aux-dbf/src/DBF4Reader.ts

DBF for price PSM

import { DBFReader } from "./DBFReader";
import { DBF_MODE } from "./DBF_MODE";
import { Column, COLUMN_TYPE } from "./Column";
const iconv = require("iconv-lite");

export class DBF4Reader extends DBFReader {
  protected sizeFieldDescriptior = 32;
  protected sizeHeadLength = 32;

  readHeader() {
    this.TypeTable = this.file.readInt8(0);
    this.DateHeaderY = this.file.readInt8(1) - 100 + 2000;
    this.DateHeaderM = this.file.readInt8(2);
    this.DateHeaderD = this.file.readInt8(3) % 31;
    this.RecordsCount = this.file.readInt32LE(4);

    this.HeaderSize = this.file.readInt16LE(8);
    this.RecordSize = this.file.readInt16LE(10);
    this.Encode = this.file.readInt8(29);
    this.ColumnCount =
      (this.HeaderSize - this.sizeHeadLength - 1) / this.sizeFieldDescriptior;

    if (this.mode == DBF_MODE.TEST) {
      this.printHeader();
    }
  }

  readSignature() {
    this.columns = Array(this.ColumnCount)
      .fill(new Column())
      .map<Column>((_) => new Column())
      .map<Column>((column, index) => {
        let offset = index * this.sizeHeadLength + this.sizeFieldDescriptior;

        let name = this.file
          .slice(offset, offset + 10)
          .filter((r) => r != 0)
          .toString();

        let size = this.file.readUInt8(offset + 16);
        let type = this.readChar(offset + 11) as COLUMN_TYPE;
        let decimalPlaces = this.file.readUInt8(offset + 17);
        let isMDX = this.file.readUInt8(offset + 31).toString() != "0";

        column.Add(name, size, type, index, decimalPlaces, isMDX);

        return column;
      });

    if (this.mode == DBF_MODE.TEST) {
      this.printColumns();
    }
  }

  readTable(): any[][] {
    console.time("READ DATA SOURCE");
    let array = Array(this.RecordsCount)
      .fill(new Array(this.ColumnCount).fill(null))
      .map((r) => {
        return new Array(this.ColumnCount);
      });
    const startPosition = this.HeaderSize;

    let offsetLeft = 0;
    for (let column = 0; column < this.ColumnCount; column++) {
      let position = startPosition + 1;

      if (this.columns[column].getType() == COLUMN_TYPE.CHARACTER) {
        let size = this.columns[column].getSize();
        for (let row = 0; row < this.RecordsCount; row++) {
          // TODO
          array[row][column] =
            //iconv.decode(
            this.file.subarray(
              position + offsetLeft,
              position + offsetLeft + size
            );
          //, "win1251" ).trim();
          position += this.RecordSize;
        }
      } else if (this.columns[column].getType() == COLUMN_TYPE.NUMBER) {
        let size = this.columns[column].getSize();
        for (let row = 0; row < this.RecordsCount; row++) {
          array[row][column] = +this.file.toString(
            "ascii",
            position + offsetLeft,
            position + offsetLeft + size
          );
          position += this.RecordSize;
        }
      } else if (this.columns[column].getType() == COLUMN_TYPE.FLOAT) {
        let size = this.columns[column].getSize();
        for (let row = 0; row < this.RecordsCount; row++) {
          array[row][column] = +this.file.toString(
            "ascii",
            position + offsetLeft,
            position + offsetLeft + size
          );
          position += this.RecordSize;
        }
      } else if (this.columns[column].getType() == COLUMN_TYPE.DATE) {
        for (let row = 0; row < this.RecordsCount; row++) {
          array[row][column] = this.readDate(
            this.file.subarray(position + offsetLeft, position + offsetLeft + 8)
          );
          let p = position + offsetLeft;
          position += this.RecordSize;
        }
      } else {
        throw new Error("[X] Непредсказуемый тип колонки");
      }
      offsetLeft += this.columns[column].getSize();
    }
    console.timeEnd("READ DATA SOURCE");
    return array;
  }
  private readDate(buffer: Buffer) {
    let date = (
      buffer.toString("ascii", 0, 4) +
      "-" +
      buffer.toString("ascii", 4, 6) +
      "-" +
      buffer.toString("ascii", 6, 8)
    );
    if(/(\d{4}-\d{2}-\d{2})/.test(date)) {
      return date;
    } else {
      return "0000-00-00";
    }
  }
}