Official Perforce Video: Perforce Streams Quickstart

Official Perforce Video: Incorporate Code from One Feature Stream to Another

Overview

Streams in Perforce are isolated lineages of source files, providing a structured way to manage changes across different scopes of work like features, releases, or bug fixes. This page outlines the key concepts and operations for branching, merging (down), and copying (up) with streams and virtual streams.

Branching with Streams

"Branching" with streams is simply put, creating a new stream. Either mainline, development, release, or virtual, in scope. Branching in streams allows developers to diverge from the main line of development to work on features or fixes in parallel, without affecting the main codebase.

Creating a Stream

Steps for creating a new stream can be found in Installation Guide.

Switching Streams

It is important to note that to properly merge or copy from one stream to another, the stream that is doing the merging or copying must be the active stream. It is good to get a handle of switching streams.

Official Perforce Video: Switching Streams Workspaces

Merging with Streams

Merging integrates changes from one stream to another, typically from feature streams back to the mainline or parent stream, ensuring that new developments are incorporated into the broader project.

Merging Changes

To merge changes down to a less stable stream:

  1. In the Streams tab, right-click the target stream and choose Merge/Integrate to target_stream… or double-click and choose Merge changes.
  2. Ensure you are working in the target stream, as changes must be merged down or copied up while in the target stream.
  3. If prompted, select or create a workspace for the target stream.
  4. The Merge/Integrate dialog will appear. Verify that the correct source and target streams are specified.
  5. For additional details about the Merge/Integrate dialog, refer to the documentation on "Merge files between codelines."
  6. (Optional) To specify how the merge is to be resolved, click Resolve and Submit.
  7. To enable specific p4 resolve flags, click Advanced.
  8. Click Merge.
  9. If necessary, resolve the merges manually, then submit the resulting changelist.

Diagram: Merging Workflow

Copying with Streams

Copying is used to create an exact replica of one stream into another. This is often used to seed new development lines or archive existing states.

Copying a Stream

When copying changes up to a more stable stream, you are propagating a duplicate of the less stable stream.

  1. In the Streams tab, right-click the target stream, or double-click the stream and select Copy changes.
  2. If prompted, select a workspace for the target stream.
  3. Ensure you are working in the target stream as required when merging down or copying up.
  4. In the Copy dialog, review the propagation information or refine the operation using the options on the Filter, Submit, and Advanced tabs.
  5. To propagate changes to the more stable stream, click Copy and submit the resulting changelist.

Diagram: Copying Workflow

Virtual Streams

Virtual streams do not host file content but instead serve as a view or a filter of another stream. You merge changes down or copy changes up to a virtual stream just as you would to a real stream, however the merge or copy is actually submitted to the virtual stream’s base parent. You might find it more straightforward to copy and merge directly between real streams.

Diagram: Virtual Streams

Official Helix Core Documentation: Merge Down/Copy Up - https://www.perforce.com/manuals/p4v/Content/P4V/streams.merge_copy.html#Merge_down_and_copy_up_between_streams

Official Helix Core Documentation: Managing Codelines - https://www.perforce.com/manuals/p4v/Content/P4V/chapter.branches.html