77 lines
2.8 KiB
HTML
77 lines
2.8 KiB
HTML
<html>
|
|
<head>
|
|
<meta charset="utf-8">
|
|
<meta name="viewport" content="width=device-width, initial-scale=1">
|
|
<style type="text/css">
|
|
pre {
|
|
font-family: "courier";
|
|
display: block;
|
|
white-space: pre;
|
|
}
|
|
</style>
|
|
</head>
|
|
<body>
|
|
<script type="text/javascript">
|
|
function encodeNumber(n) {
|
|
const a = (n & 0xFFFF);
|
|
const b = (n & 0xFFFF0000) >> 16;
|
|
const c = (n & 0xFFFF00000000) >> 32;
|
|
const d = (n & 0xFFFF000000000000) >> 48;
|
|
return String.fromCharCode(a, b, c, d);
|
|
}
|
|
function formatArg(a) {
|
|
if (typeof a === "string") {
|
|
return `"${a}"`;
|
|
}
|
|
if (Array.isArray(a)) {
|
|
return `[${a.map(formatArg)}]`;
|
|
}
|
|
return a+"";
|
|
}
|
|
function cmp(a, b) {
|
|
let value;
|
|
try {
|
|
const result = indexedDB.cmp(encodeNumber(a), encodeNumber(b));
|
|
if (result < 0) {
|
|
value = "a < b";
|
|
} else if (result === 0) {
|
|
value = "a = b";
|
|
} else if (result > 0) {
|
|
value = "a > b";
|
|
}
|
|
} catch(err) {
|
|
value = err.message;
|
|
}
|
|
return `cmp(${formatArg(a)},\n ${formatArg(b)}): ${value}`;
|
|
}
|
|
|
|
try {
|
|
const tests = [
|
|
(cmp) => cmp(Number.MIN_SAFE_INTEGER, Number.MAX_SAFE_INTEGER),
|
|
(cmp) => cmp([Number.MIN_SAFE_INTEGER], [Number.MAX_SAFE_INTEGER]),
|
|
// see https://stackoverflow.com/questions/28413947/space-efficient-way-to-encode-numbers-as-sortable-strings
|
|
// need to encode numbers with base 256 and zero padded at start
|
|
// should still fit in 8 bytes then?
|
|
(cmp) => cmp("foo-9", "foo-10000"),
|
|
(cmp) => cmp("foo-\u0000", "foo-\uFFFF"),
|
|
(cmp) => cmp("foo-\u0000", "foo-0"),
|
|
(cmp) => cmp("foo-" + Number.MAX_SAFE_INTEGER, "foo-\uFFFF"),
|
|
(cmp) => cmp("!abc:host.tld,"+Number.MIN_SAFE_INTEGER, "!abc:host.tld,"+(Number.MIN_SAFE_INTEGER + 1)),
|
|
(cmp) => cmp("!abc:host.tld,"+0, "!abc:host.tld,"+(Number.MAX_SAFE_INTEGER)),
|
|
(cmp) => cmp("!abc:host.tld,"+Math.floor(Number.MAX_SAFE_INTEGER / 2), "!abc:host.tld,"+(Number.MAX_SAFE_INTEGER)),
|
|
];
|
|
|
|
for (const fn of tests) {
|
|
const txt = document.createTextNode(fn(cmp));
|
|
const p = document.createElement("pre");
|
|
p.appendChild(txt);
|
|
document.body.appendChild(p);
|
|
}
|
|
} catch(err) {
|
|
alert(err.message);
|
|
}
|
|
</script>
|
|
</body>
|
|
</html>
|
|
|