cunning burrow
i just want to be able to readItem() T and writeItem(T). seems like maybe the answer for dynamic would be to use Io.Writer.Allocating and mem.toBytes() or other similar methods from mem? and then for static use a Io.Writer.Fixed?
i haven't been following the Io changes too closely. is there a generic LinearFifo replacement already or in the works?
i know i could use an array list but was hesitant since orderedRemove(0) is O(N)
and i'm hoping for something thats more efficient.
light egret
if your not using the reader/writer it still works due to zigs lazy evaluation
cunning burrow
you mean LinearFifo still works? i'm using 0.15.0-dev.1149+4e6a04929 and its been removed.
cunning burrow
i guess you're right. anyway i think LinearFifo will be removed soon.
and if thats the case, i'd prefer to use something else.
its gone in this branch at least https://github.com/ziglang/zig/tree/wrangle-writer-buffering/lib/std
light egret
you can just copy the implementation and update the parts that break
cunning burrow
thats not what i want to do. thanks
i'm more curious about learning to use the new Io api to do this.
elfin kiln
isn't the new way reader.takeStruct(T, .endian) ?
cunning burrow
hmm maybe. likely i need to sit down and just trial and error try to implement some of this stuff to learn more.
that works for structs. but they need to have well defined memory layout i think. and then i'd need to use takeInt(T) if that exists.
but i'm still looking for ideas if anyone has them. and hoping for news when/if std will get a generic ring buffer.
tired monolith
Not sure I have much value to add here, but I am also confused with what replaces std.fifo.LinearFifo. The release notes say std.io.Writer and std.io.Reader are ring buffers but looking at the API I don't see how I replace what I had.
https://ziglang.org/download/0.15.1/release-notes.html#Ring-Buffers
finite onyx
Not sure I have much value to add here, but I am also confused with what replace...
Just from that link, perhaps a glance at the zstd code might help you see how to update
Similarly, std.RingBuffer is removed since it was only used by the zstd implementation which has been upgraded to use New std.Io.Writer and std.Io.Reader API.
Thinking about it, I think if you wanted to write some data to somewhere and then do something with it you can call .buffered() on something to get what you wrote
The writer I'm assuming?
What did you have before?
tired monolith
Here's where I was using LinearFifo:
event_queue: std.fifo.LinearFifo(sdl3.events.Event, .{ .Static = event_queue_size }),
frame_times: std.fifo.LinearFifo(u64, .{ .Static = frame_time_logging_interval }),
...
var paint_total: u64 = 0;
while (app_state.frame_times.readItem()) |interval| {
paint_total += interval;
}
...
app_state.frame_times.writeItemAssumeCapacity(frame_time);
So a queue right?
tired monolith
Yeah
finite onyx
While I too am unclear on how exactly you would use Writer as specifically a RING buffer, a queue I think is possible via Writer.Allocating or Writer.fixed(&buf).
Haven't tried it though
tired monolith
Okay ty for the tips! I'll take a look at those and post back if I get something working
tough crypt
maybe with a fixed writer and a fixed reader on its buffer?? but the seek positions wouldn’t move right
elfin kiln
i mean you could always copy it into your project
tired monolith
First draft 😆 :
var w = std.io.Writer.fixed(&frame_time_buffer);
...
const frame_time = sdl3.timer.getNanosecondsSinceInit() - current_ns_since_init;
// RingBuffer
w.writeInt(u64, frame_time, .little) catch |err| switch (err) {
error.WriteFailed => {
w.end = 0;
},
};
try w.flush();
Is this dumb or reasonable?:
// RingBuffer
if (w.end + @sizeOf(u64) >= frame_time_buffer.len) {
w.end = 0;
}
try w.writeInt(u64, frame_time, .little);
can't you get that with a []u64 and an index?
tired monolith
can't you get that with a ``[]u64`` and an index?
Yeah, that's what I did originally, then I discovered std.fifo.LinearFifo and it removed the responsibility of me having to worry about wrapping around, I just wrote and it did that part. My frame time example is dumb since it's easy to just use frame % frame_time_buffer.len, but the events are nice to have as a ring buffer or deque.
I think I'm just confused since RingBuffers are called out explicitly (in https://ziglang.org/download/0.15.1/release-notes.html#New-stdIoWriter-and-stdIoReader-API), it's mentioned how the std had like 10 of them, so I assumed there's a replacement. Or if there's not, and this is something we need to do, I'd like to know that is the direction of the language.
Maybe it's being cheeky?
elfin kiln
There’s a Deque PR that might be the future story
cunning burrow
its here incase anyone wants to follow https://github.com/ziglang/zig/pull/24968. i was thinking about suggesting to add Io.Reader/Writer to this. not sure how welcome that would as is be since this only supports push/popping one item at a time and lacks something like pushSliceFront(items) which might make adding a Writer api more efficient.
but i did manage go get isaac to add iterator() and at() methods.