| 1 | package moves |
| 2 | |
| 3 | import ( |
| 4 | "fmt" |
| 5 | "strconv" |
| 6 | "strings" |
| 7 | |
| 8 | "github.com/carlosframework/platform/internal/hostclaim" |
| 9 | "github.com/superfly/ltx" |
| 10 | ) |
| 11 | |
| 12 | // ReplicaSource is where a move's source copy reads from (§7.3, round-3 |
| 13 | // finding 5): the claim holder's location and generation, never the |
| 14 | // legacy HibernatePrefix guess. keep admits, relative to prefix, only the |
| 15 | // generation's own LTX files, `<level>/<min>-<max>.ltx` with a level from |
| 16 | // 0000 to 0009, so the staging lane holds the generation's files flat |
| 17 | // under replica/<level>/ and nothing else: no other generation (g-*/), no |
| 18 | // child incarnation, no generation.json, lock.json or closed/. |
| 19 | // |
| 20 | // The holder's location never carries a trailing slash (Claim.Validate |
| 21 | // accepts only instances/<host> or instances/<host>/<incarnation>), so the |
| 22 | // separator is added here, as genselect.requestLocation does (round-4 |
| 23 | // finding 4). A generation of "" or hostclaim.RootGeneration is the root |
| 24 | // layout: the level directories sit directly under the location. |
| 25 | // |
| 26 | // The generation prefix rule has twins: hostbox.GenerationPrefix (which |
| 27 | // refuses the root generation and a holder with no session, so a source |
| 28 | // copy cannot use it) and genselect's unexported prefix and coordinates. |
| 29 | // The three change together. |
| 30 | func ReplicaSource(h hostclaim.Holder) (prefix string, keep func(rel string) bool) { |
| 31 | base := strings.TrimSuffix(h.Location, "/") + "/" |
| 32 | prefix = base |
| 33 | if g := h.Generation; g != "" && g != hostclaim.RootGeneration { |
| 34 | prefix = base + "g-" + g + "/" |
| 35 | } |
| 36 | return prefix, levelFile |
| 37 | } |
| 38 | |
| 39 | // levelFile is ReplicaSource's keep: exactly two path parts, a level |
| 40 | // directory of four lowercase hex digits from 0000 to 0009, and an LTX |
| 41 | // file name in its canonical form with 0 < min <= max. |
| 42 | func levelFile(rel string) bool { |
| 43 | parts := strings.Split(rel, "/") |
| 44 | if len(parts) != 2 || len(parts[0]) != 4 { |
| 45 | return false |
| 46 | } |
| 47 | level, err := strconv.ParseUint(parts[0], 16, 16) |
| 48 | if err != nil || level > 9 || fmt.Sprintf("%04x", level) != parts[0] { |
| 49 | return false |
| 50 | } |
| 51 | min, max, err := ltx.ParseFilename(parts[1]) |
| 52 | return err == nil && min != 0 && min <= max && ltx.FormatFilename(min, max) == parts[1] |
| 53 | } |
| 54 | |
amadan