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hub / github.com/Stuk/jszip / string2buf

Function string2buf

lib/utf8.js:23–78  ·  view source on GitHub ↗
(str)

Source from the content-addressed store, hash-verified

21
22// convert string to array (typed, when possible)
23var string2buf = function (str) {
24 var buf, c, c2, m_pos, i, str_len = str.length, buf_len = 0;
25
26 // count binary size
27 for (m_pos = 0; m_pos < str_len; m_pos++) {
28 c = str.charCodeAt(m_pos);
29 if ((c & 0xfc00) === 0xd800 && (m_pos+1 < str_len)) {
30 c2 = str.charCodeAt(m_pos+1);
31 if ((c2 & 0xfc00) === 0xdc00) {
32 c = 0x10000 + ((c - 0xd800) << 10) + (c2 - 0xdc00);
33 m_pos++;
34 }
35 }
36 buf_len += c < 0x80 ? 1 : c < 0x800 ? 2 : c < 0x10000 ? 3 : 4;
37 }
38
39 // allocate buffer
40 if (support.uint8array) {
41 buf = new Uint8Array(buf_len);
42 } else {
43 buf = new Array(buf_len);
44 }
45
46 // convert
47 for (i=0, m_pos = 0; i < buf_len; m_pos++) {
48 c = str.charCodeAt(m_pos);
49 if ((c & 0xfc00) === 0xd800 && (m_pos+1 < str_len)) {
50 c2 = str.charCodeAt(m_pos+1);
51 if ((c2 & 0xfc00) === 0xdc00) {
52 c = 0x10000 + ((c - 0xd800) << 10) + (c2 - 0xdc00);
53 m_pos++;
54 }
55 }
56 if (c < 0x80) {
57 /* one byte */
58 buf[i++] = c;
59 } else if (c < 0x800) {
60 /* two bytes */
61 buf[i++] = 0xC0 | (c >>> 6);
62 buf[i++] = 0x80 | (c & 0x3f);
63 } else if (c < 0x10000) {
64 /* three bytes */
65 buf[i++] = 0xE0 | (c >>> 12);
66 buf[i++] = 0x80 | (c >>> 6 & 0x3f);
67 buf[i++] = 0x80 | (c & 0x3f);
68 } else {
69 /* four bytes */
70 buf[i++] = 0xf0 | (c >>> 18);
71 buf[i++] = 0x80 | (c >>> 12 & 0x3f);
72 buf[i++] = 0x80 | (c >>> 6 & 0x3f);
73 buf[i++] = 0x80 | (c & 0x3f);
74 }
75 }
76
77 return buf;
78};
79
80// Calculate max possible position in utf8 buffer,

Callers 1

utf8.jsFile · 0.85

Calls

no outgoing calls

Tested by

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