Chunked ReadFile from file manager

This commit is contained in:
Zhen Zhang 2016-07-24 11:37:34 +02:00
parent 2de3b119a9
commit 9c8ebd3ce1
7 changed files with 163 additions and 57 deletions

View file

@ -6,7 +6,8 @@ use ipc_channel::ipc::{self, IpcReceiver, IpcSender};
use mime_guess::guess_mime_type_opt;
use net_traits::blob_url_store::{BlobBuf, BlobURLStoreError};
use net_traits::filemanager_thread::{FileManagerThreadMsg, FileManagerResult, FilterPattern, FileOrigin};
use net_traits::filemanager_thread::{SelectedFile, RelativePos, FileManagerThreadError, SelectedFileId};
use net_traits::filemanager_thread::{SelectedFile, RelativePos, FileManagerThreadError};
use net_traits::filemanager_thread::{SelectedFileId, ReadFileProgress};
use std::collections::HashMap;
use std::fs::File;
use std::io::{Read, Seek, SeekFrom};
@ -156,11 +157,8 @@ impl<UI: 'static + UIProvider> FileManager<UI> {
}
FileManagerThreadMsg::ReadFile(sender, id, check_url_validity, origin) => {
spawn_named("read file".to_owned(), move || {
match store.try_read_file(id, check_url_validity, origin) {
Ok(buffer) => { let _ = sender.send(Ok(buffer)); }
Err(e) => {
let _ = sender.send(Err(FileManagerThreadError::BlobURLStoreError(e)));
}
if let Err(e) = store.try_read_file(sender.clone(), id, check_url_validity, origin) {
let _ = sender.send(Err(FileManagerThreadError::BlobURLStoreError(e)));
}
})
}
@ -370,8 +368,8 @@ impl <UI: 'static + UIProvider> FileManagerStore<UI> {
fn create_entry(&self, file_path: &Path, origin: &str) -> Result<SelectedFile, FileManagerThreadError> {
use net_traits::filemanager_thread::FileManagerThreadError::FileSystemError;
let handler = try!(File::open(file_path).map_err(|e| FileSystemError(e.to_string())));
let metadata = try!(handler.metadata().map_err(|e| FileSystemError(e.to_string())));
let file = try!(File::open(file_path).map_err(|e| FileSystemError(e.to_string())));
let metadata = try!(file.metadata().map_err(|e| FileSystemError(e.to_string())));
let modified = try!(metadata.modified().map_err(|e| FileSystemError(e.to_string())));
let elapsed = try!(modified.elapsed().map_err(|e| FileSystemError(e.to_string())));
// Unix Epoch: https://doc.servo.org/std/time/constant.UNIX_EPOCH.html
@ -410,22 +408,28 @@ impl <UI: 'static + UIProvider> FileManagerStore<UI> {
})
}
fn get_blob_buf(&self, id: &Uuid, origin_in: &FileOrigin, rel_pos: RelativePos,
check_url_validity: bool) -> Result<BlobBuf, BlobURLStoreError> {
fn get_blob_buf(&self, sender: IpcSender<FileManagerResult<ReadFileProgress>>,
id: &Uuid, origin_in: &FileOrigin, rel_pos: RelativePos,
check_url_validity: bool) -> Result<(), BlobURLStoreError> {
let file_impl = try!(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);
Ok(BlobBuf {
let buf = BlobBuf {
filename: None,
type_string: buf.type_string,
size: range.len() as u64,
bytes: buf.bytes.index(range).to_vec(),
})
};
let _ = sender.send(Ok(ReadFileProgress::Meta(buf)));
let _ = sender.send(Ok(ReadFileProgress::EOF));
Ok(())
}
FileImpl::MetaDataOnly(metadata) => {
/* XXX: Snapshot state check (optional) https://w3c.github.io/FileAPI/#snapshot-state.
Concretely, here we create another handler, and this handler might not
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.
*/
@ -437,25 +441,19 @@ impl <UI: 'static + UIProvider> FileManagerStore<UI> {
let mime = guess_mime_type_opt(metadata.path.clone());
let range = rel_pos.to_abs_range(metadata.size as usize);
let mut handler = try!(File::open(&metadata.path)
let mut file = try!(File::open(&metadata.path)
.map_err(|e| BlobURLStoreError::External(e.to_string())));
let seeked_start = try!(handler.seek(SeekFrom::Start(range.start as u64))
let seeked_start = try!(file.seek(SeekFrom::Start(range.start as u64))
.map_err(|e| BlobURLStoreError::External(e.to_string())));
if seeked_start == (range.start as u64) {
let mut bytes = vec![0; range.len()];
try!(handler.read_exact(&mut bytes)
.map_err(|e| BlobURLStoreError::External(e.to_string())));
let type_string = match mime {
Some(x) => format!("{}", x),
None => "".to_string(),
};
Ok(BlobBuf {
filename: opt_filename,
type_string: match mime {
Some(x) => format!("{}", x),
None => "".to_string(),
},
size: range.len() as u64,
bytes: bytes,
})
chunked_read(sender, &mut file, range.len(), opt_filename, type_string);
Ok(())
} else {
Err(BlobURLStoreError::InvalidEntry)
}
@ -463,16 +461,17 @@ impl <UI: 'static + UIProvider> FileManagerStore<UI> {
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.get_blob_buf(&parent_id, origin_in, rel_pos.slice_inner(&inner_rel_pos), false)
self.get_blob_buf(sender, &parent_id, origin_in, rel_pos.slice_inner(&inner_rel_pos), false)
}
}
}
// Convenient wrapper over get_blob_buf
fn try_read_file(&self, id: SelectedFileId, check_url_validity: bool,
origin_in: FileOrigin) -> Result<BlobBuf, BlobURLStoreError> {
fn try_read_file(&self, sender: IpcSender<FileManagerResult<ReadFileProgress>>,
id: SelectedFileId, check_url_validity: bool,
origin_in: FileOrigin) -> Result<(), BlobURLStoreError> {
let id = try!(Uuid::parse_str(&id.0).map_err(|_| BlobURLStoreError::InvalidFileID));
self.get_blob_buf(&id, &origin_in, RelativePos::full_range(), check_url_validity)
self.get_blob_buf(sender, &id, &origin_in, RelativePos::full_range(), check_url_validity)
}
fn dec_ref(&self, id: &Uuid, origin_in: &FileOrigin,
@ -563,3 +562,46 @@ fn select_files_pref_enabled() -> bool {
PREFS.get("dom.testing.htmlinputelement.select_files.enabled")
.as_boolean().unwrap_or(false)
}
const CHUNK_SIZE: usize = 8192;
fn chunked_read(sender: IpcSender<FileManagerResult<ReadFileProgress>>,
file: &mut File, size: usize, opt_filename: Option<String>, type_string: String) {
// 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,
};
let _ = sender.send(Ok(ReadFileProgress::Meta(blob_buf)));
}
Err(e) => {
let _ = sender.send(Err(FileManagerThreadError::FileSystemError(e.to_string())));
return;
}
}
// Send the remaining chunks
loop {
let mut buf = vec![0; CHUNK_SIZE];
match file.read(&mut buf) {
Ok(0) => {
let _ = sender.send(Ok(ReadFileProgress::EOF));
return;
}
Ok(n) => {
buf.truncate(n);
let _ = sender.send(Ok(ReadFileProgress::Partial(buf)));
}
Err(e) => {
let _ = sender.send(Err(FileManagerThreadError::FileSystemError(e.to_string())));
return;
}
}
}
}