First commit

node_modules/mongodb/lib/gridfs/download.js

@@ -0,0 +1,313 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.GridFSBucketReadStream = void 0;
+const stream_1 = require("stream");
+const error_1 = require("../error");
+/**
+ * A readable stream that enables you to read buffers from GridFS.
+ *
+ * Do not instantiate this class directly. Use `openDownloadStream()` instead.
+ * @public
+ */
+class GridFSBucketReadStream extends stream_1.Readable {
+    /**
+     * @param chunks - Handle for chunks collection
+     * @param files - Handle for files collection
+     * @param readPreference - The read preference to use
+     * @param filter - The filter to use to find the file document
+     * @internal
+     */
+    constructor(chunks, files, readPreference, filter, options) {
+        super();
+        this.s = {
+            bytesToTrim: 0,
+            bytesToSkip: 0,
+            bytesRead: 0,
+            chunks,
+            expected: 0,
+            files,
+            filter,
+            init: false,
+            expectedEnd: 0,
+            options: {
+                start: 0,
+                end: 0,
+                ...options
+            },
+            readPreference
+        };
+    }
+    /**
+     * Reads from the cursor and pushes to the stream.
+     * Private Impl, do not call directly
+     * @internal
+     */
+    _read() {
+        if (this.destroyed)
+            return;
+        waitForFile(this, () => doRead(this));
+    }
+    /**
+     * Sets the 0-based offset in bytes to start streaming from. Throws
+     * an error if this stream has entered flowing mode
+     * (e.g. if you've already called `on('data')`)
+     *
+     * @param start - 0-based offset in bytes to start streaming from
+     */
+    start(start = 0) {
+        throwIfInitialized(this);
+        this.s.options.start = start;
+        return this;
+    }
+    /**
+     * Sets the 0-based offset in bytes to start streaming from. Throws
+     * an error if this stream has entered flowing mode
+     * (e.g. if you've already called `on('data')`)
+     *
+     * @param end - Offset in bytes to stop reading at
+     */
+    end(end = 0) {
+        throwIfInitialized(this);
+        this.s.options.end = end;
+        return this;
+    }
+    /**
+     * Marks this stream as aborted (will never push another `data` event)
+     * and kills the underlying cursor. Will emit the 'end' event, and then
+     * the 'close' event once the cursor is successfully killed.
+     */
+    async abort() {
+        this.push(null);
+        this.destroyed = true;
+        if (this.s.cursor) {
+            try {
+                await this.s.cursor.close();
+            }
+            finally {
+                this.emit(GridFSBucketReadStream.CLOSE);
+            }
+        }
+        else {
+            if (!this.s.init) {
+                // If not initialized, fire close event because we will never
+                // get a cursor
+                this.emit(GridFSBucketReadStream.CLOSE);
+            }
+        }
+    }
+}
+exports.GridFSBucketReadStream = GridFSBucketReadStream;
+/**
+ * An error occurred
+ * @event
+ */
+GridFSBucketReadStream.ERROR = 'error';
+/**
+ * Fires when the stream loaded the file document corresponding to the provided id.
+ * @event
+ */
+GridFSBucketReadStream.FILE = 'file';
+/**
+ * Emitted when a chunk of data is available to be consumed.
+ * @event
+ */
+GridFSBucketReadStream.DATA = 'data';
+/**
+ * Fired when the stream is exhausted (no more data events).
+ * @event
+ */
+GridFSBucketReadStream.END = 'end';
+/**
+ * Fired when the stream is exhausted and the underlying cursor is killed
+ * @event
+ */
+GridFSBucketReadStream.CLOSE = 'close';
+function throwIfInitialized(stream) {
+    if (stream.s.init) {
+        throw new error_1.MongoGridFSStreamError('Options cannot be changed after the stream is initialized');
+    }
+}
+function doRead(stream) {
+    if (stream.destroyed)
+        return;
+    if (!stream.s.cursor)
+        return;
+    if (!stream.s.file)
+        return;
+    const handleReadResult = ({ error, doc }) => {
+        if (stream.destroyed) {
+            return;
+        }
+        if (error) {
+            stream.emit(GridFSBucketReadStream.ERROR, error);
+            return;
+        }
+        if (!doc) {
+            stream.push(null);
+            stream.s.cursor?.close().then(() => {
+                stream.emit(GridFSBucketReadStream.CLOSE);
+            }, error => {
+                stream.emit(GridFSBucketReadStream.ERROR, error);
+            });
+            return;
+        }
+        if (!stream.s.file)
+            return;
+        const bytesRemaining = stream.s.file.length - stream.s.bytesRead;
+        const expectedN = stream.s.expected++;
+        const expectedLength = Math.min(stream.s.file.chunkSize, bytesRemaining);
+        if (doc.n > expectedN) {
+            return stream.emit(GridFSBucketReadStream.ERROR, new error_1.MongoGridFSChunkError(`ChunkIsMissing: Got unexpected n: ${doc.n}, expected: ${expectedN}`));
+        }
+        if (doc.n < expectedN) {
+            return stream.emit(GridFSBucketReadStream.ERROR, new error_1.MongoGridFSChunkError(`ExtraChunk: Got unexpected n: ${doc.n}, expected: ${expectedN}`));
+        }
+        let buf = Buffer.isBuffer(doc.data) ? doc.data : doc.data.buffer;
+        if (buf.byteLength !== expectedLength) {
+            if (bytesRemaining <= 0) {
+                return stream.emit(GridFSBucketReadStream.ERROR, new error_1.MongoGridFSChunkError(`ExtraChunk: Got unexpected n: ${doc.n}, expected file length ${stream.s.file.length} bytes but already read ${stream.s.bytesRead} bytes`));
+            }
+            return stream.emit(GridFSBucketReadStream.ERROR, new error_1.MongoGridFSChunkError(`ChunkIsWrongSize: Got unexpected length: ${buf.byteLength}, expected: ${expectedLength}`));
+        }
+        stream.s.bytesRead += buf.byteLength;
+        if (buf.byteLength === 0) {
+            return stream.push(null);
+        }
+        let sliceStart = null;
+        let sliceEnd = null;
+        if (stream.s.bytesToSkip != null) {
+            sliceStart = stream.s.bytesToSkip;
+            stream.s.bytesToSkip = 0;
+        }
+        const atEndOfStream = expectedN === stream.s.expectedEnd - 1;
+        const bytesLeftToRead = stream.s.options.end - stream.s.bytesToSkip;
+        if (atEndOfStream && stream.s.bytesToTrim != null) {
+            sliceEnd = stream.s.file.chunkSize - stream.s.bytesToTrim;
+        }
+        else if (stream.s.options.end && bytesLeftToRead < doc.data.byteLength) {
+            sliceEnd = bytesLeftToRead;
+        }
+        if (sliceStart != null || sliceEnd != null) {
+            buf = buf.slice(sliceStart || 0, sliceEnd || buf.byteLength);
+        }
+        stream.push(buf);
+        return;
+    };
+    stream.s.cursor.next().then(doc => handleReadResult({ error: null, doc }), error => handleReadResult({ error, doc: null }));
+}
+function init(stream) {
+    const findOneOptions = {};
+    if (stream.s.readPreference) {
+        findOneOptions.readPreference = stream.s.readPreference;
+    }
+    if (stream.s.options && stream.s.options.sort) {
+        findOneOptions.sort = stream.s.options.sort;
+    }
+    if (stream.s.options && stream.s.options.skip) {
+        findOneOptions.skip = stream.s.options.skip;
+    }
+    const handleReadResult = ({ error, doc }) => {
+        if (error) {
+            return stream.emit(GridFSBucketReadStream.ERROR, error);
+        }
+        if (!doc) {
+            const identifier = stream.s.filter._id
+                ? stream.s.filter._id.toString()
+                : stream.s.filter.filename;
+            const errmsg = `FileNotFound: file ${identifier} was not found`;
+            // TODO(NODE-3483)
+            const err = new error_1.MongoRuntimeError(errmsg);
+            err.code = 'ENOENT'; // TODO: NODE-3338 set property as part of constructor
+            return stream.emit(GridFSBucketReadStream.ERROR, err);
+        }
+        // If document is empty, kill the stream immediately and don't
+        // execute any reads
+        if (doc.length <= 0) {
+            stream.push(null);
+            return;
+        }
+        if (stream.destroyed) {
+            // If user destroys the stream before we have a cursor, wait
+            // until the query is done to say we're 'closed' because we can't
+            // cancel a query.
+            stream.emit(GridFSBucketReadStream.CLOSE);
+            return;
+        }
+        try {
+            stream.s.bytesToSkip = handleStartOption(stream, doc, stream.s.options);
+        }
+        catch (error) {
+            return stream.emit(GridFSBucketReadStream.ERROR, error);
+        }
+        const filter = { files_id: doc._id };
+        // Currently (MongoDB 3.4.4) skip function does not support the index,
+        // it needs to retrieve all the documents first and then skip them. (CS-25811)
+        // As work around we use $gte on the "n" field.
+        if (stream.s.options && stream.s.options.start != null) {
+            const skip = Math.floor(stream.s.options.start / doc.chunkSize);
+            if (skip > 0) {
+                filter['n'] = { $gte: skip };
+            }
+        }
+        stream.s.cursor = stream.s.chunks.find(filter).sort({ n: 1 });
+        if (stream.s.readPreference) {
+            stream.s.cursor.withReadPreference(stream.s.readPreference);
+        }
+        stream.s.expectedEnd = Math.ceil(doc.length / doc.chunkSize);
+        stream.s.file = doc;
+        try {
+            stream.s.bytesToTrim = handleEndOption(stream, doc, stream.s.cursor, stream.s.options);
+        }
+        catch (error) {
+            return stream.emit(GridFSBucketReadStream.ERROR, error);
+        }
+        stream.emit(GridFSBucketReadStream.FILE, doc);
+        return;
+    };
+    stream.s.files.findOne(stream.s.filter, findOneOptions).then(doc => handleReadResult({ error: null, doc }), error => handleReadResult({ error, doc: null }));
+}
+function waitForFile(stream, callback) {
+    if (stream.s.file) {
+        return callback();
+    }
+    if (!stream.s.init) {
+        init(stream);
+        stream.s.init = true;
+    }
+    stream.once('file', () => {
+        callback();
+    });
+}
+function handleStartOption(stream, doc, options) {
+    if (options && options.start != null) {
+        if (options.start > doc.length) {
+            throw new error_1.MongoInvalidArgumentError(`Stream start (${options.start}) must not be more than the length of the file (${doc.length})`);
+        }
+        if (options.start < 0) {
+            throw new error_1.MongoInvalidArgumentError(`Stream start (${options.start}) must not be negative`);
+        }
+        if (options.end != null && options.end < options.start) {
+            throw new error_1.MongoInvalidArgumentError(`Stream start (${options.start}) must not be greater than stream end (${options.end})`);
+        }
+        stream.s.bytesRead = Math.floor(options.start / doc.chunkSize) * doc.chunkSize;
+        stream.s.expected = Math.floor(options.start / doc.chunkSize);
+        return options.start - stream.s.bytesRead;
+    }
+    throw new error_1.MongoInvalidArgumentError('Start option must be defined');
+}
+function handleEndOption(stream, doc, cursor, options) {
+    if (options && options.end != null) {
+        if (options.end > doc.length) {
+            throw new error_1.MongoInvalidArgumentError(`Stream end (${options.end}) must not be more than the length of the file (${doc.length})`);
+        }
+        if (options.start == null || options.start < 0) {
+            throw new error_1.MongoInvalidArgumentError(`Stream end (${options.end}) must not be negative`);
+        }
+        const start = options.start != null ? Math.floor(options.start / doc.chunkSize) : 0;
+        cursor.limit(Math.ceil(options.end / doc.chunkSize) - start);
+        stream.s.expectedEnd = Math.ceil(options.end / doc.chunkSize);
+        return Math.ceil(options.end / doc.chunkSize) * doc.chunkSize - options.end;
+    }
+    throw new error_1.MongoInvalidArgumentError('End option must be defined');
+}
+//# sourceMappingURL=download.js.map