span.h File Reference

Value-type views that fold the SDK's recurring argument shapes into single parameters, keeping every function at <=3 args without a calling cost: More...

#include "common/platform/sys/syscall.h"

Go to the source code of this file.

Data Structures
struct	quic_span
	Read-only view of a byte range. More...
struct	quic_mspan
	Mutable view of a byte range. More...
struct	quic_obuf
	Growing output buffer view for variable-length results. More...

Functions
static quic_span	quic_span_of (const u8 *p, usz n)
	Make a read-only span over p[0..n).
static quic_mspan	quic_mspan_of (u8 *p, usz n)
	Make a mutable span over p[0..n).
static quic_obuf	quic_obuf_of (u8 *p, usz cap)
	Make an output buffer over p[0..cap) with len starting at 0.

Detailed Description

Value-type views that fold the SDK's recurring argument shapes into single parameters, keeping every function at <=3 args without a calling cost:

(const u8 *p, usz n) -> quic_span (by value: 16 bytes, two (u8 *p, usz n) -> quic_mspan registers under SysV, the same as the loose pair) (u8 *out, usz cap, usz *out_len)-> quic_obuf * (one register instead of three; callee fills .len)

These are views, not owners: a span never copies and never frees. The caller's buffer must stay alive for as long as the span (or anything the span was handed to) is in use. Build them with the quic_span_of / quic_mspan_of / quic_obuf_of constructors below.

Function Documentation

quic_mspan_of()

quic_mspan quic_mspan_of ( u8 * p, usz n )

inlinestatic

Make a mutable span over p[0..n).

The span borrows p; the buffer must outlive every use of the returned value. Example: quic_mspan out = quic_mspan_of(key, sizeof key);

Parameters

p	first byte of the writable range
n	number of writable bytes

Returns

the view as a value type

quic_obuf_of()

quic_obuf quic_obuf_of ( u8 * p, usz cap )

inlinestatic

Make an output buffer over p[0..cap) with len starting at 0.

The buffer borrows p; the storage must outlive every use of the returned value. Pass its address to the producing call and read .len afterwards: quic_obuf ob = quic_obuf_of(buf, sizeof buf); ... use ob.len.

Parameters

p	caller-provided storage
cap	capacity of p in bytes

Returns

the buffer view with len = 0

quic_span_of()

quic_span quic_span_of ( const u8 * p, usz n )

inlinestatic

Make a read-only span over p[0..n).

The span borrows p; the buffer must outlive every use of the returned value. Example: quic_span msg = quic_span_of(buf, buf_len);

Parameters

p	first byte of the range (may be 0 when n is 0)
n	number of readable bytes

Returns

the view as a value type