def post(self, project_id):
        """Initiates a new snapshot for this project."""
        project = Project.get(project_id)
        if not project:
            return '', 404

        args = self.post_parser.parse_args()

        repository = project.repository

        try:
            revision = identify_revision(repository, args.sha)
        except MissingRevision:
            # if the default fails, we absolutely can't continue and the
            # client should send a valid revision
            return error("Unable to find a matching revision.")

        if revision:
            sha = revision.sha
        else:
            sha = args.sha

        plan_list = get_snapshottable_plans(project)

        if not plan_list:
            return error("No snapshottable plans associated with project.")

        source, _ = get_or_create(Source, where={
            'repository': repository,
            'revision_sha': sha,
            'patch_id': None,
        })

        build = Build(
            source_id=source.id,
            source=source,
            project_id=project.id,
            project=project,
            label='Create Snapshot',
            status=Status.queued,
            cause=Cause.snapshot,
            target=sha[:12],
            tags=['snapshot'],
            # Snapshot builds are often part of the solution to queueing, so we make them
            # high priority to schedule them sooner.
            priority=BuildPriority.high,
        )
        db.session.add(build)

        # TODO(dcramer): this needs to update with the build result
        snapshot = Snapshot(
            project_id=project.id,
            source_id=source.id,
            build_id=build.id,
            status=SnapshotStatus.pending,
        )
        db.session.add(snapshot)

        jobs = []
        for plan in plan_list:
            job = Job(
                build=build,
                build_id=build.id,
                project=project,
                project_id=project.id,
                source=build.source,
                source_id=build.source_id,
                status=build.status,
                label='Create Snapshot: %s' + (plan.label,),
            )
            db.session.add(job)

            jobplan = JobPlan.build_jobplan(plan, job)
            db.session.add(jobplan)

            image = SnapshotImage(
                job=job,
                snapshot=snapshot,
                plan=plan,
            )
            db.session.add(image)

            jobs.append(job)

        db.session.commit()

        for job in jobs:
            create_job.delay(
                job_id=job.id.hex,
                task_id=job.id.hex,
                parent_task_id=job.build_id.hex,
            )

        db.session.commit()

        sync_build.delay(
            build_id=build.id.hex,
            task_id=build.id.hex,
        )

        return self.respond(snapshot)
dataset/ETHPy150Open dropbox/changes/changes/api/project_snapshot_index.py/ProjectSnapshotIndexAPIView.post/operator `%` -> `+`