Add patch checkpointing

1 files changed, 27 insertions, 0 deletions

diff --git a/makima/migrations/20250122000001_checkpoint_patches.sql b/makima/migrations/20250122000001_checkpoint_patches.sql
new file mode 100644
index 0000000..19da66e
--- /dev/null
+++ b/makima/migrations/20250122000001_checkpoint_patches.sql
@@ -0,0 +1,27 @@
+-- Checkpoint patches table for storing git diffs to enable task recovery
+-- When a local worktree is deleted/corrupted, the patch can be used to restore state
+
+CREATE TABLE IF NOT EXISTS checkpoint_patches (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    task_id UUID NOT NULL REFERENCES tasks(id) ON DELETE CASCADE,
+    checkpoint_id UUID REFERENCES task_checkpoints(id) ON DELETE CASCADE,
+    base_commit_sha VARCHAR(40) NOT NULL,     -- Commit to apply patch on top of
+    patch_data BYTEA NOT NULL,                -- Compressed git diff (gzip)
+    patch_size_bytes INTEGER NOT NULL,
+    files_count INTEGER NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    expires_at TIMESTAMPTZ NOT NULL,          -- TTL for auto-cleanup
+    CONSTRAINT patch_size_limit CHECK (patch_size_bytes <= 10485760)  -- 10MB limit
+);
+
+CREATE INDEX idx_checkpoint_patches_task ON checkpoint_patches(task_id);
+CREATE INDEX idx_checkpoint_patches_expires ON checkpoint_patches(expires_at);
+
+-- Link checkpoints to their patches
+ALTER TABLE task_checkpoints
+ADD COLUMN IF NOT EXISTS patch_id UUID REFERENCES checkpoint_patches(id) ON DELETE SET NULL;
+
+COMMENT ON TABLE checkpoint_patches IS 'Stores compressed git diffs for task recovery when local worktree is lost';
+COMMENT ON COLUMN checkpoint_patches.base_commit_sha IS 'The commit SHA that the patch should be applied on top of';
+COMMENT ON COLUMN checkpoint_patches.patch_data IS 'Gzip-compressed git diff data';
+COMMENT ON COLUMN checkpoint_patches.expires_at IS 'Automatic cleanup time (TTL)';