src/zip/inflate.js
function inflate_fast(bl, bd, tl, tl_index, td, td_index, s, z) {
			var t; // temporary pointer
			var tp; // temporary pointer
			var tp_index; // temporary pointer
			var e; // extra bits or operation
			var b; // bit buffer
			var k; // bits in bit buffer
			var p; // input data pointer
			var n; // bytes available there
			var q; // output window write pointer
			var m; // bytes to end of window or read pointer
			var ml; // mask for literal/length tree
			var md; // mask for distance tree
			var c; // bytes to copy
			var d; // distance back to copy from
			var r; // copy source pointer

			var tp_index_t_3; // (tp_index+t)*3

			// load input, output, bit values
			p = z.next_in_index;
			n = z.avail_in;
			b = s.bitb;
			k = s.bitk;
			q = s.write;
			m = q < s.read ? s.read - q - 1 : s.end - q;

			// initialize masks
			ml = inflate_mask[bl];
			md = inflate_mask[bd];

			// do until not enough input or output space for fast loop
			do { // assume called with m >= 258 && n >= 10
				// get literal/length code
				while (k < (20)) { // max bits for literal/length code
					n--;
					b |= (z.read_byte(p++) & 0xff) << k;
					k += 8;
				}

				t = b & ml;
				tp = tl;
				tp_index = tl_index;
				tp_index_t_3 = (tp_index + t) * 3;
				if ((e = tp[tp_index_t_3]) === 0) {
					b >>= (tp[tp_index_t_3 + 1]);
					k -= (tp[tp_index_t_3 + 1]);

					s.window[q++] = /* (byte) */tp[tp_index_t_3 + 2];
					m--;
					continue;
				}
				do {

					b >>= (tp[tp_index_t_3 + 1]);
					k -= (tp[tp_index_t_3 + 1]);

					if ((e & 16) !== 0) {
						e &= 15;
						c = tp[tp_index_t_3 + 2] + (/* (int) */b & inflate_mask[e]);

						b >>= e;
						k -= e;

						// decode distance base of block to copy
						while (k < (15)) { // max bits for distance code
							n--;
							b |= (z.read_byte(p++) & 0xff) << k;
							k += 8;
						}

						t = b & md;
						tp = td;
						tp_index = td_index;
						tp_index_t_3 = (tp_index + t) * 3;
						e = tp[tp_index_t_3];

						do {

							b >>= (tp[tp_index_t_3 + 1]);
							k -= (tp[tp_index_t_3 + 1]);

							if ((e & 16) !== 0) {
								// get extra bits to add to distance base
								e &= 15;
								while (k < (e)) { // get extra bits (up to 13)
									n--;
									b |= (z.read_byte(p++) & 0xff) << k;
									k += 8;
								}

								d = tp[tp_index_t_3 + 2] + (b & inflate_mask[e]);

								b >>= (e);
								k -= (e);

								// do the copy
								m -= c;
								if (q >= d) { // offset before dest
									// just copy
									r = q - d;
									if (q - r > 0 && 2 > (q - r)) {
										s.window[q++] = s.window[r++]; // minimum
										// count is
										// three,
										s.window[q++] = s.window[r++]; // so unroll
										// loop a
										// little
										c -= 2;
									} else {
										s.window.set(s.window.subarray(r, r + 2), q);
										q += 2;
										r += 2;
										c -= 2;
									}
								} else { // else offset after destination
									r = q - d;
									do {
										r += s.end; // force pointer in window
									} while (r < 0); // covers invalid distances
									e = s.end - r;
									if (c > e) { // if source crosses,
										c -= e; // wrapped copy
										if (q - r > 0 && e > (q - r)) {
											do {
												s.window[q++] = s.window[r++];
											} while (--e !== 0);
										} else {
											s.window.set(s.window.subarray(r, r + e), q);
											q += e;
											r += e;
											e = 0;
										}
										r = 0; // copy rest from start of window
									}

								}

								// copy all or what's left
								if (q - r > 0 && c > (q - r)) {
									do {
										s.window[q++] = s.window[r++];
									} while (--c !== 0);
								} else {
									s.window.set(s.window.subarray(r, r + c), q);
									q += c;
									r += c;
									c = 0;
								}
								break;
							} else if ((e & 64) === 0) {
								t += tp[tp_index_t_3 + 2];
								t += (b & inflate_mask[e]);
								tp_index_t_3 = (tp_index + t) * 3;
								e = tp[tp_index_t_3];
							} else {
								z.msg = "invalid distance code";

								c = z.avail_in - n;
								c = (k >> 3) < c ? k >> 3 : c;
								n += c;
								p -= c;
								k -= c << 3;

								s.bitb = b;
								s.bitk = k;
								z.avail_in = n;
								z.total_in += p - z.next_in_index;
								z.next_in_index = p;
								s.write = q;

								return Z_DATA_ERROR;
							}
						} while (true);
						break;
					}

					if ((e & 64) === 0) {
						t += tp[tp_index_t_3 + 2];
						t += (b & inflate_mask[e]);
						tp_index_t_3 = (tp_index + t) * 3;
						if ((e = tp[tp_index_t_3]) === 0) {

							b >>= (tp[tp_index_t_3 + 1]);
							k -= (tp[tp_index_t_3 + 1]);

							s.window[q++] = /* (byte) */tp[tp_index_t_3 + 2];
							m--;
							break;
						}
					} else if ((e & 32) !== 0) {

						c = z.avail_in - n;
						c = (k >> 3) < c ? k >> 3 : c;
						n += c;
						p -= c;
						k -= c << 3;

						s.bitb = b;
						s.bitk = k;
						z.avail_in = n;
						z.total_in += p - z.next_in_index;
						z.next_in_index = p;
						s.write = q;

						return Z_STREAM_END;
					} else {
						z.msg = "invalid literal/length code";

						c = z.avail_in - n;
						c = (k >> 3) < c ? k >> 3 : c;
						n += c;
						p -= c;
						k -= c << 3;

						s.bitb = b;
						s.bitk = k;
						z.avail_in = n;
						z.total_in += p - z.next_in_index;
						z.next_in_index = p;
						s.write = q;

						return Z_DATA_ERROR;
					}
				} while (true);
			} while (m >= 258 && n >= 10);

			// not enough input or output--restore pointers and return
			c = z.avail_in - n;
			c = (k >> 3) < c ? k >> 3 : c;
			n += c;
			p -= c;
			k -= c << 3;

			s.bitb = b;
			s.bitk = k;
			z.avail_in = n;
			z.total_in += p - z.next_in_index;
			z.next_in_index = p;
			s.write = q;

			return Z_OK;
		}
function inflate_fast(bl, bd, tl, tl_index, td, td_index, s, z) {
			var t; // temporary pointer
			var tp; // temporary pointer
			var tp_index; // temporary pointer
			var e; // extra bits or operation
			var b; // bit buffer
			var k; // bits in bit buffer
			var p; // input data pointer
			var n; // bytes available there
			var q; // output window write pointer
			var m; // bytes to end of window or read pointer
			var ml; // mask for literal/length tree
			var md; // mask for distance tree
			var c; // bytes to copy
			var d; // distance back to copy from
			var r; // copy source pointer

			var tp_index_t_3; // (tp_index+t)*3

			// load input, output, bit values
			p = z.next_in_index;
			n = z.avail_in;
			b = s.bitb;
			k = s.bitk;
			q = s.write;
			m = q < s.read ? s.read - q - 1 : s.end - q;

			// initialize masks
			ml = inflate_mask[bl];
			md = inflate_mask[bd];

			// do until not enough input or output space for fast loop
			do { // assume called with m >= 258 && n >= 10
				// get literal/length code
				while (k < (20)) { // max bits for literal/length code
					n--;
					b |= (z.read_byte(p++) & 0xff) << k;
					k += 8;
				}

				t = b & ml;
				tp = tl;
				tp_index = tl_index;
				tp_index_t_3 = (tp_index + t) * 3;
				if ((e = tp[tp_index_t_3]) === 0) {
					b >>= (tp[tp_index_t_3 + 1]);
					k -= (tp[tp_index_t_3 + 1]);

					s.window[q++] = /* (byte) */tp[tp_index_t_3 + 2];
					m--;
					continue;
				}
				do {

					b >>= (tp[tp_index_t_3 + 1]);
					k -= (tp[tp_index_t_3 + 1]);

					if ((e & 16) !== 0) {
						e &= 15;
						c = tp[tp_index_t_3 + 2] + (/* (int) */b & inflate_mask[e]);

						b >>= e;
						k -= e;

						// decode distance base of block to copy
						while (k < (15)) { // max bits for distance code
							n--;
							b |= (z.read_byte(p++) & 0xff) << k;
							k += 8;
						}

						t = b & md;
						tp = td;
						tp_index = td_index;
						tp_index_t_3 = (tp_index + t) * 3;
						e = tp[tp_index_t_3];

						do {

							b >>= (tp[tp_index_t_3 + 1]);
							k -= (tp[tp_index_t_3 + 1]);

							if ((e & 16) !== 0) {
								// get extra bits to add to distance base
								e &= 15;
								while (k < (e)) { // get extra bits (up to 13)
									n--;
									b |= (z.read_byte(p++) & 0xff) << k;
									k += 8;
								}

								d = tp[tp_index_t_3 + 2] + (b & inflate_mask[e]);

								b >>= (e);
								k -= (e);

								// do the copy
								m -= c;
								if (q >= d) { // offset before dest
									// just copy
									r = q - d;
									if (q - r > 0 && 2 > (q - r)) {
										s.window[q++] = s.window[r++]; // minimum
										// count is
										// three,
										s.window[q++] = s.window[r++]; // so unroll
										// loop a
										// little
										c -= 2;
									} else {
										s.window.set(s.window.subarray(r, r + 2), q);
										q += 2;
										r += 2;
										c -= 2;
									}
								} else { // else offset after destination
									r = q - d;
									do {
										r += s.end; // force pointer in window
									} while (r < 0); // covers invalid distances
									e = s.end - r;
									if (c > e) { // if source crosses,
										c -= e; // wrapped copy
										if (q - r > 0 && e > (q - r)) {
											do {
												s.window[q++] = s.window[r++];
											} while (--e !== 0);
										} else {
											s.window.set(s.window.subarray(r, r + e), q);
											q += e;
											r += e;
											e = 0;
										}
										r = 0; // copy rest from start of window
									}

								}

								// copy all or what's left
								if (q - r > 0 && c > (q - r)) {
									do {
										s.window[q++] = s.window[r++];
									} while (--c !== 0);
								} else {
									s.window.set(s.window.subarray(r, r + c), q);
									q += c;
									r += c;
									c = 0;
								}
								break;
							} else if ((e & 64) === 0) {
								t += tp[tp_index_t_3 + 2];
								t += (b & inflate_mask[e]);
								tp_index_t_3 = (tp_index + t) * 3;
								e = tp[tp_index_t_3];
							} else {
								z.msg = "invalid distance code";

								c = z.avail_in - n;
								c = (k >> 3) < c ? k >> 3 : c;
								n += c;
								p -= c;
								k -= c << 3;

								s.bitb = b;
								s.bitk = k;
								z.avail_in = n;
								z.total_in += p - z.next_in_index;
								z.next_in_index = p;
								s.write = q;

								return Z_DATA_ERROR;
							}
						} while (true);
						break;
					}

					if ((e & 64) === 0) {
						t += tp[tp_index_t_3 + 2];
						t += (b & inflate_mask[e]);
						tp_index_t_3 = (tp_index + t) * 3;
						if ((e = tp[tp_index_t_3]) === 0) {

							b >>= (tp[tp_index_t_3 + 1]);
							k -= (tp[tp_index_t_3 + 1]);

							s.window[q++] = /* (byte) */tp[tp_index_t_3 + 2];
							m--;
							break;
						}
					} else if ((e & 32) !== 0) {

						c = z.avail_in - n;
						c = (k >> 3) < c ? k >> 3 : c;
						n += c;
						p -= c;
						k -= c << 3;

						s.bitb = b;
						s.bitk = k;
						z.avail_in = n;
						z.total_in += p - z.next_in_index;
						z.next_in_index = p;
						s.write = q;

						return Z_STREAM_END;
					} else {
						z.msg = "invalid literal/length code";

						c = z.avail_in - n;
						c = (k >> 3) < c ? k >> 3 : c;
						n += c;
						p -= c;
						k -= c << 3;

						s.bitb = b;
						s.bitk = k;
						z.avail_in = n;
						z.total_in += p - z.next_in_index;
						z.next_in_index = p;
						s.write = q;

						return Z_DATA_ERROR;
					}
				} while (true);
			} while (m >= 258 && n >= 10);

			// not enough input or output--restore pointers and return
			c = z.avail_in - n;
			c = (k >> 3) < c ? k >> 3 : c;
			n += c;
			p -= c;
			k -= c << 3;

			s.bitb = b;
			s.bitk = k;
			z.avail_in = n;
			z.total_in += p - z.next_in_index;
			z.next_in_index = p;
			s.write = q;

			return Z_OK;
		}
Called with number of bytes left to write in window at least 258 (the maximum string length) and number of input bytes available at least ten. The ten bytes are six bytes for the longest length/ distance pair plus four bytes for overloading the bit buffer.