@tanstack/db
Version:
A reactive client store for building super fast apps on sync
120 lines (119 loc) • 4 kB
JavaScript
;
Object.defineProperty(exports, Symbol.toStringTag, { value: "Module" });
const dbIvm = require("@tanstack/db-ivm");
const functions = require("../builder/functions.cjs");
const ir = require("../ir.cjs");
class SubsetDemandController {
constructor() {
this.states = /* @__PURE__ */ new Map();
this.warnedPlans = /* @__PURE__ */ new Set();
}
setDemand(subscription, plan, keys) {
const nextKeys = canonicalizeKeys(keys);
const previous = this.states.get(plan.id);
const hasFailedCoverage = previous?.segments.some(
(segment) => segment.state === `failed` && intersects(segment.keys, nextKeys)
);
if (previous && equalKeySets(previous.keys, nextKeys) && !hasFailedCoverage) {
return { changed: false, empty: nextKeys.size === 0, ready: true };
}
const segments = [];
for (const segment of previous?.segments ?? []) {
if (segment.state !== `failed` && intersects(segment.keys, nextKeys)) {
segments.push(segment);
continue;
}
segment.abortController.abort();
subscription.releaseSnapshot(segment.where);
}
const coveredKeys = new Set(
segments.flatMap((segment) => [...segment.keys.keys()])
);
const added = new Map(
[...nextKeys].filter(([key]) => !coveredKeys.has(key))
);
if (added.size > 0) {
segments.push(
requestSegment(
subscription,
plan,
added,
() => this.warnUnoptimized(plan)
)
);
}
if (nextKeys.size === 0) {
this.states.delete(plan.id);
} else {
this.states.set(plan.id, { keys: nextKeys, segments });
}
const activeSegments = segments.filter(
(segment) => intersects(segment.keys, nextKeys)
);
const pending = activeSegments.map((segment) => segment.ready).filter((ready) => ready instanceof Promise);
return {
changed: true,
empty: nextKeys.size === 0,
ready: pending.length > 0 ? Promise.all(pending).then(() => void 0) : true
};
}
clear() {
for (const state of this.states.values()) {
for (const segment of state.segments) segment.abortController.abort();
}
this.states.clear();
this.warnedPlans.clear();
}
warnUnoptimized(plan) {
if (this.warnedPlans.has(plan.id)) return;
this.warnedPlans.add(plan.id);
const path = plan.path.join(`.`);
console.warn(
`[TanStack DB]${plan.collectionId ? ` [${plan.collectionId}]` : ``} Join requires an index on "${path}" for efficient loading. Falling back to scanning local data. Consider creating an index on the collection with collection.createIndex((row) => row.${path}) or enable auto-indexing with autoIndex: 'eager' and a defaultIndexType.`
);
}
}
function canonicalizeKeys(keys) {
return new Map([...keys].map((key) => [dbIvm.serializeValue(key), key]));
}
function equalKeySets(left, right) {
return left.size === right.size && [...left.keys()].every((key) => right.has(key));
}
function intersects(left, right) {
return [...left.keys()].some((key) => right.has(key));
}
function requestSegment(subscription, plan, keys, onUnoptimized) {
const where = functions.inArray(new ir.PropRef(plan.path), [...keys.values()]);
const abortController = new AbortController();
const load = { ready: true };
subscription.requestSnapshot({
where,
signal: abortController.signal,
trackLoadSubsetPromise: false,
onUnoptimized,
onLoadSubsetResult: (result) => {
load.ready = result;
}
});
const ready = load.ready;
const segment = {
keys,
where,
abortController,
ready,
state: ready instanceof Promise ? `pending` : `settled`
};
if (ready instanceof Promise) {
void ready.then(
() => {
segment.state = `settled`;
},
() => {
segment.state = `failed`;
}
);
}
return segment;
}
exports.SubsetDemandController = SubsetDemandController;
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