Zig 0.17.0-dev (Split by item)

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fileReadPositional

Uring.fileReadPositional

fn fileReadPositional(
    userdata: ?*anyopaque,
    file: File,
    data: []const []u8,
    offset: u64,
) File.ReadPositionalError!usize

File

lib/std/Io/Uring.zig:3715

Code

fn fileReadPositional(
    userdata: ?*anyopaque,
    file: File,
    data: []const []u8,
    offset: u64,
) File.ReadPositionalError!usize {
    const ev: *Evented = @ptrCast(@alignCast(userdata));

    var iovecs_buffer: [max_iovecs_len]iovec = undefined;
    var i: usize = 0;
    for (data) |buf| {
        if (iovecs_buffer.len - i == 0) break;
        if (buf.len > 0) {
            iovecs_buffer[i] = .{ .base = buf.ptr, .len = buf.len };
            i += 1;
        }
    }
    if (i == 0) return 0;
    const dest = iovecs_buffer[0..i];
    assert(dest[0].len > 0);

    var cancel_region: CancelRegion = .init();
    defer cancel_region.deinit();
    return ev.preadv(&cancel_region, file.handle, dest, offset) catch |err| switch (err) {
        error.SocketUnconnected => return errnoBug(.NOTCONN), // not a socket
        error.ConnectionResetByPeer => return errnoBug(.CONNRESET), // not a socket
        else => |e| return e,
    };
}