Module migrate 

Migration helpers – safe version upgrades for on-chain accounts.

Hopper’s migration system supports three patterns:

1. Append-safe: New fields appended to the end, realloc to larger size
2. Segment-safe: New segments added to the segment table
3. Full migration: Data reshuffled between versions

Safety

• Migration always validates the source layout_id before touching data
• The destination version must be strictly greater than the source
• Realloc is rent-safe (payer provides lamports for the delta)

Structs

MigrationDescriptor

Migration descriptor for schema export.

Enums

MigrationKind

The kind of migration.

Functions

is_append_compatible

Check if a migration from OldLayout to NewLayout would be append-compatible.

migrate_append

Migrate an account in-place by appending new fields.