49 lines
2.6 KiB
Go
49 lines
2.6 KiB
Go
// Copyright 2016-2018, Pulumi Corporation.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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// Package graph defines resource graphs. Each graph is directed and acyclic, and the nodes have been topologically
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// sorted based on dependencies (edges) between them. Each node in the graph has a type and a set of properties.
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//
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// There are two forms of graph: complete and incomplete. A complete graph is one in which all nodes and their property
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// values are known. An incomplete graph is one where two uncertainties may arise: (1) an edge might be "conditional",
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// indicating that its presence or absence is dependent on a piece of information not yet available (like an output
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// property from a resource), and/or (2) a property may either be similarly conditional or computed as an output value.
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//
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// In general, programs may be evaluated to produce graphs. These may then be compared to other graphs to produce
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// and/or carry out deployment plans. This package therefore also exposes operations necessary for diffing graphs.
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package graph
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// Graph is an instance of a resource digraph. Each is associated with a single program input, along
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// with a set of optional arguments used to evaluate it, along with the output DAG with node types and properties.
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type Graph interface {
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Roots() []Edge // the root edges.
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}
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// Vertex is a single vertex within an overall resource graph.
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type Vertex interface {
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Data() interface{} // arbitrary data associated with this vertex.
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Label() string // the vertex's label.
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Ins() []Edge // incoming edges from other vertices within the graph to this vertex.
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Outs() []Edge // outgoing edges from this vertex to other vertices within the graph.
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}
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// Edge is a directed edge from one vertex to another.
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type Edge interface {
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Data() interface{} // arbitrary data associated with this edge.
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Label() string // this edge's label.
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To() Vertex // the vertex this edge connects to.
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From() Vertex // the vertex this edge connects from.
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Color() string // an optional color for this edge, for when this graph is displayed.
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}
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