sheetjs-clone/packages/dta/dta.ts

544 lines
16 KiB
TypeScript
Raw Normal View History

2023-11-13 11:03:35 +00:00
import { DenseWorkSheet, WorkBook, type utils } from 'xlsx';
export { parse, set_utils };
let _utils: typeof utils;
/** Set internal instance of `utils`
*
* Usage:
*
* ```js
* const XLSX = require("xlsx");
* const DTA = require("dta");
* DTA.set_utils(XLSX.utils);
* ```
*
* @param utils utils object
*/
function set_utils(utils: any): void {
_utils = utils;
}
interface Payload {
/** Offset */
ptr: number;
/** Raw data */
raw: Uint8Array;
/** Latin-1 encoded */
str: string;
/** DataView */
dv: DataView;
}
function u8_to_dataview(array: Uint8Array): DataView { return new DataView(array.buffer, array.byteOffset, array.byteLength); }
function valid_inc(p: Payload, n: string): boolean {
if(p.str.slice(p.ptr, p.ptr + n.length) != n) return false;
p.ptr += n.length;
return true;
}
function skip_end(p: Payload, n: string): void {
const idx = p.str.indexOf(n, p.ptr);
if(idx == -1) throw new Error(`Expected ${n} after offset ${p.ptr}`);
p.ptr = idx + n.length;
}
function slice_end(p: Payload, n: string): Payload {
const idx = p.str.indexOf(n, p.ptr);
if(idx == -1) throw new Error(`Expected ${n} after offset ${p.ptr}`);
const raw = p.raw.slice(p.ptr, idx);
const res = {
ptr: 0,
raw,
str: p.str.slice(p.ptr, idx),
dv: u8_to_dataview(raw)
};
p.ptr = idx + n.length;
return res;
}
function read_f64(p: Payload, LE: boolean): number | null {
p.ptr += 8;
const d = p.dv.getFloat64(p.ptr - 8, LE);
return d > 8.988e+307 ? null : d;
}
function read_f32(p: Payload, LE: boolean): number | null {
p.ptr += 4;
const d = p.dv.getFloat32(p.ptr - 4, LE);
return d > 1.701e+38 ? null : d;
}
function read_u32(p: Payload, LE: boolean) {
p.ptr += 4;
return p.dv.getUint32(p.ptr - 4, LE);
}
function read_i32(p: Payload, LE: boolean): number | null {
p.ptr += 4;
const u = p.dv.getInt32(p.ptr - 4, LE);
return u > 0x7fffffe4 ? null : u;
}
function read_u16(p: Payload, LE: boolean) {
p.ptr += 2;
return p.dv.getUint16(p.ptr - 2, LE);
}
function read_i16(p: Payload, LE: boolean): number | null {
p.ptr += 2;
const u = p.dv.getInt16(p.ptr - 2, LE);
return u > 32740 ? null : u;
}
function read_u8(p: Payload) {
return p.raw[p.ptr++];
}
function read_i8(p: Payload): number | null {
let u = p.raw[p.ptr++];
u = u < 128 ? u : u - 256;
return u > 100 ? null : u;
}
const SUPPORTED_VERSIONS_TAGGED = [
"117", // stata 13
"118", // stata 14-18
// "119", // stata 15/16/17/18 (> 32767 variables)
// "120", // stata 18 (<= 32767, with aliases)
// "121", // stata 18 (> 32767, with aliases)
];
function parse_tagged(raw: Uint8Array): WorkBook {
const err = ("Not a DTA file");
/* sadly the web zealots decided to abandon binary strings */
const str = new TextDecoder('latin1').decode(raw);
const d: Payload = {
ptr: 0,
raw,
str,
dv: u8_to_dataview(raw)
}
let vers: number = 118;
let LE: boolean = true;
let nvar: number = 0, nobs: number = 0, nobs_lo = 0, nobs_hi = 0;
let label: string = "", timestamp: string = "";
const var_types: number[] = [];
const var_names: string[] = [];
const formats: string[] = [];
/* 5. Dataset format definition */
if(!valid_inc(d, "<stata_dta>")) throw err;
/* 5.1 Header <header> */
{
if(!valid_inc(d, "<header>")) throw err;
/* <release> */
{
if(!valid_inc(d, "<release>")) throw err;
const res = slice_end(d, "</release>");
if(SUPPORTED_VERSIONS_TAGGED.indexOf(res.str) == -1) throw (`Unsupported DTA ${res.str} file`);
vers = +res.str;
}
/* <byteorder> */
{
if(!valid_inc(d, "<byteorder>")) throw err;
const res = slice_end(d, "</byteorder>");
switch(res.str) {
case "MSF": LE = false; break;
case "LSF": LE = true; break;
default: throw (`Unsupported byteorder ${res.str}`);
}
}
/* <K> */
{
if(!valid_inc(d, "<K>")) throw err;
const res = slice_end(d, "</K>");
nvar = read_u16(res, LE);
}
/* <N> */
{
if(!valid_inc(d, "<N>")) throw err;
const res = slice_end(d, "</N>");
if(vers == 117) nobs = nobs_lo = read_u32(res, LE);
else {
const lo = read_u32(res, LE), hi = read_u32(res, LE);
nobs = LE ? ((nobs_lo = lo) + (nobs_hi = hi) * Math.pow(2,32)) : ((nobs_lo = hi) + (nobs_hi = lo) * Math.pow(2,32));
}
if(nobs > 1e6) console.error(`More than 1 million observations -- extra rows will be dropped`);
}
/* <label> */
{
if(!valid_inc(d, "<label>")) throw err;
const res = slice_end(d, "</label>");
const w = vers >= 118 ? 2 : 1;
const strlen = w == 1 ? read_u8(res) : read_u16(res, LE);
if(strlen + w != res.str.length) throw (`Expected string length ${strlen} but actual length was ${res.str.length - w}`);
if(strlen > 0) label = new TextDecoder().decode(res.raw.slice(w));
}
/* <timestamp> */
{
if(!valid_inc(d, "<timestamp>")) throw err;
const res = slice_end(d, "</timestamp>");
const strlen = read_u8(res);
if(strlen + 1 != res.str.length) throw (`Expected string length ${strlen} but actual length was ${res.str.length - 1}`);
if(strlen > 0) timestamp = res.str.slice(1);
}
if(!valid_inc(d, "</header>")) throw err;
}
/* 5.2 Map <map> */
{
/* TODO: validate map? */
if(!valid_inc(d, "<map>")) throw err;
/* 14 8-byte offsets for:
<stata_data>
<map>
<variable_types>
<varnames>
<sortlist>
<formats>
<value_label_names>
<variable_labels>
<characteristics>
<data>
<strls>
<value_labels>
</stata_data>
EOF
*/
skip_end(d, "</map>");
}
let stride = 0;
/* 5.3 Variable types <variable_types> */
{
if(!valid_inc(d, "<variable_types>")) throw err;
const res = slice_end(d, "</variable_types>");
if(res.raw.length != 2 * nvar) throw (`Expected variable_types length ${nvar * 2}, found ${res.raw.length}`);
while(res.ptr < res.raw.length) {
const type = read_u16(res, LE);
var_types.push(type);
if(type >= 1 && type <= 2045) stride += type;
else switch(type) {
case 32768: stride += 8; break;
case 65526: stride += 8; break;
case 65527: stride += 4; break;
case 65528: stride += 4; break;
case 65529: stride += 2; break;
case 65530: stride += 1; break;
default: throw (`Unsupported field type ${type}`);
}
}
}
/* 5.4 Variable names <varnames> */
{
if(!valid_inc(d, "<varnames>")) throw err;
const res = slice_end(d, "</varnames>");
const w = vers >= 118 ? 129 : 33;
if(res.raw.length != w * nvar) throw (`Expected variable_types length ${nvar * w}, found ${res.raw.length}`);
while(res.ptr < res.raw.length) {
const name = new TextDecoder().decode(res.raw.slice(res.ptr, res.ptr + w));
res.ptr += w;
var_names.push(name.replace(/\x00[\s\S]*/,""));
}
}
/* 5.5 Sort order of observations <sortlist> */
{
/* TODO: check sort list? */
if(!valid_inc(d, "<sortlist>")) throw err;
const res = slice_end(d, "</sortlist>");
if(res.raw.length != 2 * nvar + 2) throw (`Expected sortlist length ${nvar * 2 + 2}, found ${res.raw.length}`);
}
/* 5.6 Display formats <formats> */
{
if(!valid_inc(d, "<formats>")) throw err;
const res = slice_end(d, "</formats>");
const w = vers >= 118 ? 57 : 49;
if(res.raw.length != w * nvar) throw (`Expected formats length ${nvar * w}, found ${res.raw.length}`);
while(res.ptr < res.raw.length) {
const name = new TextDecoder().decode(res.raw.slice(res.ptr, res.ptr + w));
res.ptr += w;
formats.push(name.replace(/\x00[\s\S]*/,""));
}
}
/* TODO: <value_label_names> */
{
if(!valid_inc(d, "<value_label_names>")) throw err;
const w = vers >= 118 ? 129 : 33;
const res = slice_end(d, "</value_label_names>");
}
/* TODO: <variable_labels> */
{
if(!valid_inc(d, "<variable_labels>")) throw err;
const w = vers >= 118 ? 321 : 81;
const res = slice_end(d, "</variable_labels>");
}
/* 5.9 Characteristics <characteristics> */
{
if(!valid_inc(d, "<characteristics>")) throw err;
while(d.str.slice(d.ptr, d.ptr + 4) == "<ch>") {
d.ptr += 4;
const len = read_u32(d, LE);
d.ptr += len;
if(!valid_inc(d, "</ch>")) throw err;
}
if(!valid_inc(d, "</characteristics>")) throw err;
}
const ws: DenseWorkSheet = (_utils.aoa_to_sheet([var_names], {dense: true}) as DenseWorkSheet);
var ptrs: Array<[number, number, Uint8Array]> = []
/* 5.10 Data <data> */
{
if(!valid_inc(d, "<data>")) throw err;
for(let R = 0; R < nobs; ++R) {
const row: any[] = [];
for(let C = 0; C < nvar; ++C) {
let t = var_types[C];
// TODO: formats, dta_12{0,1} aliases?
if(t >= 1 && t <= 2045) {
/* NOTE: dta_117 restricts strf to ASCII */
let s = new TextDecoder().decode(d.raw.slice(d.ptr, d.ptr + t));
s = s.replace(/\x00[\s\S]*/,"");
row[C] = s;
d.ptr += t;
} else switch(t) {
case 65526: row[C] = read_f64(d, LE); break;
case 65527: row[C] = read_f32(d, LE); break;
case 65528: row[C] = read_i32(d, LE); break;
case 65529: row[C] = read_i16(d, LE); break;
case 65530: row[C] = read_i8(d); break;
case 32768: {
row[C] = "##SheetJStrL##";
ptrs.push([R+1,C, d.raw.slice(d.ptr, d.ptr + 8)]);
d.ptr += 8;
} break;
default: throw (`Unsupported field type ${t} for ${var_names[C]}`);
}
}
_utils.sheet_add_aoa(ws, [row], {origin: -1, sheetStubs: true});
}
if(!valid_inc(d, "</data>")) throw err;
}
/* 5.11 StrLs <strls> */
{
if(!valid_inc(d, "<strls>")) throw err;
const strl_tbl: string[][] = [];
while(d.raw[d.ptr] == 71 /* G */) {
if(!valid_inc(d, "GSO")) throw err;
const v = read_u32(d, LE);
let o = 0;
if(vers == 117) o = read_u32(d, LE);
else {
const lo = read_u32(d, LE), hi = read_u32(d, LE);
o = LE ? (lo + hi * Math.pow(2,32)) : (hi + lo * Math.pow(2,32));
if(o > 1e6) console.error(`More than 1 million observations -- data will be dropped`);
}
const t = read_u8(d);
const len = read_u32(d, LE);
if(!strl_tbl[o]) strl_tbl[o] = [];
let str = "";
if(t == 129) {
// TODO: codepage
str = new TextDecoder("latin1").decode(d.raw.slice(d.ptr, d.ptr + len));
d.ptr += len;
} else {
str = new TextDecoder("latin1").decode(d.raw.slice(d.ptr, d.ptr + len)).replace(/\x00$/,"");
d.ptr += len;
}
strl_tbl[o][v] = str;
}
if(!valid_inc(d, "</strls>")) throw err;
ptrs.forEach(([R,C,buf]) => {
const dv = u8_to_dataview(buf);
let v = 0, o = 0;
switch(vers) {
case 117: { // v(4) o(4)
v = dv.getUint32(0, LE);
o = dv.getUint32(4, LE);
} break;
case 118: case 120: { // v(2) o(6)
v = dv.getUint16(0, LE);
const o1 = dv.getUint16(2, LE), o2 = dv.getUint32(4, LE);
o = LE ? o1 + o2 * 65536 : o2 + o1 * (2**32);
} break;
case 119: case 121: { // v(3) o(5)
const v1 = dv.getUint16(0, LE), v2 = buf[2];
v = LE ? v1 + (v2 << 16) : v2 + (v1 << 8);
const o1 = buf[3], o2 = dv.getUint32(4, LE);
o = LE ? o1 + o2 * 256 : o2 + o1 * (2**32);
}
}
ws["!data"][R][C].v = strl_tbl[o][v];
});
}
/* 5.12 Value labels <value_labels> */
{
if(!valid_inc(d, "<value_labels>")) throw err;
const res = slice_end(d, "</value_labels>");
}
if(!valid_inc(d, "</stata_dta>")) throw err;
const wb = _utils.book_new();
_utils.book_append_sheet(wb, ws, "Sheet1");
return wb;
}
function parse_legacy(raw: Uint8Array): WorkBook {
let vers: number = raw[0];
switch(vers) {
case 102: // stata 1
case 112: // stata 8/9
throw (`Unsupported DTA ${vers} file`);
case 103: // stata 2/3
case 104: // stata 4
case 105: // stata 5
case 108: // stata 6
case 110: // stata 7
case 111: // stata 7
case 113: // stata 8/9
case 114: // stata 10/11
case 115: // stata 12
break;
default: throw new Error("Not a DTA file");
}
const d: Payload = {
ptr: 1,
raw,
str:"",
dv: u8_to_dataview(raw)
}
let LE: boolean = true;
let nvar: number = 0, nobs: number = 0;
let label: string = "", timestamp: string = "";
const var_types: number[] = [];
const var_names: string[] = [];
const formats: string[] = [];
/* 5.1 Header */
{
const byteorder = read_u8(d);
switch(byteorder) {
case 1: LE = false; break;
case 2: LE = true; break;
default: throw (`DTA ${vers} Unexpected byteorder ${byteorder}`);
}
let byte = read_u8(d);
if(byte != 1) throw (`DTA ${vers} Unexpected filetype ${byte}`);
// NOTE: dta_105 technically supports filetype 2
d.ptr++; // "unused"
nvar = read_u16(d, LE);
nobs = read_u32(d, LE);
d.ptr += (vers >= 108 ? 81 : 32); // TODO: data_label
if(vers >= 105) d.ptr += 18; // TODO: time_stamp
}
/* 5.2 Descriptors */
{
let C = 0;
// typlist
for(C = 0; C < nvar; ++C) var_types.push(read_u8(d));
// varlist
const w = vers >= 110 ? 33 : 9;
for(C = 0; C < nvar; ++C) {
var_names.push(new TextDecoder().decode(d.raw.slice(d.ptr, d.ptr + w)).replace(/\x00[\s\S]*$/,""));
d.ptr += w;
}
// srtlist
d.ptr += 2*(nvar + 1);
// fmtlist
const fw = (vers >= 114 ? 49 : vers >= 105 ? 12 : 7);
for(C = 0; C < nvar; ++C) {
formats.push(new TextDecoder().decode(d.raw.slice(d.ptr, d.ptr + fw)).replace(/\x00[\s\S]*$/,""));
d.ptr += fw;
}
// lbllist
d.ptr += (vers >= 110 ? 33 : 9) * nvar;
}
/* 5.3 Variable labels */
// TODO: should these names be used in the worksheet?
d.ptr += (vers >= 106 ? 81 : 32) * nvar;
/* 5.4 Expansion fields */
if(vers >= 105) while(d.ptr < d.raw.length) {
const dt = read_u8(d), len = (vers >= 111 ? read_u32 : read_u16)(d, LE);
if(dt == 0 && len == 0) break;
d.ptr += len;
}
const ws: DenseWorkSheet = (_utils.aoa_to_sheet([var_names], {dense: true}) as DenseWorkSheet);
/* 5.5 Data */
for(let R = 0; R < nobs; ++R) {
const row: any[] = [];
for(let C = 0; C < nvar; ++C) {
let t = var_types[C];
// TODO: data type processing
if(vers >= 111 && t >= 1 && t <= 244) {
/* NOTE: dta_117 restricts strf to ASCII */
let s = new TextDecoder().decode(d.raw.slice(d.ptr, d.ptr + t));
s = s.replace(/\x00[\s\S]*/,"");
row[C] = s;
d.ptr += t;
} else switch(t) {
case 251: case 0x62: row[C] = read_i8(d); break; // byte
case 252: case 0x69: row[C] = read_i16(d, LE); break; // int
case 253: case 0x6c: row[C] = read_i32(d, LE); break; // long
case 254: case 0x66: row[C] = read_f32(d, LE); break; // float
case 255: case 0x64: row[C] = read_f64(d, LE); break; // double
default: throw (`Unsupported field type ${t} for ${var_names[C]}`);
}
}
_utils.sheet_add_aoa(ws, [row], {origin: -1, sheetStubs: true});
}
/* 5.6 Value labels */
// EOF or labels
const wb: WorkBook = _utils.book_new();
_utils.book_append_sheet(wb, ws, "Sheet1");
return wb;
}
/** Parse DTA file
*
* NOTE: In NodeJS, `Buffer` extends `Uint8Array`
*
* @param {Uint8Array} data File data
*/
function parse(data: Uint8Array): WorkBook {
if(data[0] >= 102 && data[0] <= 115) return parse_legacy(data);
if(data[0] === 60) return parse_tagged(data);
throw new Error("Not a DTA file");
}