fflate
Version:
High performance (de)compression in an 8kB package
1,475 lines (1,473 loc) • 89.2 kB
JavaScript
// DEFLATE is a complex format; to read this code, you should probably check the RFC first:
// https://tools.ietf.org/html/rfc1951
// You may also wish to take a look at the guide I made about this program:
// https://gist.github.com/101arrowz/253f31eb5abc3d9275ab943003ffecad
// Some of the following code is similar to that of UZIP.js:
// https://github.com/photopea/UZIP.js
// However, the vast majority of the codebase has diverged from UZIP.js to increase performance and reduce bundle size.
// Sometimes 0 will appear where -1 would be more appropriate. This is because using a uint
// is better for memory in most engines (I *think*).
var ch2 = {};
var wk = (function (c, id, msg, transfer, cb) {
var w = new Worker(ch2[id] || (ch2[id] = URL.createObjectURL(new Blob([
c + ';addEventListener("error",function(e){e=e.error;postMessage({$e$:[e.message,e.code,e.stack]})})'
], { type: 'text/javascript' }))));
w.onmessage = function (e) {
var d = e.data, ed = d.$e$;
if (ed) {
var err = new Error(ed[0]);
err['code'] = ed[1];
err.stack = ed[2];
cb(err, null);
}
else
cb(null, d);
};
w.postMessage(msg, transfer);
return w;
});
// aliases for shorter compressed code (most minifers don't do this)
var u8 = Uint8Array, u16 = Uint16Array, i32 = Int32Array;
// 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
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 i32(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: b, r: r };
};
var _a = freb(fleb, 2), fl = _a.b, revfl = _a.r;
// 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.b, revfd = _b.r;
// 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) {
if (cd[i])
++l[cd[i] - 1];
}
// u16 "map": index -> minimum code for bit length = index
var le = new u16(mb);
for (i = 1; 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 flm = /*#__PURE__*/ hMap(flt, 9, 0), flrm = /*#__PURE__*/ hMap(flt, 9, 1);
// fixed distance map
var fdm = /*#__PURE__*/ hMap(fdt, 5, 0), 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
return new u8(v.subarray(s, e));
};
/**
* Codes for errors generated within this library
*/
export var FlateErrorCode = {
UnexpectedEOF: 0,
InvalidBlockType: 1,
InvalidLengthLiteral: 2,
InvalidDistance: 3,
StreamFinished: 4,
NoStreamHandler: 5,
InvalidHeader: 6,
NoCallback: 7,
InvalidUTF8: 8,
ExtraFieldTooLong: 9,
InvalidDate: 10,
FilenameTooLong: 11,
StreamFinishing: 12,
InvalidZipData: 13,
UnknownCompressionMethod: 14
};
// 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, st, buf, dict) {
// source length dict length
var sl = dat.length, dl = dict ? dict.length : 0;
if (!sl || st.f && !st.l)
return buf || new u8(0);
var noBuf = !buf;
// have to estimate size
var resize = noBuf || st.i != 2;
// no state
var noSt = st.i;
// Assumes roughly 33% compression ratio average
if (noBuf)
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 (resize)
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 (resize)
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 (resize)
cbuf(bt + 131072);
var end = bt + add;
if (bt < dt) {
var shift = dl - dt, dend = Math.min(dt, end);
if (shift + bt < 0)
err(3);
for (; bt < dend; ++bt)
buf[bt] = dict[shift + bt];
}
for (; bt < end; ++bt)
buf[bt] = buf[bt - dt];
}
}
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);
// don't reallocate for streams or user buffers
return bt != buf.length && noBuf ? slc(buf, 0, bt) : buf.subarray(0, bt);
};
// starting at p, write the minimum number of bits that can hold v to d
var wbits = function (d, p, v) {
v <<= p & 7;
var o = (p / 8) | 0;
d[o] |= v;
d[o + 1] |= v >> 8;
};
// starting at p, write the minimum number of bits (>8) that can hold v to d
var wbits16 = function (d, p, v) {
v <<= p & 7;
var o = (p / 8) | 0;
d[o] |= v;
d[o + 1] |= v >> 8;
d[o + 2] |= v >> 16;
};
// creates code lengths from a frequency table
var hTree = function (d, mb) {
// Need extra info to make a tree
var t = [];
for (var i = 0; i < d.length; ++i) {
if (d[i])
t.push({ s: i, f: d[i] });
}
var s = t.length;
var t2 = t.slice();
if (!s)
return { t: et, l: 0 };
if (s == 1) {
var v = new u8(t[0].s + 1);
v[t[0].s] = 1;
return { t: v, l: 1 };
}
t.sort(function (a, b) { return a.f - b.f; });
// after i2 reaches last ind, will be stopped
// freq must be greater than largest possible number of symbols
t.push({ s: -1, f: 25001 });
var l = t[0], r = t[1], i0 = 0, i1 = 1, i2 = 2;
t[0] = { s: -1, f: l.f + r.f, l: l, r: r };
// efficient algorithm from UZIP.js
// i0 is lookbehind, i2 is lookahead - after processing two low-freq
// symbols that combined have high freq, will start processing i2 (high-freq,
// non-composite) symbols instead
// see https://reddit.com/r/photopea/comments/ikekht/uzipjs_questions/
while (i1 != s - 1) {
l = t[t[i0].f < t[i2].f ? i0++ : i2++];
r = t[i0 != i1 && t[i0].f < t[i2].f ? i0++ : i2++];
t[i1++] = { s: -1, f: l.f + r.f, l: l, r: r };
}
var maxSym = t2[0].s;
for (var i = 1; i < s; ++i) {
if (t2[i].s > maxSym)
maxSym = t2[i].s;
}
// code lengths
var tr = new u16(maxSym + 1);
// max bits in tree
var mbt = ln(t[i1 - 1], tr, 0);
if (mbt > mb) {
// more algorithms from UZIP.js
// TODO: find out how this code works (debt)
// ind debt
var i = 0, dt = 0;
// left cost
var lft = mbt - mb, cst = 1 << lft;
t2.sort(function (a, b) { return tr[b.s] - tr[a.s] || a.f - b.f; });
for (; i < s; ++i) {
var i2_1 = t2[i].s;
if (tr[i2_1] > mb) {
dt += cst - (1 << (mbt - tr[i2_1]));
tr[i2_1] = mb;
}
else
break;
}
dt >>= lft;
while (dt > 0) {
var i2_2 = t2[i].s;
if (tr[i2_2] < mb)
dt -= 1 << (mb - tr[i2_2]++ - 1);
else
++i;
}
for (; i >= 0 && dt; --i) {
var i2_3 = t2[i].s;
if (tr[i2_3] == mb) {
--tr[i2_3];
++dt;
}
}
mbt = mb;
}
return { t: new u8(tr), l: mbt };
};
// get the max length and assign length codes
var ln = function (n, l, d) {
return n.s == -1
? Math.max(ln(n.l, l, d + 1), ln(n.r, l, d + 1))
: (l[n.s] = d);
};
// length codes generation
var lc = function (c) {
var s = c.length;
// Note that the semicolon was intentional
while (s && !c[--s])
;
var cl = new u16(++s);
// ind num streak
var cli = 0, cln = c[0], cls = 1;
var w = function (v) { cl[cli++] = v; };
for (var i = 1; i <= s; ++i) {
if (c[i] == cln && i != s)
++cls;
else {
if (!cln && cls > 2) {
for (; cls > 138; cls -= 138)
w(32754);
if (cls > 2) {
w(cls > 10 ? ((cls - 11) << 5) | 28690 : ((cls - 3) << 5) | 12305);
cls = 0;
}
}
else if (cls > 3) {
w(cln), --cls;
for (; cls > 6; cls -= 6)
w(8304);
if (cls > 2)
w(((cls - 3) << 5) | 8208), cls = 0;
}
while (cls--)
w(cln);
cls = 1;
cln = c[i];
}
}
return { c: cl.subarray(0, cli), n: s };
};
// calculate the length of output from tree, code lengths
var clen = function (cf, cl) {
var l = 0;
for (var i = 0; i < cl.length; ++i)
l += cf[i] * cl[i];
return l;
};
// writes a fixed block
// returns the new bit pos
var wfblk = function (out, pos, dat) {
// no need to write 00 as type: TypedArray defaults to 0
var s = dat.length;
var o = shft(pos + 2);
out[o] = s & 255;
out[o + 1] = s >> 8;
out[o + 2] = out[o] ^ 255;
out[o + 3] = out[o + 1] ^ 255;
for (var i = 0; i < s; ++i)
out[o + i + 4] = dat[i];
return (o + 4 + s) * 8;
};
// writes a block
var wblk = function (dat, out, final, syms, lf, df, eb, li, bs, bl, p) {
wbits(out, p++, final);
++lf[256];
var _a = hTree(lf, 15), dlt = _a.t, mlb = _a.l;
var _b = hTree(df, 15), ddt = _b.t, mdb = _b.l;
var _c = lc(dlt), lclt = _c.c, nlc = _c.n;
var _d = lc(ddt), lcdt = _d.c, ndc = _d.n;
var lcfreq = new u16(19);
for (var i = 0; i < lclt.length; ++i)
++lcfreq[lclt[i] & 31];
for (var i = 0; i < lcdt.length; ++i)
++lcfreq[lcdt[i] & 31];
var _e = hTree(lcfreq, 7), lct = _e.t, mlcb = _e.l;
var nlcc = 19;
for (; nlcc > 4 && !lct[clim[nlcc - 1]]; --nlcc)
;
var flen = (bl + 5) << 3;
var ftlen = clen(lf, flt) + clen(df, fdt) + eb;
var dtlen = clen(lf, dlt) + clen(df, ddt) + eb + 14 + 3 * nlcc + clen(lcfreq, lct) + 2 * lcfreq[16] + 3 * lcfreq[17] + 7 * lcfreq[18];
if (bs >= 0 && flen <= ftlen && flen <= dtlen)
return wfblk(out, p, dat.subarray(bs, bs + bl));
var lm, ll, dm, dl;
wbits(out, p, 1 + (dtlen < ftlen)), p += 2;
if (dtlen < ftlen) {
lm = hMap(dlt, mlb, 0), ll = dlt, dm = hMap(ddt, mdb, 0), dl = ddt;
var llm = hMap(lct, mlcb, 0);
wbits(out, p, nlc - 257);
wbits(out, p + 5, ndc - 1);
wbits(out, p + 10, nlcc - 4);
p += 14;
for (var i = 0; i < nlcc; ++i)
wbits(out, p + 3 * i, lct[clim[i]]);
p += 3 * nlcc;
var lcts = [lclt, lcdt];
for (var it = 0; it < 2; ++it) {
var clct = lcts[it];
for (var i = 0; i < clct.length; ++i) {
var len = clct[i] & 31;
wbits(out, p, llm[len]), p += lct[len];
if (len > 15)
wbits(out, p, (clct[i] >> 5) & 127), p += clct[i] >> 12;
}
}
}
else {
lm = flm, ll = flt, dm = fdm, dl = fdt;
}
for (var i = 0; i < li; ++i) {
var sym = syms[i];
if (sym > 255) {
var len = (sym >> 18) & 31;
wbits16(out, p, lm[len + 257]), p += ll[len + 257];
if (len > 7)
wbits(out, p, (sym >> 23) & 31), p += fleb[len];
var dst = sym & 31;
wbits16(out, p, dm[dst]), p += dl[dst];
if (dst > 3)
wbits16(out, p, (sym >> 5) & 8191), p += fdeb[dst];
}
else {
wbits16(out, p, lm[sym]), p += ll[sym];
}
}
wbits16(out, p, lm[256]);
return p + ll[256];
};
// deflate options (nice << 13) | chain
var deo = /*#__PURE__*/ new i32([65540, 131080, 131088, 131104, 262176, 1048704, 1048832, 2114560, 2117632]);
// empty
var et = /*#__PURE__*/ new u8(0);
// compresses data into a raw DEFLATE buffer
var dflt = function (dat, lvl, plvl, pre, post, st) {
var s = st.z || dat.length;
var o = new u8(pre + s + 5 * (1 + Math.ceil(s / 7000)) + post);
// writing to this writes to the output buffer
var w = o.subarray(pre, o.length - post);
var lst = st.l;
var pos = (st.r || 0) & 7;
if (lvl) {
if (pos)
w[0] = st.r >> 3;
var opt = deo[lvl - 1];
var n = opt >> 13, c = opt & 8191;
var msk_1 = (1 << plvl) - 1;
// prev 2-byte val map curr 2-byte val map
var prev = st.p || new u16(32768), head = st.h || new u16(msk_1 + 1);
var bs1_1 = Math.ceil(plvl / 3), bs2_1 = 2 * bs1_1;
var hsh = function (i) { return (dat[i] ^ (dat[i + 1] << bs1_1) ^ (dat[i + 2] << bs2_1)) & msk_1; };
// 24576 is an arbitrary number of maximum symbols per block
// 424 buffer for last block
var syms = new i32(25000);
// length/literal freq distance freq
var lf = new u16(288), df = new u16(32);
// l/lcnt exbits index l/lind waitdx blkpos
var lc_1 = 0, eb = 0, i = st.i || 0, li = 0, wi = st.w || 0, bs = 0;
for (; i + 2 < s; ++i) {
// hash value
var hv = hsh(i);
// index mod 32768 previous index mod
var imod = i & 32767, pimod = head[hv];
prev[imod] = pimod;
head[hv] = imod;
// We always should modify head and prev, but only add symbols if
// this data is not yet processed ("wait" for wait index)
if (wi <= i) {
// bytes remaining
var rem = s - i;
if ((lc_1 > 7000 || li > 24576) && (rem > 423 || !lst)) {
pos = wblk(dat, w, 0, syms, lf, df, eb, li, bs, i - bs, pos);
li = lc_1 = eb = 0, bs = i;
for (var j = 0; j < 286; ++j)
lf[j] = 0;
for (var j = 0; j < 30; ++j)
df[j] = 0;
}
// len dist chain
var l = 2, d = 0, ch_1 = c, dif = imod - pimod & 32767;
if (rem > 2 && hv == hsh(i - dif)) {
var maxn = Math.min(n, rem) - 1;
var maxd = Math.min(32767, i);
// max possible length
// not capped at dif because decompressors implement "rolling" index population
var ml = Math.min(258, rem);
while (dif <= maxd && --ch_1 && imod != pimod) {
if (dat[i + l] == dat[i + l - dif]) {
var nl = 0;
for (; nl < ml && dat[i + nl] == dat[i + nl - dif]; ++nl)
;
if (nl > l) {
l = nl, d = dif;
// break out early when we reach "nice" (we are satisfied enough)
if (nl > maxn)
break;
// now, find the rarest 2-byte sequence within this
// length of literals and search for that instead.
// Much faster than just using the start
var mmd = Math.min(dif, nl - 2);
var md = 0;
for (var j = 0; j < mmd; ++j) {
var ti = i - dif + j & 32767;
var pti = prev[ti];
var cd = ti - pti & 32767;
if (cd > md)
md = cd, pimod = ti;
}
}
}
// check the previous match
imod = pimod, pimod = prev[imod];
dif += imod - pimod & 32767;
}
}
// d will be nonzero only when a match was found
if (d) {
// store both dist and len data in one int32
// Make sure this is recognized as a len/dist with 28th bit (2^28)
syms[li++] = 268435456 | (revfl[l] << 18) | revfd[d];
var lin = revfl[l] & 31, din = revfd[d] & 31;
eb += fleb[lin] + fdeb[din];
++lf[257 + lin];
++df[din];
wi = i + l;
++lc_1;
}
else {
syms[li++] = dat[i];
++lf[dat[i]];
}
}
}
for (i = Math.max(i, wi); i < s; ++i) {
syms[li++] = dat[i];
++lf[dat[i]];
}
pos = wblk(dat, w, lst, syms, lf, df, eb, li, bs, i - bs, pos);
if (!lst) {
st.r = (pos & 7) | w[(pos / 8) | 0] << 3;
// shft(pos) now 1 less if pos & 7 != 0
pos -= 7;
st.h = head, st.p = prev, st.i = i, st.w = wi;
}
}
else {
for (var i = st.w || 0; i < s + lst; i += 65535) {
// end
var e = i + 65535;
if (e >= s) {
// write final block
w[(pos / 8) | 0] = lst;
e = s;
}
pos = wfblk(w, pos + 1, dat.subarray(i, e));
}
st.i = s;
}
return slc(o, 0, pre + shft(pos) + post);
};
// CRC32 table
var crct = /*#__PURE__*/ (function () {
var t = new Int32Array(256);
for (var i = 0; i < 256; ++i) {
var c = i, k = 9;
while (--k)
c = ((c & 1) && -306674912) ^ (c >>> 1);
t[i] = c;
}
return t;
})();
// CRC32
var crc = function () {
var c = -1;
return {
p: function (d) {
// closures have awful performance
var cr = c;
for (var i = 0; i < d.length; ++i)
cr = crct[(cr & 255) ^ d[i]] ^ (cr >>> 8);
c = cr;
},
d: function () { return ~c; }
};
};
// Adler32
var adler = function () {
var a = 1, b = 0;
return {
p: function (d) {
// closures have awful performance
var n = a, m = b;
var l = d.length | 0;
for (var i = 0; i != l;) {
var e = Math.min(i + 2655, l);
for (; i < e; ++i)
m += n += d[i];
n = (n & 65535) + 15 * (n >> 16), m = (m & 65535) + 15 * (m >> 16);
}
a = n, b = m;
},
d: function () {
a %= 65521, b %= 65521;
return (a & 255) << 24 | (a & 0xFF00) << 8 | (b & 255) << 8 | (b >> 8);
}
};
};
;
// deflate with opts
var dopt = function (dat, opt, pre, post, st) {
if (!st) {
st = { l: 1 };
if (opt.dictionary) {
var dict = opt.dictionary.subarray(-32768);
var newDat = new u8(dict.length + dat.length);
newDat.set(dict);
newDat.set(dat, dict.length);
dat = newDat;
st.w = dict.length;
}
}
return dflt(dat, opt.level == null ? 6 : opt.level, opt.mem == null ? (st.l ? Math.ceil(Math.max(8, Math.min(13, Math.log(dat.length))) * 1.5) : 20) : (12 + opt.mem), pre, post, st);
};
// Walmart object spread
var mrg = function (a, b) {
var o = {};
for (var k in a)
o[k] = a[k];
for (var k in b)
o[k] = b[k];
return o;
};
// worker clone
// This is possibly the craziest part of the entire codebase, despite how simple it may seem.
// The only parameter to this function is a closure that returns an array of variables outside of the function scope.
// We're going to try to figure out the variable names used in the closure as strings because that is crucial for workerization.
// We will return an object mapping of true variable name to value (basically, the current scope as a JS object).
// The reason we can't just use the original variable names is minifiers mangling the toplevel scope.
// This took me three weeks to figure out how to do.
var wcln = function (fn, fnStr, td) {
var dt = fn();
var st = fn.toString();
var ks = st.slice(st.indexOf('[') + 1, st.lastIndexOf(']')).replace(/\s+/g, '').split(',');
for (var i = 0; i < dt.length; ++i) {
var v = dt[i], k = ks[i];
if (typeof v == 'function') {
fnStr += ';' + k + '=';
var st_1 = v.toString();
if (v.prototype) {
// for global objects
if (st_1.indexOf('[native code]') != -1) {
var spInd = st_1.indexOf(' ', 8) + 1;
fnStr += st_1.slice(spInd, st_1.indexOf('(', spInd));
}
else {
fnStr += st_1;
for (var t in v.prototype)
fnStr += ';' + k + '.prototype.' + t + '=' + v.prototype[t].toString();
}
}
else
fnStr += st_1;
}
else
td[k] = v;
}
return fnStr;
};
var ch = [];
// clone bufs
var cbfs = function (v) {
var tl = [];
for (var k in v) {
if (v[k].buffer) {
tl.push((v[k] = new v[k].constructor(v[k])).buffer);
}
}
return tl;
};
// use a worker to execute code
var wrkr = function (fns, init, id, cb) {
if (!ch[id]) {
var fnStr = '', td_1 = {}, m = fns.length - 1;
for (var i = 0; i < m; ++i)
fnStr = wcln(fns[i], fnStr, td_1);
ch[id] = { c: wcln(fns[m], fnStr, td_1), e: td_1 };
}
var td = mrg({}, ch[id].e);
return wk(ch[id].c + ';onmessage=function(e){for(var k in e.data)self[k]=e.data[k];onmessage=' + init.toString() + '}', id, td, cbfs(td), cb);
};
// base async inflate fn
var bInflt = function () { return [u8, u16, i32, fleb, fdeb, clim, fl, fd, flrm, fdrm, rev, ec, hMap, max, bits, bits16, shft, slc, err, inflt, inflateSync, pbf, gopt]; };
var bDflt = function () { return [u8, u16, i32, fleb, fdeb, clim, revfl, revfd, flm, flt, fdm, fdt, rev, deo, et, hMap, wbits, wbits16, hTree, ln, lc, clen, wfblk, wblk, shft, slc, dflt, dopt, deflateSync, pbf]; };
// gzip extra
var gze = function () { return [gzh, gzhl, wbytes, crc, crct]; };
// gunzip extra
var guze = function () { return [gzs, gzl]; };
// zlib extra
var zle = function () { return [zlh, wbytes, adler]; };
// unzlib extra
var zule = function () { return [zls]; };
// post buf
var pbf = function (msg) { return postMessage(msg, [msg.buffer]); };
// get opts
var gopt = function (o) { return o && {
out: o.size && new u8(o.size),
dictionary: o.dictionary
}; };
// async helper
var cbify = function (dat, opts, fns, init, id, cb) {
var w = wrkr(fns, init, id, function (err, dat) {
w.terminate();
cb(err, dat);
});
w.postMessage([dat, opts], opts.consume ? [dat.buffer] : []);
return function () { w.terminate(); };
};
// auto stream
var astrm = function (strm) {
strm.ondata = function (dat, final) { return postMessage([dat, final], [dat.buffer]); };
return function (ev) {
if (ev.data.length) {
strm.push(ev.data[0], ev.data[1]);
postMessage([ev.data[0].length]);
}
else
strm.flush();
};
};
// async stream attach
var astrmify = function (fns, strm, opts, init, id, flush, ext) {
var t;
var w = wrkr(fns, init, id, function (err, dat) {
if (err)
w.terminate(), strm.ondata.call(strm, err);
else if (!Array.isArray(dat))
ext(dat);
else if (dat.length == 1) {
strm.queuedSize -= dat[0];
if (strm.ondrain)
strm.ondrain(dat[0]);
}
else {
if (dat[1])
w.terminate();
strm.ondata.call(strm, err, dat[0], dat[1]);
}
});
w.postMessage(opts);
strm.queuedSize = 0;
strm.push = function (d, f) {
if (!strm.ondata)
err(5);
if (t)
strm.ondata(err(4, 0, 1), null, !!f);
strm.queuedSize += d.length;
w.postMessage([d, t = f], [d.buffer]);
};
strm.terminate = function () { w.terminate(); };
if (flush) {
strm.flush = function () { w.postMessage([]); };
}
};
// read 2 bytes
var b2 = function (d, b) { return d[b] | (d[b + 1] << 8); };
// read 4 bytes
var b4 = function (d, b) { return (d[b] | (d[b + 1] << 8) | (d[b + 2] << 16) | (d[b + 3] << 24)) >>> 0; };
var b8 = function (d, b) { return b4(d, b) + (b4(d, b + 4) * 4294967296); };
// write bytes
var wbytes = function (d, b, v) {
for (; v; ++b)
d[b] = v, v >>>= 8;
};
// gzip header
var gzh = function (c, o) {
var fn = o.filename;
c[0] = 31, c[1] = 139, c[2] = 8, c[8] = o.level < 2 ? 4 : o.level == 9 ? 2 : 0, c[9] = 3; // assume Unix
if (o.mtime != 0)
wbytes(c, 4, Math.floor(new Date(o.mtime || Date.now()) / 1000));
if (fn) {
c[3] = 8;
for (var i = 0; i <= fn.length; ++i)
c[i + 10] = fn.charCodeAt(i);
}
};
// 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;
};
// gzip header length
var gzhl = function (o) { return 10 + (o.filename ? o.filename.length + 1 : 0); };
// zlib header
var zlh = function (c, o) {
var lv = o.level, fl = lv == 0 ? 0 : lv < 6 ? 1 : lv == 9 ? 3 : 2;
c[0] = 120, c[1] = (fl << 6) | (o.dictionary && 32);
c[1] |= 31 - ((c[0] << 8) | c[1]) % 31;
if (o.dictionary) {
var h = adler();
h.p(o.dictionary);
wbytes(c, 2, h.d());
}
};
// zlib start
var zls = function (d, dict) {
if ((d[0] & 15) != 8 || (d[0] >> 4) > 7 || ((d[0] << 8 | d[1]) % 31))
err(6, 'invalid zlib data');
if ((d[1] >> 5 & 1) == +!dict)
err(6, 'invalid zlib data: ' + (d[1] & 32 ? 'need' : 'unexpected') + ' dictionary');
return (d[1] >> 3 & 4) + 2;
};
function StrmOpt(opts, cb) {
if (typeof opts == 'function')
cb = opts, opts = {};
this.ondata = cb;
return opts;
}
/**
* Streaming DEFLATE compression
*/
var Deflate = /*#__PURE__*/ (function () {
function Deflate(opts, cb) {
if (typeof opts == 'function')
cb = opts, opts = {};
this.ondata = cb;
this.o = opts || {};
this.s = { l: 0, i: 32768, w: 32768, z: 32768 };
// Buffer length must always be 0 mod 32768 for index calculations to be correct when modifying head and prev
// 98304 = 32768 (lookback) + 65536 (common chunk size)
this.b = new u8(98304);
if (this.o.dictionary) {
var dict = this.o.dictionary.subarray(-32768);
this.b.set(dict, 32768 - dict.length);
this.s.i = 32768 - dict.length;
}
}
Deflate.prototype.p = function (c, f) {
this.ondata(dopt(c, this.o, 0, 0, this.s), f);
};
/**
* Pushes a chunk to be deflated
* @param chunk The chunk to push
* @param final Whether this is the last chunk
*/
Deflate.prototype.push = function (chunk, final) {
if (!this.ondata)
err(5);
if (this.s.l)
err(4);
var endLen = chunk.length + this.s.z;
if (endLen > this.b.length) {
if (endLen > 2 * this.b.length - 32768) {
var newBuf = new u8(endLen & -32768);
newBuf.set(this.b.subarray(0, this.s.z));
this.b = newBuf;
}
var split = this.b.length - this.s.z;
this.b.set(chunk.subarray(0, split), this.s.z);
this.s.z = this.b.length;
this.p(this.b, false);
this.b.set(this.b.subarray(-32768));
this.b.set(chunk.subarray(split), 32768);
this.s.z = chunk.length - split + 32768;
this.s.i = 32766, this.s.w = 32768;
}
else {
this.b.set(chunk, this.s.z);
this.s.z += chunk.length;
}
this.s.l = final & 1;
if (this.s.z > this.s.w + 8191 || final) {
this.p(this.b, final || false);
this.s.w = this.s.i, this.s.i -= 2;
}
};
/**
* Flushes buffered uncompressed data. Useful to immediately retrieve the
* deflated output for small inputs.
*/
Deflate.prototype.flush = function () {
if (!this.ondata)
err(5);
if (this.s.l)
err(4);
this.p(this.b, false);
this.s.w = this.s.i, this.s.i -= 2;
};
return Deflate;
}());
export { Deflate };
/**
* Asynchronous streaming DEFLATE compression
*/
var AsyncDeflate = /*#__PURE__*/ (function () {
function AsyncDeflate(opts, cb) {
astrmify([
bDflt,
function () { return [astrm, Deflate]; }
], this, StrmOpt.call(this, opts, cb), function (ev) {
var strm = new Deflate(ev.data);
onmessage = astrm(strm);
}, 6, 1);
}
return AsyncDeflate;
}());
export { AsyncDeflate };
export function deflate(data, opts, cb) {
if (!cb)
cb = opts, opts = {};
if (typeof cb != 'function')
err(7);
return cbify(data, opts, [
bDflt,
], function (ev) { return pbf(deflateSync(ev.data[0], ev.data[1])); }, 0, cb);
}
/**
* Compresses data with DEFLATE without any wrapper
* @param data The data to compress
* @param opts The compression options
* @returns The deflated version of the data
*/
export function deflateSync(data, opts) {
return dopt(data, opts || {}, 0, 0);
}
/**
* Streaming DEFLATE decompression
*/
var Inflate = /*#__PURE__*/ (function () {
function Inflate(opts, cb) {
// no StrmOpt here to avoid adding to workerizer
if (typeof opts == 'function')
cb = opts, opts = {};
this.ondata = cb;
var dict = opts && opts.dictionary && opts.dictionary.subarray(-32768);
this.s = { i: 0, b: dict ? dict.length : 0 };
this.o = new u8(32768);
this.p = new u8(0);
if (dict)
this.o.set(dict);
}
Inflate.prototype.e = function (c) {
if (!this.ondata)
err(5);
if (this.d)
err(4);
if (!this.p.length)
this.p = c;
else if (c.length) {
var n = new u8(this.p.length + c.length);
n.set(this.p), n.set(c, this.p.length), this.p = n;
}
};
Inflate.prototype.c = function (final) {
this.s.i = +(this.d = final || false);
var bts = this.s.b;
var dt = inflt(this.p, this.s, this.o);
this.ondata(slc(dt, bts, this.s.b), this.d);
this.o = slc(dt, this.s.b - 32768), this.s.b = this.o.length;
this.p = slc(this.p, (this.s.p / 8) | 0), this.s.p &= 7;
};
/**
* Pushes a chunk to be inflated
* @param chunk The chunk to push
* @param final Whether this is the final chunk
*/
Inflate.prototype.push = function (chunk, final) {
this.e(chunk), this.c(final);
};
return Inflate;
}());
export { Inflate };
/**
* Asynchronous streaming DEFLATE decompression
*/
var AsyncInflate = /*#__PURE__*/ (function () {
function AsyncInflate(opts, cb) {
astrmify([
bInflt,
function () { return [astrm, Inflate]; }
], this, StrmOpt.call(this, opts, cb), function (ev) {
var strm = new Inflate(ev.data);
onmessage = astrm(strm);
}, 7, 0);
}
return AsyncInflate;
}());
export { AsyncInflate };
export function inflate(data, opts, cb) {
if (!cb)
cb = opts, opts = {};
if (typeof cb != 'function')
err(7);
return cbify(data, opts, [
bInflt
], function (ev) { return pbf(inflateSync(ev.data[0], gopt(ev.data[1]))); }, 1, cb);
}
/**
* Expands DEFLATE data with no wrapper
* @param data The data to decompress
* @param opts The decompression options
* @returns The decompressed version of the data
*/
export function inflateSync(data, opts) {
return inflt(data, { i: 2 }, opts && opts.out, opts && opts.dictionary);
}
// before you yell at me for not just using extends, my reason is that TS inheritance is hard to workerize.
/**
* Streaming GZIP compression
*/
var Gzip = /*#__PURE__*/ (function () {
function Gzip(opts, cb) {
this.c = crc();
this.l = 0;
this.v = 1;
Deflate.call(this, opts, cb);
}
/**
* Pushes a chunk to be GZIPped
* @param chunk The chunk to push
* @param final Whether this is the last chunk
*/
Gzip.prototype.push = function (chunk, final) {
this.c.p(chunk);
this.l += chunk.length;
Deflate.prototype.push.call(this, chunk, final);
};
Gzip.prototype.p = function (c, f) {
var raw = dopt(c, this.o, this.v && gzhl(this.o), f && 8, this.s);
if (this.v)
gzh(raw, this.o), this.v = 0;
if (f)
wbytes(raw, raw.length - 8, this.c.d()), wbytes(raw, raw.length - 4, this.l);
this.ondata(raw, f);
};
/**
* Flushes buffered uncompressed data. Useful to immediately retrieve the
* GZIPped output for small inputs.
*/
Gzip.prototype.flush = function () {
Deflate.prototype.flush.call(this);
};
return Gzip;
}());
export { Gzip };
/**
* Asynchronous streaming GZIP compression
*/
var AsyncGzip = /*#__PURE__*/ (function () {
function AsyncGzip(opts, cb) {
astrmify([
bDflt,
gze,
function () { return [astrm, Deflate, Gzip]; }
], this, StrmOpt.call(this, opts, cb), function (ev) {
var strm = new Gzip(ev.data);
onmessage = astrm(strm);
}, 8, 1);
}
return AsyncGzip;
}());
export { AsyncGzip };
export function gzip(data, opts, cb) {
if (!cb)
cb = opts, opts = {};
if (typeof cb != 'function')
err(7);
return cbify(data, opts, [
bDflt,
gze,
function () { return [gzipSync]; }
], function (ev) { return pbf(gzipSync(ev.data[0], ev.data[1])); }, 2, cb);
}
/**
* Compresses data with GZIP
* @param data The data to compress
* @param opts The compression options
* @returns The gzipped version of the data
*/
export function gzipSync(data, opts) {
if (!opts)
opts = {};
var c = crc(), l = data.length;
c.p(data);
var d = dopt(data, opts, gzhl(opts), 8), s = d.length;
return gzh(d, opts), wbytes(d, s - 8, c.d()), wbytes(d, s - 4, l), d;
}
/**
* Streaming single or multi-member GZIP decompression
*/
var Gunzip = /*#__PURE__*/ (function () {
function Gunzip(opts, cb) {
this.v = 1;
this.r = 0;
Inflate.call(this, opts, cb);
}
/**
* Pushes a chunk to be GUNZIPped
* @param chunk The chunk to push
* @param final Whether this is the last chunk
*/
Gunzip.prototype.push = function (chunk, final) {
Inflate.prototype.e.call(this, chunk);
this.r += chunk.length;
if (this.v) {
var p = this.p.subarray(this.v - 1);
var s = p.length > 3 ? gzs(p) : 4;
if (s > p.length) {
if (!final)
return;
}
else if (this.v > 1 && this.onmember) {
this.onmember(this.r - p.length);
}
this.p = p.subarray(s), this.v = 0;
}
// necessary to prevent TS from using the closure value
// This allows for workerization to function correctly
Inflate.prototype.c.call(this, final);
// process concatenated GZIP
if (this.s.f && !this.s.l && !final) {
this.v = shft(this.s.p) + 9;
this.s = { i: 0 };
this.o = new u8(0);
this.push(new u8(0), final);
}
};
return Gunzip;
}());
export { Gunzip };
/**
* Asynchronous streaming single or multi-member GZIP decompression
*/
var AsyncGunzip = /*#__PURE__*/ (function () {
function AsyncGunzip(opts, cb) {
var _this = this;
astrmify([
bInflt,
guze,
function () { return [astrm, Inflate, Gunzip]; }
], this, StrmOpt.call(this, opts, cb), function (ev) {
var strm = new Gunzip(ev.data);
strm.onmember = function (offset) { return postMessage(offset); };
onmessage = astrm(strm);
}, 9, 0, function (offset) { return _this.onmember && _this.onmember(offset); });
}
return AsyncGunzip;
}());
export { AsyncGunzip };
export function gunzip(data, opts, cb) {
if (!cb)
cb = opts, opts = {};
if (typeof cb != 'function')
err(7);
return cbify(data, opts, [
bInflt,
guze,
function () { return [gunzipSync]; }
], function (ev) { return pbf(gunzipSync(ev.data[0], ev.data[1])); }, 3, cb);
}
/**
* Expands GZIP data
* @param data The data to decompress
* @param opts The decompression options
* @returns The decompressed version of the data
*/
export function gunzipSync(data, opts) {
var st = gzs(data);
if (st + 8 > data.length)
err(6, 'invalid gzip data');
return inflt(data.subarray(st, -8), { i: 2 }, opts && opts.out || new u8(gzl(data)), opts && opts.dictionary);
}
/**
* Streaming Zlib compression
*/
var Zlib = /*#__PURE__*/ (function () {
function Zlib(opts, cb) {
this.c = adler();
this.v = 1;
Deflate.call(this, opts, cb);
}
/**
* Pushes a chunk to be zlibbed
* @param chunk The chunk to push
* @param final Whether this is the last chunk
*/
Zlib.prototype.push = function (chunk, final) {
this.c.p(chunk);
Deflate.prototype.push.call(this, chunk, final);
};
Zlib.prototype.p = function (c, f) {
var raw = dopt(c, this.o, this.v && (this.o.dictionary ? 6 : 2), f && 4, this.s);
if (this.v)
zlh(raw, this.o), this.v = 0;
if (f)
wbytes(raw, raw.length - 4, this.c.d());
this.ondata(raw, f);
};
/**
* Flushes buffered uncompressed data. Useful to immediately retrieve the
* zlibbed output for small inputs.
*/
Zlib.prototype.flush = function () {
Deflate.prototype.flush.call(this);
};
return Zlib;
}());
export { Zlib };
/**
* Asynchronous streaming Zlib compression
*/
var AsyncZlib = /*#__PURE__*/ (function () {
function AsyncZlib(opts, cb) {
astrmify([
bDflt,
zle,
function () { return [astrm, Deflate, Zlib]; }
], this, StrmOpt.call(this, opts, cb), function (ev) {
var strm = new Zlib(ev.data);
onmessage = astrm(strm);
}, 10, 1);
}
return AsyncZlib;
}());
export { AsyncZlib };
export function zlib(data, opts, cb) {
if (!cb)
cb = opts, opts = {};
if (typeof cb != 'function')
err(7);
return cbify(data, opts, [
bDflt,
zle,
function () { return [zlibSync]; }
], function (ev) { return pbf(zlibSync(ev.data[0], ev.data[1])); }, 4, cb);
}
/**
* Compress data with Zlib
* @param data The data to compress
* @param opts The compression options
* @returns The zlib-compressed version of the data
*/
export function zlibSync(data, opts) {
if (!opts)
opts = {};
var a = adler();
a.p(data);
var d = dopt(data, opts, opts.dictionary ? 6 : 2, 4);
return zlh(d, opts), wbytes(d, d.length - 4, a.d()), d;
}
/**
* Streaming Zlib decompression
*/
var Unzlib = /*#__PURE__*/ (function () {
function Unzlib(opts, cb) {
Inflate.call(this, opts, cb);
this.v = opts && opts.dictionary ? 2 : 1;
}
/**
* Pushes a chunk to be unzlibbed
* @param chunk The chunk to push
* @param final Whether this is the last chunk
*/
Unzlib.prototype.push = function (chunk, final) {
Inflate.prototype.e.call(this, chunk);
if (this.v) {
if (this.p.length < 6 && !final)
return;
this.p = this.p.subarray(zls(this.p, this.v - 1)), this.v = 0;
}
if (final) {
if (this.p.length < 4)