UXKVEntry

UXKVEntry is one entry in a UXKeyValueStore’s cache.

#use <UXKit>            // or #import "UXKeyValueStore.xc"

Overview

class UXKVEntry : Object {
    u8* key;
    i32 type;     // UXKV_STRING / UXKV_INT / UXKV_BOOL
    u8* str;      // when type is STRING
    i32 num;      // when type is INT or BOOL
}

One class holds three types, and type says which field is live. A bool is stored in num rather than in a field of its own, as an integer with a narrower range.

It is cache, not storage

The entry is a copy of what the persistent store holds, kept so a repeated read costs nothing. The value itself lives wherever the platform keeps preferences: the system registry on XTOS, NSUserDefaults on macOS, an .ini under %APPDATA% on Windows.

For this reason invalidate exists, and another process writing the same key mid-run is not seen. An entry tells you what this process last knew, not what is on disk now.

Registered defaults are entries too

A registration and a set value are both entries, so hasKey cannot test only whether an entry exists. The store tracks the distinction separately, so that removeKey can revert to the registration rather than deleting it.

A UXKVEntry means the store has an answer for this key, not the user chose it.

Type is not enforced on read

Reading a key with the wrong accessor returns the field that accessor uses, whatever type says. An intFor on a string entry reads num, which the string path never filled in.

The type is normally fixed by the code that registers the default at startup, so this only goes wrong through the app’s own mistake. It matters if you change a setting’s type between versions: the stored value does not migrate, and the old value is read through the new accessor.

Fields

key

u8* key

type

i32 type       // UXKV_STRING, UXKV_INT, UXKV_BOOL

str

u8* str

Always a copy the store made. Settings come back through a shared scratch buffer that the next call overwrites, so the entry duplicates the text on the way in, using UXStr.dup.

num

i32 num

The integer, or 0/1 for a bool.

Conforms to

Inherits Object