const MaxCap
MaxCap bounds a buffer so allocation stays predictable.
v0 source pure
Package ringbuffer is a fixed-capacity FIFO that overwrites its oldest entry when full, as a pure, reusable package.
View source
gno.land/p/moul/x/daily/ringbuffer/v0
Fixed-capacity FIFO that overwrites its oldest entry — New, Push, Pop,
Peek, At, Slice, Reset, Len, Cap, Full, Empty, MaxCap.
The bounded cousin of a queue, and the bound is the point: on chain an unbounded queue is an unbounded storage bill, whereas a ring buffer's cost is decided once, at construction. The right shape for "last N events", "recent messages", or any rolling window.
1import "gno.land/p/moul/x/daily/ringbuffer/v0"
2
3r := ringbuffer.New(3)
4r.Push("a"); r.Push("b"); r.Push("c")
5evicted, dropped := r.Push("d") // "a", true
6r.Slice() // ["b" "c" "d"]
Push returns what it evicted, so a rolling window never loses data
silently — the one thing this shape must not do. Backed by a flat slice with
head/length indices: no per-element allocation, no shifting on Pop. Pop and
Reset clear the vacated slots so no reference is pinned after it is logically
gone.
A zero-capacity buffer stores nothing and says so (Push hands the value
straight back), and is never reported as Full — a buffer that holds nothing
cannot be full.
Live demo: r/moul/x/daily/ringbufferdemo
· render it at /r/moul/x/daily/ringbufferdemo/v0.
Part of moul/gno-contracts — moul's versioned gno.land contracts. See the repository for the full catalog, build/test tooling, and usage.
🧪 Highly experimental — potentially vibe-coded. Not audited; may break, change, or be removed at any time. Do not use with anything of value. Full disclaimer: DISCLAIMER.
Package ringbuffer is a fixed-capacity FIFO that overwrites its oldest entry when full, as a pure, reusable package.
This is the bounded cousin of an unbounded queue, and the bound is the point: on chain an unbounded queue is an unbounded storage bill, whereas a ring buffer's cost is decided once, at construction. It is the right shape for "last N events", "recent messages", or any rolling window.
Backed by a flat slice with head/length indices — no per-element allocation, no shifting on Pop.
A live demo of this package is at r/moul/x/daily/ringbufferdemo(/r/moul/x/daily/ringbufferdemo/v0).
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type RingBuffer
structRingBuffer is a fixed-capacity FIFO of strings.
Methods on RingBuffer
func At
method on RingBufferAt returns the i-th element counting from the oldest (0 = oldest).
func Cap
method on RingBufferCap returns the capacity.
func Empty
method on RingBufferEmpty reports whether there is nothing to read.
func Full
method on RingBufferFull reports whether the next Push will overwrite.
func Len
method on RingBufferLen returns how many elements are live.
func Peek
method on RingBufferPeek returns the oldest element without removing it.
func Pop
method on RingBufferPop removes and returns the oldest element; ok is false when empty.
func Push
method on RingBufferPush appends v. When the buffer is full the OLDEST element is dropped to make room, and that element is returned with dropped=true — losing data silently is the one thing a rolling window must not do.
A zero-capacity buffer accepts nothing and reports the value straight back.
func Reset
method on RingBufferReset empties the buffer, releasing every stored reference.
func Slice
method on RingBufferSlice returns the live elements oldest-first, as an independent copy.