Add columns param to parquetQueryWorker (#269)

Author: platypii

src/lib/workers/parquetWorker.ts

@@ -51,10 +51,10 @@ self.onmessage = async ({ data }: { data: ClientMessage }) => {
       postErrorMessage({ error: error as Error, queryId })
     }
   } else {
-    const { rowStart, rowEnd, orderBy, filter, chunks } = data
+    const { rowStart, rowEnd, columns, orderBy, filter, chunks } = data
     const onChunk = chunks ? (chunk: ColumnData) => { postChunkMessage({ chunk, queryId }) } : undefined
     try {
-      const result = await parquetQuery({ metadata, file, rowStart, rowEnd, orderBy, filter, compressors, onChunk })
+      const result = await parquetQuery({ metadata, file, rowStart, rowEnd, columns, orderBy, filter, compressors, onChunk })
       postResultMessage({ result, queryId })
     } catch (error) {
       postErrorMessage({ error: error as Error, queryId })

src/lib/workers/parquetWorkerClient.ts

@@ -66,7 +66,7 @@ function getWorker() {
  * Instead of taking an AsyncBuffer, it takes a AsyncBufferFrom, because it needs
  * to be serialized to the worker.
  */
-export function parquetQueryWorker({ metadata, from, rowStart, rowEnd, orderBy, filter, onChunk }: QueryWorkerOptions): Promise<Cells[]> {
+export function parquetQueryWorker({ metadata, from, rowStart, rowEnd, columns, orderBy, filter, onChunk }: QueryWorkerOptions): Promise<Cells[]> {
   // TODO(SL) Support passing columns?
   return new Promise((resolve, reject) => {
     const queryId = nextQueryId++
@@ -75,7 +75,7 @@ export function parquetQueryWorker({ metadata, from, rowStart, rowEnd, orderBy,
 
     // If caller provided an onChunk callback, worker will send chunks as they are parsed
     const chunks = onChunk !== undefined
-    const message: QueryClientMessage = { queryId, metadata, from, rowStart, rowEnd, orderBy, filter, chunks, kind: 'query' }
+    const message: QueryClientMessage = { queryId, metadata, from, rowStart, rowEnd, columns, orderBy, filter, chunks, kind: 'query' }
     worker.postMessage(message)
   })
 }

src/lib/workers/types.ts

@@ -30,6 +30,7 @@ export interface ErrorMessage extends Message {
 export interface QueryWorkerOptions extends CommonWorkerOptions {
   rowStart?: number,
   rowEnd?: number,
+  columns?: string[],
   orderBy?: string,
   filter?: ParquetQueryFilter,
   onChunk?: (chunk: ColumnData) => void