mirrors/serenity
1
0
Fork 0
mirror of https://github.com/SerenityOS/serenity.git synced 2025-01-23 09:51:57 -05:00
Code Issues Projects Releases Packages Wiki Activity

Kernel: Add Inode::read_until_filled_or_end

Browse source 
The existing `read_entire` is quite slow due to allocating and copying
multiple times, but it is simultaneously quite hard to get rid of in a
single step. As a replacement, add a new function that reads as much as
possible directly into a user-provided buffer.
This commit is contained in:
Tim Schumacher 2023-04-16 18:48:38 +02:00 • committed by Linus Groh
parent c403f8e92c
commit acd8c8dba4
2 changed files with 16 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

15
Kernel/FileSystem/Inode.cpp
View file

@ -118,6 +118,21 @@ ErrorOr<size_t> Inode::read_bytes(off_t offset, size_t length, UserOrKernelBuffe
return read_bytes_locked(offset, length, buffer, open_description);
}
ErrorOr<size_t> Inode::read_until_filled_or_end(off_t offset, size_t length, UserOrKernelBuffer buffer, OpenFileDescription* open_description) const
{
auto remaining_length = length;
while (remaining_length > 0) {
auto filled_bytes = TRY(read_bytes(offset, remaining_length, buffer, open_description));
if (filled_bytes == 0)
break;
offset += filled_bytes;
remaining_length -= filled_bytes;
}
return length - remaining_length;
}
ErrorOr<void> Inode::update_timestamps([[maybe_unused]] Optional<Time> atime, [[maybe_unused]] Optional<Time> ctime, [[maybe_unused]] Optional<Time> mtime)
{
return ENOTIMPL;

1
Kernel/FileSystem/Inode.h
View file

@ -57,6 +57,7 @@ public:
ErrorOr<size_t> write_bytes(off_t, size_t, UserOrKernelBuffer const& data, OpenFileDescription*);
ErrorOr<size_t> read_bytes(off_t, size_t, UserOrKernelBuffer& buffer, OpenFileDescription*) const;
ErrorOr<size_t> read_until_filled_or_end(off_t, size_t, UserOrKernelBuffer buffer, OpenFileDescription*) const;
virtual ErrorOr<void> attach(OpenFileDescription&) { return {}; }
virtual void detach(OpenFileDescription&) { }