JSDoc: Class: InflateAuto

new InflateAuto(optsopt)

Decompressor for DEFLATE compressed data in either zlib, gzip, or "raw" format.

This class is intended to be a drop-in replacement for zlib.Inflate, zlib.InflateRaw, and/or zlib.Gunzip.

This class emits the additional event 'format' when the compression format has been set or detected with the instance of the format class which will be used to decode the data.

Parameters:

Name	Type	Attributes	Description
`opts`	InflateAuto.InflateAutoOptions	<optional>	Combined options for this class and for the detected format.

Source:

index.js, line 180

Extends

stream.Transform

Members

(static, constant) detectors :InflateAuto.FormatDetector

Format detectors supported by default.

Type:

InflateAuto.FormatDetector

Properties:

Name	Type	Description
`detectDeflate`	InflateAuto.FormatDetector	Detects the ZLIB DEFLATE format, as specified in RFC 1950.
`detectGzip`	InflateAuto.FormatDetector	Detects the GZIP format, as specified in RFC 1952.

Source:

index.js, line 328

Methods

(static) createInflateAuto(optsopt) → {InflateAuto}

Creates an instance of InflateAuto. Analogous to zlib.createInflate.

Parameters:

Name	Type	Attributes	Description
`opts`	object	<optional>	Constructor options.

Source:

index.js, line 318

Returns:

Instance of InflateAuto with opts.

Type: InflateAuto

(static) inflateAuto(buffernon-null, optsopt, callbacknon-null)

Decompresses a compressed Buffer. Analogous to zlib.inflate.

Parameters:

Name	Type	Attributes	Description
`buffer`	Buffer		Compressed data to decompress.
`opts`	object	<optional>	Decompression options.
`callback`	function		Callback which receives the decompressed data.

Source:

index.js, line 396

(static) inflateAutoSync(buffernon-null, optsopt) → (non-null) {Buffer}

Decompresses a compressed Buffer synchronously. Analogous to zlib.inflateSync.

Parameters:

Name	Type	Attributes	Description
`buffer`	Buffer		Compressed data to decompress.
`opts`	object	<optional>	Decompression options.

Source:

index.js, line 411

Returns:

Decompressed data.

Type: Buffer

_destroy(err, callback)

Implements #destroy on this stream by ensuring _handle is set null (for _closed) as done by zlib.ZlibBase#_destroy since nodejs/node@8a02d941b6c (v12) and nodejs/node@c6a43fa2ef (v10.15.1).

Parameters:

Name	Type	Description
`err`	Error	Error passed to #destroy.
`callback`	function	Callback once destroyed.

Source:

index.js, line 423

(protected) _detectFormat(chunk, end) → (nullable) {function}

Detects the format of a given Buffer. This method passes chunk to each of the InflateAutoOptions.detectors. The first detector to match is returned. If at least one detector is indeterminate and end is false, null is returned. Otherwise InflateAutoOptions.defaultFormat is returned or an Error is thrown.

Parameters:

Name	Type	Description
`chunk`	Buffer	Beginning of data for which to detect the compression format.
`end`	boolean	Is `chunk` the end of the data stream?

Source:

index.js, line 449

Throws:

If any detector throws or end is true and no default format is given.

Returns:

An instance of the zlib type which will decode chunk and subsequent data, or null if chunk is too short to deduce the format conclusively and end is false.

Type: function

(protected) _flush(callback)

Flushes any buffered data when the stream is ending.

Parameters:

Name	Type	Description
`callback`	function	Callback once stream has ended.

Source:

index.js, line 477

(protected) _processChunk(chunknon-null, flushFlag, cbopt, nullable) → {Buffer|undefined}

Process a chunk of data, synchronously or asynchronously.

Parameters:

Name	Type	Attributes	Description
`chunk`	external:ArrayBufferView		Chunk of data to write.
`flushFlag`	number		Flush flag with which to write the data.
`cb`	function	<optional> <nullable>	Callback. Synchronous if falsey.

Source:

index.js, line 519

Throws:

If a detector or format constructor throws and cb is not a function.

Returns:

Decompressed chunk if synchronous, otherwise undefined.

Type: Buffer | undefined

(protected) _queueMethodCall(name, argsnon-null)

Queues a method call for the format until one is set.

In addition to queueing the method call, if the arguments includes a callback function, that function is invoked immediately in order to prevent deadlocks in existing code which doesn't write until the callback completes.

Parameters:

Name	Type	Description
`name`	string	Name of the method to call.
`args`	arguments \| Array	Arguments to pass to the method call.

Source:

index.js, line 833

(protected) _transform(chunk, encodingnullable, callbackopt, nullable)

Inflates a chunk of data.

Parameters:

Name	Type	Attributes	Description
`chunk`	Buffer		Chunk of data to inflate.
`encoding`	string	<nullable>	Ignored.
`callback`	function	<optional> <nullable>	Callback once chunk has been written.

Source:

index.js, line 667

close(callbackopt, nullable)

Closes this stream and its underlying resources (zlib handle).

Parameters:

Name	Type	Attributes	Description
`callback`	function	<optional> <nullable>	Callback once resources have been freed.

Source:

index.js, line 729

flush(kindopt, callbackopt, nullable)

Flushes queued writes with a given zlib flush behavior.

Parameters:

Name	Type	Attributes	Description
`kind`	number	<optional>	Flush behavior of writes to zlib. Must be one of the zlib flush constant values.
`callback`	function	<optional> <nullable>	Callback once data has been flushed.

Source:

index.js, line 760

getFormat() → (nullable) {function}

Gets the constructor function used to create the decoder for data written to this stream.

Source:

index.js, line 748

See:

Returns:

Constructor for the stream class which is used to decode data written to this stream, or undefined if the format has not been detected or set.

Type: function

params(level, strategy, callbackopt, nullable)

Sets the inflate compression parameters.

For inflate, this has no effect. This method is kept for compatibility only. It is only defined when Inflate.prototype.params is defined.

Note: Parameter checking is not performed if the format hasn't been determined. Although this is currently possible (since parameters are currently independent of format) it requires instantiating a zlib object with bindings, which is heavy for checking args which haven't changed since this method was added to the Node API. If there is a use case for such checking, please open an issue.

Parameters:

Name	Type	Attributes	Description
`level`	number		Compression level (between zlib.Z_MIN_LEVEL and zlib.Z_MAX_LEVEL).
`strategy`	number		Compression strategy (one of the zlib strategy constant values).
`callback`	function	<optional> <nullable>	Callback once parameters have been set.

Source:

index.js, line 792

reset()

Discards any buffered data and resets the decoder to its initial state.

Note: If a format has been detected, reset does not currently clear the detection (for performance and to reduce complexity). If there is a real-world use case for this type of "full reset", please open an issue.

Source:

index.js, line 811

setFormat(Format)

Sets the format which will be used to decode data written to this stream. Note: The current implementation only allows the format to be set once. Calling this method after the format has been set will throw an exception.

Parameters:

Name	Type	Description
`Format`	function	Constructor for the stream class which will be used to decode data written to this stream.

Source:

index.js, line 610

See:

#_detectFormat()

Throws:

If previously set to a different Format or Format constructor throws.

Type Definitions

FormatDetector(chunknon-null) → {function|undefined}

A function which detects the format for a given chunk of data. The function may be called any number of times with non-null, non-empty Buffers. The return value can be any of the following:

If a format can be definitively determined: A constructor for the stream.Duplex class of the format which takes the options Object as an argument. An instance of the class will be used to decode data written to this stream.
If all formats supported by this detector can be definitively ruled out: null. This function will not be called again unless the stream is reset.
None of the above: undefined. This function will be called again when more data is available.

Parameters:

Name	Type	Description
`chunk`	Buffer	Non-empty chunk of data to check.

Source:

index.js, line 95

Returns:

Constructor for a stream.Duplex class to decode chunk and subsequent data written to the stream, null if the format is unrecognized/unsupported, undefined if format detection requires more data.

Type: function | undefined

InflateAutoOptions

Options for InflateAuto. Note that the InflateAuto options object is passed to the constructor for the detected data format to allow drop-in replacement. It may have additional properties to the ones defined here.

Type:

Object

Properties:

Name	Type	Attributes	Description
`defaultFormat`	function \| boolean		Constructor of the format which is used if no detectors match. Pass `null` or `false` for no default. (default: `InflateRaw`)
`detectors`	Array.<!InflateAuto.FormatDetector>	<optional>	Functions which detect the data format for a chunk of data and return the constructor for a class to decode the data. If any detector requires large amounts of data, adjust `highWaterMark` appropriately. (default: `[detectDeflate, detectGzip]`)

Source:

index.js, line 140