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"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.CsvParserStream = void 0;
const string_decoder_1 = require("string_decoder");
const stream_1 = require("stream");
const transforms_1 = require("./transforms");
const parser_1 = require("./parser");
class CsvParserStream extends stream_1.Transform {
constructor(parserOptions) {
super({ objectMode: parserOptions.objectMode });
this.lines = '';
this.rowCount = 0;
this.parsedRowCount = 0;
this.parsedLineCount = 0;
this.endEmitted = false;
this.headersEmitted = false;
this.parserOptions = parserOptions;
this.parser = new parser_1.Parser(parserOptions);
this.headerTransformer = new transforms_1.HeaderTransformer(parserOptions);
this.decoder = new string_decoder_1.StringDecoder(parserOptions.encoding);
this.rowTransformerValidator = new transforms_1.RowTransformerValidator();
}
get hasHitRowLimit() {
return this.parserOptions.limitRows && this.rowCount >= this.parserOptions.maxRows;
}
get shouldEmitRows() {
return this.parsedRowCount > this.parserOptions.skipRows;
}
get shouldSkipLine() {
return this.parsedLineCount <= this.parserOptions.skipLines;
}
transform(transformFunction) {
this.rowTransformerValidator.rowTransform = transformFunction;
return this;
}
validate(validateFunction) {
this.rowTransformerValidator.rowValidator = validateFunction;
return this;
}
// eslint-disable-next-line @typescript-eslint/no-explicit-any
emit(event, ...rest) {
if (event === 'end') {
if (!this.endEmitted) {
this.endEmitted = true;
super.emit('end', this.rowCount);
}
return false;
}
return super.emit(event, ...rest);
}
_transform(data, encoding, done) {
// if we have hit our maxRows parsing limit then skip parsing
if (this.hasHitRowLimit) {
return done();
}
const wrappedCallback = CsvParserStream.wrapDoneCallback(done);
try {
const { lines } = this;
const newLine = lines + this.decoder.write(data);
const rows = this.parse(newLine, true);
return this.processRows(rows, wrappedCallback);
}
catch (e) {
return wrappedCallback(e);
}
}
_flush(done) {
const wrappedCallback = CsvParserStream.wrapDoneCallback(done);
// if we have hit our maxRows parsing limit then skip parsing
if (this.hasHitRowLimit) {
return wrappedCallback();
}
try {
const newLine = this.lines + this.decoder.end();
const rows = this.parse(newLine, false);
return this.processRows(rows, wrappedCallback);
}
catch (e) {
return wrappedCallback(e);
}
}
parse(data, hasMoreData) {
if (!data) {
return [];
}
const { line, rows } = this.parser.parse(data, hasMoreData);
this.lines = line;
return rows;
}
processRows(rows, cb) {
const rowsLength = rows.length;
const iterate = (i) => {
const callNext = (err) => {
if (err) {
return cb(err);
}
if (i % 100 === 0) {
// incase the transform are sync insert a next tick to prevent stack overflow
setImmediate(() => iterate(i + 1));
return undefined;
}
return iterate(i + 1);
};
this.checkAndEmitHeaders();
// if we have emitted all rows or we have hit the maxRows limit option
// then end
if (i >= rowsLength || this.hasHitRowLimit) {
return cb();
}
this.parsedLineCount += 1;
if (this.shouldSkipLine) {
return callNext();
}
const row = rows[i];
this.rowCount += 1;
this.parsedRowCount += 1;
const nextRowCount = this.rowCount;
return this.transformRow(row, (err, transformResult) => {
if (err) {
this.rowCount -= 1;
return callNext(err);
}
if (!transformResult) {
return callNext(new Error('expected transform result'));
}
if (!transformResult.isValid) {
this.emit('data-invalid', transformResult.row, nextRowCount, transformResult.reason);
}
else if (transformResult.row) {
return this.pushRow(transformResult.row, callNext);
}
return callNext();
});
};
iterate(0);
}
transformRow(parsedRow, cb) {
try {
this.headerTransformer.transform(parsedRow, (err, withHeaders) => {
if (err) {
return cb(err);
}
if (!withHeaders) {
return cb(new Error('Expected result from header transform'));
}
if (!withHeaders.isValid) {
if (this.shouldEmitRows) {
return cb(null, { isValid: false, row: parsedRow });
}
// skipped because of skipRows option remove from total row count
return this.skipRow(cb);
}
if (withHeaders.row) {
if (this.shouldEmitRows) {
return this.rowTransformerValidator.transformAndValidate(withHeaders.row, cb);
}
// skipped because of skipRows option remove from total row count
return this.skipRow(cb);
}
// this is a header row dont include in the rowCount or parsedRowCount
this.rowCount -= 1;
this.parsedRowCount -= 1;
return cb(null, { row: null, isValid: true });
});
}
catch (e) {
cb(e);
}
}
checkAndEmitHeaders() {
if (!this.headersEmitted && this.headerTransformer.headers) {
this.headersEmitted = true;
this.emit('headers', this.headerTransformer.headers);
}
}
skipRow(cb) {
// skipped because of skipRows option remove from total row count
this.rowCount -= 1;
return cb(null, { row: null, isValid: true });
}
pushRow(row, cb) {
try {
if (!this.parserOptions.objectMode) {
this.push(JSON.stringify(row));
}
else {
this.push(row);
}
cb();
}
catch (e) {
cb(e);
}
}
static wrapDoneCallback(done) {
let errorCalled = false;
// eslint-disable-next-line @typescript-eslint/no-explicit-any
return (err, ...args) => {
if (err) {
if (errorCalled) {
throw err;
}
errorCalled = true;
done(err);
return;
}
done(...args);
};
}
}
exports.CsvParserStream = CsvParserStream;
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