Copying and moving

Coming in 4.0

CopyResourceAsync copies a version, the current one unless you name another, to a name in the same or another container. MoveResourceAsync moves a resource, every version of it, and RenameResourceAsync is a move within the container:

ResourceInfo? copy = await container.CopyResourceAsync("report.pdf", "archive", "2026/report.pdf");
ResourceInfo? moved = await container.MoveResourceAsync("draft.txt", "published", "final.txt");
ResourceInfo? renamed = await container.RenameResourceAsync("draft.txt", "final.txt");

All three return null when the source doesn't exist. A rename is a move to container.Name, so everything below about moves applies to it too.

• A copy is a new version at the destination. It has its own VersionId and LastModified, and the source's content, hash, type and metadata. It's stored like an upload: an existing name is refused unless you set Mode = ResourceWriteMode.Replace, and then the copy becomes the name's new current version and older ones are pruned past the destination's version limit. DestinationConditions work as an upload's conditions do, and need Replace.
• A copy remembers its source. CopiedFrom on its ResourceInfo names the container, name and version it was copied from, and stays even when that source is deleted. A restored version records the version it restored.
• A move keeps everything: every version, with its VersionId, LastModified and CopiedFrom, all at once. The destination name must not exist (ResourceConflictException), and SourceConditions let it go ahead only if the resource hasn't changed.
• No content passes through your application with SQL Server: the server copies the content, and a move only re-points the versions to their new container and name. The exception is copying a version stored before 3.0 that has no hash yet, which is read through the application until the hash backfill records it.
• Container policies apply: a copy is checked as an upload to the destination, and a move needs a source that isn't read-only and a destination with room for every version it brings.
• With the file-system provider, a rename copies nothing, but a move to another container copies each version's content through your application, so it takes longer the larger the versions are.
• With the S3 and Azure Blob providers, a rename copies nothing, but a move to another container has the store copy each version's content, so it takes longer the larger the versions are. The content still doesn't pass through your application. Their pages explain how a move stays all or nothing without transactions.