Auto merge of #22134 - ferjm:load_better_blob, r=jdm

Support range requests for blob URLs

- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors
- [X] These changes fix #21467 and fix #22053
- [X] There are tests for these changes.

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---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/22134)
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9 files changed, 520 insertions, 236 deletions

diff --git a/components/net/blob_loader.rs b/components/net/blob_loader.rs
deleted file mode 100644
index e6d64acc16e..00000000000
--- a/components/net/blob_loader.rs
+++ /dev/null
@@ -1,108 +0,0 @@
-/* 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 https://mozilla.org/MPL/2.0/. */
-
-use crate::filemanager_thread::FileManager;
-use headers_core::HeaderMapExt;
-use headers_ext::{ContentLength, ContentType};
-use http::header::{self, HeaderValue};
-use http::HeaderMap;
-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::{http_percent_encode, NetworkError};
-use servo_url::ServoUrl;
-
-// 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(
-    url: ServoUrl,
-    filemanager: FileManager,
-) -> Result<(HeaderMap, Vec<u8>), NetworkError> {
-    let (id, origin) = match parse_blob_url(&url) {
-        Ok((id, origin)) => (id, origin),
-        Err(()) => {
-            let e = format!("Invalid blob URL format {:?}", url);
-            return Err(NetworkError::Internal(e));
-        },
-    };
-
-    let (sender, receiver) = ipc::channel().unwrap();
-    let check_url_validity = true;
-    filemanager.read_file(sender, id, check_url_validity, origin);
-
-    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)));
-            },
-        }
-    }
-}
diff --git a/components/net/fetch/methods.rs b/components/net/fetch/methods.rs
index 70dcf4d7983..7eb963fcd5e 100644
--- a/components/net/fetch/methods.rs
+++ b/components/net/fetch/methods.rs
@@ -2,10 +2,9 @@
  * 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::data_loader::decode;
 use crate::fetch::cors_cache::CorsCache;
-use crate::filemanager_thread::FileManager;
+use crate::filemanager_thread::{fetch_file_in_chunks, FileManager, FILE_CHUNK_SIZE};
 use crate::http_loader::{determine_request_referrer, http_fetch, HttpState};
 use crate::http_loader::{set_default_accept, set_default_accept_language};
 use crate::subresource_integrity::is_response_integrity_valid;
@@ -19,6 +18,8 @@ use hyper::StatusCode;
 use ipc_channel::ipc::IpcReceiver;
 use mime::{self, Mime};
 use mime_guess::guess_mime_type;
+use net_traits::blob_url_store::{parse_blob_url, BlobURLStoreError};
+use net_traits::filemanager_thread::RelativePos;
 use net_traits::request::{CredentialsMode, Destination, Referrer, Request, RequestMode};
 use net_traits::request::{Origin, ResponseTainting, Window};
 use net_traits::response::{Response, ResponseBody, ResponseType};
@@ -26,21 +27,18 @@ use net_traits::{FetchTaskTarget, NetworkError, ReferrerPolicy, ResourceFetchTim
 use servo_url::ServoUrl;
 use std::borrow::Cow;
 use std::fs::File;
-use std::io::{BufRead, BufReader, Seek, SeekFrom};
+use std::io::{BufReader, Seek, SeekFrom};
 use std::mem;
 use std::ops::Bound;
 use std::str;
 use std::sync::atomic::Ordering;
 use std::sync::{Arc, Mutex};
-use std::thread;
 
 lazy_static! {
     static ref X_CONTENT_TYPE_OPTIONS: HeaderName =
         HeaderName::from_static("x-content-type-options");
 }
 
-const FILE_CHUNK_SIZE: usize = 32768; //32 KB
-
 pub type Target<'a> = &'a mut (dyn FetchTaskTarget + Send);
 
 pub enum Data {
@@ -492,6 +490,74 @@ fn wait_for_response(response: &mut Response, target: Target, done_chan: &mut Do
     }
 }
 
+/// Range header start and end values.
+pub enum RangeRequestBounds {
+    /// The range bounds are known and set to final values.
+    Final(RelativePos),
+    /// We need extra information to set the range bounds.
+    /// i.e. buffer or file size.
+    Pending(u64),
+}
+
+impl RangeRequestBounds {
+    pub fn get_final(&self, len: Option<u64>) -> Result<RelativePos, ()> {
+        match self {
+            RangeRequestBounds::Final(pos) => {
+                if let Some(len) = len {
+                    if pos.start <= len as i64 {
+                        return Ok(pos.clone());
+                    }
+                }
+                Err(())
+            },
+            RangeRequestBounds::Pending(offset) => Ok(RelativePos::from_opts(
+                if let Some(len) = len {
+                    Some((len - u64::min(len, *offset)) as i64)
+                } else {
+                    Some(0)
+                },
+                None,
+            )),
+        }
+    }
+}
+
+/// Get the range bounds if the `Range` header is present.
+fn get_range_request_bounds(range: Option<Range>) -> RangeRequestBounds {
+    if let Some(ref range) = range {
+        let (start, end) = match range
+            .iter()
+            .collect::<Vec<(Bound<u64>, Bound<u64>)>>()
+            .first()
+        {
+            Some(&(Bound::Included(start), Bound::Unbounded)) => (start, None),
+            Some(&(Bound::Included(start), Bound::Included(end))) => {
+                // `end` should be less or equal to `start`.
+                (start, Some(i64::max(start as i64, end as i64)))
+            },
+            Some(&(Bound::Unbounded, Bound::Included(offset))) => {
+                return RangeRequestBounds::Pending(offset);
+            },
+            _ => (0, None),
+        };
+        RangeRequestBounds::Final(RelativePos::from_opts(Some(start as i64), end))
+    } else {
+        RangeRequestBounds::Final(RelativePos::from_opts(Some(0), None))
+    }
+}
+
+fn partial_content(response: &mut Response) {
+    let reason = "Partial Content".to_owned();
+    response.status = Some((StatusCode::PARTIAL_CONTENT, reason.clone()));
+    response.raw_status = Some((StatusCode::PARTIAL_CONTENT.as_u16(), reason.into()));
+}
+
+fn range_not_satisfiable_error(response: &mut Response) {
+    let reason = "Range Not Satisfiable".to_owned();
+    response.status = Some((StatusCode::RANGE_NOT_SATISFIABLE, reason.clone()));
+    response.raw_status = Some((StatusCode::RANGE_NOT_SATISFIABLE.as_u16(), reason.into()));
+}
+
 /// [Scheme fetch](https://fetch.spec.whatwg.org#scheme-fetch)
 fn scheme_fetch(
     request: &mut Request,
@@ -537,106 +603,56 @@ fn scheme_fetch(
             }
             if let Ok(file_path) = url.to_file_path() {
                 if let Ok(file) = File::open(file_path.clone()) {
-                    let mime = guess_mime_type(file_path);
+                    // Get range bounds (if any) and try to seek to the requested offset.
+                    // If seeking fails, bail out with a NetworkError.
+                    let file_size = match file.metadata() {
+                        Ok(metadata) => Some(metadata.len()),
+                        Err(_) => None,
+                    };
 
                     let mut response =
                         Response::new(url, ResourceFetchTiming::new(request.timing_type()));
+
+                    let range_header = request.headers.typed_get::<Range>();
+                    let is_range_request = range_header.is_some();
+                    let range = match get_range_request_bounds(range_header).get_final(file_size) {
+                        Ok(range) => range,
+                        Err(_) => {
+                            range_not_satisfiable_error(&mut response);
+                            return response;
+                        },
+                    };
+                    let mut reader = BufReader::with_capacity(FILE_CHUNK_SIZE, file);
+                    if reader.seek(SeekFrom::Start(range.start as u64)).is_err() {
+                        return Response::network_error(NetworkError::Internal(
+                            "Unexpected method for file".into(),
+                        ));
+                    }
+
+                    // Set response status to 206 if Range header is present.
+                    // At this point we should have already validated the header.
+                    if is_range_request {
+                        partial_content(&mut response);
+                    }
+
+                    // Set Content-Type header.
+                    let mime = guess_mime_type(file_path);
                     response.headers.typed_insert(ContentType::from(mime));
 
+                    // Setup channel to receive cross-thread messages about the file fetch
+                    // operation.
                     let (done_sender, done_receiver) = unbounded();
                     *done_chan = Some((done_sender.clone(), done_receiver));
                     *response.body.lock().unwrap() = ResponseBody::Receiving(vec![]);
 
-                    let res_body = response.body.clone();
-
-                    let cancellation_listener = context.cancellation_listener.clone();
+                    fetch_file_in_chunks(
+                        done_sender,
+                        reader,
+                        response.body.clone(),
+                        context.cancellation_listener.clone(),
+                        range,
+                    );
 
-                    let (start, end) = if let Some(ref range) = request.headers.typed_get::<Range>()
-                    {
-                        match range
-                            .iter()
-                            .collect::<Vec<(Bound<u64>, Bound<u64>)>>()
-                            .first()
-                        {
-                            Some(&(Bound::Included(start), Bound::Unbounded)) => (start, None),
-                            Some(&(Bound::Included(start), Bound::Included(end))) => {
-                                // `end` should be less or equal to `start`.
-                                (start, Some(u64::max(start, end)))
-                            },
-                            Some(&(Bound::Unbounded, Bound::Included(offset))) => {
-                                if let Ok(metadata) = file.metadata() {
-                                    // `offset` cannot be bigger than the file size.
-                                    (metadata.len() - u64::min(metadata.len(), offset), None)
-                                } else {
-                                    (0, None)
-                                }
-                            },
-                            _ => (0, None),
-                        }
-                    } else {
-                        (0, None)
-                    };
-
-                    thread::Builder::new()
-                        .name("fetch file worker thread".to_string())
-                        .spawn(move || {
-                            let mut reader = BufReader::with_capacity(FILE_CHUNK_SIZE, file);
-                            if reader.seek(SeekFrom::Start(start)).is_err() {
-                                warn!("Fetch - could not seek to {:?}", start);
-                            }
-
-                            loop {
-                                if cancellation_listener.lock().unwrap().cancelled() {
-                                    *res_body.lock().unwrap() = ResponseBody::Done(vec![]);
-                                    let _ = done_sender.send(Data::Cancelled);
-                                    return;
-                                }
-                                let length = {
-                                    let buffer = reader.fill_buf().unwrap().to_vec();
-                                    let mut buffer_len = buffer.len();
-                                    if let ResponseBody::Receiving(ref mut body) =
-                                        *res_body.lock().unwrap()
-                                    {
-                                        let offset = usize::min(
-                                            {
-                                                if let Some(end) = end {
-                                                    let remaining_bytes =
-                                                        end as usize - start as usize - body.len();
-                                                    if remaining_bytes <= FILE_CHUNK_SIZE {
-                                                        // This is the last chunk so we set buffer
-                                                        // len to 0 to break the reading loop.
-                                                        buffer_len = 0;
-                                                        remaining_bytes
-                                                    } else {
-                                                        FILE_CHUNK_SIZE
-                                                    }
-                                                } else {
-                                                    FILE_CHUNK_SIZE
-                                                }
-                                            },
-                                            buffer.len(),
-                                        );
-                                        body.extend_from_slice(&buffer[0..offset]);
-                                        let _ = done_sender.send(Data::Payload(buffer));
-                                    }
-                                    buffer_len
-                                };
-                                if length == 0 {
-                                    let mut body = res_body.lock().unwrap();
-                                    let completed_body = match *body {
-                                        ResponseBody::Receiving(ref mut body) => {
-                                            mem::replace(body, vec![])
-                                        },
-                                        _ => vec![],
-                                    };
-                                    *body = ResponseBody::Done(completed_body);
-                                    let _ = done_sender.send(Data::Done);
-                                    break;
-                                }
-                                reader.consume(length);
-                            }
-                        })
-                        .expect("Failed to create fetch file worker thread");
                     response
                 } else {
                     Response::network_error(NetworkError::Internal("Opening file failed".into()))
@@ -649,7 +665,7 @@ fn scheme_fetch(
         },
 
         "blob" => {
-            println!("Loading blob {}", url.as_str());
+            debug!("Loading blob {}", url.as_str());
             // Step 2.
             if request.method != Method::GET {
                 return Response::network_error(NetworkError::Internal(
@@ -657,19 +673,51 @@ 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 range_header = request.headers.typed_get::<Range>();
+            let is_range_request = range_header.is_some();
+            // We will get a final version of this range once we have
+            // the length of the data backing the blob.
+            let range = get_range_request_bounds(range_header);
+
+            let (id, origin) = match parse_blob_url(&url) {
+                Ok((id, origin)) => (id, origin),
+                Err(()) => {
+                    return Response::network_error(NetworkError::Internal(
+                        "Invalid blob url".into(),
+                    ));
                 },
+            };
+
+            let mut response = Response::new(url, ResourceFetchTiming::new(request.timing_type()));
+            if is_range_request {
+                partial_content(&mut response);
             }
+
+            let (done_sender, done_receiver) = unbounded();
+            *done_chan = Some((done_sender.clone(), done_receiver));
+            *response.body.lock().unwrap() = ResponseBody::Receiving(vec![]);
+            let check_url_validity = true;
+            if let Err(err) = context.filemanager.fetch_file(
+                &done_sender,
+                context.cancellation_listener.clone(),
+                id,
+                check_url_validity,
+                origin,
+                &mut response,
+                range,
+            ) {
+                let _ = done_sender.send(Data::Done);
+                let err = match err {
+                    BlobURLStoreError::InvalidRange => {
+                        range_not_satisfiable_error(&mut response);
+                        return response;
+                    },
+                    _ => format!("{:?}", err),
+                };
+                return Response::network_error(NetworkError::Internal(err));
+            };
+
+            response
         },
 
         "ftp" => {
diff --git a/components/net/filemanager_thread.rs b/components/net/filemanager_thread.rs
index 8f0fb05b229..f0779df632b 100644
--- a/components/net/filemanager_thread.rs
+++ b/components/net/filemanager_thread.rs
@@ -2,26 +2,37 @@
  * 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::fetch::methods::{CancellationListener, Data, RangeRequestBounds};
+use crossbeam_channel::Sender;
 use embedder_traits::{EmbedderMsg, EmbedderProxy, FilterPattern};
+use headers_ext::{ContentLength, ContentType, HeaderMap, HeaderMapExt};
+use http::header::{self, HeaderValue};
 use ipc_channel::ipc::{self, IpcSender};
+use mime::{self, Mime};
 use mime_guess::guess_mime_type_opt;
 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::http_percent_encode;
+use net_traits::response::{Response, ResponseBody};
+use servo_arc::Arc as ServoArc;
 use servo_config::prefs::PREFS;
 use std::collections::HashMap;
 use std::fs::File;
-use std::io::{Read, Seek, SeekFrom};
+use std::io::{BufRead, BufReader, Read, Seek, SeekFrom};
+use std::mem;
 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, Mutex, RwLock};
 use std::thread;
 use url::Url;
 use uuid::Uuid;
 
+pub const FILE_CHUNK_SIZE: usize = 32768; //32 KB
+
 /// FileManagerStore's entry
 struct FileStoreEntry {
     /// Origin of the entry's "creator"
@@ -91,6 +102,30 @@ impl FileManager {
             .expect("Thread spawning failed");
     }
 
+    // Read a file for the Fetch implementation.
+    // It gets the required headers synchronously and reads the actual content
+    // in a separate thread.
+    pub fn fetch_file(
+        &self,
+        done_sender: &Sender<Data>,
+        cancellation_listener: Arc<Mutex<CancellationListener>>,
+        id: Uuid,
+        check_url_validity: bool,
+        origin: FileOrigin,
+        response: &mut Response,
+        range: RangeRequestBounds,
+    ) -> Result<(), BlobURLStoreError> {
+        self.store.fetch_blob_buf(
+            done_sender,
+            cancellation_listener,
+            &id,
+            &origin,
+            range,
+            check_url_validity,
+            response,
+        )
+    }
+
     pub fn promote_memory(
         &self,
         blob_buf: BlobBuf,
@@ -452,7 +487,7 @@ impl FileManagerStore {
                         None => "".to_string(),
                     };
 
-                    chunked_read(sender, &mut file, range.len(), opt_filename, type_string);
+                    read_file_in_chunks(sender, &mut file, range.len(), opt_filename, type_string);
                     Ok(())
                 } else {
                     Err(BlobURLStoreError::InvalidEntry)
@@ -489,6 +524,109 @@ impl FileManagerStore {
         )
     }
 
+    fn fetch_blob_buf(
+        &self,
+        done_sender: &Sender<Data>,
+        cancellation_listener: Arc<Mutex<CancellationListener>>,
+        id: &Uuid,
+        origin_in: &FileOrigin,
+        range: RangeRequestBounds,
+        check_url_validity: bool,
+        response: &mut Response,
+    ) -> Result<(), BlobURLStoreError> {
+        let file_impl = self.get_impl(id, origin_in, check_url_validity)?;
+        match file_impl {
+            FileImpl::Memory(buf) => {
+                let range = match range.get_final(Some(buf.size)) {
+                    Ok(range) => range,
+                    Err(_) => {
+                        return Err(BlobURLStoreError::InvalidRange);
+                    },
+                };
+
+                let range = range.to_abs_range(buf.size as usize);
+                let len = range.len() as u64;
+
+                set_headers(
+                    &mut response.headers,
+                    len,
+                    buf.type_string.parse().unwrap_or(mime::TEXT_PLAIN),
+                    /* filename */ None,
+                );
+
+                let mut bytes = vec![];
+                bytes.extend_from_slice(buf.bytes.index(range));
+
+                let _ = done_sender.send(Data::Payload(bytes));
+                let _ = done_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 file = File::open(&metadata.path)
+                    .map_err(|e| BlobURLStoreError::External(e.to_string()))?;
+
+                let range = match range.get_final(Some(metadata.size)) {
+                    Ok(range) => range,
+                    Err(_) => {
+                        return Err(BlobURLStoreError::InvalidRange);
+                    },
+                };
+
+                let mut reader = BufReader::with_capacity(FILE_CHUNK_SIZE, file);
+                if reader.seek(SeekFrom::Start(range.start as u64)).is_err() {
+                    return Err(BlobURLStoreError::External(
+                        "Unexpected method for blob".into(),
+                    ));
+                }
+
+                let filename = metadata
+                    .path
+                    .file_name()
+                    .and_then(|osstr| osstr.to_str())
+                    .map(|s| s.to_string());
+
+                set_headers(
+                    &mut response.headers,
+                    metadata.size,
+                    guess_mime_type_opt(metadata.path).unwrap_or(mime::TEXT_PLAIN),
+                    filename,
+                );
+
+                fetch_file_in_chunks(
+                    done_sender.clone(),
+                    reader,
+                    response.body.clone(),
+                    cancellation_listener,
+                    range,
+                );
+
+                Ok(())
+            },
+            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.
+                return self.fetch_blob_buf(
+                    done_sender,
+                    cancellation_listener,
+                    &parent_id,
+                    origin_in,
+                    RangeRequestBounds::Final(
+                        RelativePos::full_range().slice_inner(&inner_rel_pos),
+                    ),
+                    false,
+                    response,
+                );
+            },
+        }
+    }
+
     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) => {
@@ -609,9 +747,7 @@ fn select_files_pref_enabled() -> bool {
         .unwrap_or(false)
 }
 
-const CHUNK_SIZE: usize = 8192;
-
-fn chunked_read(
+fn read_file_in_chunks(
     sender: &IpcSender<FileManagerResult<ReadFileProgress>>,
     file: &mut File,
     size: usize,
@@ -619,7 +755,7 @@ fn chunked_read(
     type_string: String,
 ) {
     // First chunk
-    let mut buf = vec![0; CHUNK_SIZE];
+    let mut buf = vec![0; FILE_CHUNK_SIZE];
     match file.read(&mut buf) {
         Ok(n) => {
             buf.truncate(n);
@@ -639,7 +775,7 @@ fn chunked_read(
 
     // Send the remaining chunks
     loop {
-        let mut buf = vec![0; CHUNK_SIZE];
+        let mut buf = vec![0; FILE_CHUNK_SIZE];
         match file.read(&mut buf) {
             Ok(0) => {
                 let _ = sender.send(Ok(ReadFileProgress::EOF));
@@ -656,3 +792,104 @@ fn chunked_read(
         }
     }
 }
+
+pub fn fetch_file_in_chunks(
+    done_sender: Sender<Data>,
+    mut reader: BufReader<File>,
+    res_body: ServoArc<Mutex<ResponseBody>>,
+    cancellation_listener: Arc<Mutex<CancellationListener>>,
+    range: RelativePos,
+) {
+    thread::Builder::new()
+        .name("fetch file worker thread".to_string())
+        .spawn(move || {
+            loop {
+                if cancellation_listener.lock().unwrap().cancelled() {
+                    *res_body.lock().unwrap() = ResponseBody::Done(vec![]);
+                    let _ = done_sender.send(Data::Cancelled);
+                    return;
+                }
+                let length = {
+                    let buffer = reader.fill_buf().unwrap().to_vec();
+                    let mut buffer_len = buffer.len();
+                    if let ResponseBody::Receiving(ref mut body) = *res_body.lock().unwrap() {
+                        let offset = usize::min(
+                            {
+                                if let Some(end) = range.end {
+                                    // HTTP Range requests are specified with closed ranges,
+                                    // while Rust uses half-open ranges. We add +1 here so
+                                    // we don't skip the last requested byte.
+                                    let remaining_bytes =
+                                        end as usize - range.start as usize - body.len() + 1;
+                                    if remaining_bytes <= FILE_CHUNK_SIZE {
+                                        // This is the last chunk so we set buffer
+                                        // len to 0 to break the reading loop.
+                                        buffer_len = 0;
+                                        remaining_bytes
+                                    } else {
+                                        FILE_CHUNK_SIZE
+                                    }
+                                } else {
+                                    FILE_CHUNK_SIZE
+                                }
+                            },
+                            buffer.len(),
+                        );
+                        let chunk = &buffer[0..offset];
+                        body.extend_from_slice(chunk);
+                        let _ = done_sender.send(Data::Payload(chunk.to_vec()));
+                    }
+                    buffer_len
+                };
+                if length == 0 {
+                    let mut body = res_body.lock().unwrap();
+                    let completed_body = match *body {
+                        ResponseBody::Receiving(ref mut body) => mem::replace(body, vec![]),
+                        _ => vec![],
+                    };
+                    *body = ResponseBody::Done(completed_body);
+                    let _ = done_sender.send(Data::Done);
+                    break;
+                }
+                reader.consume(length);
+            }
+        })
+        .expect("Failed to create fetch file worker thread");
+}
+
+fn set_headers(headers: &mut HeaderMap, content_length: u64, mime: Mime, filename: Option<String>) {
+    headers.typed_insert(ContentLength(content_length));
+    headers.typed_insert(ContentType::from(mime.clone()));
+    let name = match filename {
+        Some(name) => name,
+        None => return,
+    };
+    let charset = mime.get_param(mime::CHARSET);
+    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
+    //                 https://github.com/hyperium/headers/issues/8
+    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(),
+    );
+}
diff --git a/components/net/lib.rs b/components/net/lib.rs
index 04d41dd8d30..d5943fa380c 100644
--- a/components/net/lib.rs
+++ b/components/net/lib.rs
@@ -17,7 +17,6 @@ extern crate profile_traits;
 #[macro_use]
 extern crate serde;
 
-mod blob_loader;
 pub mod connector;
 pub mod cookie;
 pub mod cookie_storage;
diff --git a/components/net/tests/fetch.rs b/components/net/tests/fetch.rs
index 51f25059ad1..6831ca7aa46 100644
--- a/components/net/tests/fetch.rs
+++ b/components/net/tests/fetch.rs
@@ -29,14 +29,15 @@ use mime::{self, Mime};
 use msg::constellation_msg::TEST_PIPELINE_ID;
 use net::connector::create_ssl_connector_builder;
 use net::fetch::cors_cache::CorsCache;
-use net::fetch::methods::{CancellationListener, FetchContext};
+use net::fetch::methods::{self, CancellationListener, FetchContext};
 use net::filemanager_thread::FileManager;
 use net::hsts::HstsEntry;
 use net::test::HttpState;
 use net_traits::request::{Destination, Origin, RedirectMode, Referrer, Request, RequestMode};
 use net_traits::response::{CacheState, Response, ResponseBody, ResponseType};
 use net_traits::{
-    IncludeSubdomains, NetworkError, ReferrerPolicy, ResourceFetchTiming, ResourceTimingType,
+    FetchTaskTarget, IncludeSubdomains, NetworkError, ReferrerPolicy, ResourceFetchTiming,
+    ResourceTimingType,
 };
 use servo_url::{ImmutableOrigin, ServoUrl};
 use std::fs::File;
@@ -127,7 +128,27 @@ fn test_fetch_blob() {
     use ipc_channel::ipc;
     use net_traits::blob_url_store::BlobBuf;
 
-    let mut context = new_fetch_context(None, None);
+    struct FetchResponseCollector {
+        sender: Sender<Response>,
+        buffer: Vec<u8>,
+        expected: Vec<u8>,
+    }
+
+    impl FetchTaskTarget for FetchResponseCollector {
+        fn process_request_body(&mut self, _: &Request) {}
+        fn process_request_eof(&mut self, _: &Request) {}
+        fn process_response(&mut self, _: &Response) {}
+        fn process_response_chunk(&mut self, chunk: Vec<u8>) {
+            self.buffer.extend_from_slice(chunk.as_slice());
+        }
+        /// Fired when the response is fully fetched
+        fn process_response_eof(&mut self, response: &Response) {
+            assert_eq!(self.buffer, self.expected);
+            let _ = self.sender.send(response.clone());
+        }
+    }
+
+    let context = new_fetch_context(None, None);
 
     let bytes = b"content";
     let blob_buf = BlobBuf {
@@ -147,7 +168,18 @@ fn test_fetch_blob() {
     let url = ServoUrl::parse(&format!("blob:{}{}", origin.as_str(), id.to_simple())).unwrap();
 
     let mut request = Request::new(url, Some(Origin::Origin(origin.origin())), None);
-    let fetch_response = fetch_with_context(&mut request, &mut context);
+
+    let (sender, receiver) = unbounded();
+
+    let mut target = FetchResponseCollector {
+        sender,
+        buffer: vec![],
+        expected: bytes.to_vec(),
+    };
+
+    methods::fetch(&mut request, &mut target, &context);
+
+    let fetch_response = receiver.recv().unwrap();
 
     assert!(!fetch_response.is_network_error());
 
@@ -165,7 +197,7 @@ fn test_fetch_blob() {
 
     assert_eq!(
         *fetch_response.body.lock().unwrap(),
-        ResponseBody::Done(bytes.to_vec())
+        ResponseBody::Receiving(vec![])
     );
 }
 
diff --git a/components/net_traits/blob_url_store.rs b/components/net_traits/blob_url_store.rs
index a429c6880bc..c9bb670ee29 100644
--- a/components/net_traits/blob_url_store.rs
+++ b/components/net_traits/blob_url_store.rs
@@ -9,7 +9,7 @@ use url::Url;
 use uuid::Uuid;
 
 /// Errors returned to Blob URL Store request
-#[derive(Clone, Debug, Deserialize, Serialize)]
+#[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
 pub enum BlobURLStoreError {
     /// Invalid File UUID
     InvalidFileID,
@@ -17,6 +17,8 @@ pub enum BlobURLStoreError {
     InvalidOrigin,
     /// Invalid entry content
     InvalidEntry,
+    /// Invalid range
+    InvalidRange,
     /// External error, from like file system, I/O etc.
     External(String),
 }
diff --git a/tests/wpt/mozilla/meta/MANIFEST.json b/tests/wpt/mozilla/meta/MANIFEST.json
index eddddddeb97..66b49e51489 100644
--- a/tests/wpt/mozilla/meta/MANIFEST.json
+++ b/tests/wpt/mozilla/meta/MANIFEST.json
@@ -14270,6 +14270,12 @@
      {}
     ]
    ], 
+   "mozilla/range_request_blob_url.html": [
+    [
+     "/_mozilla/mozilla/range_request_blob_url.html", 
+     {}
+    ]
+   ], 
    "mozilla/range_request_file_url.html": [
     [
      "/_mozilla/mozilla/range_request_file_url.html", 
@@ -27064,7 +27070,7 @@
    "testharness"
   ], 
   "mozilla/interfaces.html": [
-   "ad17e930ddb5bc2daecb86216efe8885ae399173",
+   "ad17e930ddb5bc2daecb86216efe8885ae399173", 
    "testharness"
   ], 
   "mozilla/interfaces.js": [
@@ -27072,7 +27078,7 @@
    "support"
   ], 
   "mozilla/interfaces.worker.js": [
-   "a5f2e00f234ea66b80e8a9bd4dbbc5433926191f",
+   "a5f2e00f234ea66b80e8a9bd4dbbc5433926191f", 
    "testharness"
   ], 
   "mozilla/invalid-this.html": [
@@ -27239,8 +27245,12 @@
    "8de03455bcb0d18258f76af20f58c14868fe1c21", 
    "testharness"
   ], 
+  "mozilla/range_request_blob_url.html": [
+   "075397620e989dafc814c0ed2bca46bd476bccf6", 
+   "testharness"
+  ], 
   "mozilla/range_request_file_url.html": [
-   "65fe13fe93d97cebc2846ff7d7deab3eb84c1787", 
+   "4fd4ddc8b1a9959e90b243795267c220d6a05f5e", 
    "testharness"
   ], 
   "mozilla/referrer-policy/OWNERS": [
@@ -32904,11 +32914,11 @@
    "testharness"
   ], 
   "mozilla/window_performance.html": [
-   "690870b7080e179481ca0255f7c30337e8b6636a",
+   "690870b7080e179481ca0255f7c30337e8b6636a", 
    "testharness"
   ], 
   "mozilla/window_performance_topLevelDomComplete.html": [
-   "50bbc2917b5ac900b5061a0b2c30b6c1fef1067e",
+   "50bbc2917b5ac900b5061a0b2c30b6c1fef1067e", 
    "testharness"
   ], 
   "mozilla/window_requestAnimationFrame.html": [
diff --git a/tests/wpt/mozilla/tests/mozilla/range_request_blob_url.html b/tests/wpt/mozilla/tests/mozilla/range_request_blob_url.html
new file mode 100644
index 00000000000..075397620e9
--- /dev/null
+++ b/tests/wpt/mozilla/tests/mozilla/range_request_blob_url.html
@@ -0,0 +1,60 @@
+<html>
+<head>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+[{
+  range: "bytes=0-",
+  status: 206,
+  expected: "abcdefghijklmnopqrstuvwxyz"
+}, {
+  range: "bytes=0-9",
+  status: 206,
+  expected: "abcdefghi"
+}, {
+  range: "bytes=1-9",
+  status: 206,
+  expected: "bcdefghi"
+}, {
+  range: "bytes=-10",
+  status: 206,
+  expected: "qrstuvwxyz"
+}, {
+  range: "bytes=0-100",
+  status: 206,
+  expected: "abcdefghijklmnopqrstuvwxyz"
+}, {
+  range: "bytes=100-",
+  status: 416,
+  expected: ""
+}, {
+  range: "bytes=-100",
+  status: 206,
+  expected: "abcdefghijklmnopqrstuvwxyz"
+}].forEach(test => {
+  promise_test(function() {
+    const abc = "abcdefghijklmnopqrstuvwxyz";
+    const blob = new Blob([abc], { "type": "text/plain" });
+    return fetch(URL.createObjectURL(blob), {
+      headers: {
+        "Range": test.range
+      }
+    })
+    .then(response => {
+      assert_equals(response.status, test.status);
+      if (response.status != 206) {
+        return "";
+      }
+      return response.text();
+    })
+    .then(response => {
+      assert_equals(response, test.expected);
+    });
+  });
+});
+
+</script>
+</head>
+</body>
+</html>
+
diff --git a/tests/wpt/mozilla/tests/mozilla/range_request_file_url.html b/tests/wpt/mozilla/tests/mozilla/range_request_file_url.html
index 65fe13fe93d..4fd4ddc8b1a 100644
--- a/tests/wpt/mozilla/tests/mozilla/range_request_file_url.html
+++ b/tests/wpt/mozilla/tests/mozilla/range_request_file_url.html
@@ -3,6 +3,10 @@
 <script src="/resources/testharness.js"></script>
 <script src="/resources/testharnessreport.js"></script>
 <script>
+
+// FIXME(ferjm) https://github.com/servo/servo/issues/22269
+//              This is not using file:// urls.
+
 [{
   file: "resources/range_small.txt",
   range: "bytes=0-",