| Collapser | Reduces a window of journal ops to the net effect on each subject. |
| SegmentBuilder | Turns a window of journal operations into a manifest, storing each payload as it goes. |
| SegmentManifest | The ordered record of what one flush captured. |
| SegmentReader | Reads segment manifests back out of the store. |
| SegmentWriter | Writes a segment manifest to the store. |