x/bareon-allocator
Code Issues Proposed changes

Fix weights, first disk may have weight too

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This commit is contained in:
Evgeniy L 2015-12-25 19:22:37 +03:00
parent 62c38355a1
commit 1dbf91100e
1 changed files with 12 additions and 8 deletions
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20
bareon_dynamic_allocator/allocators.py
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@ -219,15 +219,19 @@ class DynamicAllocationLinearProgram(object):
self.upper_bound_constraint_vector.append(max_size)
def _init_weight(self):
"""Create min and max constraints for each space.
"""Create weight constraints for spaces which have same
max constraint or for those which don't have it at all.
In case of 2 disks and 2 spaces
* take first space which can be used in order to calculate weight.
* create an equation first + N / weight = 0 using weight
For first space min_size >= 10 and max_size <= 20
1 * x1 + 0 * x2 + 1 * x3 + 0 * x4 >= 10
1 * x1 + 0 * x2 + 1 * x3 + 0 * x4 <= 20
Lets say, second's space is equal to max of the third and fourth,
we will have next equation:
0 * x1 + (1 / weight) * x2 + (-1 / weight) * x3 +
0 * x4 + (1 / weight) * x5 + (-1 / weight) * x6 = 0
"""
idx_first_with_weight = None
first_weight = None
for space_idx, space in enumerate(self.spaces[1:]):
row = self._make_matrix_row()
weight = getattr(space, 'weight', 1)
@ -238,12 +242,12 @@ class DynamicAllocationLinearProgram(object):
if max_size != max_size_next or max_size is not None:
continue
if idx_first_with_weight is None:
if idx_first_with_weight is None or first_weight is None:
idx_first_with_weight = space_idx
first_weight = getattr(self.spaces[space_idx], 'weight', 1)
for disk_idx in range(len(self.disks)):
# row[disk_idx * len(self.spaces) + space_idx] = 1
row[disk_idx * len(self.spaces) + idx_first_with_weight] = 1
row[disk_idx * len(self.spaces) + idx_first_with_weight] = 1 / first_weight
row[disk_idx * len(self.spaces) + space_idx + 1] = -1 / weight