@react-native-firebase/app/lib/internal/web/memidb/FDBCursor.js

A well tested, feature rich Firebase implementation for React Native, supporting iOS & Android. Individual module support for Admob, Analytics, Auth, Crash Reporting, Cloud Firestore, Database, Dynamic Links, Functions, Messaging (FCM), Remote Config, Sto

import FDBKeyRange from './FDBKeyRange.js';
import FDBObjectStore from './FDBObjectStore.js';
import cmp from './lib/cmp.js';
import {
  DataError,
  InvalidAccessError,
  InvalidStateError,
  ReadOnlyError,
  TransactionInactiveError,
} from './lib/errors.js';
import extractKey from './lib/extractKey.js';
import valueToKey from './lib/valueToKey.js';
const getEffectiveObjectStore = cursor => {
  if (cursor.source instanceof FDBObjectStore) {
    return cursor.source;
  }
  return cursor.source.objectStore;
};

// This takes a key range, a list of lower bounds, and a list of upper bounds and combines them all into a single key
// range. It does not handle gt/gte distinctions, because it doesn't really matter much anyway, since for next/prev
// cursor iteration it'd also have to look at values to be precise, which would be complicated. This should get us 99%
// of the way there.
const makeKeyRange = (range, lowers, uppers) => {
  // Start with bounds from range
  let lower = range !== undefined ? range.lower : undefined;
  let upper = range !== undefined ? range.upper : undefined;

  // Augment with values from lowers and uppers
  for (const lowerTemp of lowers) {
    if (lowerTemp === undefined) {
      continue;
    }
    if (lower === undefined || cmp(lower, lowerTemp) === 1) {
      lower = lowerTemp;
    }
  }
  for (const upperTemp of uppers) {
    if (upperTemp === undefined) {
      continue;
    }
    if (upper === undefined || cmp(upper, upperTemp) === -1) {
      upper = upperTemp;
    }
  }
  if (lower !== undefined && upper !== undefined) {
    return FDBKeyRange.bound(lower, upper);
  }
  if (lower !== undefined) {
    return FDBKeyRange.lowerBound(lower);
  }
  if (upper !== undefined) {
    return FDBKeyRange.upperBound(upper);
  }
};

// http://www.w3.org/TR/2015/REC-IndexedDB-20150108/#cursor
class FDBCursor {
  _gotValue = false;
  _position = undefined; // Key of previously returned record
  _objectStorePosition = undefined;
  _keyOnly = false;
  _key = undefined;
  _primaryKey = undefined;
  constructor(source, range, direction = 'next', request, keyOnly = false) {
    this._range = range;
    this._source = source;
    this._direction = direction;
    this._request = request;
    this._keyOnly = keyOnly;
  }

  // Read only properties
  get source() {
    return this._source;
  }
  set source(val) {
    /* For babel */
  }
  get request() {
    return this._request;
  }
  set request(val) {
    /* For babel */
  }
  get direction() {
    return this._direction;
  }
  set direction(val) {
    /* For babel */
  }
  get key() {
    return this._key;
  }
  set key(val) {
    /* For babel */
  }
  get primaryKey() {
    return this._primaryKey;
  }
  set primaryKey(val) {
    /* For babel */
  }

  // https://w3c.github.io/IndexedDB/#iterate-a-cursor
  _iterate(key, primaryKey) {
    const sourceIsObjectStore = this.source instanceof FDBObjectStore;

    // Can't use sourceIsObjectStore because TypeScript
    const records =
      this.source instanceof FDBObjectStore
        ? this.source._rawObjectStore.records
        : this.source._rawIndex.records;
    let foundRecord;
    if (this.direction === 'next') {
      const range = makeKeyRange(this._range, [key, this._position], []);
      for (const record of records.values(range)) {
        const cmpResultKey = key !== undefined ? cmp(record.key, key) : undefined;
        const cmpResultPosition =
          this._position !== undefined ? cmp(record.key, this._position) : undefined;
        if (key !== undefined) {
          if (cmpResultKey === -1) {
            continue;
          }
        }
        if (primaryKey !== undefined) {
          if (cmpResultKey === -1) {
            continue;
          }
          const cmpResultPrimaryKey = cmp(record.value, primaryKey);
          if (cmpResultKey === 0 && cmpResultPrimaryKey === -1) {
            continue;
          }
        }
        if (this._position !== undefined && sourceIsObjectStore) {
          if (cmpResultPosition !== 1) {
            continue;
          }
        }
        if (this._position !== undefined && !sourceIsObjectStore) {
          if (cmpResultPosition === -1) {
            continue;
          }
          if (cmpResultPosition === 0 && cmp(record.value, this._objectStorePosition) !== 1) {
            continue;
          }
        }
        if (this._range !== undefined) {
          if (!this._range.includes(record.key)) {
            continue;
          }
        }
        foundRecord = record;
        break;
      }
    } else if (this.direction === 'nextunique') {
      // This could be done without iterating, if the range was defined slightly better (to handle gt/gte cases).
      // But the performance difference should be small, and that wouldn't work anyway for directions where the
      // value needs to be used (like next and prev).
      const range = makeKeyRange(this._range, [key, this._position], []);
      for (const record of records.values(range)) {
        if (key !== undefined) {
          if (cmp(record.key, key) === -1) {
            continue;
          }
        }
        if (this._position !== undefined) {
          if (cmp(record.key, this._position) !== 1) {
            continue;
          }
        }
        if (this._range !== undefined) {
          if (!this._range.includes(record.key)) {
            continue;
          }
        }
        foundRecord = record;
        break;
      }
    } else if (this.direction === 'prev') {
      const range = makeKeyRange(this._range, [], [key, this._position]);
      for (const record of records.values(range, 'prev')) {
        const cmpResultKey = key !== undefined ? cmp(record.key, key) : undefined;
        const cmpResultPosition =
          this._position !== undefined ? cmp(record.key, this._position) : undefined;
        if (key !== undefined) {
          if (cmpResultKey === 1) {
            continue;
          }
        }
        if (primaryKey !== undefined) {
          if (cmpResultKey === 1) {
            continue;
          }
          const cmpResultPrimaryKey = cmp(record.value, primaryKey);
          if (cmpResultKey === 0 && cmpResultPrimaryKey === 1) {
            continue;
          }
        }
        if (this._position !== undefined && sourceIsObjectStore) {
          if (cmpResultPosition !== -1) {
            continue;
          }
        }
        if (this._position !== undefined && !sourceIsObjectStore) {
          if (cmpResultPosition === 1) {
            continue;
          }
          if (cmpResultPosition === 0 && cmp(record.value, this._objectStorePosition) !== -1) {
            continue;
          }
        }
        if (this._range !== undefined) {
          if (!this._range.includes(record.key)) {
            continue;
          }
        }
        foundRecord = record;
        break;
      }
    } else if (this.direction === 'prevunique') {
      let tempRecord;
      const range = makeKeyRange(this._range, [], [key, this._position]);
      for (const record of records.values(range, 'prev')) {
        if (key !== undefined) {
          if (cmp(record.key, key) === 1) {
            continue;
          }
        }
        if (this._position !== undefined) {
          if (cmp(record.key, this._position) !== -1) {
            continue;
          }
        }
        if (this._range !== undefined) {
          if (!this._range.includes(record.key)) {
            continue;
          }
        }
        tempRecord = record;
        break;
      }
      if (tempRecord) {
        foundRecord = records.get(tempRecord.key);
      }
    }
    let result;
    if (!foundRecord) {
      this._key = undefined;
      if (!sourceIsObjectStore) {
        this._objectStorePosition = undefined;
      }

      // "this instanceof FDBCursorWithValue" would be better and not require (this as any), but causes runtime
      // error due to circular dependency.
      if (!this._keyOnly && this.toString() === '[object IDBCursorWithValue]') {
        this.value = undefined;
      }
      result = null;
    } else {
      this._position = foundRecord.key;
      if (!sourceIsObjectStore) {
        this._objectStorePosition = foundRecord.value;
      }
      this._key = foundRecord.key;
      if (sourceIsObjectStore) {
        this._primaryKey = structuredClone(foundRecord.key);
        if (!this._keyOnly && this.toString() === '[object IDBCursorWithValue]') {
          this.value = structuredClone(foundRecord.value);
        }
      } else {
        this._primaryKey = structuredClone(foundRecord.value);
        if (!this._keyOnly && this.toString() === '[object IDBCursorWithValue]') {
          if (this.source instanceof FDBObjectStore) {
            // Can't use sourceIsObjectStore because TypeScript
            throw new Error('This should never happen');
          }
          const value = this.source.objectStore._rawObjectStore.getValue(foundRecord.value);
          this.value = structuredClone(value);
        }
      }
      this._gotValue = true;
      // eslint-disable-next-line @typescript-eslint/no-this-alias
      result = this;
    }
    return result;
  }

  // http://www.w3.org/TR/2015/REC-IndexedDB-20150108/#widl-IDBCursor-update-IDBRequest-any-value
  update(value) {
    if (value === undefined) {
      throw new TypeError();
    }
    const effectiveObjectStore = getEffectiveObjectStore(this);
    const effectiveKey = Object.hasOwn(this.source, '_rawIndex') ? this.primaryKey : this._position;
    const transaction = effectiveObjectStore.transaction;
    if (transaction._state !== 'active') {
      throw new TransactionInactiveError();
    }
    if (transaction.mode === 'readonly') {
      throw new ReadOnlyError();
    }
    if (effectiveObjectStore._rawObjectStore.deleted) {
      throw new InvalidStateError();
    }
    if (!(this.source instanceof FDBObjectStore) && this.source._rawIndex.deleted) {
      throw new InvalidStateError();
    }
    if (!this._gotValue || !Object.hasOwn(this, 'value')) {
      throw new InvalidStateError();
    }
    const clone = structuredClone(value);
    if (effectiveObjectStore.keyPath !== null) {
      let tempKey;
      try {
        tempKey = extractKey(effectiveObjectStore.keyPath, clone);
      } catch (_) {
        /* Handled immediately below */
      }
      if (cmp(tempKey, effectiveKey) !== 0) {
        throw new DataError();
      }
    }
    const record = {
      key: effectiveKey,
      value: clone,
    };
    return transaction._execRequestAsync({
      operation: effectiveObjectStore._rawObjectStore.storeRecord.bind(
        effectiveObjectStore._rawObjectStore,
        record,
        false,
        transaction._rollbackLog,
      ),
      source: this,
    });
  }

  // http://www.w3.org/TR/2015/REC-IndexedDB-20150108/#widl-IDBCursor-advance-void-unsigned-long-count
  advance(count) {
    if (!Number.isInteger(count) || count <= 0) {
      throw new TypeError();
    }
    const effectiveObjectStore = getEffectiveObjectStore(this);
    const transaction = effectiveObjectStore.transaction;
    if (transaction._state !== 'active') {
      throw new TransactionInactiveError();
    }
    if (effectiveObjectStore._rawObjectStore.deleted) {
      throw new InvalidStateError();
    }
    if (!(this.source instanceof FDBObjectStore) && this.source._rawIndex.deleted) {
      throw new InvalidStateError();
    }
    if (!this._gotValue) {
      throw new InvalidStateError();
    }
    if (this._request) {
      this._request.readyState = 'pending';
    }
    transaction._execRequestAsync({
      operation: () => {
        let result;
        for (let i = 0; i < count; i++) {
          result = this._iterate();

          // Not sure why this is needed
          if (!result) {
            break;
          }
        }
        return result;
      },
      request: this._request,
      source: this.source,
    });
    this._gotValue = false;
  }

  // http://www.w3.org/TR/2015/REC-IndexedDB-20150108/#widl-IDBCursor-continue-void-any-key
  continue(key) {
    const effectiveObjectStore = getEffectiveObjectStore(this);
    const transaction = effectiveObjectStore.transaction;
    if (transaction._state !== 'active') {
      throw new TransactionInactiveError();
    }
    if (effectiveObjectStore._rawObjectStore.deleted) {
      throw new InvalidStateError();
    }
    if (!(this.source instanceof FDBObjectStore) && this.source._rawIndex.deleted) {
      throw new InvalidStateError();
    }
    if (!this._gotValue) {
      throw new InvalidStateError();
    }
    if (key !== undefined) {
      key = valueToKey(key);
      const cmpResult = cmp(key, this._position);
      if (
        (cmpResult <= 0 && (this.direction === 'next' || this.direction === 'nextunique')) ||
        (cmpResult >= 0 && (this.direction === 'prev' || this.direction === 'prevunique'))
      ) {
        throw new DataError();
      }
    }
    if (this._request) {
      this._request.readyState = 'pending';
    }
    transaction._execRequestAsync({
      operation: this._iterate.bind(this, key),
      request: this._request,
      source: this.source,
    });
    this._gotValue = false;
  }

  // hthttps://w3c.github.io/IndexedDB/#dom-idbcursor-continueprimarykey
  continuePrimaryKey(key, primaryKey) {
    const effectiveObjectStore = getEffectiveObjectStore(this);
    const transaction = effectiveObjectStore.transaction;
    if (transaction._state !== 'active') {
      throw new TransactionInactiveError();
    }
    if (effectiveObjectStore._rawObjectStore.deleted) {
      throw new InvalidStateError();
    }
    if (!(this.source instanceof FDBObjectStore) && this.source._rawIndex.deleted) {
      throw new InvalidStateError();
    }
    if (
      this.source instanceof FDBObjectStore ||
      (this.direction !== 'next' && this.direction !== 'prev')
    ) {
      throw new InvalidAccessError();
    }
    if (!this._gotValue) {
      throw new InvalidStateError();
    }

    // Not sure about this
    if (key === undefined || primaryKey === undefined) {
      throw new DataError();
    }
    key = valueToKey(key);
    const cmpResult = cmp(key, this._position);
    if (
      (cmpResult === -1 && this.direction === 'next') ||
      (cmpResult === 1 && this.direction === 'prev')
    ) {
      throw new DataError();
    }
    const cmpResult2 = cmp(primaryKey, this._objectStorePosition);
    if (cmpResult === 0) {
      if (
        (cmpResult2 <= 0 && this.direction === 'next') ||
        (cmpResult2 >= 0 && this.direction === 'prev')
      ) {
        throw new DataError();
      }
    }
    if (this._request) {
      this._request.readyState = 'pending';
    }
    transaction._execRequestAsync({
      operation: this._iterate.bind(this, key, primaryKey),
      request: this._request,
      source: this.source,
    });
    this._gotValue = false;
  }
  delete() {
    const effectiveObjectStore = getEffectiveObjectStore(this);
    const effectiveKey = Object.hasOwn(this.source, '_rawIndex') ? this.primaryKey : this._position;
    const transaction = effectiveObjectStore.transaction;
    if (transaction._state !== 'active') {
      throw new TransactionInactiveError();
    }
    if (transaction.mode === 'readonly') {
      throw new ReadOnlyError();
    }
    if (effectiveObjectStore._rawObjectStore.deleted) {
      throw new InvalidStateError();
    }
    if (!(this.source instanceof FDBObjectStore) && this.source._rawIndex.deleted) {
      throw new InvalidStateError();
    }
    if (!this._gotValue || !Object.hasOwn(this, 'value')) {
      throw new InvalidStateError();
    }
    return transaction._execRequestAsync({
      operation: effectiveObjectStore._rawObjectStore.deleteRecord.bind(
        effectiveObjectStore._rawObjectStore,
        effectiveKey,
        transaction._rollbackLog,
      ),
      source: this,
    });
  }
  toString() {
    return '[object IDBCursor]';
  }
}
export default FDBCursor;