[xferbuf] Add generic data-transfer buffer

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

diff --git a/src/core/xferbuf.c b/src/core/xferbuf.c
new file mode 100644 (file)
index 0000000..a0457fe
--- /dev/null
+++ b/src/core/xferbuf.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <ipxe/xfer.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/xferbuf.h>
+
+/** @file
+ *
+ * Data transfer buffer
+ *
+ */
+
+/**
+ * Finish using data transfer buffer
+ *
+ * @v xferbuf          Data transfer buffer
+ */
+void xferbuf_done ( struct xfer_buffer *xferbuf ) {
+       free ( xferbuf->data );
+       xferbuf->data = NULL;
+       xferbuf->len = 0;
+       xferbuf->pos = 0;
+}
+
+/**
+ * Ensure that data transfer buffer is large enough for the specified size
+ *
+ * @v xferbuf          Data transfer buffer
+ * @v len              Required minimum size
+ * @ret rc             Return status code
+ */
+static int xferbuf_ensure_size ( struct xfer_buffer *xferbuf, size_t len ) {
+       void *new_data;
+
+       /* If buffer is already large enough, do nothing */
+       if ( len <= xferbuf->len )
+               return 0;
+
+       /* Extend buffer */
+       new_data = realloc ( xferbuf->data, len );
+       if ( ! new_data ) {
+               DBGC ( xferbuf, "XFERBUF %p could not extend buffer to "
+                      "%zd bytes\n", xferbuf, len );
+               return -ENOSPC;
+       }
+       xferbuf->data = new_data;
+       xferbuf->len = len;
+
+       return 0;
+}
+
+/**
+ * Add received data to data transfer buffer
+ *
+ * @v xferbuf          Data transfer buffer
+ * @v iobuf            I/O buffer
+ * @v meta             Data transfer metadata
+ * @ret rc             Return status code
+ */
+int xferbuf_deliver ( struct xfer_buffer *xferbuf, struct io_buffer *iobuf,
+                     struct xfer_metadata *meta ) {
+       size_t len;
+       size_t max;
+       int rc;
+
+       /* Calculate new buffer position */
+       if ( meta->flags & XFER_FL_ABS_OFFSET )
+               xferbuf->pos = 0;
+       xferbuf->pos += meta->offset;
+
+       /* Ensure that we have enough buffer space for this data */
+       len = iob_len ( iobuf );
+       max = ( xferbuf->pos + len );
+       if ( ( rc = xferbuf_ensure_size ( xferbuf, max ) ) != 0 )
+               goto done;
+
+       /* Copy data to buffer */
+       memcpy ( ( xferbuf->data + xferbuf->pos ), iobuf->data, len );
+
+       /* Update current buffer position */
+       xferbuf->pos += len;
+
+ done:
+       free_iob ( iobuf );
+       return rc;
+}

diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h
index fbdeb0a39e7516d16a5d9ed235ca626632d7827b..2109cf2f95a0e3958e71c34321c79fac5f150f76 100644 (file)
--- a/src/include/ipxe/errfile.h
+++ b/src/include/ipxe/errfile.h
@@ -61,6 +61,7 @@ FILE_LICENCE ( GPL2_OR_LATER );
 #define ERRFILE_edd                   ( ERRFILE_CORE | 0x00150000 )
 #define ERRFILE_parseopt              ( ERRFILE_CORE | 0x00160000 )
 #define ERRFILE_test                  ( ERRFILE_CORE | 0x00170000 )
+#define ERRFILE_xferbuf                       ( ERRFILE_CORE | 0x00180000 )
 
 #define ERRFILE_eisa                ( ERRFILE_DRIVER | 0x00000000 )
 #define ERRFILE_isa                 ( ERRFILE_DRIVER | 0x00010000 )

diff --git a/src/include/ipxe/xferbuf.h b/src/include/ipxe/xferbuf.h
new file mode 100644 (file)
index 0000000..2ca871e
--- /dev/null
+++ b/src/include/ipxe/xferbuf.h
@@ -0,0 +1,31 @@
+#ifndef _IPXE_XFERBUF_H
+#define _IPXE_XFERBUF_H
+
+/** @file
+ *
+ * Data transfer buffer
+ *
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <ipxe/iobuf.h>
+#include <ipxe/xfer.h>
+
+/** A data transfer buffer */
+struct xfer_buffer {
+       /** Data */
+       void *data;
+       /** Size of data */
+       size_t len;
+       /** Current offset within data */
+       size_t pos;
+};
+
+extern void xferbuf_done ( struct xfer_buffer *xferbuf );
+extern int xferbuf_deliver ( struct xfer_buffer *xferbuf,
+                            struct io_buffer *iobuf,
+                            struct xfer_metadata *meta );
+
+#endif /* _IPXE_XFERBUF_H */