Function preadv [src]
Prototype
pub fn preadv(self: File, iovecs: []const posix.iovec, offset: u64) PReadError!usize Parameters
self: Fileiovecs: []const posix.iovecoffset: u64 Possible Errors
In WASI, this error occurs when the file descriptor does not hold the required rights to read from it.
reading a timerfd with CANCEL_ON_SET will lead to this error when the clock goes through a discontinuous change
Unable to read file due to lock.
This error occurs in Linux if the process to be read from no longer exists.
The Operating System returned an undocumented error code.
This error is in theory not possible, but it would be better to handle this error than to invoke undefined behavior.
When this error code is observed, it usually means the Zig Standard Library needs a small patch to add the error code to the error set for the respective function.
This error occurs when no global event loop is configured, and reading from the file descriptor would block.
Source
pub fn preadv(self: File, iovecs: []const posix.iovec, offset: u64) PReadError!usize {
if (is_windows) {
// TODO improve this to use ReadFileScatter
if (iovecs.len == 0) return @as(usize, 0);
const first = iovecs[0];
return windows.ReadFile(self.handle, first.base[0..first.len], offset);
}
return posix.preadv(self.handle, iovecs, offset);
}