@ -6,9 +6,12 @@
package views
import (
"bytes"
"encoding/json"
"errors"
"maps"
"go4.org/mem"
)
func unmarshalSliceFromJSON [ T any ] ( b [ ] byte , x * [ ] T ) error {
@ -21,6 +24,83 @@ func unmarshalSliceFromJSON[T any](b []byte, x *[]T) error {
return json . Unmarshal ( b , x )
}
// ByteSlice is a read-only accessor for types that are backed by a []byte.
type ByteSlice [ T ~ [ ] byte ] struct {
// ж is the underlying mutable value, named with a hard-to-type
// character that looks pointy like a pointer.
// It is named distinctively to make you think of how dangerous it is to escape
// to callers. You must not let callers be able to mutate it.
ж T
}
// ByteSliceOf returns a ByteSlice for the provided slice.
func ByteSliceOf [ T ~ [ ] byte ] ( x T ) ByteSlice [ T ] {
return ByteSlice [ T ] { x }
}
// Len returns the length of the slice.
func ( v ByteSlice [ T ] ) Len ( ) int {
return len ( v . ж )
}
// IsNil reports whether the underlying slice is nil.
func ( v ByteSlice [ T ] ) IsNil ( ) bool {
return v . ж == nil
}
// Mem returns a read-only view of the underlying slice.
func ( v ByteSlice [ T ] ) Mem ( ) mem . RO {
return mem . B ( v . ж )
}
// Equal reports whether the underlying slice is equal to b.
func ( v ByteSlice [ T ] ) Equal ( b T ) bool {
return bytes . Equal ( v . ж , b )
}
// EqualView reports whether the underlying slice is equal to b.
func ( v ByteSlice [ T ] ) EqualView ( b ByteSlice [ T ] ) bool {
return bytes . Equal ( v . ж , b . ж )
}
// AsSlice returns a copy of the underlying slice.
func ( v ByteSlice [ T ] ) AsSlice ( ) T {
return v . AppendTo ( v . ж [ : 0 : 0 ] )
}
// AppendTo appends the underlying slice values to dst.
func ( v ByteSlice [ T ] ) AppendTo ( dst T ) T {
return append ( dst , v . ж ... )
}
// LenIter returns a slice the same length as the v.Len().
// The caller can then range over it to get the valid indexes.
// It does not allocate.
func ( v ByteSlice [ T ] ) LenIter ( ) [ ] struct { } { return make ( [ ] struct { } , len ( v . ж ) ) }
// At returns the byte at index `i` of the slice.
func ( v ByteSlice [ T ] ) At ( i int ) byte { return v . ж [ i ] }
// SliceFrom returns v[i:].
func ( v ByteSlice [ T ] ) SliceFrom ( i int ) ByteSlice [ T ] { return ByteSlice [ T ] { v . ж [ i : ] } }
// SliceTo returns v[:i]
func ( v ByteSlice [ T ] ) SliceTo ( i int ) ByteSlice [ T ] { return ByteSlice [ T ] { v . ж [ : i ] } }
// Slice returns v[i:j]
func ( v ByteSlice [ T ] ) Slice ( i , j int ) ByteSlice [ T ] { return ByteSlice [ T ] { v . ж [ i : j ] } }
// MarshalJSON implements json.Marshaler.
func ( v ByteSlice [ T ] ) MarshalJSON ( ) ( [ ] byte , error ) { return json . Marshal ( v . ж ) }
// UnmarshalJSON implements json.Unmarshaler.
func ( v * ByteSlice [ T ] ) UnmarshalJSON ( b [ ] byte ) error {
if v . ж != nil {
return errors . New ( "already initialized" )
}
return json . Unmarshal ( b , & v . ж )
}
// StructView represents the corresponding StructView of a Viewable. The concrete types are
// typically generated by tailscale.com/cmd/viewer.
type StructView [ T any ] interface {
@ -47,8 +127,9 @@ func SliceOfViews[T ViewCloner[T, V], V StructView[T]](x []T) SliceView[T, V] {
return SliceView [ T , V ] { x }
}
// SliceView is a read-only wrapper around a struct which should only be exposed
// as a View.
// SliceView wraps []T to provide accessors which return an immutable view V of
// T. It is used to provide the equivalent of SliceOf([]V) without having to
// allocate []V from []T.
type SliceView [ T ViewCloner [ T , V ] , V StructView [ T ] ] struct {
// ж is the underlying mutable value, named with a hard-to-type
// character that looks pointy like a pointer.
Maisem Ali
1 year ago
committed by