@splitsoftware/splitio-commons
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Split JavaScript SDK common components
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JavaScript
"use strict";
/*
Trimmed version of "fflate" library (https://www.npmjs.com/package/fflate/v/0.7.1)
used for GZIP/Zlib decompression in JavaScript, with the minimal modules used by the SDK.
MIT License
Copyright (c) 2020 Arjun Barrett
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.
*/
/* eslint-disable */
// @ts-nocheck
Object.defineProperty(exports, "__esModule", { value: true });
exports.algorithms = void 0;
exports.algorithms = (function iifeDecompress() {
// Handle runtimes without typed arrays
if ([typeof Uint8Array, typeof Uint16Array, typeof Uint32Array].some(function (v) { return v != 'function'; })) {
return 'global Uint8Array object is not available for gzip/zlib decompression';
}
// DEFLATE is a complex format; to read this code, you should probably check the RFC first:
// aliases for shorter compressed code (most minifers don't do this)
var u8 = Uint8Array, u16 = Uint16Array, u32 = Uint32Array;
// fixed length extra bits
var fleb = new u8([0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, /* unused */ 0, 0, /* impossible */ 0]);
// fixed distance extra bits
// see fleb note
var fdeb = new u8([0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, /* unused */ 0, 0]);
// code length index map
var clim = new u8([16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15]);
// get base, reverse index map from extra bits
var freb = function (eb, start) {
var b = new u16(31);
for (var i = 0; i < 31; ++i) {
b[i] = start += 1 << eb[i - 1];
}
// numbers here are at max 18 bits
var r = new u32(b[30]);
for (var i = 1; i < 30; ++i) {
for (var j = b[i]; j < b[i + 1]; ++j) {
r[j] = ((j - b[i]) << 5) | i;
}
}
return [b, r];
};
var _a = freb(fleb, 2), fl = _a[0], revfl = _a[1];
// we can ignore the fact that the other numbers are wrong; they never happen anyway
fl[28] = 258, revfl[258] = 28;
var _b = freb(fdeb, 0), fd = _b[0];
// map of value to reverse (assuming 16 bits)
var rev = new u16(32768);
for (var i = 0; i < 32768; ++i) {
// reverse table algorithm from SO
var x = ((i & 0xAAAA) >>> 1) | ((i & 0x5555) << 1);
x = ((x & 0xCCCC) >>> 2) | ((x & 0x3333) << 2);
x = ((x & 0xF0F0) >>> 4) | ((x & 0x0F0F) << 4);
rev[i] = (((x & 0xFF00) >>> 8) | ((x & 0x00FF) << 8)) >>> 1;
}
// create huffman tree from u8 "map": index -> code length for code index
// mb (max bits) must be at most 15
// TODO: optimize/split up?
var hMap = (function (cd, mb, r) {
var s = cd.length;
// index
var i = 0;
// u16 "map": index -> # of codes with bit length = index
var l = new u16(mb);
// length of cd must be 288 (total # of codes)
for (; i < s; ++i)
++l[cd[i] - 1];
// u16 "map": index -> minimum code for bit length = index
var le = new u16(mb);
for (i = 0; i < mb; ++i) {
le[i] = (le[i - 1] + l[i - 1]) << 1;
}
var co;
if (r) {
// u16 "map": index -> number of actual bits, symbol for code
co = new u16(1 << mb);
// bits to remove for reverser
var rvb = 15 - mb;
for (i = 0; i < s; ++i) {
// ignore 0 lengths
if (cd[i]) {
// num encoding both symbol and bits read
var sv = (i << 4) | cd[i];
// free bits
var r_1 = mb - cd[i];
// start value
var v = le[cd[i] - 1]++ << r_1;
// m is end value
for (var m = v | ((1 << r_1) - 1); v <= m; ++v) {
// every 16 bit value starting with the code yields the same result
co[rev[v] >>> rvb] = sv;
}
}
}
}
else {
co = new u16(s);
for (i = 0; i < s; ++i) {
if (cd[i]) {
co[i] = rev[le[cd[i] - 1]++] >>> (15 - cd[i]);
}
}
}
return co;
});
// fixed length tree
var flt = new u8(288);
for (var i = 0; i < 144; ++i)
flt[i] = 8;
for (var i = 144; i < 256; ++i)
flt[i] = 9;
for (var i = 256; i < 280; ++i)
flt[i] = 7;
for (var i = 280; i < 288; ++i)
flt[i] = 8;
// fixed distance tree
var fdt = new u8(32);
for (var i = 0; i < 32; ++i)
fdt[i] = 5;
// fixed length map
var flrm = /*#__PURE__*/ hMap(flt, 9, 1);
// fixed distance map
var fdrm = /*#__PURE__*/ hMap(fdt, 5, 1);
// find max of array
var max = function (a) {
var m = a[0];
for (var i = 1; i < a.length; ++i) {
if (a[i] > m)
m = a[i];
}
return m;
};
// read d, starting at bit p and mask with m
var bits = function (d, p, m) {
var o = (p / 8) | 0;
return ((d[o] | (d[o + 1] << 8)) >> (p & 7)) & m;
};
// read d, starting at bit p continuing for at least 16 bits
var bits16 = function (d, p) {
var o = (p / 8) | 0;
return ((d[o] | (d[o + 1] << 8) | (d[o + 2] << 16)) >> (p & 7));
};
// get end of byte
var shft = function (p) { return ((p + 7) / 8) | 0; };
// typed array slice - allows garbage collector to free original reference,
// while being more compatible than .slice
var slc = function (v, s, e) {
if (s == null || s < 0)
s = 0;
if (e == null || e > v.length)
e = v.length;
// can't use .constructor in case user-supplied
var n = new (v instanceof u16 ? u16 : v instanceof u32 ? u32 : u8)(e - s);
n.set(v.subarray(s, e));
return n;
};
// error codes
var ec = [
'unexpected EOF',
'invalid block type',
'invalid length/literal',
'invalid distance',
'stream finished',
'no stream handler',
,
'no callback',
'invalid UTF-8 data',
'extra field too long',
'date not in range 1980-2099',
'filename too long',
'stream finishing',
'invalid zip data'
// determined by unknown compression method
];
var err = function (ind, msg, nt) {
var e = new Error(msg || ec[ind]);
e.code = ind;
if (Error.captureStackTrace)
Error.captureStackTrace(e, err);
if (!nt)
throw e;
return e;
};
// expands raw DEFLATE data
var inflt = function (dat, buf, st) {
// source length
var sl = dat.length;
if (!sl || (st && st.f && !st.l))
return buf || new u8(0);
// have to estimate size
var noBuf = !buf || st;
// no state
var noSt = !st || st.i;
if (!st)
st = {};
// Assumes roughly 33% compression ratio average
if (!buf)
buf = new u8(sl * 3);
// ensure buffer can fit at least l elements
var cbuf = function (l) {
var bl = buf.length;
// need to increase size to fit
if (l > bl) {
// Double or set to necessary, whichever is greater
var nbuf = new u8(Math.max(bl * 2, l));
nbuf.set(buf);
buf = nbuf;
}
};
// last chunk bitpos bytes
var final = st.f || 0, pos = st.p || 0, bt = st.b || 0, lm = st.l, dm = st.d, lbt = st.m, dbt = st.n;
// total bits
var tbts = sl * 8;
do {
if (!lm) {
// BFINAL - this is only 1 when last chunk is next
final = bits(dat, pos, 1);
// type: 0 = no compression, 1 = fixed huffman, 2 = dynamic huffman
var type = bits(dat, pos + 1, 3);
pos += 3;
if (!type) {
// go to end of byte boundary
var s = shft(pos) + 4, l = dat[s - 4] | (dat[s - 3] << 8), t = s + l;
if (t > sl) {
if (noSt)
err(0);
break;
}
// ensure size
if (noBuf)
cbuf(bt + l);
// Copy over uncompressed data
buf.set(dat.subarray(s, t), bt);
// Get new bitpos, update byte count
st.b = bt += l, st.p = pos = t * 8, st.f = final;
continue;
}
else if (type == 1)
lm = flrm, dm = fdrm, lbt = 9, dbt = 5;
else if (type == 2) {
// literal lengths
var hLit = bits(dat, pos, 31) + 257, hcLen = bits(dat, pos + 10, 15) + 4;
var tl = hLit + bits(dat, pos + 5, 31) + 1;
pos += 14;
// length+distance tree
var ldt = new u8(tl);
// code length tree
var clt = new u8(19);
for (var i = 0; i < hcLen; ++i) {
// use index map to get real code
clt[clim[i]] = bits(dat, pos + i * 3, 7);
}
pos += hcLen * 3;
// code lengths bits
var clb = max(clt), clbmsk = (1 << clb) - 1;
// code lengths map
var clm = hMap(clt, clb, 1);
for (var i = 0; i < tl;) {
var r = clm[bits(dat, pos, clbmsk)];
// bits read
pos += r & 15;
// symbol
var s = r >>> 4;
// code length to copy
if (s < 16) {
ldt[i++] = s;
}
else {
// copy count
var c = 0, n = 0;
if (s == 16)
n = 3 + bits(dat, pos, 3), pos += 2, c = ldt[i - 1];
else if (s == 17)
n = 3 + bits(dat, pos, 7), pos += 3;
else if (s == 18)
n = 11 + bits(dat, pos, 127), pos += 7;
while (n--)
ldt[i++] = c;
}
}
// length tree distance tree
var lt = ldt.subarray(0, hLit), dt = ldt.subarray(hLit);
// max length bits
lbt = max(lt);
// max dist bits
dbt = max(dt);
lm = hMap(lt, lbt, 1);
dm = hMap(dt, dbt, 1);
}
else
err(1);
if (pos > tbts) {
if (noSt)
err(0);
break;
}
}
// Make sure the buffer can hold this + the largest possible addition
// Maximum chunk size (practically, theoretically infinite) is 2^17;
if (noBuf)
cbuf(bt + 131072);
var lms = (1 << lbt) - 1, dms = (1 << dbt) - 1;
var lpos = pos;
for (;; lpos = pos) {
// bits read, code
var c = lm[bits16(dat, pos) & lms], sym = c >>> 4;
pos += c & 15;
if (pos > tbts) {
if (noSt)
err(0);
break;
}
if (!c)
err(2);
if (sym < 256)
buf[bt++] = sym;
else if (sym == 256) {
lpos = pos, lm = null;
break;
}
else {
var add = sym - 254;
// no extra bits needed if less
if (sym > 264) {
// index
var i = sym - 257, b = fleb[i];
add = bits(dat, pos, (1 << b) - 1) + fl[i];
pos += b;
}
// dist
var d = dm[bits16(dat, pos) & dms], dsym = d >>> 4;
if (!d)
err(3);
pos += d & 15;
var dt = fd[dsym];
if (dsym > 3) {
var b = fdeb[dsym];
dt += bits16(dat, pos) & ((1 << b) - 1), pos += b;
}
if (pos > tbts) {
if (noSt)
err(0);
break;
}
if (noBuf)
cbuf(bt + 131072);
var end = bt + add;
for (; bt < end; bt += 4) {
buf[bt] = buf[bt - dt];
buf[bt + 1] = buf[bt + 1 - dt];
buf[bt + 2] = buf[bt + 2 - dt];
buf[bt + 3] = buf[bt + 3 - dt];
}
bt = end;
}
}
st.l = lm, st.p = lpos, st.b = bt, st.f = final;
if (lm)
final = 1, st.m = lbt, st.d = dm, st.n = dbt;
} while (!final);
return bt == buf.length ? buf : slc(buf, 0, bt);
};
// gzip footer: -8 to -4 = CRC, -4 to -0 is length
// gzip start
var gzs = function (d) {
if (d[0] != 31 || d[1] != 139 || d[2] != 8)
err(6, 'invalid gzip data');
var flg = d[3];
var st = 10;
if (flg & 4)
st += d[10] | (d[11] << 8) + 2;
for (var zs = (flg >> 3 & 1) + (flg >> 4 & 1); zs > 0; zs -= !d[st++])
;
return st + (flg & 2);
};
// gzip length
var gzl = function (d) {
var l = d.length;
return ((d[l - 4] | d[l - 3] << 8 | d[l - 2] << 16) | (d[l - 1] << 24)) >>> 0;
};
// zlib valid
var zlv = function (d) {
if ((d[0] & 15) != 8 || (d[0] >>> 4) > 7 || ((d[0] << 8 | d[1]) % 31))
err(6, 'invalid zlib data');
if (d[1] & 32)
err(6, 'invalid zlib data: preset dictionaries not supported');
};
return {
/**
* Expands GZIP data
* @param data - The data to decompress
* @param out - Where to write the data. GZIP already encodes the output size, so providing this doesn't save memory.
* @returns The decompressed version of the data
*/
gunzipSync: function (data, out) {
return inflt(data.subarray(gzs(data), -8), out || new u8(gzl(data)));
},
/**
* Expands Zlib data
* @param data - The data to decompress
* @param out - Where to write the data. Saves memory if you know the decompressed size and provide an output buffer of that length.
* @returns The decompressed version of the data
*/
unzlibSync: function (data, out) {
return inflt((zlv(data), data.subarray(2, -4)), out);
}
};
})();