migration: introduce new constructors for QEMUFile

Prepare for the elimination of QEMUFileOps by introducing a pair of new
constructors. This lets us distinguish between an input and output file
object explicitly rather than via the existance of specific callbacks.

Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

1 files changed, 16 insertions, 2 deletions

diff --git a/migration/qemu-file.c b/migration/qemu-file.c
index 30e2160041..2d6ceb53af 100644
--- a/migration/qemu-file.c
+++ b/migration/qemu-file.c
@@ -38,6 +38,7 @@ struct QEMUFile {
     const QEMUFileOps *ops;
     const QEMUFileHooks *hooks;
     QIOChannel *ioc;
+    bool is_writable;
 
     /*
      * Maximum amount of data in bytes to transfer during one
@@ -111,7 +112,9 @@ bool qemu_file_mode_is_not_valid(const char *mode)
     return false;
 }
 
-QEMUFile *qemu_fopen_ops(QIOChannel *ioc, const QEMUFileOps *ops)
+static QEMUFile *qemu_file_new_impl(QIOChannel *ioc,
+                                    const QEMUFileOps *ops,
+                                    bool is_writable)
 {
     QEMUFile *f;
 
@@ -119,10 +122,21 @@ QEMUFile *qemu_fopen_ops(QIOChannel *ioc, const QEMUFileOps *ops)
 
     f->ioc = ioc;
     f->ops = ops;
+    f->is_writable = is_writable;
 
     return f;
 }
 
+QEMUFile *qemu_file_new_output(QIOChannel *ioc, const QEMUFileOps *ops)
+{
+    return qemu_file_new_impl(ioc, ops, true);
+}
+
+QEMUFile *qemu_file_new_input(QIOChannel *ioc, const QEMUFileOps *ops)
+{
+    return qemu_file_new_impl(ioc, ops, false);
+}
+
 
 void qemu_file_set_hooks(QEMUFile *f, const QEMUFileHooks *hooks)
 {
@@ -181,7 +195,7 @@ void qemu_file_set_error(QEMUFile *f, int ret)
 
 bool qemu_file_is_writable(QEMUFile *f)
 {
-    return f->ops->writev_buffer;
+    return f->is_writable;
 }
 
 static void qemu_iovec_release_ram(QEMUFile *f)