Expose a generic read method that can be extended to have more control over how the readFn is called, for example concurrency limits or combination of requests that are close in offsets

Author: ZJONSSON

lib/reader.js

@@ -201,11 +201,15 @@ class ParquetEnvelopeReader {
   }
 
   constructor(readFn, closeFn, fileSize) {
-    this.read = readFn;
+    this.readFn = readFn;
     this.close = closeFn;
     this.fileSize = fileSize;
   }
 
+  async read(offset, length) {
+    return this.readFn(offset, length);
+  }
+
   async readHeader() {
     let buf = await this.read(0, PARQUET_MAGIC.length);