23400890631

Committed 22 Mar 2026 10:14AM UTC coverage: 97.856% (+0.03%) from 97.826%

Build # 23400890631

Build Type

Pull #254

github

Committed by

web-flow

Commit Message

Merge fcd5390fb into ea855be31

Pull Request Pull Request #254: iterateRange: use k-way partition merge by sequenceNumber when index=false

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Branch coverage included in aggregate %.

39 of 39 new or added lines in 2 files covered. (100.0%)

1 existing line in 1 file now uncovered.

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96.28

/src/Storage/ReadableStorage.js

const fs = require('fs');
const path = require('path');
const events = require('events');
const Partition = require('../Partition');
const Index = require('../Index');
const { assert, createHmac, matches, wrapAndCheck, buildMetadataForMatcher } = require('../util');

const DEFAULT_READ_BUFFER_SIZE = 4 * 1024;

/**
 * Reverses the items of an iterable
 * @param {Generator|Iterable} iterator
 * @returns {Generator<*>}
 */
function *reverse(iterator) {
    const items = Array.from(iterator);
    for (let i = items.length - 1; i >= 0; i--) {
        yield items[i];
    }
}

/**
 * @typedef {object|function(object):boolean} Matcher
 */

/**
 * An append-only storage with highly performant positional range scans.
 * It's highly optimized for an event-store and hence does not support compaction or data-rewrite, nor any querying
 */
class ReadableStorage extends events.EventEmitter {

    /**
     * @param {string} [storageName] The name of the storage.
     * @param {object} [config] An object with storage parameters.
     * @param {object} [config.serializer] A serializer object with methods serialize(document) and deserialize(data).
     * @param {function(object): string} config.serializer.serialize Default is JSON.stringify.
     * @param {function(string): object} config.serializer.deserialize Default is JSON.parse.
     * @param {string} [config.dataDirectory] The path where the storage data should reside. Default '.'.
     * @param {string} [config.indexDirectory] The path where the indexes should be stored. Defaults to dataDirectory.
     * @param {string} [config.indexFile] The name of the primary index. Default '{storageName}.index'.
     * @param {number} [config.readBufferSize] Size of the read buffer in bytes. Default 4096.
     * @param {object} [config.indexOptions] An options object that should be passed to all indexes on construction.
     * @param {string} [config.hmacSecret] A private key that is used to verify matchers retrieved from indexes.
     * @param {object} [config.metadata] A metadata object to be stored in all partitions belonging to this storage.
     */
    constructor(storageName = 'storage', config = {}) {
        super();
        if (typeof storageName !== 'string') {
            config = storageName;
            storageName = undefined;
        }

        this.storageFile = storageName || 'storage';
        const defaults = {
            serializer: { serialize: JSON.stringify, deserialize: JSON.parse },
            dataDirectory: '.',
            indexFile: this.storageFile + '.index',
            indexOptions: {},
            hmacSecret: '',
            metadata: {}
        };
        config = Object.assign(defaults, config);
        this.serializer = config.serializer;

        this.hmac = createHmac(config.hmacSecret);

        this.dataDirectory = path.resolve(config.dataDirectory);

        this.initializeIndexes(config);
        this.scanPartitions(config);
    }

    /**
     * @protected
     * @param {string} name
     * @param {object} [options]
     * @returns {{ index: ReadableIndex, matcher?: Matcher }}
     */
    createIndex(name, options = {}) {
        /** @type ReadableIndex */
        const index = new Index.ReadOnly(name, options);
        return { index };
    }

    /**
     * @protected
     * @param {string} name
     * @param {object} [options]
     * @returns {ReadablePartition}
     */
    createPartition(name, options = {}) {
        return new Partition.ReadOnly(name, options);
    }

    /**
     * Create/open the primary index and build the base configuration for all secondary indexes.
     *
     * @private
     * @param {object} config The configuration object
     * @returns void
     */
    initializeIndexes(config) {
        this.indexDirectory = path.resolve(config.indexDirectory || this.dataDirectory);

        this.indexOptions = config.indexOptions;
        this.indexOptions.dataDirectory = this.indexDirectory;
        // Safety precaution to prevent accidentally restricting main index
        delete this.indexOptions.matcher;
        const { index } = this.createIndex(config.indexFile, this.indexOptions);
        this.index = index;
        this.secondaryIndexes = {};
        this.readonlyIndexes = {};
    }

    /**
     * The amount of documents in the storage.
     * @returns {number}
     */
    get length() {
        return this.index.length;
    }

    /**
     * Scan the data directory for all existing partitions.
     * Every file beginning with the storageFile name is considered a partition.
     *
     * @private
     * @param {object} config The configuration object containing options for the partitions.
     * @returns void
     */
    scanPartitions(config) {
        const defaults = {
            readBufferSize: DEFAULT_READ_BUFFER_SIZE
        };
        this.partitionConfig = Object.assign(defaults, config);
        this.partitions = Object.create(null);

        const files = fs.readdirSync(this.dataDirectory);
        for (let file of files) {
            if (file.substr(-6) === '.index') continue;
            if (file.substr(-7) === '.branch') continue;
            if (file.substr(-5) === '.lock') continue;
            if (file.substr(0, this.storageFile.length) !== this.storageFile) continue;

            const partition = this.createPartition(file, this.partitionConfig);
            this.partitions[partition.id] = partition;
        }
    }

    /**
     * Open the storage and indexes and create read and write buffers eagerly.
     * Will emit an 'opened' event if finished.
     *
     * @api
     * @returns {boolean}
     */
    open() {
        this.index.open();

        this.forEachSecondaryIndex(index => index.open());

        this.emit('opened');
        return true;
    }

    /**
     * Close the storage and frees up all resources.
     * Will emit a 'closed' event when finished.
     *
     * @api
     * @returns void
     */
    close() {
        this.index.close();
        this.forEachSecondaryIndex(index => index.close());
        for (let index of Object.values(this.readonlyIndexes)) {
            index.close();
        }
        this.forEachPartition(partition => partition.close());
        this.emit('closed');
    }

    /**
     * Get a partition either by name or by id.
     * If a partition with the given name does not exist, a new one will be created.
     * If a partition with the given id does not exist, an error is thrown.
     *
     * @protected
     * @param {string|number} partitionIdentifier The partition name or the partition Id
     * @returns {ReadablePartition}
     * @throws {Error} If an id is given and no such partition exists.
     */
    getPartition(partitionIdentifier) {
        assert(partitionIdentifier in this.partitions, `Partition #${partitionIdentifier} does not exist.`);

        this.partitions[partitionIdentifier].open();
        return this.partitions[partitionIdentifier];
    }

    /**
     * Register a handler that is called before a document is read from a partition.
     * The handler receives the position and the partition metadata and may throw to abort the read.
     * Multiple handlers can be registered; all run on every read in registration order.
     * Equivalent to `storage.on('preRead', hook)`.
     *
     * @api
     * @param {function(number, object): void} hook A function receiving (position, partitionMetadata).
     */
    preRead(hook) {
        this.on('preRead', hook);
    }

    /**
     * @protected
     * @param {number} partitionId The partition to read from.
     * @param {number} position The file position to read from.
     * @param {number} [size] The expected byte size of the document at the given position.
     * @returns {object} The document stored at the given position.
     * @throws {Error} if the document at the given position can not be deserialized.
     */
    readFrom(partitionId, position, size) {
        const partition = this.getPartition(partitionId);
        if (this.listenerCount('preRead') > 0) {
            this.emit('preRead', position, partition.metadata);
        }
        const data = partition.readFrom(position, size);
        return this.serializer.deserialize(data);
    }

    /**
     * Read a single document from the given position, in the full index or in the provided index.
     *
     * @api
     * @param {number} number The 1-based document number (inside the given index) to read.
     * @param {ReadableIndex} [index] The index to use for finding the document position.
     * @returns {object} The document at the given position inside the index.
     */
    read(number, index) {
        index = index || this.index;

        if (!index.isOpen()) {
            index.open();
        }

        const entry = index.get(number);
        if (entry === false) {
            return false;
        }

        return this.readFrom(entry.partition, entry.position, entry.size);
    }

    /**
     * Read a range of documents from the given position range, in the full index or in the provided index.
     * Returns a generator in order to reduce memory usage and be able to read lots of documents with little latency.
     *
     * @api
     * @param {number} from The 1-based document number (inclusive) to start reading from.
     * @param {number} [until] The 1-based document number (inclusive) to read until. Defaults to index.length.
     * @param {ReadableIndex|false} [index] The index to use for finding the documents in the range.
     *   Pass `false` to skip the global index and iterate all partitions directly in sequenceNumber order
     *   (useful when the global index is unavailable or corrupted).
     * @returns {Generator<object>} A generator that will read each document in the range one by one.
     */
    *readRange(from, until = -1, index = null) {
        const lengthSource = index || this.index;
        if (!lengthSource.isOpen()) {
            lengthSource.open();
        }

        const readFrom = wrapAndCheck(from, lengthSource.length);
        const readUntil = wrapAndCheck(until, lengthSource.length);
        assert(readFrom > 0 && readUntil > 0, `Range scan error for range ${from} - ${until}.`);

        if (readFrom > readUntil) {
            const batchSize = 10;
            let batchUntil = readFrom;
            while (batchUntil >= readUntil) {
                const batchFrom = Math.max(readUntil, batchUntil - batchSize);
                yield* reverse(this.iterateRange(batchFrom, batchUntil, index));
                batchUntil = batchFrom - 1;
            }
            return undefined;
        }

        yield* this.iterateRange(readFrom, readUntil, index);
    }

    /**
     * Iterate all documents in this storage in range from to until inside the index.
     * If index is false, iterates all partitions directly in sequenceNumber order.
     * @private
     * @param {number} from
     * @param {number} until
     * @param {ReadableIndex|false|null} index
     * @returns {Generator<object>}
     */
    *iterateRange(from, until, index) {
        if (index === false) {
            // Explicitly disabled index: iterate all partitions and merge by sequenceNumber.
            // Document header sequenceNumber is 0-based; from/until are 1-based index positions.
            yield* this.iteratePartitionsBySequenceNumber(from - 1, until - 1);
            return;
        }

        const idx = index || this.index;
        const entries = idx.range(from, until);
        for (let entry of entries) {
            const document = this.readFrom(entry.partition, entry.position, entry.size);
            yield document;
        }
    }

    /**
     * Iterate documents across all partitions in sequenceNumber order using a k-way merge.
     * SequenceNumbers stored in document headers are 0-based.
     * @private
     * @param {number} fromSeq The 0-based sequenceNumber to start from (inclusive).
     * @param {number} untilSeq The 0-based sequenceNumber to read until (inclusive).
     * @returns {Generator<object>}
     */
    *iteratePartitionsBySequenceNumber(fromSeq, untilSeq) {
        const iterators = [];

        for (const partition of Object.values(this.partitions)) {
            if (!partition.isOpen()) {
                partition.open();
            }
            const headerOut = {};
            const gen = partition.readAll(0, headerOut);

            // Advance to the first document with sequenceNumber >= fromSeq
            let result = gen.next();
            while (!result.done && headerOut.sequenceNumber < fromSeq) {
                result = gen.next();
            }

            if (!result.done && headerOut.sequenceNumber <= untilSeq) {
                iterators.push({ gen, headerOut, data: result.value, sequenceNumber: headerOut.sequenceNumber });
            }
        }

        // K-way merge: at each step, yield the document with the smallest sequenceNumber
        while (iterators.length > 0) {
            let minIdx = 0;
            for (let i = 1; i < iterators.length; i++) {
                if (iterators[i].sequenceNumber < iterators[minIdx].sequenceNumber) {
                    minIdx = i;
                }
            }

            yield this.serializer.deserialize(iterators[minIdx].data);

            const next = iterators[minIdx].gen.next();
            if (!next.done && iterators[minIdx].headerOut.sequenceNumber <= untilSeq) {
                iterators[minIdx].data = next.value;
                iterators[minIdx].sequenceNumber = iterators[minIdx].headerOut.sequenceNumber;
            } else {
                iterators.splice(minIdx, 1);
            }
        }
    }

    /**
     * Open an existing readonly index for reading, without registering it in the secondary indexes write path.
     * Use this for indexes whose files carry a status marker (e.g. `stream-foo.closed.index`).
     *
     * @api
     * @param {string} name The readonly index name (e.g. 'stream-foo.closed').
     * @returns {ReadableIndex}
     * @throws {Error} if the readonly index does not exist.
     */
    openReadonlyIndex(name) {
        if (name in this.readonlyIndexes) {
            return this.readonlyIndexes[name];
        }
        const indexName = this.storageFile + '.' + name + '.index';
        assert(fs.existsSync(path.join(this.indexDirectory, indexName)), `Index "${name}" does not exist.`);
        const { index } = this.createIndex(indexName, Object.assign({}, this.indexOptions));
        index.open();
        this.readonlyIndexes[name] = index;
        return index;
    }

    /**
     * Open an existing index.
     *
     * @api
     * @param {string} name The index name.
     * @param {Matcher} [matcher] The matcher object or function that the index needs to have been defined with. If not given it will not be validated.
     * @returns {ReadableIndex}
     * @throws {Error} if the index with that name does not exist.
     * @throws {Error} if the HMAC for the matcher does not match.
     */
    openIndex(name, matcher) {
        if (name === '_all') {
            return this.index;
        }
        if (name in this.secondaryIndexes) {
            return this.secondaryIndexes[name].index;
        }

        const indexName = this.storageFile + '.' + name + '.index';
        assert(fs.existsSync(path.join(this.indexDirectory, indexName)), `Index "${name}" does not exist.`);

        const metadata = buildMetadataForMatcher(matcher, this.hmac);
        let { index } = this.secondaryIndexes[name] = this.createIndex(indexName, Object.assign({}, this.indexOptions, { metadata }));

        index.open();
        return index;
    }

    /**
     * Helper method to iterate over all documents.
     *
     * @protected
     * @param {function(object, EntryInterface)} iterationHandler
     */
    forEachDocument(iterationHandler) {
        /* istanbul ignore if  */
        if (typeof iterationHandler !== 'function') {
            return;
        }

        const entries = this.index.all();

        for (let entry of entries) {
            const document = this.readFrom(entry.partition, entry.position, entry.size);
            iterationHandler(document, entry);
        }
    }

    /**
     * Helper method to iterate over all secondary indexes.
     *
     * @protected
     * @param {function(ReadableIndex, string)} iterationHandler
     * @param {object} [matchDocument] If supplied, only indexes the document matches on will be iterated.
     */
    forEachSecondaryIndex(iterationHandler, matchDocument) {
        /* istanbul ignore if  */
        if (typeof iterationHandler !== 'function') {
            return;
        }

        for (let indexName of Object.keys(this.secondaryIndexes)) {
            if (!matchDocument || matches(matchDocument, this.secondaryIndexes[indexName].matcher)) {
                iterationHandler(this.secondaryIndexes[indexName].index, indexName);
            }
        }
    }

    /**
     * Helper method to iterate over all partitions.
     *
     * @protected
     * @param {function(ReadablePartition)} iterationHandler
     */
    forEachPartition(iterationHandler) {
        /* istanbul ignore if  */
        if (typeof iterationHandler !== 'function') {
            return;
        }

        for (let partition of Object.keys(this.partitions)) {
            iterationHandler(this.partitions[partition]);
        }
    }

}

module.exports = ReadableStorage;
module.exports.matches = matches;

1	const fs = require('fs');	4✔
2	const path = require('path');	4✔
3	const events = require('events');	4✔
4	const Partition = require('../Partition');	4✔
5	const Index = require('../Index');	4✔
6	const { assert, createHmac, matches, wrapAndCheck, buildMetadataForMatcher } = require('../util');	4✔
7
8	const DEFAULT_READ_BUFFER_SIZE = 4 * 1024;	4✔
9
10	/**
11	* Reverses the items of an iterable
12	* @param {Generator\|Iterable} iterator
13	* @returns {Generator<*>}
14	*/
15	function *reverse(iterator) {
16	const items = Array.from(iterator);	68✔
17	for (let i = items.length - 1; i >= 0; i--) {	68✔
18	yield items[i];	580✔
19	}
20	}
21
22	/**
23	* @typedef {object\|function(object):boolean} Matcher
24	*/
25
26	/**
27	* An append-only storage with highly performant positional range scans.
28	* It's highly optimized for an event-store and hence does not support compaction or data-rewrite, nor any querying
29	*/
30	class ReadableStorage extends events.EventEmitter {
31
32	/**
33	* @param {string} [storageName] The name of the storage.
34	* @param {object} [config] An object with storage parameters.
35	* @param {object} [config.serializer] A serializer object with methods serialize(document) and deserialize(data).
36	* @param {function(object): string} config.serializer.serialize Default is JSON.stringify.
37	* @param {function(string): object} config.serializer.deserialize Default is JSON.parse.
38	* @param {string} [config.dataDirectory] The path where the storage data should reside. Default '.'.
39	* @param {string} [config.indexDirectory] The path where the indexes should be stored. Defaults to dataDirectory.
40	* @param {string} [config.indexFile] The name of the primary index. Default '{storageName}.index'.
41	* @param {number} [config.readBufferSize] Size of the read buffer in bytes. Default 4096.
42	* @param {object} [config.indexOptions] An options object that should be passed to all indexes on construction.
43	* @param {string} [config.hmacSecret] A private key that is used to verify matchers retrieved from indexes.
44	* @param {object} [config.metadata] A metadata object to be stored in all partitions belonging to this storage.
45	*/
46	constructor(storageName = 'storage', config = {}) {	448!
47	super();	884✔
48	if (typeof storageName !== 'string') {	884✔
49	config = storageName;	52✔
50	storageName = undefined;	52✔
51	}
52
53	this.storageFile = storageName \|\| 'storage';	884✔
54	const defaults = {	884✔
55	serializer: { serialize: JSON.stringify, deserialize: JSON.parse },
56	dataDirectory: '.',
57	indexFile: this.storageFile + '.index',
58	indexOptions: {},
59	hmacSecret: '',
60	metadata: {}
61	};
62	config = Object.assign(defaults, config);	884✔
63	this.serializer = config.serializer;	884✔
64
65	this.hmac = createHmac(config.hmacSecret);	884✔
66
67	this.dataDirectory = path.resolve(config.dataDirectory);	884✔
68
69	this.initializeIndexes(config);	884✔
70	this.scanPartitions(config);	880✔
71	}
72
73	/**
74	* @protected
75	* @param {string} name
76	* @param {object} [options]
77	* @returns {{ index: ReadableIndex, matcher?: Matcher }}
78	*/
79	createIndex(name, options = {}) {	×
80	/** @type ReadableIndex */
81	const index = new Index.ReadOnly(name, options);	136✔
82	return { index };	132✔
83	}
84
85	/**
86	* @protected
87	* @param {string} name
88	* @param {object} [options]
89	* @returns {ReadablePartition}
90	*/
91	createPartition(name, options = {}) {	×
92	return new Partition.ReadOnly(name, options);	52✔
93	}
94
95	/**
96	* Create/open the primary index and build the base configuration for all secondary indexes.
97	*
98	* @private
99	* @param {object} config The configuration object
100	* @returns void
101	*/
102	initializeIndexes(config) {
103	this.indexDirectory = path.resolve(config.indexDirectory \|\| this.dataDirectory);	884✔
104
105	this.indexOptions = config.indexOptions;	884✔
106	this.indexOptions.dataDirectory = this.indexDirectory;	884✔
107	// Safety precaution to prevent accidentally restricting main index
108	delete this.indexOptions.matcher;	884✔
109	const { index } = this.createIndex(config.indexFile, this.indexOptions);	884✔
110	this.index = index;	880✔
111	this.secondaryIndexes = {};	880✔
112	this.readonlyIndexes = {};	880✔
113	}
114
115	/**
116	* The amount of documents in the storage.
117	* @returns {number}
118	*/
119	get length() {
120	return this.index.length;	3,624✔
121	}
122
123	/**
124	* Scan the data directory for all existing partitions.
125	* Every file beginning with the storageFile name is considered a partition.
126	*
127	* @private
128	* @param {object} config The configuration object containing options for the partitions.
129	* @returns void
130	*/
131	scanPartitions(config) {
132	const defaults = {	880✔
133	readBufferSize: DEFAULT_READ_BUFFER_SIZE
134	};
135	this.partitionConfig = Object.assign(defaults, config);	880✔
136	this.partitions = Object.create(null);	880✔
137
138	const files = fs.readdirSync(this.dataDirectory);	880✔
139	for (let file of files) {	880✔
140	if (file.substr(-6) === '.index') continue;	1,100✔
141	if (file.substr(-7) === '.branch') continue;	552!
142	if (file.substr(-5) === '.lock') continue;	552✔
143	if (file.substr(0, this.storageFile.length) !== this.storageFile) continue;	468✔
144
145	const partition = this.createPartition(file, this.partitionConfig);	88✔
146	this.partitions[partition.id] = partition;	88✔
147	}
148	}
149
150	/**
151	* Open the storage and indexes and create read and write buffers eagerly.
152	* Will emit an 'opened' event if finished.
153	*
154	* @api
155	* @returns {boolean}
156	*/
157	open() {
158	this.index.open();	824✔
159
160	this.forEachSecondaryIndex(index => index.open());	824✔
161
162	this.emit('opened');	824✔
163	return true;	824✔
164	}
165
166	/**
167	* Close the storage and frees up all resources.
168	* Will emit a 'closed' event when finished.
169	*
170	* @api
171	* @returns void
172	*/
173	close() {
174	this.index.close();	1,364✔
175	this.forEachSecondaryIndex(index => index.close());	1,364✔
176	for (let index of Object.values(this.readonlyIndexes)) {	1,364✔
177	index.close();	44✔
178	}
179	this.forEachPartition(partition => partition.close());	1,376✔
180	this.emit('closed');	1,364✔
181	}
182
183	/**
184	* Get a partition either by name or by id.
185	* If a partition with the given name does not exist, a new one will be created.
186	* If a partition with the given id does not exist, an error is thrown.
187	*
188	* @protected
189	* @param {string\|number} partitionIdentifier The partition name or the partition Id
190	* @returns {ReadablePartition}
191	* @throws {Error} If an id is given and no such partition exists.
192	*/
193	getPartition(partitionIdentifier) {
194	assert(partitionIdentifier in this.partitions, `Partition #${partitionIdentifier} does not exist.`);	3,716✔
195
196	this.partitions[partitionIdentifier].open();	3,716✔
197	return this.partitions[partitionIdentifier];	3,716✔
198	}
199
200	/**
201	* Register a handler that is called before a document is read from a partition.
202	* The handler receives the position and the partition metadata and may throw to abort the read.
203	* Multiple handlers can be registered; all run on every read in registration order.
204	* Equivalent to `storage.on('preRead', hook)`.
205	*
206	* @api
207	* @param {function(number, object): void} hook A function receiving (position, partitionMetadata).
208	*/
209	preRead(hook) {
210	this.on('preRead', hook);	12✔
211	}
212
213	/**
214	* @protected
215	* @param {number} partitionId The partition to read from.
216	* @param {number} position The file position to read from.
217	* @param {number} [size] The expected byte size of the document at the given position.
218	* @returns {object} The document stored at the given position.
219	* @throws {Error} if the document at the given position can not be deserialized.
220	*/
221	readFrom(partitionId, position, size) {
222	const partition = this.getPartition(partitionId);	3,676✔
223	if (this.listenerCount('preRead') > 0) {	3,676✔
224	this.emit('preRead', position, partition.metadata);	64✔
225	}
226	const data = partition.readFrom(position, size);	3,668✔
227	return this.serializer.deserialize(data);	3,668✔
228	}
229
230	/**
231	* Read a single document from the given position, in the full index or in the provided index.
232	*
233	* @api
234	* @param {number} number The 1-based document number (inside the given index) to read.
235	* @param {ReadableIndex} [index] The index to use for finding the document position.
236	* @returns {object} The document at the given position inside the index.
237	*/
238	read(number, index) {
239	index = index \|\| this.index;	176✔
240
241	if (!index.isOpen()) {	176✔
242	index.open();	4✔
243	}
244
245	const entry = index.get(number);	176✔
246	if (entry === false) {	176✔
247	return false;	4✔
248	}
249
250	return this.readFrom(entry.partition, entry.position, entry.size);	172✔
251	}
252
253	/**
254	* Read a range of documents from the given position range, in the full index or in the provided index.
255	* Returns a generator in order to reduce memory usage and be able to read lots of documents with little latency.
256	*
257	* @api
258	* @param {number} from The 1-based document number (inclusive) to start reading from.
259	* @param {number} [until] The 1-based document number (inclusive) to read until. Defaults to index.length.
260	* @param {ReadableIndex\|false} [index] The index to use for finding the documents in the range.
261	* Pass `false` to skip the global index and iterate all partitions directly in sequenceNumber order
262	* (useful when the global index is unavailable or corrupted).
263	* @returns {Generator<object>} A generator that will read each document in the range one by one.
264	*/
265	*readRange(from, until = -1, index = null) {	72✔
266	const lengthSource = index \|\| this.index;	524✔
267	if (!lengthSource.isOpen()) {	524✔
268	lengthSource.open();	4✔
269	}
270
271	const readFrom = wrapAndCheck(from, lengthSource.length);	524✔
272	const readUntil = wrapAndCheck(until, lengthSource.length);	524✔
273	assert(readFrom > 0 && readUntil > 0, `Range scan error for range ${from} - ${until}.`);	524✔
274
275	if (readFrom > readUntil) {	508✔
276	const batchSize = 10;	48✔
277	let batchUntil = readFrom;	48✔
278	while (batchUntil >= readUntil) {	48✔
279	const batchFrom = Math.max(readUntil, batchUntil - batchSize);	68✔
280	yield* reverse(this.iterateRange(batchFrom, batchUntil, index));	68✔
281	batchUntil = batchFrom - 1;	68✔
282	}
283	return undefined;	48✔
284	}
285
286	yield* this.iterateRange(readFrom, readUntil, index);	460✔
287	}
288
289	/**
290	* Iterate all documents in this storage in range from to until inside the index.
291	* If index is false, iterates all partitions directly in sequenceNumber order.
292	* @private
293	* @param {number} from
294	* @param {number} until
295	* @param {ReadableIndex\|false\|null} index
296	* @returns {Generator<object>}
297	*/
298	*iterateRange(from, until, index) {
299	if (index === false) {	528✔
300	// Explicitly disabled index: iterate all partitions and merge by sequenceNumber.
301	// Document header sequenceNumber is 0-based; from/until are 1-based index positions.
302	yield* this.iteratePartitionsBySequenceNumber(from - 1, until - 1);	12✔
303	return;	12✔
304	}
305
306	const idx = index \|\| this.index;	516✔
307	const entries = idx.range(from, until);	516✔
308	for (let entry of entries) {	516✔
309	const document = this.readFrom(entry.partition, entry.position, entry.size);	1,760✔
310	yield document;	1,756✔
311	}
312	}
313
314	/**
315	* Iterate documents across all partitions in sequenceNumber order using a k-way merge.
316	* SequenceNumbers stored in document headers are 0-based.
317	* @private
318	* @param {number} fromSeq The 0-based sequenceNumber to start from (inclusive).
319	* @param {number} untilSeq The 0-based sequenceNumber to read until (inclusive).
320	* @returns {Generator<object>}
321	*/
322	*iteratePartitionsBySequenceNumber(fromSeq, untilSeq) {
323	const iterators = [];	12✔
324
325	for (const partition of Object.values(this.partitions)) {	12✔
326	if (!partition.isOpen()) {	36!
327	partition.open();	36✔
328	}
329	const headerOut = {};	36✔
330	const gen = partition.readAll(0, headerOut);	36✔
331
332	// Advance to the first document with sequenceNumber >= fromSeq
333	let result = gen.next();	36✔
334	while (!result.done && headerOut.sequenceNumber < fromSeq) {	36✔
335	result = gen.next();	8✔
336	}
337
338	if (!result.done && headerOut.sequenceNumber <= untilSeq) {	36!
339	iterators.push({ gen, headerOut, data: result.value, sequenceNumber: headerOut.sequenceNumber });	36✔
340	}
341	}
342
343	// K-way merge: at each step, yield the document with the smallest sequenceNumber
344	while (iterators.length > 0) {	12✔
345	let minIdx = 0;	92✔
346	for (let i = 1; i < iterators.length; i++) {	92✔
347	if (iterators[i].sequenceNumber < iterators[minIdx].sequenceNumber) {	148✔
348	minIdx = i;	72✔
349	}
350	}
351
352	yield this.serializer.deserialize(iterators[minIdx].data);	92✔
353
354	const next = iterators[minIdx].gen.next();	92✔
355	if (!next.done && iterators[minIdx].headerOut.sequenceNumber <= untilSeq) {	92✔
356	iterators[minIdx].data = next.value;	56✔
357	iterators[minIdx].sequenceNumber = iterators[minIdx].headerOut.sequenceNumber;	56✔
358	} else {
359	iterators.splice(minIdx, 1);	36✔
360	}
361	}
362	}
363
364	/**
365	* Open an existing readonly index for reading, without registering it in the secondary indexes write path.
366	* Use this for indexes whose files carry a status marker (e.g. `stream-foo.closed.index`).
367	*
368	* @api
369	* @param {string} name The readonly index name (e.g. 'stream-foo.closed').
370	* @returns {ReadableIndex}
371	* @throws {Error} if the readonly index does not exist.
372	*/
373	openReadonlyIndex(name) {
374	if (name in this.readonlyIndexes) {	44!
UNCOV 375	return this.readonlyIndexes[name];	×
376	}
377	const indexName = this.storageFile + '.' + name + '.index';	44✔
378	assert(fs.existsSync(path.join(this.indexDirectory, indexName)), `Index "${name}" does not exist.`);	44✔
379	const { index } = this.createIndex(indexName, Object.assign({}, this.indexOptions));	44✔
380	index.open();	44✔
381	this.readonlyIndexes[name] = index;	44✔
382	return index;	44✔
383	}
384
385	/**
386	* Open an existing index.
387	*
388	* @api
389	* @param {string} name The index name.
390	* @param {Matcher} [matcher] The matcher object or function that the index needs to have been defined with. If not given it will not be validated.
391	* @returns {ReadableIndex}
392	* @throws {Error} if the index with that name does not exist.
393	* @throws {Error} if the HMAC for the matcher does not match.
394	*/
395	openIndex(name, matcher) {
396	if (name === '_all') {	680✔
397	return this.index;	8✔
398	}
399	if (name in this.secondaryIndexes) {	672✔
400	return this.secondaryIndexes[name].index;	600✔
401	}
402
403	const indexName = this.storageFile + '.' + name + '.index';	72✔
404	assert(fs.existsSync(path.join(this.indexDirectory, indexName)), `Index "${name}" does not exist.`);	72✔
405
406	const metadata = buildMetadataForMatcher(matcher, this.hmac);	68✔
407	let { index } = this.secondaryIndexes[name] = this.createIndex(indexName, Object.assign({}, this.indexOptions, { metadata }));	68✔
408
409	index.open();	56✔
410	return index;	56✔
411	}
412
413	/**
414	* Helper method to iterate over all documents.
415	*
416	* @protected
417	* @param {function(object, EntryInterface)} iterationHandler
418	*/
419	forEachDocument(iterationHandler) {
420	/* istanbul ignore if */
421	if (typeof iterationHandler !== 'function') {	804✔
422	return;
423	}
424
425	const entries = this.index.all();	804✔
426
427	for (let entry of entries) {	804✔
428	const document = this.readFrom(entry.partition, entry.position, entry.size);	1,732✔
429	iterationHandler(document, entry);	1,732✔
430	}
431	}
432
433	/**
434	* Helper method to iterate over all secondary indexes.
435	*
436	* @protected
437	* @param {function(ReadableIndex, string)} iterationHandler
438	* @param {object} [matchDocument] If supplied, only indexes the document matches on will be iterated.
439	*/
440	forEachSecondaryIndex(iterationHandler, matchDocument) {
441	/* istanbul ignore if */
442	if (typeof iterationHandler !== 'function') {	4,816✔
443	return;
444	}
445
446	for (let indexName of Object.keys(this.secondaryIndexes)) {	4,816✔
447	if (!matchDocument \|\| matches(matchDocument, this.secondaryIndexes[indexName].matcher)) {	4,648✔
448	iterationHandler(this.secondaryIndexes[indexName].index, indexName);	2,408✔
449	}
450	}
451	}
452
453	/**
454	* Helper method to iterate over all partitions.
455	*
456	* @protected
457	* @param {function(ReadablePartition)} iterationHandler
458	*/
459	forEachPartition(iterationHandler) {
460	/* istanbul ignore if */
461	if (typeof iterationHandler !== 'function') {	1,432✔
462	return;
463	}
464
465	for (let partition of Object.keys(this.partitions)) {	1,432✔
466	iterationHandler(this.partitions[partition]);	1,436✔
467	}
468	}
469
470	}
471
472	module.exports = ReadableStorage;	4✔
473	module.exports.matches = matches;	4✔

albe / node-event-storage / 23400890631

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