node-firebird-driver-native/src/lib/fb-util.ts

Firebird Native Driver for Node.js

import { charSets, sqlTypes, Descriptor } from 'node-firebird-driver/dist/lib/impl';
export * from 'node-firebird-driver/dist/lib/impl';

import * as fb from 'node-firebird-native-api';

/** Fix metadata descriptors to types we want to read. */
export function fixMetadata(status: fb.Status, metadata?: fb.MessageMetadata): fb.MessageMetadata | undefined {
  if (!metadata) {
    return undefined;
  }

  let ret: fb.MessageMetadata;

  const outBuilder = metadata.getBuilderSync(status)!;
  try {
    for (let i = metadata.getCountSync(status) - 1; i >= 0; --i) {
      switch (metadata.getTypeSync(status, i)) {
        // Transform CHAR descriptors to VARCHAR.
        case sqlTypes.SQL_TEXT:
          outBuilder.setTypeSync(status, i, sqlTypes.SQL_VARYING);
          break;

        // Transform numeric descriptors to DOUBLE PRECISION.
        case sqlTypes.SQL_SHORT:
        case sqlTypes.SQL_LONG:
        case sqlTypes.SQL_INT64:
        case sqlTypes.SQL_FLOAT:
          outBuilder.setTypeSync(status, i, sqlTypes.SQL_DOUBLE);
          outBuilder.setLengthSync(status, i, 8);
          outBuilder.setScaleSync(status, i, 0);
          break;

        // Transform TIME_TZ to TIME_TZ_EX.
        case sqlTypes.SQL_TIME_TZ:
          outBuilder.setTypeSync(status, i, sqlTypes.SQL_TIME_TZ_EX);
          break;

        // Transform TIMESTAMP_TZ to TIMESTAMP_TZ_EX.
        case sqlTypes.SQL_TIMESTAMP_TZ:
          outBuilder.setTypeSync(status, i, sqlTypes.SQL_TIMESTAMP_TZ_EX);
          break;

        // Transform INT128, DEC16 and DEC34 descriptors to VARCHAR.
        case sqlTypes.SQL_INT128:
        case sqlTypes.SQL_DEC16:
        case sqlTypes.SQL_DEC34:
          outBuilder.setTypeSync(status, i, sqlTypes.SQL_VARYING);
          outBuilder.setLengthSync(status, i, 45);
          outBuilder.setCharSetSync(status, i, charSets.ascii);
          break;
      }
    }

    ret = outBuilder.getMetadataSync(status)!;
  } finally {
    outBuilder.releaseSync();
  }

  metadata.releaseSync();

  return ret;
}

export function createDescriptors(status: fb.Status, metadata?: fb.MessageMetadata): Descriptor[] {
  if (!metadata) {
    return [];
  }

  const count = metadata.getCountSync(status);
  const ret: Descriptor[] = [];

  for (let i = 0; i < count; ++i) {
    ret.push({
      type: metadata.getTypeSync(status, i),
      subType: metadata.getSubTypeSync(status, i),
      nullOffset: metadata.getNullOffsetSync(status, i),
      offset: metadata.getOffsetSync(status, i),
      length: metadata.getLengthSync(status, i),
      scale: metadata.getScaleSync(status, i),
    });
  }

  return ret;
}