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// 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 Buffer = require('buffer').Buffer;
const Transform = require('_stream_transform');
const { _extend } = require('util');
const binding = process.binding('zlib');
const assert = require('assert').ok;
const kMaxLength = require('buffer').kMaxLength;
const kRangeErrorMessage = 'Cannot create final Buffer. It would be larger ' +
`than 0x${kMaxLength.toString(16)} bytes`;
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 (ArrayBuffer.isView(buffer) &&
Object.getPrototypeOf(buffer) !== Buffer.prototype) {
buffer = Buffer.from(buffer.buffer, buffer.byteOffset, buffer.byteLength);
}
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 RangeError(kRangeErrorMessage);
} 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 (!ArrayBuffer.isView(buffer)) {
throw new TypeError('"buffer" argument must be a string, Buffer, ' +
'TypedArray, or DataView');
}
buffer = processChunkSync(engine, buffer, engine._finishFlushFlag);
if (engine._info)
return { buffer, engine };
else
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;
var 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();
}
}
// 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) {
Transform.call(this, opts);
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;
if (opts) {
chunkSize = opts.chunkSize;
if (chunkSize !== undefined && chunkSize === chunkSize) {
if (chunkSize < Z_MIN_CHUNK || !Number.isFinite(chunkSize))
throw new RangeError('Invalid chunk size: ' + chunkSize);
} else {
chunkSize = Z_DEFAULT_CHUNK;
}
flush = opts.flush;
if (flush !== undefined && flush === flush) {
if (flush < Z_NO_FLUSH || flush > Z_BLOCK || !Number.isFinite(flush))
throw new RangeError('Invalid flush flag: ' + flush);
} else {
flush = Z_NO_FLUSH;
}
finishFlush = opts.finishFlush;
if (finishFlush !== undefined && finishFlush === finishFlush) {
if (finishFlush < Z_NO_FLUSH || finishFlush > Z_BLOCK ||
!Number.isFinite(finishFlush)) {
throw new RangeError('Invalid flush flag: ' + finishFlush);
}
} else {
finishFlush = Z_FINISH;
}
windowBits = opts.windowBits;
if (windowBits !== undefined && windowBits === windowBits) {
if (windowBits < Z_MIN_WINDOWBITS || windowBits > Z_MAX_WINDOWBITS ||
!Number.isFinite(windowBits)) {
throw new RangeError('Invalid windowBits: ' + windowBits);
}
} else {
windowBits = Z_DEFAULT_WINDOWBITS;
}
level = opts.level;
if (level !== undefined && level === level) {
if (level < Z_MIN_LEVEL || level > Z_MAX_LEVEL ||
!Number.isFinite(level)) {
throw new RangeError('Invalid compression level: ' + level);
}
} else {
level = Z_DEFAULT_COMPRESSION;
}
memLevel = opts.memLevel;
if (memLevel !== undefined && memLevel === memLevel) {
if (memLevel < Z_MIN_MEMLEVEL || memLevel > Z_MAX_MEMLEVEL ||
!Number.isFinite(memLevel)) {
throw new RangeError('Invalid memLevel: ' + memLevel);
}
} else {
memLevel = Z_DEFAULT_MEMLEVEL;
}
strategy = opts.strategy;
if (strategy !== undefined && strategy === strategy) {
if (strategy < Z_DEFAULT_STRATEGY || strategy > Z_FIXED ||
!Number.isFinite(strategy)) {
throw new TypeError('Invalid strategy: ' + strategy);
}
} else {
strategy = Z_DEFAULT_STRATEGY;
}
dictionary = opts.dictionary;
if (dictionary !== undefined && !ArrayBuffer.isView(dictionary)) {
throw new TypeError(
'Invalid dictionary: it should be a Buffer, TypedArray, or DataView');
}
if (opts.encoding || opts.objectMode || opts.writableObjectMode) {
opts = _extend({}, opts);
opts.encoding = null;
opts.objectMode = false;
opts.writableObjectMode = false;
}
}
this.bytesRead = 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);
this._handle.init(windowBits, level, memLevel, strategy, this._writeState,
processCallback, dictionary);
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;
}
});
Zlib.prototype.params = function params(level, strategy, callback) {
if (level < Z_MIN_LEVEL || level > Z_MAX_LEVEL)
throw new RangeError('Invalid compression level: ' + level);
if (strategy !== undefined &&
(strategy < Z_DEFAULT_STRATEGY || strategy > Z_FIXED ||
!Number.isFinite(strategy))) {
throw new TypeError('Invalid strategy: ' + strategy);
}
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);
process.nextTick(emitCloseNT, this);
};
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.bytesRead = inputRead;
if (nread >= kMaxLength) {
_close(self);
throw new RangeError(kRangeErrorMessage);
}
_close(self);
return (buffers.length === 1 ? buffers[0] : Buffer.concat(buffers, nread));
}
function processChunk(self, chunk, flushFlag, cb) {
var handle = self._handle;
if (!handle)
return cb(new Error('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];
var inDelta = (handle.availInBefore - availInAfter);
self.bytesRead += 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;
}
function emitCloseNT(self) {
self.emit('close');
}
// 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 (!(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
});
}