@drorgl/xml-streamer
Version:
XML stream parser for parsing large files efficiently with less usage of memory.
220 lines • 9 kB
JavaScript
;
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
// Source: https://github.com/xmppjs/ltx/blob/master/lib/parsers/ltx.js
const events_1 = __importDefault(require("events"));
const unescape_1 = require("./unescape");
const STATE_TEXT = 0;
const STATE_IGNORE_COMMENT = 1;
const STATE_IGNORE_INSTRUCTION = 2;
const STATE_TAG_NAME = 3;
const STATE_TAG = 4;
const STATE_ATTR_NAME = 5;
const STATE_ATTR_EQ = 6;
const STATE_ATTR_QUOT = 7;
const STATE_ATTR_VALUE = 8;
const STATE_CDATA = 9;
const lineCounterRegExp = new RegExp("\n", "g");
class SaxLtx extends events_1.default.EventEmitter {
constructor() {
super();
this.recordStart = 0;
this.state = STATE_TEXT;
this.currentLineNumber = 0;
}
getCurrentLineNumber() {
return this.currentLineNumber + 1;
}
end(data) {
if (data) {
this.write(data);
}
this.removeAllListeners();
}
write(data) {
if (typeof data !== "string") {
data = data.toString();
}
let pos = 0;
const self = this;
/* Anything from previous write()? */
if (self.remainder) {
data = self.remainder + data;
pos += self.remainder.length;
self.remainder = null;
}
function endRecording() {
if (typeof self.recordStart === "number") {
const recorded = data.substring(self.recordStart, pos);
self.recordStart = undefined;
return recorded;
}
}
let prevPos = pos;
for (; pos < data.length; pos++) {
if (self.state === STATE_TEXT) {
// if we're looping through text, fast-forward using indexOf to
// the next '<' character
const lt = data.indexOf("<", pos);
if (lt !== -1 && pos !== lt) {
pos = lt;
}
}
else if (self.state === STATE_ATTR_VALUE) {
// if we're looping through an attribute, fast-forward using
// indexOf to the next end quote character
const quot = data.indexOf(self.attrQuoteChar, pos);
if (quot !== -1) {
pos = quot;
}
}
else if (self.state === STATE_IGNORE_COMMENT) {
// if we're looping through a comment, fast-forward using
// indexOf to the first end-comment character
const endcomment = data.indexOf("-->", pos);
if (endcomment !== -1) {
pos = endcomment + 2; // target the '>' character
}
}
const newLines = (data.substring(prevPos, pos + 1).match(lineCounterRegExp) || []).length;
self.currentLineNumber += newLines;
prevPos = pos;
const c = data.charCodeAt(pos);
switch (self.state) {
case STATE_TEXT:
if (c === 60 /* < */) {
const text = endRecording();
if (text) {
self.emit("text", unescape_1.unescapeXML(text));
}
self.state = STATE_TAG_NAME;
self.recordStart = pos + 1;
self.attrs = {};
}
break;
case STATE_CDATA:
if (c === 93 /* ] */ && data.substr(pos + 1, 2) === "]>") {
const cData = endRecording();
if (cData) {
self.emit("text", cData);
}
self.state = STATE_IGNORE_COMMENT;
}
break;
case STATE_TAG_NAME:
if (c === 47 /* / */ && self.recordStart === pos) {
self.recordStart = pos + 1;
self.endTag = true;
}
else if (c === 33 /* ! */) {
if (data.substr(pos + 1, 7) === "[CDATA[") {
self.recordStart = pos + 8;
self.state = STATE_CDATA;
}
else if (data.substr(pos + 1, 7) === "DOCTYPE") {
self.recordStart = pos + 8;
self.state = STATE_TEXT;
}
else {
self.recordStart = undefined;
self.state = STATE_IGNORE_COMMENT;
}
}
else if (c === 63 /* ? */) {
self.recordStart = undefined;
self.state = STATE_IGNORE_INSTRUCTION;
}
else if (c <= 32 || c === 47 /* / */ || c === 62 /* > */) {
self.tagName = endRecording();
pos--;
self.state = STATE_TAG;
}
break;
case STATE_IGNORE_COMMENT:
if (c === 62 /* > */) {
const prevFirst = data.charCodeAt(pos - 1);
const prevSecond = data.charCodeAt(pos - 2);
if ((prevFirst === 45 /* - */ && prevSecond === 45 /* - */) ||
(prevFirst === 93 /* ] */ && prevSecond === 93 /* ] */)) {
self.state = STATE_TEXT;
}
}
break;
case STATE_IGNORE_INSTRUCTION:
if (c === 62 /* > */) {
const prev = data.charCodeAt(pos - 1);
if (prev === 63 /* ? */) {
self.state = STATE_TEXT;
}
}
break;
case STATE_TAG:
if (c === 62 /* > */) {
self._handleTagOpening(self.endTag, self.tagName, self.attrs);
self.tagName = undefined;
self.attrs = undefined;
self.endTag = undefined;
self.selfClosing = undefined;
self.state = STATE_TEXT;
self.recordStart = pos + 1;
}
else if (c === 47 /* / */) {
self.selfClosing = true;
}
else if (c > 32) {
self.recordStart = pos;
self.state = STATE_ATTR_NAME;
}
break;
case STATE_ATTR_NAME:
if (c <= 32 || c === 61 /* = */) {
self.attrName = endRecording();
pos--;
self.state = STATE_ATTR_EQ;
}
break;
case STATE_ATTR_EQ:
if (c === 61 /* = */) {
self.state = STATE_ATTR_QUOT;
}
break;
case STATE_ATTR_QUOT:
if (c === 34 /* " */ || c === 39 /* ' */) {
self.attrQuote = c;
self.attrQuoteChar = c === 34 ? '"' : "'";
self.state = STATE_ATTR_VALUE;
self.recordStart = pos + 1;
}
break;
case STATE_ATTR_VALUE:
if (c === self.attrQuote) {
const value = unescape_1.unescapeXML(endRecording());
self.attrs[self.attrName] = value;
self.attrName = undefined;
self.state = STATE_TAG;
}
break;
}
}
if (typeof self.recordStart === "number" &&
self.recordStart <= data.length) {
self.remainder = data.slice(self.recordStart);
self.recordStart = 0;
}
}
_handleTagOpening(endTag, tagName, attrs) {
if (!endTag) {
this.emit("startElement", tagName, attrs);
if (this.selfClosing) {
this.emit("endElement", tagName);
}
}
else {
this.emit("endElement", tagName);
}
}
}
exports.SaxLtx = SaxLtx;
//# sourceMappingURL=ltx.js.map