'use strict'
|
/* eslint camelcase: "off" */
|
|
var assert = require('assert')
|
|
var Zstream = require('pako/lib/zlib/zstream')
|
var zlib_deflate = require('pako/lib/zlib/deflate.js')
|
var zlib_inflate = require('pako/lib/zlib/inflate.js')
|
var constants = require('pako/lib/zlib/constants')
|
|
for (var key in constants) {
|
exports[key] = constants[key]
|
}
|
|
// zlib modes
|
exports.NONE = 0
|
exports.DEFLATE = 1
|
exports.INFLATE = 2
|
exports.GZIP = 3
|
exports.GUNZIP = 4
|
exports.DEFLATERAW = 5
|
exports.INFLATERAW = 6
|
exports.UNZIP = 7
|
|
var GZIP_HEADER_ID1 = 0x1f
|
var GZIP_HEADER_ID2 = 0x8b
|
|
/**
|
* Emulate Node's zlib C++ layer for use by the JS layer in index.js
|
*/
|
function Zlib (mode) {
|
if (typeof mode !== 'number' || mode < exports.DEFLATE || mode > exports.UNZIP) {
|
throw new TypeError('Bad argument')
|
}
|
|
this.dictionary = null
|
this.err = 0
|
this.flush = 0
|
this.init_done = false
|
this.level = 0
|
this.memLevel = 0
|
this.mode = mode
|
this.strategy = 0
|
this.windowBits = 0
|
this.write_in_progress = false
|
this.pending_close = false
|
this.gzip_id_bytes_read = 0
|
}
|
|
Zlib.prototype.close = function () {
|
if (this.write_in_progress) {
|
this.pending_close = true
|
return
|
}
|
|
this.pending_close = false
|
|
assert(this.init_done, 'close before init')
|
assert(this.mode <= exports.UNZIP)
|
|
if (this.mode === exports.DEFLATE || this.mode === exports.GZIP || this.mode === exports.DEFLATERAW) {
|
zlib_deflate.deflateEnd(this.strm)
|
} else if (this.mode === exports.INFLATE || this.mode === exports.GUNZIP ||
|
this.mode === exports.INFLATERAW || this.mode === exports.UNZIP) {
|
zlib_inflate.inflateEnd(this.strm)
|
}
|
|
this.mode = exports.NONE
|
|
this.dictionary = null
|
}
|
|
Zlib.prototype.write = function (flush, input, in_off, in_len, out, out_off, out_len) {
|
return this._write(true, flush, input, in_off, in_len, out, out_off, out_len)
|
}
|
|
Zlib.prototype.writeSync = function (flush, input, in_off, in_len, out, out_off, out_len) {
|
return this._write(false, flush, input, in_off, in_len, out, out_off, out_len)
|
}
|
|
Zlib.prototype._write = function (async, flush, input, in_off, in_len, out, out_off, out_len) {
|
assert.equal(arguments.length, 8)
|
|
assert(this.init_done, 'write before init')
|
assert(this.mode !== exports.NONE, 'already finalized')
|
assert.equal(false, this.write_in_progress, 'write already in progress')
|
assert.equal(false, this.pending_close, 'close is pending')
|
|
this.write_in_progress = true
|
|
assert.equal(false, flush === undefined, 'must provide flush value')
|
|
this.write_in_progress = true
|
|
if (flush !== exports.Z_NO_FLUSH &&
|
flush !== exports.Z_PARTIAL_FLUSH &&
|
flush !== exports.Z_SYNC_FLUSH &&
|
flush !== exports.Z_FULL_FLUSH &&
|
flush !== exports.Z_FINISH &&
|
flush !== exports.Z_BLOCK) {
|
throw new Error('Invalid flush value')
|
}
|
|
if (input == null) {
|
input = Buffer.alloc(0)
|
in_len = 0
|
in_off = 0
|
}
|
|
this.strm.avail_in = in_len
|
this.strm.input = input
|
this.strm.next_in = in_off
|
this.strm.avail_out = out_len
|
this.strm.output = out
|
this.strm.next_out = out_off
|
this.flush = flush
|
|
if (!async) {
|
// sync version
|
this._process()
|
|
if (this._checkError()) {
|
return this._afterSync()
|
}
|
return
|
}
|
|
// async version
|
var self = this
|
process.nextTick(function () {
|
self._process()
|
self._after()
|
})
|
|
return this
|
}
|
|
Zlib.prototype._afterSync = function () {
|
var avail_out = this.strm.avail_out
|
var avail_in = this.strm.avail_in
|
|
this.write_in_progress = false
|
|
return [avail_in, avail_out]
|
}
|
|
Zlib.prototype._process = function () {
|
var next_expected_header_byte = null
|
|
// If the avail_out is left at 0, then it means that it ran out
|
// of room. If there was avail_out left over, then it means
|
// that all of the input was consumed.
|
switch (this.mode) {
|
case exports.DEFLATE:
|
case exports.GZIP:
|
case exports.DEFLATERAW:
|
this.err = zlib_deflate.deflate(this.strm, this.flush)
|
break
|
case exports.UNZIP:
|
if (this.strm.avail_in > 0) {
|
next_expected_header_byte = this.strm.next_in
|
}
|
|
switch (this.gzip_id_bytes_read) {
|
case 0:
|
if (next_expected_header_byte === null) {
|
break
|
}
|
|
if (this.strm.input[next_expected_header_byte] === GZIP_HEADER_ID1) {
|
this.gzip_id_bytes_read = 1
|
next_expected_header_byte++
|
|
if (this.strm.avail_in === 1) {
|
// The only available byte was already read.
|
break
|
}
|
} else {
|
this.mode = exports.INFLATE
|
break
|
}
|
|
// fallthrough
|
case 1:
|
if (next_expected_header_byte === null) {
|
break
|
}
|
|
if (this.strm.input[next_expected_header_byte] === GZIP_HEADER_ID2) {
|
this.gzip_id_bytes_read = 2
|
this.mode = exports.GUNZIP
|
} else {
|
// There is no actual difference between INFLATE and INFLATERAW
|
// (after initialization).
|
this.mode = exports.INFLATE
|
}
|
|
break
|
default:
|
throw new Error('invalid number of gzip magic number bytes read')
|
}
|
|
// fallthrough
|
case exports.INFLATE:
|
case exports.GUNZIP:
|
case exports.INFLATERAW:
|
this.err = zlib_inflate.inflate(this.strm, this.flush)
|
|
// If data was encoded with dictionary
|
if (this.err === exports.Z_NEED_DICT && this.dictionary) {
|
// Load it
|
this.err = zlib_inflate.inflateSetDictionary(this.strm, this.dictionary)
|
if (this.err === exports.Z_OK) {
|
// And try to decode again
|
this.err = zlib_inflate.inflate(this.strm, this.flush)
|
} else if (this.err === exports.Z_DATA_ERROR) {
|
// Both inflateSetDictionary() and inflate() return Z_DATA_ERROR.
|
// Make it possible for After() to tell a bad dictionary from bad
|
// input.
|
this.err = exports.Z_NEED_DICT
|
}
|
}
|
while (this.strm.avail_in > 0 &&
|
this.mode === exports.GUNZIP &&
|
this.err === exports.Z_STREAM_END &&
|
this.strm.next_in[0] !== 0x00) {
|
// Bytes remain in input buffer. Perhaps this is another compressed
|
// member in the same archive, or just trailing garbage.
|
// Trailing zero bytes are okay, though, since they are frequently
|
// used for padding.
|
|
this.reset()
|
this.err = zlib_inflate.inflate(this.strm, this.flush)
|
}
|
break
|
default:
|
throw new Error('Unknown mode ' + this.mode)
|
}
|
}
|
|
Zlib.prototype._checkError = function () {
|
// Acceptable error states depend on the type of zlib stream.
|
switch (this.err) {
|
case exports.Z_OK:
|
case exports.Z_BUF_ERROR:
|
if (this.strm.avail_out !== 0 && this.flush === exports.Z_FINISH) {
|
this._error('unexpected end of file')
|
return false
|
}
|
break
|
case exports.Z_STREAM_END:
|
// normal statuses, not fatal
|
break
|
case exports.Z_NEED_DICT:
|
if (this.dictionary == null) {
|
this._error('Missing dictionary')
|
} else {
|
this._error('Bad dictionary')
|
}
|
return false
|
default:
|
// something else.
|
this._error('Zlib error')
|
return false
|
}
|
|
return true
|
}
|
|
Zlib.prototype._after = function () {
|
if (!this._checkError()) {
|
return
|
}
|
|
var avail_out = this.strm.avail_out
|
var avail_in = this.strm.avail_in
|
|
this.write_in_progress = false
|
|
// call the write() cb
|
this.callback(avail_in, avail_out)
|
|
if (this.pending_close) {
|
this.close()
|
}
|
}
|
|
Zlib.prototype._error = function (message) {
|
if (this.strm.msg) {
|
message = this.strm.msg
|
}
|
this.onerror(message, this.err)
|
|
// no hope of rescue.
|
this.write_in_progress = false
|
if (this.pending_close) {
|
this.close()
|
}
|
}
|
|
Zlib.prototype.init = function (windowBits, level, memLevel, strategy, dictionary) {
|
assert(arguments.length === 4 || arguments.length === 5, 'init(windowBits, level, memLevel, strategy, [dictionary])')
|
|
assert(windowBits >= 8 && windowBits <= 15, 'invalid windowBits')
|
assert(level >= -1 && level <= 9, 'invalid compression level')
|
|
assert(memLevel >= 1 && memLevel <= 9, 'invalid memlevel')
|
|
assert(strategy === exports.Z_FILTERED ||
|
strategy === exports.Z_HUFFMAN_ONLY ||
|
strategy === exports.Z_RLE ||
|
strategy === exports.Z_FIXED ||
|
strategy === exports.Z_DEFAULT_STRATEGY, 'invalid strategy')
|
|
this._init(level, windowBits, memLevel, strategy, dictionary)
|
this._setDictionary()
|
}
|
|
Zlib.prototype.params = function () {
|
throw new Error('deflateParams Not supported')
|
}
|
|
Zlib.prototype.reset = function () {
|
this._reset()
|
this._setDictionary()
|
}
|
|
Zlib.prototype._init = function (level, windowBits, memLevel, strategy, dictionary) {
|
this.level = level
|
this.windowBits = windowBits
|
this.memLevel = memLevel
|
this.strategy = strategy
|
|
this.flush = exports.Z_NO_FLUSH
|
|
this.err = exports.Z_OK
|
|
if (this.mode === exports.GZIP || this.mode === exports.GUNZIP) {
|
this.windowBits += 16
|
}
|
|
if (this.mode === exports.UNZIP) {
|
this.windowBits += 32
|
}
|
|
if (this.mode === exports.DEFLATERAW || this.mode === exports.INFLATERAW) {
|
this.windowBits = -1 * this.windowBits
|
}
|
|
this.strm = new Zstream()
|
|
switch (this.mode) {
|
case exports.DEFLATE:
|
case exports.GZIP:
|
case exports.DEFLATERAW:
|
this.err = zlib_deflate.deflateInit2(
|
this.strm,
|
this.level,
|
exports.Z_DEFLATED,
|
this.windowBits,
|
this.memLevel,
|
this.strategy
|
)
|
break
|
case exports.INFLATE:
|
case exports.GUNZIP:
|
case exports.INFLATERAW:
|
case exports.UNZIP:
|
this.err = zlib_inflate.inflateInit2(
|
this.strm,
|
this.windowBits
|
)
|
break
|
default:
|
throw new Error('Unknown mode ' + this.mode)
|
}
|
|
if (this.err !== exports.Z_OK) {
|
this._error('Init error')
|
}
|
|
this.dictionary = dictionary
|
|
this.write_in_progress = false
|
this.init_done = true
|
}
|
|
Zlib.prototype._setDictionary = function () {
|
if (this.dictionary == null) {
|
return
|
}
|
|
this.err = exports.Z_OK
|
|
switch (this.mode) {
|
case exports.DEFLATE:
|
case exports.DEFLATERAW:
|
this.err = zlib_deflate.deflateSetDictionary(this.strm, this.dictionary)
|
break
|
default:
|
break
|
}
|
|
if (this.err !== exports.Z_OK) {
|
this._error('Failed to set dictionary')
|
}
|
}
|
|
Zlib.prototype._reset = function () {
|
this.err = exports.Z_OK
|
|
switch (this.mode) {
|
case exports.DEFLATE:
|
case exports.DEFLATERAW:
|
case exports.GZIP:
|
this.err = zlib_deflate.deflateReset(this.strm)
|
break
|
case exports.INFLATE:
|
case exports.INFLATERAW:
|
case exports.GUNZIP:
|
this.err = zlib_inflate.inflateReset(this.strm)
|
break
|
default:
|
break
|
}
|
|
if (this.err !== exports.Z_OK) {
|
this._error('Failed to reset stream')
|
}
|
}
|
|
exports.Zlib = Zlib
|
