10 Commits (4835deddaef450198bba00a50311f2ada6f79b96)

Author	SHA1	Message	Date
Nick Fagerlund	ccd7bd017e	Clarify some comments in internal/dag ... When reading this code to check Terraform's graph sorting behavior, I got very confused about the direction of traversal for several methods. Although some of these methods would also probably benefit from renames, this commit only updates their doc comments to use the same directional terminology that we use in the `Edge` interface (source/target).	4 years ago
Martin Atkins	2e177cd632	core: Eliminate NodePlannableResource indirection ... We previously did two levels of DynamicExpand to go from ConfigResource to AbsResource and then from AbsResource to AbsResourceInstance. We'll now do the full expansion from ConfigResource to AbsResourceInstance in a single DynamicExpand step inside nodeExpandPlannableResource. The new approach is essentially functionally equivalent to the old except that it fixes a bug in the previous implementation: we will now call checkState.ReportCheckableObjects only once for the entire set of instances for a particular resource, which is what the checkable objects infrastructure expects so that it can always mention all of the checkable objects in the check report even if we bail out partway through due to a downstream error. This is essentially the same code but now turned into additional methods on nodeExpandPlannableResource instead of having the extra graph node type. This has the further advantage of this now being straight-through code with standard control flow, instead of the unusual inversion of control we were doing before bouncing in and out of different Execute and DynamicExpand implementations to get this done.	4 years ago
James Bardin	ca272b2107	Add methods for topological sorts ... A topological walk was previously only done in Terraform via the concurrent method used for walking the primary dependency graph in core. Sometime however we want a dependency ordering without the overhead of instantiating the concurrent walk with the channel-based edges. Add TopologicalOrder and ReverseTopologicalOrder to obtain a list of nodes which can be used to visit each while ensuring that all dependencies are satisfied.	4 years ago
James Bardin	95019e3d02	Implement breadth-first walks and add tests ... Make DAG walks test-able, and add tests for more complex graph ordering. We also add breadth-first for comparison, though it's not used currently in Terraform.	4 years ago
Katy Moe	f8fdb6de3f	do not use pointer addr strings as map keys in set ... When creating a Set of BasicEdges, the Hashcode function is used to determine map keys for the underlying set data structure. The string hex representation of the two vertices' pointers is unsafe to use as a map key, since these addresses may change between the time they are added to the set and the time the set is operated on. Instead we modify the Hashcode function to maintain the references to the underlying vertices so they cannot be garbage collected during the lifetime of the Set.	4 years ago
James Bardin	344adb6c50	clarify dag comments ... TransitiveReduction does not rely on having a single root, and only must be free of cycles. DepthFirstWalk and ReverseDepthFirstWalk do not do a topological sort, so if order matters TransitiveReduction must be run first.	4 years ago
James Bardin	fae68f166f	Remove sorted walk functions ... These two functions were left during a refactor to ensure the old behavior of a sorted walk was still accessible in some manner. The package has since been removed from any public API, and the sorted versions are no longer called, so we can remove them.	4 years ago
James Bardin	863963e7a6	de-linting	5 years ago
Martin Atkins	05caff2ca3	Move tfdiags/ to internal/tfdiags/ ... This is part of a general effort to move all of Terraform's non-library package surface under internal in order to reinforce that these are for internal use within Terraform only. If you were previously importing packages under this prefix into an external codebase, you could pin to an earlier release tag as an interim solution until you've make a plan to achieve the same functionality some other way.	5 years ago
Martin Atkins	70eebe3521	Move dag/ to internal/dag/ ... This is part of a general effort to move all of Terraform's non-library package surface under internal in order to reinforce that these are for internal use within Terraform only. If you were previously importing packages under this prefix into an external codebase, you could pin to an earlier release tag as an interim solution until you've make a plan to achieve the same functionality some other way.	5 years ago