| 1 | package extension |
| 2 | |
| 3 | import ( |
| 4 | "maps" |
| 5 | "slices" |
| 6 | "strings" |
| 7 | ) |
| 8 | |
| 9 | // SubgraphKind classifies which assembly subgraph a RuntimePlan touches so |
| 10 | // Rebuild can skip unaffected work (tools/prompt, interceptors, UI, MCP). |
| 11 | type SubgraphKind uint8 |
| 12 | |
| 13 | const ( |
| 14 | // SubgraphNone means no component identity changed (full no-op). |
| 15 | SubgraphNone SubgraphKind = iota |
| 16 | // SubgraphInterceptorOnly means only interceptor contributions moved. |
| 17 | SubgraphInterceptorOnly |
| 18 | // SubgraphProviderOnly means only provider capabilities moved. |
| 19 | SubgraphProviderOnly |
| 20 | // SubgraphUIOnly means only UI capabilities moved. |
| 21 | SubgraphUIOnly |
| 22 | // SubgraphMCPOnly means only MCP-related components moved. |
| 23 | SubgraphMCPOnly |
| 24 | // SubgraphSidecar means native runtime packages changed without a single kind. |
| 25 | SubgraphSidecar |
| 26 | // SubgraphFull means mixed or host-wide changes; full rebuild is required. |
| 27 | SubgraphFull |
| 28 | ) |
| 29 | |
| 30 | // RuntimePlan describes the transition from one generation's graph/snapshot |
| 31 | // to the next. Builders and Rebuild consume it to activate only the affected |
| 32 | // subgraph. PrefixChanged is an observed post-build fact; graph diffing alone |
| 33 | // only classifies which work may be required. |
| 34 | type RuntimePlan struct { |
| 35 | FromGeneration uint64 |
| 36 | ToGeneration uint64 |
| 37 | Added []ComponentID |
| 38 | Removed []ComponentID |
| 39 | Reloaded []ComponentID |
| 40 | Unchanged []ComponentID |
| 41 | ActivateOrder []ComponentID |
| 42 | DrainOrder []ComponentID |
| 43 | // PrefixChanged reports whether the frozen provider-visible prefix actually |
| 44 | // changed between the previous and current snapshots. Boot sets it only |
| 45 | // after both snapshots exist and their CacheHash values can be compared. |
| 46 | PrefixChanged bool |
| 47 | // ProviderChanged reports whether any changed component provided a provider |
| 48 | // capability on either side of the transition. Looking at both graphs keeps |
| 49 | // provider removal visible to diagnostics. |
| 50 | ProviderChanged bool |
| 51 | // Kind is the classified subgraph of this plan (computed by DiffRuntimePlan). |
| 52 | Kind SubgraphKind |
| 53 | // Graph is the resolved target graph (may be nil for pure no-op plans). |
| 54 | Graph *DependencyGraph |
| 55 | // RestartUnchangedSidecars requests fresh native processes even when their |
| 56 | // dependency/capability identity is unchanged. It affects activation only, |
| 57 | // so IsNoOp and CacheHash remain stable. |
| 58 | RestartUnchangedSidecars bool |
| 59 | } |
| 60 | |
| 61 | // IsNoOp reports whether the plan changes no components. |
| 62 | func (p *RuntimePlan) IsNoOp() bool { |
| 63 | if p == nil { |
| 64 | return true |
| 65 | } |
| 66 | return len(p.Added) == 0 && len(p.Removed) == 0 && len(p.Reloaded) == 0 |
| 67 | } |
| 68 | |
| 69 | // MayChangePrefix is the conservative pre-build planning signal for whether a |
| 70 | // rebuild must re-evaluate provider-visible prompt/tool prefix state. It is not |
| 71 | // a diagnostic fact; PrefixChanged is set after comparing frozen snapshots. |
| 72 | // Interceptor-only and UI-only plans do not change CacheHash by contract. |
| 73 | func (p *RuntimePlan) MayChangePrefix() bool { |
| 74 | if p == nil || p.IsNoOp() { |
| 75 | return false |
| 76 | } |
| 77 | switch p.Kind { |
| 78 | case SubgraphInterceptorOnly, SubgraphUIOnly: |
| 79 | return false |
| 80 | default: |
| 81 | return true |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | // AffectsSidecars reports whether any native runtime package must start/drain. |
| 86 | func (p *RuntimePlan) AffectsSidecars() bool { |
| 87 | if p == nil { |
| 88 | return false |
| 89 | } |
| 90 | return p.RestartUnchangedSidecars || !p.IsNoOp() |
| 91 | } |
| 92 | |
| 93 | // AffectsInterceptors reports whether the interceptor chain must rebuild. |
| 94 | func (p *RuntimePlan) AffectsInterceptors() bool { |
| 95 | if p == nil || p.IsNoOp() { |
| 96 | return false |
| 97 | } |
| 98 | return p.Kind == SubgraphInterceptorOnly || p.Kind == SubgraphFull || p.Kind == SubgraphSidecar |
| 99 | } |
| 100 | |
| 101 | // AffectsUI reports whether the extension UI hub must rebind. |
| 102 | func (p *RuntimePlan) AffectsUI() bool { |
| 103 | if p == nil || p.IsNoOp() { |
| 104 | return false |
| 105 | } |
| 106 | return p.Kind == SubgraphUIOnly || p.Kind == SubgraphFull || p.Kind == SubgraphSidecar |
| 107 | } |
| 108 | |
| 109 | // AffectsProviders reports whether extension-hosted providers must re-merge. |
| 110 | func (p *RuntimePlan) AffectsProviders() bool { |
| 111 | if p == nil || p.IsNoOp() { |
| 112 | return false |
| 113 | } |
| 114 | return p.ProviderChanged || p.Kind == SubgraphProviderOnly || p.Kind == SubgraphFull || p.Kind == SubgraphSidecar |
| 115 | } |
| 116 | |
| 117 | // DiffRuntimePlan compares two graphs and produces a deterministic plan. |
| 118 | // from may be nil (cold start). PrefixChanged remains false here because graph |
| 119 | // identity cannot prove provider-visible byte changes; boot observes it after |
| 120 | // the next RuntimeSnapshot has been frozen. |
| 121 | func DiffRuntimePlan(from, to *DependencyGraph, fromGen, toGen uint64) *RuntimePlan { |
| 122 | plan := &RuntimePlan{ |
| 123 | FromGeneration: fromGen, |
| 124 | ToGeneration: toGen, |
| 125 | Graph: to, |
| 126 | } |
| 127 | if to == nil { |
| 128 | return plan |
| 129 | } |
| 130 | fromIDs := map[ComponentID]ComponentDescriptor{} |
| 131 | if from != nil { |
| 132 | maps.Copy(fromIDs, from.Components) |
| 133 | } |
| 134 | toIDs := to.Components |
| 135 | |
| 136 | var added, removed, reloaded, unchanged []ComponentID |
| 137 | for id, neo := range toIDs { |
| 138 | old, ok := fromIDs[id] |
| 139 | if !ok { |
| 140 | added = append(added, id) |
| 141 | continue |
| 142 | } |
| 143 | if componentIdentityChanged(old, neo) || epochsChanged(from, to, id) { |
| 144 | reloaded = append(reloaded, id) |
| 145 | continue |
| 146 | } |
| 147 | unchanged = append(unchanged, id) |
| 148 | } |
| 149 | for id := range fromIDs { |
| 150 | if _, ok := toIDs[id]; !ok { |
| 151 | removed = append(removed, id) |
| 152 | } |
| 153 | } |
| 154 | sortIDs(added) |
| 155 | sortIDs(removed) |
| 156 | sortIDs(reloaded) |
| 157 | sortIDs(unchanged) |
| 158 | plan.Added = added |
| 159 | plan.Removed = removed |
| 160 | plan.Reloaded = reloaded |
| 161 | plan.Unchanged = unchanged |
| 162 | plan.ActivateOrder = to.ActivateOrder() |
| 163 | // Drain only removed + reloaded, in reverse dependency order of the old graph. |
| 164 | drainSet := map[ComponentID]bool{} |
| 165 | for _, id := range removed { |
| 166 | drainSet[id] = true |
| 167 | } |
| 168 | for _, id := range reloaded { |
| 169 | drainSet[id] = true |
| 170 | } |
| 171 | if from != nil { |
| 172 | for _, id := range from.DrainOrder() { |
| 173 | if drainSet[id] { |
| 174 | plan.DrainOrder = append(plan.DrainOrder, id) |
| 175 | } |
| 176 | } |
| 177 | } else { |
| 178 | plan.DrainOrder = append(plan.DrainOrder, removed...) |
| 179 | plan.DrainOrder = append(plan.DrainOrder, reloaded...) |
| 180 | } |
| 181 | plan.Kind = classifySubgraph(plan, from, to) |
| 182 | plan.ProviderChanged = changedComponentsProvideKind(plan, from, to, "provider") |
| 183 | return plan |
| 184 | } |
| 185 | |
| 186 | // classifySubgraph inspects changed components' provides/intercepts to pick |
| 187 | // the narrowest rebuild subgraph. |
| 188 | func classifySubgraph(plan *RuntimePlan, from, to *DependencyGraph) SubgraphKind { |
| 189 | if plan == nil || plan.IsNoOp() { |
| 190 | return SubgraphNone |
| 191 | } |
| 192 | changed := append(append(append([]ComponentID{}, plan.Added...), plan.Removed...), plan.Reloaded...) |
| 193 | var hasInterceptor, hasProvider, hasUI, hasMCP, hasOther bool |
| 194 | mcpSchemaChanged := false |
| 195 | for _, id := range changed { |
| 196 | oldDesc, oldOK := graphComponent(from, id) |
| 197 | newDesc, newOK := graphComponent(to, id) |
| 198 | mcpSchemaChanged = mcpSchemaChanged || mcpCapabilitySchemaChanged(oldDesc, oldOK, newDesc, newOK) |
| 199 | componentClassified := false |
| 200 | for _, desc := range []ComponentDescriptor{oldDesc, newDesc} { |
| 201 | if len(desc.Intercepts) > 0 || len(desc.Replaces) > 0 { |
| 202 | hasInterceptor = true |
| 203 | componentClassified = true |
| 204 | } |
| 205 | for _, cap := range desc.Provides { |
| 206 | switch strings.ToLower(cap.Key.Kind) { |
| 207 | case "provider": |
| 208 | hasProvider = true |
| 209 | componentClassified = true |
| 210 | case "ui", "uiaction": |
| 211 | hasUI = true |
| 212 | componentClassified = true |
| 213 | case "mcp", "mcpserver": |
| 214 | hasMCP = true |
| 215 | componentClassified = true |
| 216 | case "interceptors", "strategies": |
| 217 | hasInterceptor = true |
| 218 | componentClassified = true |
| 219 | default: |
| 220 | if cap.Key.Kind != "" { |
| 221 | hasOther = true |
| 222 | componentClassified = true |
| 223 | } |
| 224 | } |
| 225 | } |
| 226 | } |
| 227 | // Plugin components with empty provides still count as sidecar. |
| 228 | if strings.HasPrefix(string(id), "plugin/") && !componentClassified { |
| 229 | hasOther = true |
| 230 | } |
| 231 | } |
| 232 | // An MCP backend roll may stay narrow only while its declared schema shape is |
| 233 | // unchanged. Added/removed/renamed schemas need a full snapshot rebuild so |
| 234 | // provider-visible tool bytes cannot remain stale. |
| 235 | if mcpSchemaChanged { |
| 236 | return SubgraphFull |
| 237 | } |
| 238 | kinds := 0 |
| 239 | if hasInterceptor { |
| 240 | kinds++ |
| 241 | } |
| 242 | if hasProvider { |
| 243 | kinds++ |
| 244 | } |
| 245 | if hasUI { |
| 246 | kinds++ |
| 247 | } |
| 248 | if hasMCP { |
| 249 | kinds++ |
| 250 | } |
| 251 | if hasOther { |
| 252 | kinds++ |
| 253 | } |
| 254 | if kinds > 1 { |
| 255 | if hasOther { |
| 256 | return SubgraphFull |
| 257 | } |
| 258 | return SubgraphSidecar |
| 259 | } |
| 260 | switch { |
| 261 | case hasInterceptor: |
| 262 | return SubgraphInterceptorOnly |
| 263 | case hasProvider: |
| 264 | return SubgraphProviderOnly |
| 265 | case hasUI: |
| 266 | return SubgraphUIOnly |
| 267 | case hasMCP: |
| 268 | return SubgraphMCPOnly |
| 269 | default: |
| 270 | return SubgraphFull |
| 271 | } |
| 272 | } |
| 273 | |
| 274 | func graphComponent(graph *DependencyGraph, id ComponentID) (ComponentDescriptor, bool) { |
| 275 | if graph == nil { |
| 276 | return ComponentDescriptor{}, false |
| 277 | } |
| 278 | desc, ok := graph.Components[id] |
| 279 | return desc, ok |
| 280 | } |
| 281 | |
| 282 | func changedComponentsProvideKind(plan *RuntimePlan, from, to *DependencyGraph, kind string) bool { |
| 283 | if plan == nil || plan.IsNoOp() { |
| 284 | return false |
| 285 | } |
| 286 | changed := append(append(append([]ComponentID{}, plan.Added...), plan.Removed...), plan.Reloaded...) |
| 287 | for _, id := range changed { |
| 288 | oldDesc, _ := graphComponent(from, id) |
| 289 | newDesc, _ := graphComponent(to, id) |
| 290 | for _, desc := range []ComponentDescriptor{oldDesc, newDesc} { |
| 291 | for _, capability := range desc.Provides { |
| 292 | if strings.EqualFold(strings.TrimSpace(capability.Key.Kind), kind) { |
| 293 | return true |
| 294 | } |
| 295 | } |
| 296 | } |
| 297 | } |
| 298 | return false |
| 299 | } |
| 300 | |
| 301 | func mcpCapabilitySchemaChanged(oldDesc ComponentDescriptor, oldOK bool, newDesc ComponentDescriptor, newOK bool) bool { |
| 302 | oldShape := mcpCapabilityShape(oldDesc, oldOK) |
| 303 | newShape := mcpCapabilityShape(newDesc, newOK) |
| 304 | if len(oldShape) != len(newShape) { |
| 305 | return len(oldShape) > 0 || len(newShape) > 0 |
| 306 | } |
| 307 | for key, oldHash := range oldShape { |
| 308 | if newHash, ok := newShape[key]; !ok || newHash != oldHash { |
| 309 | return true |
| 310 | } |
| 311 | } |
| 312 | return false |
| 313 | } |
| 314 | |
| 315 | func mcpCapabilityShape(desc ComponentDescriptor, ok bool) map[string]string { |
| 316 | shape := map[string]string{} |
| 317 | if !ok { |
| 318 | return shape |
| 319 | } |
| 320 | for _, capability := range desc.Provides { |
| 321 | switch strings.ToLower(strings.TrimSpace(capability.Key.Kind)) { |
| 322 | case "mcp", "mcpserver": |
| 323 | shape[capability.Key.String()] = strings.TrimSpace(capability.SchemaHash) |
| 324 | } |
| 325 | } |
| 326 | return shape |
| 327 | } |
| 328 | |
| 329 | func componentIdentityChanged(a, b ComponentDescriptor) bool { |
| 330 | if a.Priority != b.Priority || a.Optional != b.Optional { |
| 331 | return true |
| 332 | } |
| 333 | if a.Source.key() != b.Source.key() || a.Source.Version != b.Source.Version { |
| 334 | return true |
| 335 | } |
| 336 | if !slices.Equal(a.Intercepts, b.Intercepts) || !slices.Equal(a.Replaces, b.Replaces) { |
| 337 | return true |
| 338 | } |
| 339 | if len(a.Provides) != len(b.Provides) || len(a.Requires) != len(b.Requires) { |
| 340 | return true |
| 341 | } |
| 342 | for i := range a.Provides { |
| 343 | if a.Provides[i].CanonicalHash() != b.Provides[i].CanonicalHash() { |
| 344 | return true |
| 345 | } |
| 346 | } |
| 347 | for i := range a.Requires { |
| 348 | if a.Requires[i].Key != b.Requires[i].Key || |
| 349 | a.Requires[i].Version != b.Requires[i].Version || |
| 350 | a.Requires[i].VersionRange != b.Requires[i].VersionRange || |
| 351 | a.Requires[i].SchemaHash != b.Requires[i].SchemaHash || |
| 352 | a.Requires[i].Optional != b.Requires[i].Optional { |
| 353 | return true |
| 354 | } |
| 355 | } |
| 356 | return false |
| 357 | } |
| 358 | |
| 359 | func epochsChanged(from, to *DependencyGraph, id ComponentID) bool { |
| 360 | if from == nil || to == nil { |
| 361 | return false |
| 362 | } |
| 363 | c := to.Components[id] |
| 364 | for _, req := range c.Requires { |
| 365 | e1, ok1 := from.EpochFor(id, req) |
| 366 | e2, ok2 := to.EpochFor(id, req) |
| 367 | if ok1 != ok2 || e1.String() != e2.String() { |
| 368 | return true |
| 369 | } |
| 370 | } |
| 371 | return false |
| 372 | } |
| 373 | |
| 374 | func sortIDs(ids []ComponentID) { |
| 375 | slices.Sort(ids) |
| 376 | } |
| 377 |