DBF reader plugin

plugins/dbgate-plugin-dbf/src/backend/index.js

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+const reader = require('./reader');
+// const writer = require('./writer');
+
+module.exports = {
+  packageName: 'dbgate-plugin-dbf',
+  shellApi: {
+    reader,
+  },
+  initialize(dbgateEnv) {
+    reader.initialize(dbgateEnv);
+  },
+};

plugins/dbgate-plugin-dbf/src/backend/reader.js

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+const _ = require('lodash');
+const csv = require('csv');
+const fs = require('fs');
+const stream = require('stream');
+const { DBFFile } = require('dbffile');
+
+let dbgateApi;
+
+function getFieldType(field) {
+  const { type, size } = field;
+  switch (type) {
+    case 'C':
+      return `varchar(${size})`;
+    case 'N':
+      return 'numeric';
+    case 'F':
+      return 'float';
+    case 'Y':
+      return 'money';
+    case 'I':
+      return 'int';
+    case 'L':
+      return 'boolean';
+    case 'D':
+      return 'date';
+    case 'T':
+      return 'datetime';
+    case 'B':
+      return 'duouble';
+    case 'M':
+      return 'varchar(max)';
+    default:
+      return 'string';
+  }
+}
+
+async function reader({ fileName, encoding = 'ISO-8859-1', includeDeletedRecords = false, limitRows = undefined }) {
+  console.log(`Reading file ${fileName}`);
+  const downloadedFile = await dbgateApi.download(fileName);
+
+  const pass = new stream.PassThrough({
+    objectMode: true,
+  });
+
+  (async () => {
+    try {
+      // Open the DBF file
+      const dbf = await DBFFile.open(downloadedFile, { encoding, includeDeletedRecords });
+
+      const columns = dbf.fields.map((field) => ({
+        columnName: field.name,
+        dataType: getFieldType(field),
+      }));
+
+      pass.write({
+        __isStreamHeader: true,
+        columns,
+      })
+
+      let readedRows = 0;
+      // Read each record and push it into the stream
+      for await (const record of dbf) {
+        // Emit the record as a chunk
+        pass.write(record);
+        readedRows++;
+        if (limitRows && readedRows >= limitRows) {
+          break;
+        }
+      }
+
+      pass.end();
+    } catch (error) {
+      // If any error occurs, destroy the stream with the error
+      pass.end();
+    }
+  })();
+
+  return pass;
+}
+
+reader.initialize = (dbgateEnv) => {
+  dbgateApi = dbgateEnv.dbgateApi;
+};
+
+module.exports = reader;