| 1 | package agent |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "fmt" |
| 7 | |
| 8 | "reasonix/internal/i18n" |
| 9 | "reasonix/internal/provider" |
| 10 | ) |
| 11 | |
| 12 | // SessionCheckpointBoundary identifies a semantic durability barrier. A |
| 13 | // checkpoint is intentionally absent from ordinary message, todo, approval, |
| 14 | // and terminal appends; those use the session's write-behind policy. |
| 15 | type SessionCheckpointBoundary string |
| 16 | |
| 17 | const ( |
| 18 | CheckpointBeforeModel SessionCheckpointBoundary = "before_model" |
| 19 | CheckpointBeforeTopTool SessionCheckpointBoundary = "before_top_level_tool" |
| 20 | // CheckpointUserAdmitted follows the admitted user message. It is advisory: |
| 21 | // a store that already made the message durable ignores it, and a failed |
| 22 | // save does not refuse the turn. |
| 23 | CheckpointUserAdmitted SessionCheckpointBoundary = "user_admitted" |
| 24 | ) |
| 25 | |
| 26 | // SessionCheckpointer makes the side-effect boundary explicit without coupling |
| 27 | // the agent loop to a concrete session backend. |
| 28 | type SessionCheckpointer interface { |
| 29 | CheckpointSession(context.Context, SessionCheckpointBoundary) error |
| 30 | } |
| 31 | |
| 32 | // SessionEventRecorder accepts exact, already-formed provider messages at the |
| 33 | // point the agent commits them. It avoids reconstructing the authoritative |
| 34 | // event log later by comparing mutable conversation snapshots. |
| 35 | type SessionEventRecorder interface { |
| 36 | RecordSessionMessages(context.Context, string, []provider.Message) error |
| 37 | } |
| 38 | |
| 39 | // SessionMessageMutationRecorder records an explicit mutation of one stable |
| 40 | // transcript message. Local recovery/authorization metadata often changes an |
| 41 | // existing message without changing provider-visible bytes; those mutations |
| 42 | // still need a typed event and must not be rediscovered later by diffing the |
| 43 | // mutable Session.Messages slice. |
| 44 | type SessionMessageMutationRecorder interface { |
| 45 | RecordSessionMessageUpsert(context.Context, string, provider.Message) error |
| 46 | } |
| 47 | |
| 48 | // SessionModelContextCommit is an exact provider-visible projection produced by |
| 49 | // one context-maintenance transaction. OperationID must be stable across |
| 50 | // retries so the session log can deduplicate an accepted commit. |
| 51 | type SessionModelContextCommit struct { |
| 52 | OperationID string |
| 53 | Reason string |
| 54 | Messages []provider.Message |
| 55 | } |
| 56 | |
| 57 | // SessionModelContextCommitResult distinguishes a rejection before the event |
| 58 | // log accepted the projection from a durability failure after acceptance. Once |
| 59 | // accepted, the Agent must retain the matching in-memory projection even when |
| 60 | // the durability wait returns an error. |
| 61 | type SessionModelContextCommitResult struct { |
| 62 | Accepted bool |
| 63 | Durable bool |
| 64 | } |
| 65 | |
| 66 | // SessionModelContextRecorder durably records the exact context that the next |
| 67 | // provider request would receive. It must not call back into the Agent. |
| 68 | type SessionModelContextRecorder interface { |
| 69 | RecordSessionModelContext(context.Context, SessionModelContextCommit) (SessionModelContextCommitResult, error) |
| 70 | } |
| 71 | |
| 72 | func (a *Agent) SetSessionCheckpointer(checkpointer SessionCheckpointer) { |
| 73 | if a != nil { |
| 74 | a.svc.sessionCheckpointer = checkpointer |
| 75 | } |
| 76 | } |
| 77 | |
| 78 | func (a *Agent) checkpointSession(ctx context.Context, boundary SessionCheckpointBoundary) error { |
| 79 | if boundary == CheckpointBeforeModel { |
| 80 | if err := a.confirmPendingModelContext(ctx); err != nil { |
| 81 | return err |
| 82 | } |
| 83 | } |
| 84 | if a == nil || a.svc.sessionCheckpointer == nil { |
| 85 | return ctx.Err() |
| 86 | } |
| 87 | if err := a.svc.sessionCheckpointer.CheckpointSession(ctx, boundary); err != nil { |
| 88 | return sessionSaveFailure(err) |
| 89 | } |
| 90 | return ctx.Err() |
| 91 | } |
| 92 | |
| 93 | // confirmPendingModelContext completes an accepted context-maintenance commit |
| 94 | // before another model request can be prepared or dispatched. It deliberately |
| 95 | // reuses the frozen operation ID and payload retained by the original attempt. |
| 96 | func (a *Agent) confirmPendingModelContext(ctx context.Context) error { |
| 97 | if a == nil { |
| 98 | return ctx.Err() |
| 99 | } |
| 100 | a.sess.compactionMu.Lock() |
| 101 | pending := a.sess.pendingModelContextCommit |
| 102 | if pending == nil { |
| 103 | a.sess.compactionMu.Unlock() |
| 104 | return ctx.Err() |
| 105 | } |
| 106 | recorder, ok := a.svc.sessionCheckpointer.(SessionModelContextRecorder) |
| 107 | if !ok { |
| 108 | a.sess.compactionMu.Unlock() |
| 109 | return errors.New("confirm pending model context: recorder unavailable") |
| 110 | } |
| 111 | commit := cloneSessionModelContextCommit(*pending) |
| 112 | result, err := recorder.RecordSessionModelContext(ctx, commit) |
| 113 | if err != nil { |
| 114 | a.sess.compactionMu.Unlock() |
| 115 | return sessionSaveFailure(fmt.Errorf("confirm pending model context: %w", err)) |
| 116 | } |
| 117 | if !result.Accepted || !result.Durable { |
| 118 | a.sess.compactionMu.Unlock() |
| 119 | return sessionSaveFailure(errors.New("confirm pending model context: commit is not durable")) |
| 120 | } |
| 121 | if err := a.persistCompactionStateLocked(); err != nil { |
| 122 | a.sess.compactionMu.Unlock() |
| 123 | return sessionSaveFailure(fmt.Errorf("confirm pending model context sidecar: %w", err)) |
| 124 | } |
| 125 | a.sess.pendingModelContextCommit = nil |
| 126 | a.sess.checkpointState = "applied" |
| 127 | var receipt *ContextMaintenanceReceipt |
| 128 | if a.sess.compactionState.LastReceipt != nil { |
| 129 | copy := *a.sess.compactionState.LastReceipt |
| 130 | receipt = © |
| 131 | } |
| 132 | a.sess.compactionMu.Unlock() |
| 133 | if receipt != nil { |
| 134 | a.emitContextMaintenance(receipt) |
| 135 | } |
| 136 | return ctx.Err() |
| 137 | } |
| 138 | |
| 139 | func cloneSessionModelContextCommit(commit SessionModelContextCommit) SessionModelContextCommit { |
| 140 | commit.Messages = freezeProviderRequest(provider.Request{Messages: commit.Messages}).Messages |
| 141 | return commit |
| 142 | } |
| 143 | |
| 144 | // admitUserMessage publishes an admitted user message and asks the session to |
| 145 | // make it durable before the model is sampled. |
| 146 | func (a *Agent) admitUserMessage(ctx context.Context, user provider.Message) { |
| 147 | emitAdmittedUserMessage(a.svc.sink, user) |
| 148 | if a.svc.sessionCheckpointer != nil { |
| 149 | _ = a.svc.sessionCheckpointer.CheckpointSession(ctx, CheckpointUserAdmitted) |
| 150 | } |
| 151 | } |
| 152 | |
| 153 | func sessionSaveFailure(err error) error { |
| 154 | if errors.Is(err, context.Canceled) || errors.Is(err, context.DeadlineExceeded) { |
| 155 | return err |
| 156 | } |
| 157 | return fmt.Errorf("%s: %w", i18n.M.SessionSaveRecovery, err) |
| 158 | } |
| 159 | |
| 160 | func (a *Agent) appendCommittedMessages(ctx context.Context, reason string, messages ...provider.Message) error { |
| 161 | if a == nil || len(messages) == 0 { |
| 162 | return nil |
| 163 | } |
| 164 | for i := range messages { |
| 165 | if messages[i].ID == "" { |
| 166 | messages[i].ID = NewMessageID() |
| 167 | } |
| 168 | } |
| 169 | if recorder, ok := a.svc.sessionCheckpointer.(SessionEventRecorder); ok { |
| 170 | if err := recorder.RecordSessionMessages(ctx, reason, messages); err != nil { |
| 171 | return err |
| 172 | } |
| 173 | } |
| 174 | a.sess.conversation.AddBatch(messages...) |
| 175 | return nil |
| 176 | } |
| 177 | |
| 178 | // ModelHistorySnapshot returns the exact context projection that the next |
| 179 | // provider request would receive. Compaction recorders use it after an |
| 180 | // installed projection rather than deriving context from summary prose. |
| 181 | func (a *Agent) ModelHistorySnapshot() []provider.Message { |
| 182 | if a == nil { |
| 183 | return nil |
| 184 | } |
| 185 | return append([]provider.Message(nil), a.modelVisibleMessages()...) |
| 186 | } |
| 187 |