75 lines
2.3 KiB
JavaScript
75 lines
2.3 KiB
JavaScript
import { computeValue } from "../../core";
|
|
import { Lazy } from "../../lazy";
|
|
import { assert, compare, findInsertIndex, isNil, typeOf } from "../../util";
|
|
const $bucket = (collection, expr, options) => {
|
|
const bounds = [...expr.boundaries];
|
|
const defaultKey = expr.default;
|
|
const lower = bounds[0];
|
|
const upper = bounds[bounds.length - 1];
|
|
const outputExpr = expr.output || { count: { $sum: 1 } };
|
|
assert(bounds.length > 1, "$bucket must specify at least two boundaries.");
|
|
const isValid = bounds.every(
|
|
(v, i) => i === 0 || typeOf(v) === typeOf(bounds[i - 1]) && compare(v, bounds[i - 1]) > 0
|
|
);
|
|
assert(
|
|
isValid,
|
|
`$bucket: bounds must be of same type and in ascending order`
|
|
);
|
|
if (!isNil(defaultKey) && typeOf(defaultKey) === typeOf(lower)) {
|
|
assert(
|
|
compare(defaultKey, upper) >= 0 || compare(defaultKey, lower) < 0,
|
|
"$bucket 'default' expression must be out of boundaries range"
|
|
);
|
|
}
|
|
const createBuckets = () => {
|
|
const buckets = /* @__PURE__ */ new Map();
|
|
for (let i = 0; i < bounds.length - 1; i++) {
|
|
buckets.set(bounds[i], []);
|
|
}
|
|
if (!isNil(defaultKey)) buckets.set(defaultKey, []);
|
|
collection.each((obj) => {
|
|
const key = computeValue(obj, expr.groupBy, null, options);
|
|
if (isNil(key) || compare(key, lower) < 0 || compare(key, upper) >= 0) {
|
|
assert(
|
|
!isNil(defaultKey),
|
|
"$bucket require a default for out of range values"
|
|
);
|
|
buckets.get(defaultKey).push(obj);
|
|
} else {
|
|
assert(
|
|
compare(key, lower) >= 0 && compare(key, upper) < 0,
|
|
"$bucket 'groupBy' expression must resolve to a value in range of boundaries"
|
|
);
|
|
const index = findInsertIndex(bounds, key);
|
|
const boundKey = bounds[Math.max(0, index - 1)];
|
|
buckets.get(boundKey).push(obj);
|
|
}
|
|
});
|
|
bounds.pop();
|
|
if (!isNil(defaultKey)) bounds.push(defaultKey);
|
|
assert(
|
|
buckets.size === bounds.length,
|
|
"bounds and groups must be of equal size."
|
|
);
|
|
return Lazy(bounds).map((key) => {
|
|
return {
|
|
...computeValue(
|
|
buckets.get(key),
|
|
outputExpr,
|
|
null,
|
|
options
|
|
),
|
|
_id: key
|
|
};
|
|
});
|
|
};
|
|
let iterator;
|
|
return Lazy(() => {
|
|
if (!iterator) iterator = createBuckets();
|
|
return iterator.next();
|
|
});
|
|
};
|
|
export {
|
|
$bucket
|
|
};
|