Abstract: Large graph visualization embodiments are presented which generally render and display the more important elements for a current view. To this end, a measure of importance referred to as a zoom level is assigned to the vertices and rails of a graph. Each rail is a curve segment in the graph that represents an edge or a set of edges passing through it. The rendering and displaying of a graph (or a part thereof) is done quickly, even as a user moves about the graph, and the visualization of the large graph is not so dense and so full of detail that the user becomes disoriented. In general, this is accomplished by specifying a current viewport, or a current zoom level, or both. Furthermore, the visualization is stable in that the layout of vertices and rails will be the same for the same zoom level and viewport.

Abstract: Large graph visualization embodiments are presented which generally render and display the more important elements for a current view. To this end, a measure of importance referred to as a zoom level is assigned to the vertices and rails of a graph. Each rail is a curve segment in the graph that represents an edge or a set of edges passing through it. The rendering and displaying of a graph (or a part thereof) is done quickly, even as a user moves about the graph, and the visualization of the large graph is not so dense and so full of detail that the user becomes disoriented. In general, this is accomplished by specifying a current viewport, or a current zoom level, or both. Furthermore, the visualization is stable in that the layout of vertices and rails will be the same for the same zoom level and viewport.

Abstract: An edge routing system is described herein that uses a spatial decomposition to achieve faster routing, and more quickly generates a sparse visibility graph using a cone spanner. The system provides two approaches that can be used separately or in combination to achieve faster—and hence more scalable and more interactive—edge routing using approximate shortest paths. The first approach uses a spatial decomposition of the nodes in a graph, moving them slightly to obtain strictly disjoint convex hulls around groups of nodes, and then computing visibility graphs over these composite hulls rather than individual nodes. The second approach generates a sparse visibility-graph spanner to accelerate the process of producing the visibility graph. The system allows high quality obstacle avoiding edge routing for large diagrams in interactive diagramming applications where very fast refreshes of routing are used with many nodes moving at the same time.

Abstract: An edge routing system is described herein that uses a spatial decomposition to achieve faster routing, and more quickly generates a sparse visibility graph using a cone spanner. The system provides two approaches that can be used separately or in combination to achieve faster—and hence more scalable and more interactive—edge routing using approximate shortest paths. The first approach uses a spatial decomposition of the nodes in a graph, moving them slightly to obtain strictly disjoint convex hulls around groups of nodes, and then computing visibility graphs over these composite hulls rather than individual nodes. The second approach generates a sparse visibility-graph spanner to accelerate the process of producing the visibility graph. The system allows high quality obstacle avoiding edge routing for large diagrams in interactive diagramming applications where very fast refreshes of routing are used with many nodes moving at the same time.

Abstract: A graph layout technique that creates a layered graph layout with a given aspect ratio. The present layered graph layout technique better utilizes the available space and, at the same time, creates an aesthetically pleasing drawing of a directed graph. In one embodiment it determines the layout of the new graph based on a modified Sugiyama technique combined with a modified Coffman-Graham scheduling algorithm. Given a directed graph and a desired aspect ratio, it uses a binary search and the Coffman-Graham scheduling algorithm to find a layout of the graph that has an aspect ratio that matches the given aspect ratio of the available space.

Abstract: Techniques and tools for generating test cases for methods or programs with input preconditions are described. For example, after finding feasible control flow paths for a tested method along with each path's associated input conditions, a new program is created which tests these conditions along with the precondition. By analyzing this new program's control flow graph, a class of test cases is found while avoiding inefficiencies created by doing complete searches of paths through the combined control flow graph of the precondition and the method. Additional efficiencies are introduced by partitioning a control flow graph for the precondition into branched and straight sections.

Abstract: Techniques and tools for generating finite state machines (“FSMs”) for a software system with asynchronous callbacks are described. For example, method invocations in a model of the software system are partitioned into observable and controlled method invocations. The controlled method invocations are those which can be run from a test harness while the observed method invocations are those which are observed asynchronously as they are invoked in the system. An FSM is created with observation and control nodes such that observable transitions are found from observation nodes and controlled transitions are found from control nodes. If a state of the model contains both controlled and observable invocations, a timeout transition is added to the FSM to give an implementation time to come up with an observed method invocation before continuing to controlled invocations.

Abstract: Techniques and tools for testing multi-threaded or distributed software systems are described. For example, a multi-threaded system is instrumented and executed to produce logs of events that are performed by each of its agents. The agent logs contain a totally ordered series of events per agent, as well as information about accesses to resources shared between the agents. With this information, a partial ordering of the events performed by all the agents is described for the execution. The agent logs are then multiplexed into one or more serialized event orderings, which can then be compared to a specification of the system in a conformance testing engine.

Abstract: State spaces are traversed to produce test cases, or test coverage. Test coverage is a test suite of sequences. Accepting states are defined. Expected costs are assigned to the test graph states. Strategies are created providing transitions to states with lower expected costs. Linear programs and other approximations are discussed for providing expected costs. Strategies are more likely to provide access to an accepting state, based on expected costs. Strategies are used to append transitions to test segments such that the new test segment ends in an accepting state.

Abstract: Exploration algorithms are relevant to the industrial practice of generating test cases from an abstract state machine whose runs define the predicted behavior of the software system under test. Here, a new exploration algorithm allows multiple state groupings to simultaneously guide the search for states that are interesting or relevant for testing. In some cases, the algorithm allows exploration to be optimized from exponential to linear complexity. An extended example is included that illustrates the use of the algorithm.

Abstract: A computerized method creates test coverage for non-deterministic programs. The method receives a graph of edges and states representing a program under test, and creates a continuous cycle of edges that reaches each edge in the graph at least once. In one example, the method splits the continuous cycle into discrete sequences that end at edges reaching non-deterministic nodes in the graph, and verifies that the executing program conforms to the behavior represented by the discrete sequences. In another example, a method creates probabilistic strategies for reaching one or more vertices in a non-deterministic graph. The strategies provide a graph path with a high probability of reaching a desired vertex.

Abstract: The technologies allow a digital content developer to define, and a user to switch between or select, various versions of digital content for purposes of displaying, rendering, improving, or testing digital content. For example, a source code developer inserts identifiers in source code, and a source code layer viewer displays code segment choices defined by the identifiers. A user (e.g., the developer or others) selects code segments for inclusion in a source code version. The technology is also useful for providing versions of media content such as audio, video, DVD, images, text, etc.