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XC-MISC extension

Lets a long-running client ask the server which resource IDs (XIDs) are free again, so it can keep allocating IDs after exhausting its initial range.

X.require('xc-misc', (err, XCMisc) => {
    XCMisc.GetXIDRange((err, range) => {
        // {startId, count} — a contiguous block of unused XIDs
    });
});

The version is negotiated automatically while requiring; it is available as XCMisc.major / XCMisc.minor.

Requests​

GetVersion(clientMajor, clientMinor, cb)​

cb(err, [major, minor]) — the XC-MISC version the server will speak. Called automatically by X.require. QueryVersion is kept as an alias for backwards compatibility (the spec name is GetVersion).

GetXIDRange(cb)​

cb(err, {startId, count}) — the largest contiguous range of XIDs the server currently considers unused for this client. count 1 with startId 0 means no IDs are available.

GetXIDList(count, cb)​

cb(err, ids) — an array of up to count individual unused XIDs (possibly fewer when the server cannot find that many).

Events / errors​

None.

Notes​

  • The client's built-in X.AllocID allocator does not use this extension yet; XIDs released with X.ReleaseID are recycled locally. XC-MISC is the server-side mechanism for reclaiming IDs once the handshake-assigned range is exhausted.