@tanstack/db/dist/esm/SortedMap.js

A reactive client store for building super fast apps on sync

import { compareKeys } from "@tanstack/db-ivm";
class SortedMap {
  /**
   * Creates a new SortedMap instance
   *
   * @param comparator - Optional function to compare values for sorting.
   *                     If not provided, entries are sorted by key only.
   */
  constructor(comparator) {
    this.bT = /* @__PURE__ */ new Set();
    this.map = /* @__PURE__ */ new Map();
    this.am = [];
    this.comparator = comparator;
  }
  /**
   * Finds the index where a key-value pair should be inserted to maintain sort order.
   * Uses binary search to find the correct position based on the value (if comparator provided),
   * with key-based tie-breaking for deterministic ordering when values compare as equal.
   * If no comparator is provided, sorts by key only.
   * Runs in O(log n) time.
   *
   * @param key - The key to find position for (used as tie-breaker or primary sort when no comparator)
   * @param value - The value to compare against (only used if comparator is provided)
   * @param keys - The ordered keys to search
   * @returns The index where the key should be inserted
   */
  indexOf(key, value, keys = this.am) {
    let left = 0;
    let right = keys.length;
    if (!this.comparator) {
      while (left < right) {
        const mid = Math.floor((left + right) / 2);
        const midKey = keys[mid];
        const keyComparison = compareKeys(key, midKey);
        if (keyComparison < 0) {
          right = mid;
        } else if (keyComparison > 0) {
          left = mid + 1;
        } else {
          return mid;
        }
      }
      return left;
    }
    while (left < right) {
      const mid = Math.floor((left + right) / 2);
      const midKey = keys[mid];
      const midValue = this.map.get(midKey);
      const valueComparison = this.comparator(value, midValue);
      if (valueComparison < 0) {
        right = mid;
      } else if (valueComparison > 0) {
        left = mid + 1;
      } else {
        const keyComparison = compareKeys(key, midKey);
        if (keyComparison < 0) {
          right = mid;
        } else if (keyComparison > 0) {
          left = mid + 1;
        } else {
          return mid;
        }
      }
    }
    return left;
  }
  /**
   * Restore the ordered view after a synchronous batch of deferred writes.
   * Dirty keys leave their old slots by Set membership, so a deleted value or
   * one a sync source mutated in place cannot strand a slot. The dirty keys
   * still present are sorted and merged into the rest in one pass:
   * O(n + k log n) for k dirty keys. The merge rewrites sortedKeys in place,
   * so an open key iterator reads the restored order.
   */
  restoreOrder() {
    if (this.bT.size === 0) return;
    const keys = this.am;
    const kept = keys.filter((key) => !this.bT.has(key));
    const placed = [...this.bT].filter((key) => this.map.has(key)).sort(
      (left, right) => (this.comparator?.(this.map.get(left), this.map.get(right)) ?? 0) || compareKeys(left, right)
    );
    keys.length = 0;
    let next = 0;
    for (const key of placed) {
      const index = this.indexOf(key, this.map.get(key), kept);
      while (next < index) keys.push(kept[next++]);
      keys.push(key);
    }
    while (next < kept.length) keys.push(kept[next++]);
    this.bT.clear();
  }
  /** Removes a key's slot while its placed value is still mapped. */
  cz(key) {
    const sameKey = (candidate) => candidate === key || candidate !== candidate && key !== key;
    let index = this.indexOf(key, this.map.get(key));
    if (!sameKey(this.am[index])) {
      index = this.am.findIndex(sameKey);
    }
    this.am.splice(index, 1);
  }
  /**
   * Sets a key-value pair in the map and maintains sort order
   *
   * @param key - The key to set
   * @param value - The value to associate with the key
   * @param deferOrder - Defer ordering until restoreOrder or the next ordered read
   * @returns This SortedMap instance for chaining
   */
  set(key, value, deferOrder = false) {
    if (!this.comparator && this.map.has(key)) {
      this.map.set(key, value);
      return this;
    }
    if (deferOrder) {
      this.map.set(key, value);
      this.bT.add(key);
      return this;
    }
    this.restoreOrder();
    if (this.map.has(key)) this.cz(key);
    this.am.splice(this.indexOf(key, value), 0, key);
    this.map.set(key, value);
    return this;
  }
  /**
   * Gets a value by its key
   *
   * @param key - The key to look up
   * @returns The value associated with the key, or undefined if not found
   */
  get(key) {
    return this.map.get(key);
  }
  /**
   * Removes a key-value pair from the map
   *
   * @param key - The key to remove
   * @param deferOrder - Defer ordering until restoreOrder or the next ordered read
   * @returns True if the key was found and removed, false otherwise
   */
  delete(key, deferOrder = false) {
    if (deferOrder) {
      const deleted = this.map.delete(key);
      if (deleted) this.bT.add(key);
      return deleted;
    }
    this.restoreOrder();
    if (this.map.has(key)) this.cz(key);
    return this.map.delete(key);
  }
  /**
   * Checks if a key exists in the map
   *
   * @param key - The key to check
   * @returns True if the key exists, false otherwise
   */
  has(key) {
    return this.map.has(key);
  }
  /**
   * Removes all key-value pairs from the map
   */
  clear() {
    this.map.clear();
    this.am = [];
    this.bT.clear();
  }
  /**
   * Gets the number of key-value pairs in the map
   */
  get size() {
    return this.map.size;
  }
  /**
   * Default iterator that returns entries in sorted order
   *
   * @returns An iterator for the map's entries
   */
  *[Symbol.iterator]() {
    for (const key of this.keys()) yield [key, this.map.get(key)];
  }
  /**
   * Returns an iterator for the map's entries in sorted order
   *
   * @returns An iterator for the map's entries
   */
  entries() {
    return this[Symbol.iterator]();
  }
  /**
   * Returns an iterator for the map's keys in sorted order
   *
   * @returns An iterator for the map's keys
   */
  keys() {
    this.restoreOrder();
    return this.am[Symbol.iterator]();
  }
  /**
   * Returns an iterator for the map's values in sorted order
   *
   * @returns An iterator for the map's values
   */
  *values() {
    for (const key of this.keys()) yield this.map.get(key);
  }
}
export {
  SortedMap
};
//# sourceMappingURL=SortedMap.js.map