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