Class: CommandCursor

CommandCursor

Creates a new Command Cursor instance (INTERNAL TYPE, do not instantiate directly)

Fires:
Returns:
CommandCursor instance.

Extends

Methods

Set the batch size for the cursor.

Name Type Description
value number

The batchSize for the cursor.

Throws:

Clone the cursor

close(callback){Promise}

Close the cursor, sending a KillCursor command and emitting close.

Name Type Description
callback CommandCursor~resultCallback optional

The result callback.

Returns:
Promise if no callback passed

each(callback){null}

Iterates over all the documents for this cursor. As with {cursor.toArray},
not all of the elements will be iterated if this cursor had been previouly accessed.
In that case, {cursor.rewind} can be used to reset the cursor. However, unlike
{cursor.toArray}, the cursor will only hold a maximum of batch size elements
at any given time if batch size is specified. Otherwise, the caller is responsible
for making sure that the entire result can fit the memory.

Name Type Description
callback CommandCursor~resultCallback

The result callback.

Throws:

isClosed(){boolean}

Is the cursor closed

Add a maxTimeMS stage to the aggregation pipeline

Name Type Description
value number

The state maxTimeMS value.

next(callback){Promise}

Get the next available document from the cursor, returns null if no more documents are available.

Name Type Description
callback CommandCursor~resultCallback optional

The result callback.

Throws:
Returns:
Promise if no callback passed

This method will cause a stream in flowing-mode to stop emitting data events. Any data that becomes available will remain in the internal buffer.

inherited pipe(destination, options){null}

This method pulls all the data out of a readable stream, and writes it to the supplied destination, automatically managing the flow so that the destination is not overwhelmed by a fast readable stream.

Name Type Description
destination Writable

The destination for writing data

options object optional

Pipe options

inherited read(size){String|Buffer|null}

The read() method pulls some data out of the internal buffer and returns it. If there is no data available, then it will return null.

Name Type Description
size number

Optional argument to specify how much data to read.

This method will cause the readable stream to resume emitting data events.

Resets the cursor

inherited setEncoding(encoding){null}

Call this function to cause the stream to return strings of the specified encoding instead of Buffer objects.

Name Type Description
encoding string

The encoding to use.

setReadPreference(readPreference){Cursor}

Set the ReadPreference for the cursor.

Name Type Description
readPreference string | ReadPreference

The new read preference for the cursor.

Throws:

toArray(callback){Promise}

Returns an array of documents. The caller is responsible for making sure that there
is enough memory to store the results. Note that the array only contain partial
results when this cursor had been previouly accessed.

Name Type Description
callback CommandCursor~toArrayResultCallback optional

The result callback.

Throws:
Returns:
Promise if no callback passed

inherited unpipe(destination){null}

This method will remove the hooks set up for a previous pipe() call.

Name Type Description
destination Writable optional

The destination for writing data

inherited unshift(chunk){null}

This is useful in certain cases where a stream is being consumed by a parser, which needs to "un-consume" some data that it has optimistically pulled out of the source, so that the stream can be passed on to some other party.

Name Type Description
chunk Buffer | string

Chunk of data to unshift onto the read queue.

inherited wrap(stream){null}

Versions of Node prior to v0.10 had streams that did not implement the entire Streams API as it is today. (See "Compatibility" below for more information.)

Name Type Description
stream Stream

An "old style" readable stream.

Type Definitions

endCallback(error)

The callback error format for the forEach iterator method

Name Type Description
error MongoError

An error instance representing the error during the execution.

iteratorCallback(doc)

The callback format for the forEach iterator method

Name Type Description
doc Object

An emitted document for the iterator

resultCallback(error, result)

The callback format for results

Name Type Description
error MongoError

An error instance representing the error during the execution.

result object | null

The result object if the command was executed successfully.

toArrayResultCallback(error, documents)

The callback format for results

Name Type Description
error MongoError

An error instance representing the error during the execution.

documents Array.<object>

All the documents the satisfy the cursor.

Events

CommandCursor stream close event

Type:
  • null

CommandCursor stream data event, fired for each document in the cursor.

Type:
  • object

CommandCursor stream end event

Type:
  • null

CommandCursor stream readable event

Type:
  • null
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