[downloader] Use generic data-transfer buffer mechanism

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/core/downloader.c

 #include <ipxe/uaccess.h>
 #include <ipxe/umalloc.h>
 #include <ipxe/image.h>
-#include <ipxe/profile.h>
+#include <ipxe/xferbuf.h>
 #include <ipxe/downloader.h>
 
 /** @file
  *
  */
 
-/** Receive profiler */
-static struct profiler downloader_rx_profiler __profiler =
-	{ .name = "downloader.rx" };
-
-/** Data copy profiler */
-static struct profiler downloader_copy_profiler __profiler =
-	{ .name = "downloader.copy" };
-
 /** A downloader */
 struct downloader {
 	/** Reference count for this object */
 
 	/** Image to contain downloaded file */
 	struct image *image;
-	/** Current position within image buffer */
-	size_t pos;
+	/** Data transfer buffer */
+	struct xfer_buffer buffer;
 };
 
 /**
 			 downloader->image->name, strerror ( rc ) );
 	}
 
+	/* Update image length */
+	downloader->image->len = downloader->buffer.len;
+
 	/* Shut down interfaces */
 	intf_shutdown ( &downloader->xfer, rc );
 	intf_shutdown ( &downloader->job, rc );
 }
 
-/**
- * Ensure that download buffer is large enough for the specified size
- *
- * @v downloader	Downloader
- * @v len		Required minimum size
- * @ret rc		Return status code
- */
-static int downloader_ensure_size ( struct downloader *downloader,
-				    size_t len ) {
-	userptr_t new_buffer;
-
-	/* If buffer is already large enough, do nothing */
-	if ( len <= downloader->image->len )
-		return 0;
-
-	DBGC ( downloader, "Downloader %p extending to %zd bytes\n",
-	       downloader, len );
-
-	/* Extend buffer */
-	new_buffer = urealloc ( downloader->image->data, len );
-	if ( ! new_buffer ) {
-		DBGC ( downloader, "Downloader %p could not extend buffer to "
-		       "%zd bytes\n", downloader, len );
-		return -ENOSPC;
-	}
-	downloader->image->data = new_buffer;
-	downloader->image->len = len;
-
-	return 0;
-}
-
 /****************************************************************************
  *
  * Job control interface
 	 * arrive out of order (e.g. with multicast protocols), but
 	 * it's a reasonable first approximation.
 	 */
-	progress->completed = downloader->pos;
-	progress->total = downloader->image->len;
+	progress->completed = downloader->buffer.pos;
+	progress->total = downloader->buffer.len;
 
 	return 0;
 }
 static int downloader_xfer_deliver ( struct downloader *downloader,
 				     struct io_buffer *iobuf,
 				     struct xfer_metadata *meta ) {
-	size_t len;
-	size_t max;
 	int rc;
 
-	/* Start profiling */
-	profile_start ( &downloader_rx_profiler );
-
-	/* Calculate new buffer position */
-	if ( meta->flags & XFER_FL_ABS_OFFSET )
-		downloader->pos = 0;
-	downloader->pos += meta->offset;
-
-	/* Ensure that we have enough buffer space for this data */
-	len = iob_len ( iobuf );
-	max = ( downloader->pos + len );
-	if ( ( rc = downloader_ensure_size ( downloader, max ) ) != 0 )
-		goto done;
-
-	/* Copy data to buffer */
-	profile_start ( &downloader_copy_profiler );
-	copy_to_user ( downloader->image->data, downloader->pos,
-		       iobuf->data, len );
-	profile_stop ( &downloader_copy_profiler );
-
-	/* Update current buffer position */
-	downloader->pos += len;
-
- done:
-	free_iob ( iobuf );
-	if ( rc != 0 )
-		downloader_finished ( downloader, rc );
-	profile_stop ( &downloader_rx_profiler );
+	/* Add data to buffer */
+	if ( ( rc = xferbuf_deliver ( &downloader->buffer, iob_disown ( iobuf ),
+				      meta ) ) != 0 )
+		goto err_deliver;
+
+	return 0;
+
+ err_deliver:
+	downloader_finished ( downloader, rc );
 	return rc;
 }
 
 	intf_init ( &downloader->xfer, &downloader_xfer_desc,
 		    &downloader->refcnt );
 	downloader->image = image_get ( image );
+	xferbuf_umalloc_init ( &downloader->buffer, &image->data );
 
 	/* Instantiate child objects and attach to our interfaces */
 	if ( ( rc = xfer_open_uri ( &downloader->xfer, image->uri ) ) != 0 )