[experiments] Allow blocks to be ordered properly on dumps

beat/web/experiments/migrations/0007_auto_20160701_0909.py

+# -*- coding: utf-8 -*-
+# Generated by Django 1.9.4 on 2016-07-01 09:09
+from __future__ import unicode_literals
+
+from django.db import migrations, models
+from django.conf import settings
+
+import simplejson
+import beat.core.experiment
+from ...common import storage
+
+
+def set_block_order(apps, schema_editor):
+    '''Set block order for existing experiments'''
+
+    Experiment = apps.get_model("experiments", "Experiment")
+    Block = apps.get_model("experiments", "Block")
+
+    total = Experiment.objects.count()
+    for i, e in enumerate(Experiment.objects.order_by('id')):
+
+        fullname = '%s/%s/%s/%d/%s' % (
+            e.author.username,
+            e.toolchain.author.username,
+            e.toolchain.name,
+            e.toolchain.version,
+            e.name,
+            )
+
+        print("Updating blocks for experiment %d/%d (%s, id=%d)..." % \
+            (i+1, total, fullname, e.id))
+
+        xp_decl = simplejson.loads(storage.get_file_content(e,
+          'declaration_file'))
+        tc_decl = simplejson.loads(storage.get_file_content(e.toolchain,
+          'declaration_file'))
+
+        xp = beat.core.experiment.Experiment(settings.PREFIX, (xp_decl,
+          tc_decl))
+
+        if xp.errors:
+            message = "The experiment `%s' isn't valid (skipping " \
+                "block update), due to the following errors:\n  * %s"
+            print message % (fullname, '\n * '.join(xp.errors))
+            continue
+
+        # Goes, in order, setting block inner order
+        for order_0, block_name in enumerate(xp.setup().keys()):
+
+            block = Block.objects.get(experiment=e, name=block_name)
+            block.execution_order = order_0 + 1
+            block.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('experiments', '0006_auto_20160630_1644'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='block',
+            name='execution_order',
+            field=models.PositiveIntegerField(blank=True, null=True),
+        ),
+        migrations.AlterModelOptions(
+            name='block',
+            options={'ordering': ['experiment_id', 'execution_order']},
+        ),
+        migrations.RunPython(set_block_order),
+    ]

beat/web/experiments/models.py

@@ -506,7 +506,8 @@ class Experiment(Shareable):
 
         # Loads the experiment execution description, creating the Block's,
         # BlockInput's and BlockOutput's as required.
-        for block_name, description in corexp.setup().items():
+        for order_0, (block_name, description) in \
+            enumerate(corexp.setup().items()):
 
             # Checks that the Queue/Environment exists
             job_description = description['configuration']
@@ -553,6 +554,7 @@ class Experiment(Shareable):
                 b = Block(experiment=self, name=block_name, algorithm=algorithm)
             else:
                 b.algorithm = algorithm
+            b.execution_order = order_0 + 1
             b.command=simplejson.dumps(job_description, indent=4)
             b.status=Block.NOT_CACHED
             b.analyzer=algorithm.analysis()
@@ -919,6 +921,10 @@ class Block(models.Model):
                                           symmetrical=False,
                                          )
 
+    # order of this block within the experiment - useful for the `backup'
+    # command, so we can dump the blocks in the right dependence order
+    execution_order = models.PositiveIntegerField(null=True, blank=True)
+
     objects = BlockManager()
 
 
@@ -926,7 +932,7 @@ class Block(models.Model):
         unique_together = ('experiment', 'name')
 
         # setup ordering so that the dump order respects self dependencies
-        ordering = ['id']
+        ordering = ['experiment_id', 'execution_order']
 
 
     def __str__(self):