Php 按时间戳排序，然后将某些元素设置为第一个

鉴于此集合：

$payments = [{
    "timestamp": "2021-03-10 21:19:10",
    "amount": "100",
    "currency":"eur"
},
{
    "timestamp": "2021-03-10 22:11:10",
    "amount": "100",
    "currency":"gbp"
},
{
    "timestamp": "2021-03-10 23:19:10",
    "amount": "100",
    "currency":"usd"
},
{
    "timestamp": "2021-03-10 22:19:10",
    "amount": "100",
    "currency":"gbp"
}]

我想排序的方式，付款将按时间戳排序，但从特定的货币开始。例如gbp

$payments = [{
    "timestamp": "2021-03-10 22:11:10",
    "amount": "100",
    "currency":"gbp"
},
{
    "timestamp": "2021-03-10 22:19:10",
    "amount": "100",
    "currency":"gbp"
}
{
    "timestamp": "2021-03-10 21:19:10",
    "amount": "100",
    "currency":"eur"
},
{
    "timestamp": "2021-03-10 23:19:10",
    "amount": "100",
    "currency":"usd"
}]

现在，我正在以一种方式来做这件事，首先，在货币为gbp的情况下进行排序收集，然后我将其合并到货币为而非gbp的排序收集。像这样：

$paymentsInSameCurrency = $payments
    ->where('currency',$currency)
    ->sortBy('timestamp');

$paymentsInDifferentCurrency = $payments
    ->where('currency','!=',$currency)
    ->sortBy('timestamp');

$payments = $paymentsInSameCurrency->merge($paymentsInDifferentCurrency);

---

有没有办法提高效率？

简化版可以是这样的：

$payments=$payments
->sortByDesc（\DB:：raw（“currency='$currency'）；//首先，当这是真的
->排序方式（“时间戳”）；//按时间戳进行二级排序