Faster json document guid replacement during "Save as"

[bendikberg]

Purpose

All the graph item guids are replaced when Dynamo does a Save As. This function previously searched for all occurences of guid-like strings in the file, and replaced them with a new guid, by doing a string.Replace for each guid. This gets extremely slow when there are a lot of objects in the graph.

This new version does a single iteration through the json string, replacing guids as it finds them, which means this scales much better with larger amounts of graph data.

Performance

On the Car_Configurator.dyn file, this PR changes file save time from approximately 2m20s to 5s on my machine. On the MaRS file, it goes from about 15s down to less than 5s. The remaining time is completely dominated by the update to the Recent Files ObservableCollection, which this PR does not touch.

Old version using string.Replace.

New version.

Declarations

Check these if you believe they are true

• The codebase is in a better state after this PR
• Is documented according to the standards
• The level of testing this PR includes is appropriate
• User facing strings, if any, are extracted into *.resx files
• All tests pass using the self-service CI.
• Snapshot of UI changes, if any.
• Changes to the API follow Semantic Versioning and are documented in the API Changes document.
• This PR modifies some build requirements and the readme is updated
• This PR contains no files larger than 50 MB

Release Notes

N/A

Reviewers

@mjkkirschner

FYIs

@dimven