+++ b/components/net/blob_loader.rs
@@ -3,6 +3,7 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
 use crate::filemanager_thread::FileManager;
+use fetch::methods::DoneChannel;
 use headers_core::HeaderMapExt;
 use headers_ext::{ContentLength, ContentType};
 use http::header::{self, HeaderValue};
@@ -11,18 +12,21 @@ use ipc_channel::ipc;
 use mime::{self, Mime};
 use net_traits::blob_url_store::parse_blob_url;
 use net_traits::filemanager_thread::ReadFileProgress;
+use net_traits::response::{Response, ResponseBody};
 use net_traits::{http_percent_encode, NetworkError};
 use servo_url::ServoUrl;
+use std::sync::mpsc::channel;
 
 // TODO: Check on GET
 // https://w3c.github.io/FileAPI/#requestResponseModel
 
 /// https://fetch.spec.whatwg.org/#concept-basic-fetch (partial)
-// TODO: make async.
-pub fn load_blob_sync(
+pub fn load_blob_async(
     url: ServoUrl,
     filemanager: FileManager,
-) -> Result<(HeaderMap, Vec<u8>), NetworkError> {
+    response: &Response,
+    done_chan: &mut DoneChannel
+) -> Result<(), NetworkError> {
     let (id, origin) = match parse_blob_url(&url) {
         Ok((id, origin)) => (id, origin),
         Err(()) => {
@@ -31,78 +35,11 @@ pub fn load_blob_sync(
         },
     };
 
-    let (sender, receiver) = ipc::channel().unwrap();
+    let (sender, receiver) = channel();
+    *done_chan = Some((sender.clone(), receiver));
+    *response.body.lock().unwrap() = ResponseBody::Receiving(vec![]);
     let check_url_validity = true;
-    filemanager.read_file(sender, id, check_url_validity, origin);
+    filemanager.fetch_file(sender, id, check_url_validity, origin, response);
 
-    let blob_buf = match receiver.recv().unwrap() {
-        Ok(ReadFileProgress::Meta(blob_buf)) => blob_buf,
-        Ok(_) => {
-            return Err(NetworkError::Internal(
-                "Invalid filemanager reply".to_string(),
-            ));
-        },
-        Err(e) => {
-            return Err(NetworkError::Internal(format!("{:?}", e)));
-        },
-    };
-
-    let content_type: Mime = blob_buf.type_string.parse().unwrap_or(mime::TEXT_PLAIN);
-    let charset = content_type.get_param(mime::CHARSET);
-
-    let mut headers = HeaderMap::new();
-
-    if let Some(name) = blob_buf.filename {
-        let charset = charset
-            .map(|c| c.as_ref().into())
-            .unwrap_or("us-ascii".to_owned());
-        // TODO(eijebong): Replace this once the typed header is there
-        headers.insert(
-            header::CONTENT_DISPOSITION,
-            HeaderValue::from_bytes(
-                format!(
-                    "inline; {}",
-                    if charset.to_lowercase() == "utf-8" {
-                        format!(
-                            "filename=\"{}\"",
-                            String::from_utf8(name.as_bytes().into()).unwrap()
-                        )
-                    } else {
-                        format!(
-                            "filename*=\"{}\"''{}",
-                            charset,
-                            http_percent_encode(name.as_bytes())
-                        )
-                    }
-                )
-                .as_bytes(),
-            )
-            .unwrap(),
-        );
-    }
-
-    // Basic fetch, Step 4.
-    headers.typed_insert(ContentLength(blob_buf.size as u64));
-    // Basic fetch, Step 5.
-    headers.typed_insert(ContentType::from(content_type.clone()));
-
-    let mut bytes = blob_buf.bytes;
-    loop {
-        match receiver.recv().unwrap() {
-            Ok(ReadFileProgress::Partial(ref mut new_bytes)) => {
-                bytes.append(new_bytes);
-            },
-            Ok(ReadFileProgress::EOF) => {
-                return Ok((headers, bytes));
-            },
-            Ok(_) => {
-                return Err(NetworkError::Internal(
-                    "Invalid filemanager reply".to_string(),
-                ));
-            },
-            Err(e) => {
-                return Err(NetworkError::Internal(format!("{:?}", e)));
-            },
-        }
-    }
+    Ok(())
 }
diff --git a/components/net/fetch/methods.rs b/components/net/fetch/methods.rs
index 70dcf4d7983..67a02775369 100644
--- a/components/net/fetch/methods.rs
+++ b/components/net/fetch/methods.rs
@@ -2,7 +2,7 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
 
-use crate::blob_loader::load_blob_sync;
+use crate::blob_loader::load_blob_async;
 use crate::data_loader::decode;
 use crate::fetch::cors_cache::CorsCache;
 use crate::filemanager_thread::FileManager;
@@ -657,19 +657,11 @@ fn scheme_fetch(
                 ));
             }
 
-            match load_blob_sync(url.clone(), context.filemanager.clone()) {
-                Ok((headers, bytes)) => {
-                    let mut response =
-                        Response::new(url, ResourceFetchTiming::new(request.timing_type()));
-                    response.headers = headers;
-                    *response.body.lock().unwrap() = ResponseBody::Done(bytes);
-                    response
-                },
-                Err(e) => {
-                    debug!("Failed to load {}: {:?}", url, e);
-                    Response::network_error(e)
-                },
-            }
+            let mut response = Response::new(url, ResourceFetchTiming::new(request.timing_type()));
+
+            load_blob_async(url.clone(), context.filemanager.clone(), &response, done_chan);
+
+            response
         },
 
         "ftp" => {
diff --git a/components/net/filemanager_thread.rs b/components/net/filemanager_thread.rs
index 8f0fb05b229..0be8de815b4 100644
--- a/components/net/filemanager_thread.rs
+++ b/components/net/filemanager_thread.rs
@@ -4,12 +4,18 @@
 
 use embedder_traits::{EmbedderMsg, EmbedderProxy, FilterPattern};
 use ipc_channel::ipc::{self, IpcSender};
+use fetch::methods::Data;
+use hyper::header::{Charset, ContentLength, ContentType, Headers};
+use hyper::header::{ContentDisposition, DispositionParam, DispositionType};
+use mime::{Attr, Mime};
 use mime_guess::guess_mime_type_opt;
+use net_traits::NetworkError;
 use net_traits::blob_url_store::{BlobBuf, BlobURLStoreError};
 use net_traits::filemanager_thread::{FileManagerResult, FileManagerThreadMsg, FileOrigin};
 use net_traits::filemanager_thread::{
     FileManagerThreadError, ReadFileProgress, RelativePos, SelectedFile,
 };
+use net_traits::response::{Response, ResponseBody};
 use servo_config::prefs::PREFS;
 use std::collections::HashMap;
 use std::fs::File;
@@ -17,7 +23,7 @@ use std::io::{Read, Seek, SeekFrom};
 use std::ops::Index;
 use std::path::{Path, PathBuf};
 use std::sync::atomic::{self, AtomicBool, AtomicUsize, Ordering};
-use std::sync::{Arc, RwLock};
+use std::sync::{Arc, RwLock, Mutex, mpsc};
 use std::thread;
 use url::Url;
 use uuid::Uuid;
@@ -91,6 +97,19 @@ impl FileManager {
             .expect("Thread spawning failed");
     }
 
+    pub fn fetch_file(&self,
+                     sender: mpsc::Sender<Data>,
+                     id: Uuid,
+                     check_url_validity: bool,
+                     origin: FileOrigin,
+                     response: &Response) {
+        let store = self.store.clone();
+        let mut res_body = response.body.clone();
+        thread::Builder::new().name("read file".to_owned()).spawn(move || {
+            store.try_fetch_file(&sender, id, check_url_validity, origin, response, res_body)
+        }).expect("Thread spawning failed");
+    }
+
     pub fn promote_memory(
         &self,
         blob_buf: BlobBuf,
@@ -489,6 +508,94 @@ impl FileManagerStore {
         )
     }
 
+    fn fetch_blob_buf(&self, sender: &mpsc::Sender<Data>,
+                    id: &Uuid, origin_in: &FileOrigin, rel_pos: RelativePos,
+                    check_url_validity: bool, response: &Response, res_body: Arc<Mutex<ResponseBody>>) -> Result<(), BlobURLStoreError> {
+        let mut bytes = vec![];
+        let file_impl = self.get_impl(id, origin_in, check_url_validity)?;
+        match file_impl {
+            FileImpl::Memory(buf) => {
+                let range = rel_pos.to_abs_range(buf.size as usize);
+                let blob_buf = BlobBuf {
+                    filename: None,
+                    type_string: buf.type_string,
+                    size: range.len() as u64,
+                    bytes: buf.bytes.index(range).to_vec(),
+                };
+
+                let content_type: Mime = blob_buf.type_string.parse().unwrap_or(mime!(Text / Plain));
+                let charset = content_type.get_param(Attr::Charset);
+                let mut headers = Headers::new();
+
+                if let Some(name) = blob_buf.filename {
+                    let charset = charset.and_then(|c| c.as_str().parse().ok());
+                    headers.set(ContentDisposition {
+                        disposition: DispositionType::Inline,
+                        parameters: vec![
+                            DispositionParam::Filename(charset.unwrap_or(Charset::Us_Ascii),
+                                                       None, name.as_bytes().to_vec())
+                        ]
+                    });
+                }
+
+                headers.set(ContentLength(blob_buf.size as u64));
+                headers.set(ContentType(content_type.clone()));
+
+                bytes.extend_from_slice(&blob_buf.bytes);
+
+                response.headers = headers;
+                *res_body.lock().unwrap() = ResponseBody::Done(bytes);
+                let _ = sender.send(Data::Done);
+                Ok(())
+            }
+            FileImpl::MetaDataOnly(metadata) => {
+                /* XXX: Snapshot state check (optional) https://w3c.github.io/FileAPI/#snapshot-state.
+                        Concretely, here we create another file, and this file might not
+                        has the same underlying file state (meta-info plus content) as the time
+                        create_entry is called.
+                */
+
+                let opt_filename = metadata.path.file_name()
+                                           .and_then(|osstr| osstr.to_str())
+                                           .map(|s| s.to_string());
+
+                let mime = guess_mime_type_opt(metadata.path.clone());
+                let range = rel_pos.to_abs_range(metadata.size as usize);
+
+                let mut file = File::open(&metadata.path)
+                                   .map_err(|e| BlobURLStoreError::External(e.to_string()))?;
+                let seeked_start = file.seek(SeekFrom::Start(range.start as u64))
+                                       .map_err(|e| BlobURLStoreError::External(e.to_string()))?;
+
+                if seeked_start == (range.start as u64) {
+                    let type_string = match mime {
+                        Some(x) => format!("{}", x),
+                        None    => "".to_string(),
+                    };
+
+                    chunked_fetch(sender, &mut file, range.len(), opt_filename,
+                                 type_string, response, res_body, &mut bytes);
+                    Ok(())
+                } else {
+                    Err(BlobURLStoreError::InvalidEntry)
+                }
+            }
+            FileImpl::Sliced(parent_id, inner_rel_pos) => {
+                // Next time we don't need to check validity since
+                // we have already done that for requesting URL if necessary
+                self.fetch_blob_buf(sender, &parent_id, origin_in,
+                                  rel_pos.slice_inner(&inner_rel_pos), false, response, res_body)
+            }
+        }
+    }
+
+    fn try_fetch_file(&self, sender: &mpsc::Sender<Data>, id: Uuid, check_url_validity: bool,
+                      origin_in: FileOrigin, response: &Response, res_body: Arc<Mutex<ResponseBody>>)
+                     -> Result<(), BlobURLStoreError> {
+        self.fetch_blob_buf(sender, &id, &origin_in, RelativePos::full_range(), check_url_validity,
+            response, res_body)
+    }
+
     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) => {
@@ -656,3 +763,48 @@ fn chunked_read(
         }
     }
 }
+
+fn chunked_fetch(sender: &mpsc::Sender<Data>,
+                file: &mut File, size: usize, opt_filename: Option<String>,
+                type_string: String, response: &Response, res_body: Arc<Mutex<ResponseBody>>, bytes: &mut Vec<u8>) {
+    // First chunk
+    let mut buf = vec![0; CHUNK_SIZE];
+    match file.read(&mut buf) {
+        Ok(n) => {
+            buf.truncate(n);
+            let blob_buf = BlobBuf {
+                filename: opt_filename,
+                type_string: type_string,
+                size: size as u64,
+                bytes: buf,
+            };
+            bytes.extend_from_slice(&blob_buf.bytes);
+            let _ = sender.send(Data::Payload(blob_buf.bytes));
+        }
+        Err(_) => {
+            *response = Response::network_error(NetworkError::Internal("Opening file failed".into()));
+            return;
+        }
+    }
+
+    // Send the remaining chunks
+    loop {
+        let mut buf = vec![0; CHUNK_SIZE];
+        match file.read(&mut buf) {
+            Ok(0) => {
+                *res_body.lock().unwrap() = ResponseBody::Done(bytes.to_vec());
+                let _ = sender.send(Data::Done);
+                return;
+            }
+            Ok(n) => {
+                buf.truncate(n);
+                bytes.extend_from_slice(&buf);
+                let _ = sender.send(Data::Payload(buf));
+            }
+            Err(e) => {
+                *response = Response::network_error(NetworkError::Internal("Opening file failed".into()));
+                return;
+            }
+        }
+    }
+}