[PATCH parted 5/7] libparted: add ped_device_get_xxx_aligned_constraint() functions

[Hans de Goede]

Add ped_device_get_minimal_aligned_constraint() and
ped_device_get_optimal_aligned_constraint() functions to libparted.

These functions can be used to get a device constraint taking alignment into
account.
---
 include/parted/device.h |    5 +++
 libparted/device.c      |   69 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+), 0 deletions(-)

diff --git a/include/parted/device.h b/include/parted/device.h
index 7c34081..2a6c51b 100644
--- a/include/parted/device.h
+++ b/include/parted/device.h
@@ -146,6 +146,11 @@ extern PedSector ped_device_check (PedDevice* dev, void* 
buffer,
                                    PedSector start, PedSector count);
 extern PedConstraint* ped_device_get_constraint (PedDevice* dev);
 
+extern PedConstraint *ped_device_get_minimal_aligned_constraint(
+                                                         const PedDevice *dev);
+extern PedConstraint *ped_device_get_optimal_aligned_constraint(
+                                                         const PedDevice *dev);
+
 extern PedAlignment *ped_device_get_minimal_aligment(const PedDevice *dev);
 extern PedAlignment *ped_device_get_optimal_aligment(const PedDevice *dev);
 
diff --git a/libparted/device.c b/libparted/device.c
index 6210a23..c53c202 100644
--- a/libparted/device.c
+++ b/libparted/device.c
@@ -445,6 +445,75 @@ ped_device_get_constraint (PedDevice* dev)
         return c;
 }
 
+static PedConstraint*
+_ped_device_get_aligned_constraint(const PedDevice *dev,
+                                   PedAlignment* start_align)
+{
+        PedAlignment *end_align = NULL;
+        PedGeometry *whole_dev_geom = NULL;
+        PedConstraint *c = NULL;
+
+        if (start_align) {
+                end_align = ped_alignment_new(start_align->offset - 1,
+                                              start_align->grain_size);
+                if (!end_align)
+                        goto free_start_align;
+        }
+
+        whole_dev_geom = ped_geometry_new (dev, 0, dev->length);
+
+        if (start_align)
+                c =  ped_constraint_new (start_align, end_align,
+                                         whole_dev_geom, whole_dev_geom,
+                                         1, dev->length);
+        else
+                c =  ped_constraint_new (ped_alignment_any, ped_alignment_any,
+                                         whole_dev_geom, whole_dev_geom,
+                                         1, dev->length);
+
+        free (whole_dev_geom);
+        free (end_align);
+free_start_align:
+        free (start_align);
+        return c;
+}
+
+/**
+ * Get a constraint that represents hardware requirements on geometry and
+ * alignment.
+ *
+ * This function will return a constraint representing the limits imposed
+ * by the size of the disk and the minimal alignment requirements for proper
+ * performance of the disk.
+ *
+ * \return NULL on error, otherwise a pointer to a dynamically allocated
+ *         constraint.
+ */
+PedConstraint*
+ped_device_get_minimal_aligned_constraint(const PedDevice *dev)
+{
+        return _ped_device_get_aligned_constraint(dev,
+                                         ped_device_get_minimal_aligment(dev));
+}
+
+/**
+ * Get a constraint that represents hardware requirements on geometry and
+ * alignment.
+ *
+ * This function will return a constraint representing the limits imposed
+ * by the size of the disk and the alignment requirements for optimal
+ * performance of the disk.
+ *
+ * \return NULL on error, otherwise a pointer to a dynamically allocated
+ *         constraint.
+ */
+PedConstraint*
+ped_device_get_optimal_aligned_constraint(const PedDevice *dev)
+{
+        return _ped_device_get_aligned_constraint(dev,
+                                         ped_device_get_optimal_aligment(dev));
+}
+
 /**
  * Get an alignment that represents minimum hardware requirements on aligment.
  * When for example using media that has a physical sector size that is a
-- 
1.6.5.1