// Copyright Joyent, Inc. and other Node contributors.

//

// Permission is hereby granted, free of charge, to any person obtaining a

// copy of this software and associated documentation files (the

// "Software"), to deal in the Software without restriction, including

// without limitation the rights to use, copy, modify, merge, publish,

// distribute, sublicense, and/or sell copies of the Software, and to permit

// persons to whom the Software is furnished to do so, subject to the

// following conditions:

//

// The above copyright notice and this permission notice shall be included

// in all copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN

// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,

// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE

// USE OR OTHER DEALINGS IN THE SOFTWARE.

'use strict';

const {

ERR_BUFFER_TOO_LARGE,

ERR_INVALID_ARG_TYPE,

ERR_OUT_OF_RANGE,

ERR_ZLIB_INITIALIZATION_FAILED

} = require('internal/errors').codes;

const Transform = require('_stream_transform');

const {

_extend,

types: {

isAnyArrayBuffer,

isArrayBufferView

}

} = require('util');

const binding = process.binding('zlib');

const assert = require('assert').ok;

const {

Buffer,

kMaxLength

} = require('buffer');

const constants = process.binding('constants').zlib;

const {

Z_NO_FLUSH, Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, Z_FULL_FLUSH, Z_FINISH,

Z_MIN_CHUNK, Z_MIN_WINDOWBITS, Z_MAX_WINDOWBITS, Z_MIN_LEVEL, Z_MAX_LEVEL,

Z_MIN_MEMLEVEL, Z_MAX_MEMLEVEL, Z_DEFAULT_CHUNK, Z_DEFAULT_COMPRESSION,

Z_DEFAULT_STRATEGY, Z_DEFAULT_WINDOWBITS, Z_DEFAULT_MEMLEVEL, Z_FIXED,

DEFLATE, DEFLATERAW, INFLATE, INFLATERAW, GZIP, GUNZIP, UNZIP

} = constants;

const { inherits } = require('util');

// translation table for return codes.

const codes = {

Z_OK: constants.Z_OK,

Z_STREAM_END: constants.Z_STREAM_END,

Z_NEED_DICT: constants.Z_NEED_DICT,

Z_ERRNO: constants.Z_ERRNO,

Z_STREAM_ERROR: constants.Z_STREAM_ERROR,

Z_DATA_ERROR: constants.Z_DATA_ERROR,

Z_MEM_ERROR: constants.Z_MEM_ERROR,

Z_BUF_ERROR: constants.Z_BUF_ERROR,

Z_VERSION_ERROR: constants.Z_VERSION_ERROR

};

const ckeys = Object.keys(codes);

for (var ck = 0; ck < ckeys.length; ck++) {

var ckey = ckeys[ck];

codes[codes[ckey]] = ckey;

}

function zlibBuffer(engine, buffer, callback) {

// Streams do not support non-Buffer ArrayBufferViews yet. Convert it to a

// Buffer without copying.

if (isArrayBufferView(buffer) &&

Object.getPrototypeOf(buffer) !== Buffer.prototype) {

buffer = Buffer.from(buffer.buffer, buffer.byteOffset, buffer.byteLength);

} else if (isAnyArrayBuffer(buffer)) {

buffer = Buffer.from(buffer);

}

engine.buffers = null;

engine.nread = 0;

engine.cb = callback;

engine.on('data', zlibBufferOnData);

engine.on('error', zlibBufferOnError);

engine.on('end', zlibBufferOnEnd);

engine.end(buffer);

}

function zlibBufferOnData(chunk) {

if (!this.buffers)

this.buffers = [chunk];

else

this.buffers.push(chunk);

this.nread += chunk.length;

}

function zlibBufferOnError(err) {

this.removeAllListeners('end');

this.cb(err);

}

function zlibBufferOnEnd() {

var buf;

var err;

if (this.nread >= kMaxLength) {

err = new ERR_BUFFER_TOO_LARGE();

} else if (this.nread === 0) {

buf = Buffer.alloc(0);

} else {

var bufs = this.buffers;

buf = (bufs.length === 1 ? bufs[0] : Buffer.concat(bufs, this.nread));

}

this.close();

if (err)

this.cb(err);

else if (this._info)

this.cb(null, { buffer: buf, engine: this });

else

this.cb(null, buf);

}

function zlibBufferSync(engine, buffer) {

if (typeof buffer === 'string') {

buffer = Buffer.from(buffer);

} else if (!isArrayBufferView(buffer)) {

if (isAnyArrayBuffer(buffer)) {

buffer = Buffer.from(buffer);

} else {

throw new ERR_INVALID_ARG_TYPE(

'buffer',

['string', 'Buffer', 'TypedArray', 'DataView', 'ArrayBuffer'],

buffer

);

}

}

buffer = processChunkSync(engine, buffer, engine._finishFlushFlag);

if (engine._info)

return { buffer, engine };

return buffer;

}

function zlibOnError(message, errno) {

var self = this.jsref;

// there is no way to cleanly recover.

// continuing only obscures problems.

_close(self);

self._hadError = true;

// eslint-disable-next-line no-restricted-syntax

const error = new Error(message);

error.errno = errno;

error.code = codes[errno];

self.emit('error', error);

}

function flushCallback(level, strategy, callback) {

if (!this._handle)

assert(false, 'zlib binding closed');

this._handle.params(level, strategy);

if (!this._hadError) {

this._level = level;

this._strategy = strategy;

if (callback) callback();

}

}

// 1. Returns false for undefined and NaN

// 2. Returns true for finite numbers

// 3. Throws ERR_INVALID_ARG_TYPE for non-numbers

// 4. Throws ERR_OUT_OF_RANGE for infinite numbers

function checkFiniteNumber(number, name) {

// Common case

if (number === undefined) {

return false;

}

if (Number.isFinite(number)) {

return true; // Is a valid number

}

if (Number.isNaN(number)) {

return false;

}

// Other non-numbers

if (typeof number !== 'number') {

const err = new ERR_INVALID_ARG_TYPE(name, 'number', number);

Error.captureStackTrace(err, checkFiniteNumber);

throw err;

}

// Infinite numbers

const err = new ERR_OUT_OF_RANGE(name, 'a finite number', number);

Error.captureStackTrace(err, checkFiniteNumber);

throw err;

}

// 1. Returns def for undefined and NaN

// 2. Returns number for finite numbers >= lower and <= upper

// 3. Throws ERR_INVALID_ARG_TYPE for non-numbers

// 4. Throws ERR_OUT_OF_RANGE for infinite numbers or numbers > upper or < lower

function checkRangesOrGetDefault(number, name, lower, upper, def) {

if (!checkFiniteNumber(number, name, lower, upper)) {

return def;

}

if (number < lower || number > upper) {

const err = new ERR_OUT_OF_RANGE(name,

`>= ${lower} and <= ${upper}`, number);

Error.captureStackTrace(err, checkRangesOrGetDefault);

throw err;

}

return number;

}

// the Zlib class they all inherit from

// This thing manages the queue of requests, and returns

// true or false if there is anything in the queue when

// you call the .write() method.

function Zlib(opts, mode) {

var chunkSize = Z_DEFAULT_CHUNK;

var flush = Z_NO_FLUSH;

var finishFlush = Z_FINISH;

var windowBits = Z_DEFAULT_WINDOWBITS;

var level = Z_DEFAULT_COMPRESSION;

var memLevel = Z_DEFAULT_MEMLEVEL;

var strategy = Z_DEFAULT_STRATEGY;

var dictionary;

// The Zlib class is not exported to user land, the mode should only be

// passed in by us.

assert(typeof mode === 'number');

assert(mode >= DEFLATE && mode <= UNZIP);

if (opts) {

chunkSize = opts.chunkSize;

if (!checkFiniteNumber(chunkSize, 'options.chunkSize')) {

chunkSize = Z_DEFAULT_CHUNK;

} else if (chunkSize < Z_MIN_CHUNK) {

throw new ERR_OUT_OF_RANGE('options.chunkSize',

`>= ${Z_MIN_CHUNK}`, chunkSize);

}

flush = checkRangesOrGetDefault(

opts.flush, 'options.flush',

Z_NO_FLUSH, Z_BLOCK, Z_NO_FLUSH);

finishFlush = checkRangesOrGetDefault(

opts.finishFlush, 'options.finishFlush',

Z_NO_FLUSH, Z_BLOCK, Z_FINISH);

windowBits = checkRangesOrGetDefault(

opts.windowBits, 'options.windowBits',

Z_MIN_WINDOWBITS, Z_MAX_WINDOWBITS, Z_DEFAULT_WINDOWBITS);

level = checkRangesOrGetDefault(

opts.level, 'options.level',

Z_MIN_LEVEL, Z_MAX_LEVEL, Z_DEFAULT_COMPRESSION);

memLevel = checkRangesOrGetDefault(

opts.memLevel, 'options.memLevel',

Z_MIN_MEMLEVEL, Z_MAX_MEMLEVEL, Z_DEFAULT_MEMLEVEL);

strategy = checkRangesOrGetDefault(

opts.strategy, 'options.strategy',

Z_DEFAULT_STRATEGY, Z_FIXED, Z_DEFAULT_STRATEGY);

dictionary = opts.dictionary;

if (dictionary !== undefined && !isArrayBufferView(dictionary)) {

if (isAnyArrayBuffer(dictionary)) {

dictionary = Buffer.from(dictionary);

} else {

throw new ERR_INVALID_ARG_TYPE(

'options.dictionary',

['Buffer', 'TypedArray', 'DataView', 'ArrayBuffer'],

dictionary

);

}

}

if (opts.encoding || opts.objectMode || opts.writableObjectMode) {

opts = _extend({}, opts);

opts.encoding = null;

opts.objectMode = false;

opts.writableObjectMode = false;

}

}

Transform.call(this, opts);

this.bytesWritten = 0;

this._handle = new binding.Zlib(mode);

this._handle.jsref = this; // Used by processCallback() and zlibOnError()

this._handle.onerror = zlibOnError;

this._hadError = false;

this._writeState = new Uint32Array(2);

if (!this._handle.init(windowBits,

level,

memLevel,

strategy,

this._writeState,

processCallback,

dictionary)) {

throw new ERR_ZLIB_INITIALIZATION_FAILED();

}

this._outBuffer = Buffer.allocUnsafe(chunkSize);

this._outOffset = 0;

this._level = level;

this._strategy = strategy;

this._chunkSize = chunkSize;

this._flushFlag = flush;

this._scheduledFlushFlag = Z_NO_FLUSH;

this._origFlushFlag = flush;

this._finishFlushFlag = finishFlush;

this._info = opts && opts.info;

this.once('end', this.close);

}

inherits(Zlib, Transform);

Object.defineProperty(Zlib.prototype, '_closed', {

configurable: true,

enumerable: true,

get() {

return !this._handle;

}

});

// `bytesRead` made sense as a name when looking from the zlib engine's

// perspective, but it is inconsistent with all other streams exposed by Node.js

// that have this concept, where it stands for the number of bytes read

// *from* the stream (that is, net.Socket/tls.Socket & file system streams).

Object.defineProperty(Zlib.prototype, 'bytesRead', {

configurable: true,

enumerable: true,

get() {

return this.bytesWritten;

},

set(value) {

this.bytesWritten = value;

}

});

Zlib.prototype.params = function params(level, strategy, callback) {

checkRangesOrGetDefault(level, 'level', Z_MIN_LEVEL, Z_MAX_LEVEL);

checkRangesOrGetDefault(strategy, 'strategy', Z_DEFAULT_STRATEGY, Z_FIXED);

if (this._level !== level || this._strategy !== strategy) {

this.flush(Z_SYNC_FLUSH,

flushCallback.bind(this, level, strategy, callback));

} else {

process.nextTick(callback);

}

};

Zlib.prototype.reset = function reset() {

if (!this._handle)

assert(false, 'zlib binding closed');

return this._handle.reset();

};

// This is the _flush function called by the transform class,

// internally, when the last chunk has been written.

Zlib.prototype._flush = function _flush(callback) {

this._transform(Buffer.alloc(0), '', callback);

};

// If a flush is scheduled while another flush is still pending, a way to figure

// out which one is the "stronger" flush is needed.

// Roughly, the following holds:

// Z_NO_FLUSH (< Z_TREES) < Z_BLOCK < Z_PARTIAL_FLUSH <

// Z_SYNC_FLUSH < Z_FULL_FLUSH < Z_FINISH

const flushiness = [];

let i = 0;

for (const flushFlag of [Z_NO_FLUSH, Z_BLOCK, Z_PARTIAL_FLUSH,

Z_SYNC_FLUSH, Z_FULL_FLUSH, Z_FINISH]) {

flushiness[flushFlag] = i++;

}

function maxFlush(a, b) {

return flushiness[a] > flushiness[b] ? a : b;

}

Zlib.prototype.flush = function flush(kind, callback) {

var ws = this._writableState;

if (typeof kind === 'function' || (kind === undefined && !callback)) {

callback = kind;

kind = Z_FULL_FLUSH;

}

if (ws.ended) {

if (callback)

process.nextTick(callback);

} else if (ws.ending) {

if (callback)

this.once('end', callback);

} else if (ws.needDrain) {

const alreadyHadFlushScheduled = this._scheduledFlushFlag !== Z_NO_FLUSH;

this._scheduledFlushFlag = maxFlush(kind, this._scheduledFlushFlag);

// If a callback was passed, always register a new `drain` + flush handler,

// mostly because that's simpler and flush callbacks piling up is a rare

// thing anyway.

if (!alreadyHadFlushScheduled || callback) {

const drainHandler = () => this.flush(this._scheduledFlushFlag, callback);

this.once('drain', drainHandler);

}

} else {

this._flushFlag = kind;

this.write(Buffer.alloc(0), '', callback);

this._scheduledFlushFlag = Z_NO_FLUSH;

}

};

Zlib.prototype.close = function close(callback) {

_close(this, callback);

this.destroy();

};

Zlib.prototype._transform = function _transform(chunk, encoding, cb) {

// If it's the last chunk, or a final flush, we use the Z_FINISH flush flag

// (or whatever flag was provided using opts.finishFlush).

// If it's explicitly flushing at some other time, then we use

// Z_FULL_FLUSH. Otherwise, use the original opts.flush flag.

var flushFlag;

var ws = this._writableState;

if ((ws.ending || ws.ended) && ws.length === chunk.byteLength) {

flushFlag = this._finishFlushFlag;

} else {

flushFlag = this._flushFlag;

// once we've flushed the last of the queue, stop flushing and

// go back to the normal behavior.

if (chunk.byteLength >= ws.length)

this._flushFlag = this._origFlushFlag;

}

processChunk(this, chunk, flushFlag, cb);

};

Zlib.prototype._processChunk = function _processChunk(chunk, flushFlag, cb) {

// _processChunk() is left for backwards compatibility

if (typeof cb === 'function')

processChunk(this, chunk, flushFlag, cb);

else

return processChunkSync(this, chunk, flushFlag);

};

function processChunkSync(self, chunk, flushFlag) {

var availInBefore = chunk.byteLength;

var availOutBefore = self._chunkSize - self._outOffset;

var inOff = 0;

var availOutAfter;

var availInAfter;

var buffers = null;

var nread = 0;

var inputRead = 0;

var state = self._writeState;

var handle = self._handle;

var buffer = self._outBuffer;

var offset = self._outOffset;

var chunkSize = self._chunkSize;

var error;

self.on('error', function(er) {

error = er;

});

while (true) {

handle.writeSync(flushFlag,

chunk, // in

inOff, // in_off

availInBefore, // in_len

buffer, // out

offset, // out_off

availOutBefore); // out_len

if (error)

throw error;

availOutAfter = state[0];

availInAfter = state[1];

var inDelta = (availInBefore - availInAfter);

inputRead += inDelta;

var have = availOutBefore - availOutAfter;

if (have > 0) {

var out = buffer.slice(offset, offset + have);

offset += have;

if (!buffers)

buffers = [out];

else

buffers.push(out);

nread += out.byteLength;

} else if (have < 0) {

assert(false, 'have should not go down');

}

// exhausted the output buffer, or used all the input create a new one.

if (availOutAfter === 0 || offset >= chunkSize) {

availOutBefore = chunkSize;

offset = 0;

buffer = Buffer.allocUnsafe(chunkSize);

}

if (availOutAfter === 0) {

// Not actually done. Need to reprocess.

// Also, update the availInBefore to the availInAfter value,

// so that if we have to hit it a third (fourth, etc.) time,

// it'll have the correct byte counts.

inOff += inDelta;

availInBefore = availInAfter;

} else {

break;

}

}

self.bytesWritten = inputRead;

if (nread >= kMaxLength) {

_close(self);

throw new ERR_BUFFER_TOO_LARGE();

}

_close(self);

if (nread === 0)

return Buffer.alloc(0);

return (buffers.length === 1 ? buffers[0] : Buffer.concat(buffers, nread));

}

function processChunk(self, chunk, flushFlag, cb) {

var handle = self._handle;

if (!handle)

assert(false, 'zlib binding closed');

handle.buffer = chunk;

handle.cb = cb;

handle.availOutBefore = self._chunkSize - self._outOffset;

handle.availInBefore = chunk.byteLength;

handle.inOff = 0;

handle.flushFlag = flushFlag;

handle.write(flushFlag,

chunk, // in

0, // in_off

handle.availInBefore, // in_len

self._outBuffer, // out

self._outOffset, // out_off

handle.availOutBefore); // out_len

}

function processCallback() {

// This callback's context (`this`) is the `_handle` (ZCtx) object. It is

// important to null out the values once they are no longer needed since

// `_handle` can stay in memory long after the buffer is needed.

var handle = this;

var self = this.jsref;

var state = self._writeState;

if (self._hadError) {

this.buffer = null;

return;

}

if (self.destroyed) {

this.buffer = null;

return;

}

var availOutAfter = state[0];

var availInAfter = state[1];

const inDelta = handle.availInBefore - availInAfter;

self.bytesWritten += inDelta;

var have = handle.availOutBefore - availOutAfter;

if (have > 0) {

var out = self._outBuffer.slice(self._outOffset, self._outOffset + have);

self._outOffset += have;

self.push(out);

} else if (have < 0) {

assert(false, 'have should not go down');

}

// exhausted the output buffer, or used all the input create a new one.

if (availOutAfter === 0 || self._outOffset >= self._chunkSize) {

handle.availOutBefore = self._chunkSize;

self._outOffset = 0;

self._outBuffer = Buffer.allocUnsafe(self._chunkSize);

}

if (availOutAfter === 0) {

// Not actually done. Need to reprocess.

// Also, update the availInBefore to the availInAfter value,

// so that if we have to hit it a third (fourth, etc.) time,

// it'll have the correct byte counts.

handle.inOff += inDelta;

handle.availInBefore = availInAfter;

this.write(handle.flushFlag,

this.buffer, // in

handle.inOff, // in_off

handle.availInBefore, // in_len

self._outBuffer, // out

self._outOffset, // out_off

self._chunkSize); // out_len

return;

}

// finished with the chunk.

this.buffer = null;

this.cb();

}

function _close(engine, callback) {

if (callback)

process.nextTick(callback);

// Caller may invoke .close after a zlib error (which will null _handle).

if (!engine._handle)

return;

engine._handle.close();

engine._handle = null;

}

// generic zlib

// minimal 2-byte header

function Deflate(opts) {

if (!(this instanceof Deflate))

return new Deflate(opts);

Zlib.call(this, opts, DEFLATE);

}

inherits(Deflate, Zlib);

function Inflate(opts) {

if (!(this instanceof Inflate))

return new Inflate(opts);

Zlib.call(this, opts, INFLATE);

}

inherits(Inflate, Zlib);

function Gzip(opts) {

if (!(this instanceof Gzip))

return new Gzip(opts);

Zlib.call(this, opts, GZIP);

}

inherits(Gzip, Zlib);

function Gunzip(opts) {

if (!(this instanceof Gunzip))

return new Gunzip(opts);

Zlib.call(this, opts, GUNZIP);

}

inherits(Gunzip, Zlib);

function DeflateRaw(opts) {

if (opts && opts.windowBits === 8) opts.windowBits = 9;

if (!(this instanceof DeflateRaw))

return new DeflateRaw(opts);

Zlib.call(this, opts, DEFLATERAW);

}

inherits(DeflateRaw, Zlib);

function InflateRaw(opts) {

if (!(this instanceof InflateRaw))

return new InflateRaw(opts);

Zlib.call(this, opts, INFLATERAW);

}

inherits(InflateRaw, Zlib);

function Unzip(opts) {

if (!(this instanceof Unzip))

return new Unzip(opts);

Zlib.call(this, opts, UNZIP);

}

inherits(Unzip, Zlib);

function createConvenienceMethod(ctor, sync) {

if (sync) {

return function(buffer, opts) {

return zlibBufferSync(new ctor(opts), buffer);

};

} else {

return function(buffer, opts, callback) {

if (typeof opts === 'function') {

callback = opts;

opts = {};

}

return zlibBuffer(new ctor(opts), buffer, callback);

};

}

}

function createProperty(ctor) {

return {

configurable: true,

enumerable: true,

value: function(options) {

return new ctor(options);

}

};

}

module.exports = {

Deflate,

Inflate,

Gzip,

Gunzip,

DeflateRaw,

InflateRaw,

Unzip,

// Convenience methods.

// compress/decompress a string or buffer in one step.

deflate: createConvenienceMethod(Deflate, false),

deflateSync: createConvenienceMethod(Deflate, true),

gzip: createConvenienceMethod(Gzip, false),

gzipSync: createConvenienceMethod(Gzip, true),

deflateRaw: createConvenienceMethod(DeflateRaw, false),

deflateRawSync: createConvenienceMethod(DeflateRaw, true),

unzip: createConvenienceMethod(Unzip, false),

unzipSync: createConvenienceMethod(Unzip, true),

inflate: createConvenienceMethod(Inflate, false),

inflateSync: createConvenienceMethod(Inflate, true),

gunzip: createConvenienceMethod(Gunzip, false),

gunzipSync: createConvenienceMethod(Gunzip, true),

inflateRaw: createConvenienceMethod(InflateRaw, false),

inflateRawSync: createConvenienceMethod(InflateRaw, true)

};

Object.defineProperties(module.exports, {

createDeflate: createProperty(Deflate),

createInflate: createProperty(Inflate),

createDeflateRaw: createProperty(DeflateRaw),

createInflateRaw: createProperty(InflateRaw),

createGzip: createProperty(Gzip),

createGunzip: createProperty(Gunzip),

createUnzip: createProperty(Unzip),

constants: {

configurable: false,

enumerable: true,

value: constants

},

codes: {

enumerable: true,

writable: false,

value: Object.freeze(codes)

}

});

// These should be considered deprecated

// expose all the zlib constants

const bkeys = Object.keys(constants);

for (var bk = 0; bk < bkeys.length; bk++) {

var bkey = bkeys[bk];

Object.defineProperty(module.exports, bkey, {

enumerable: true, value: constants[bkey], writable: false

});

}