'use strict';
var Emitter = require('events').EventEmitter;
var GridFSBucketReadStream = require('./download');
var GridFSBucketWriteStream = require('./upload');
var shallowClone = require('../utils').shallowClone;
var toError = require('../utils').toError;
var util = require('util');
var executeOperation = require('../utils').executeOperation;
var DEFAULT_GRIDFS_BUCKET_OPTIONS = {
bucketName: 'fs',
chunkSizeBytes: 255 * 1024
};
module.exports = GridFSBucket;
/**
* Constructor for a streaming GridFS interface
* @class
* @param {Db} db A db handle
* @param {object} [options] Optional settings.
* @param {string} [options.bucketName="fs"] The 'files' and 'chunks' collections will be prefixed with the bucket name followed by a dot.
* @param {number} [options.chunkSizeBytes=255 * 1024] Number of bytes stored in each chunk. Defaults to 255KB
* @param {object} [options.writeConcern] Optional write concern to be passed to write operations, for instance `{ w: 1 }`
* @param {object} [options.readPreference] Optional read preference to be passed to read operations
* @fires GridFSBucketWriteStream#index
* @return {GridFSBucket}
*/
function GridFSBucket(db, options) {
Emitter.apply(this);
this.setMaxListeners(0);
if (options && typeof options === 'object') {
options = shallowClone(options);
var keys = Object.keys(DEFAULT_GRIDFS_BUCKET_OPTIONS);
for (var i = 0; i < keys.length; ++i) {
if (!options[keys[i]]) {
options[keys[i]] = DEFAULT_GRIDFS_BUCKET_OPTIONS[keys[i]];
}
}
} else {
options = DEFAULT_GRIDFS_BUCKET_OPTIONS;
}
this.s = {
db: db,
options: options,
_chunksCollection: db.collection(options.bucketName + '.chunks'),
_filesCollection: db.collection(options.bucketName + '.files'),
checkedIndexes: false,
calledOpenUploadStream: false,
promiseLibrary: db.s.promiseLibrary || Promise
};
}
util.inherits(GridFSBucket, Emitter);
/**
* When the first call to openUploadStream is made, the upload stream will
* check to see if it needs to create the proper indexes on the chunks and
* files collections. This event is fired either when 1) it determines that
* no index creation is necessary, 2) when it successfully creates the
* necessary indexes.
*
* @event GridFSBucket#index
* @type {Error}
*/
/**
* Returns a writable stream (GridFSBucketWriteStream) for writing
* buffers to GridFS. The stream's 'id' property contains the resulting
* file's id.
* @method
* @param {string} filename The value of the 'filename' key in the files doc
* @param {object} [options] Optional settings.
* @param {number} [options.chunkSizeBytes] Optional overwrite this bucket's chunkSizeBytes for this file
* @param {object} [options.metadata] Optional object to store in the file document's `metadata` field
* @param {string} [options.contentType] Optional string to store in the file document's `contentType` field
* @param {array} [options.aliases] Optional array of strings to store in the file document's `aliases` field
* @param {boolean} [options.disableMD5=false] If true, disables adding an md5 field to file data
* @return {GridFSBucketWriteStream}
*/
GridFSBucket.prototype.openUploadStream = function(filename, options) {
if (options) {
options = shallowClone(options);
} else {
options = {};
}
if (!options.chunkSizeBytes) {
options.chunkSizeBytes = this.s.options.chunkSizeBytes;
}
return new GridFSBucketWriteStream(this, filename, options);
};
/**
* Returns a writable stream (GridFSBucketWriteStream) for writing
* buffers to GridFS for a custom file id. The stream's 'id' property contains the resulting
* file's id.
* @method
* @param {string|number|object} id A custom id used to identify the file
* @param {string} filename The value of the 'filename' key in the files doc
* @param {object} [options] Optional settings.
* @param {number} [options.chunkSizeBytes] Optional overwrite this bucket's chunkSizeBytes for this file
* @param {object} [options.metadata] Optional object to store in the file document's `metadata` field
* @param {string} [options.contentType] Optional string to store in the file document's `contentType` field
* @param {array} [options.aliases] Optional array of strings to store in the file document's `aliases` field
* @param {boolean} [options.disableMD5=false] If true, disables adding an md5 field to file data
* @return {GridFSBucketWriteStream}
*/
GridFSBucket.prototype.openUploadStreamWithId = function(id, filename, options) {
if (options) {
options = shallowClone(options);
} else {
options = {};
}
if (!options.chunkSizeBytes) {
options.chunkSizeBytes = this.s.options.chunkSizeBytes;
}
options.id = id;
return new GridFSBucketWriteStream(this, filename, options);
};
/**
* Returns a readable stream (GridFSBucketReadStream) for streaming file
* data from GridFS.
* @method
* @param {ObjectId} id The id of the file doc
* @param {Object} [options] Optional settings.
* @param {Number} [options.start] Optional 0-based offset in bytes to start streaming from
* @param {Number} [options.end] Optional 0-based offset in bytes to stop streaming before
* @return {GridFSBucketReadStream}
*/
GridFSBucket.prototype.openDownloadStream = function(id, options) {
var filter = { _id: id };
options = {
start: options && options.start,
end: options && options.end
};
return new GridFSBucketReadStream(
this.s._chunksCollection,
this.s._filesCollection,
this.s.options.readPreference,
filter,
options
);
};
/**
* Deletes a file with the given id
* @method
* @param {ObjectId} id The id of the file doc
* @param {GridFSBucket~errorCallback} [callback]
*/
GridFSBucket.prototype.delete = function(id, callback) {
return executeOperation(this.s.db.s.topology, _delete, [this, id, callback], {
skipSessions: true
});
};
/**
* @ignore
*/
function _delete(_this, id, callback) {
_this.s._filesCollection.deleteOne({ _id: id }, function(error, res) {
if (error) {
return callback(error);
}
_this.s._chunksCollection.deleteMany({ files_id: id }, function(error) {
if (error) {
return callback(error);
}
// Delete orphaned chunks before returning FileNotFound
if (!res.result.n) {
var errmsg = 'FileNotFound: no file with id ' + id + ' found';
return callback(new Error(errmsg));
}
callback();
});
});
}
/**
* Convenience wrapper around find on the files collection
* @method
* @param {Object} filter
* @param {Object} [options] Optional settings for cursor
* @param {number} [options.batchSize] Optional batch size for cursor
* @param {number} [options.limit] Optional limit for cursor
* @param {number} [options.maxTimeMS] Optional maxTimeMS for cursor
* @param {boolean} [options.noCursorTimeout] Optionally set cursor's `noCursorTimeout` flag
* @param {number} [options.skip] Optional skip for cursor
* @param {object} [options.sort] Optional sort for cursor
* @return {Cursor}
*/
GridFSBucket.prototype.find = function(filter, options) {
filter = filter || {};
options = options || {};
var cursor = this.s._filesCollection.find(filter);
if (options.batchSize != null) {
cursor.batchSize(options.batchSize);
}
if (options.limit != null) {
cursor.limit(options.limit);
}
if (options.maxTimeMS != null) {
cursor.maxTimeMS(options.maxTimeMS);
}
if (options.noCursorTimeout != null) {
cursor.addCursorFlag('noCursorTimeout', options.noCursorTimeout);
}
if (options.skip != null) {
cursor.skip(options.skip);
}
if (options.sort != null) {
cursor.sort(options.sort);
}
return cursor;
};
/**
* Returns a readable stream (GridFSBucketReadStream) for streaming the
* file with the given name from GridFS. If there are multiple files with
* the same name, this will stream the most recent file with the given name
* (as determined by the `uploadDate` field). You can set the `revision`
* option to change this behavior.
* @method
* @param {String} filename The name of the file to stream
* @param {Object} [options] Optional settings
* @param {number} [options.revision=-1] The revision number relative to the oldest file with the given filename. 0 gets you the oldest file, 1 gets you the 2nd oldest, -1 gets you the newest.
* @param {Number} [options.start] Optional 0-based offset in bytes to start streaming from
* @param {Number} [options.end] Optional 0-based offset in bytes to stop streaming before
* @return {GridFSBucketReadStream}
*/
GridFSBucket.prototype.openDownloadStreamByName = function(filename, options) {
var sort = { uploadDate: -1 };
var skip = null;
if (options && options.revision != null) {
if (options.revision >= 0) {
sort = { uploadDate: 1 };
skip = options.revision;
} else {
skip = -options.revision - 1;
}
}
var filter = { filename: filename };
options = {
sort: sort,
skip: skip,
start: options && options.start,
end: options && options.end
};
return new GridFSBucketReadStream(
this.s._chunksCollection,
this.s._filesCollection,
this.s.options.readPreference,
filter,
options
);
};
/**
* Renames the file with the given _id to the given string
* @method
* @param {ObjectId} id the id of the file to rename
* @param {String} filename new name for the file
* @param {GridFSBucket~errorCallback} [callback]
*/
GridFSBucket.prototype.rename = function(id, filename, callback) {
return executeOperation(this.s.db.s.topology, _rename, [this, id, filename, callback], {
skipSessions: true
});
};
/**
* @ignore
*/
function _rename(_this, id, filename, callback) {
var filter = { _id: id };
var update = { $set: { filename: filename } };
_this.s._filesCollection.updateOne(filter, update, function(error, res) {
if (error) {
return callback(error);
}
if (!res.result.n) {
return callback(toError('File with id ' + id + ' not found'));
}
callback();
});
}
/**
* Removes this bucket's files collection, followed by its chunks collection.
* @method
* @param {GridFSBucket~errorCallback} [callback]
*/
GridFSBucket.prototype.drop = function(callback) {
return executeOperation(this.s.db.s.topology, _drop, [this, callback], {
skipSessions: true
});
};
/**
* Return the db logger
* @method
* @return {Logger} return the db logger
* @ignore
*/
GridFSBucket.prototype.getLogger = function() {
return this.s.db.s.logger;
};
/**
* @ignore
*/
function _drop(_this, callback) {
_this.s._filesCollection.drop(function(error) {
if (error) {
return callback(error);
}
_this.s._chunksCollection.drop(function(error) {
if (error) {
return callback(error);
}
return callback();
});
});
}
/**
* Callback format for all GridFSBucket methods that can accept a callback.
* @callback GridFSBucket~errorCallback
* @param {MongoError} error An error instance representing any errors that occurred
*/