Persist compaction checkpoints in sessions

commit: c98e701843a7c2961fba08dc69d9a65f3ed054ef
author: patriceckhart · 5mo ago · 2026-05-09 21:02 UTC
parent: facc709
signature: unsigned

4 files · +99 -12

M internal/agent/cli.go +11 -0


@@ -575,12 +575,23 @@ func runInteractive(ctx context.Context, args Args, version string) error {
575	575		}
576	576		_ = sess.AppendUsage(cum, cum)
577	577		}
	578	+	persistCompaction := func(messages []provider.Message) {
	579	+	persistMu.Lock()
	580	+	defer persistMu.Unlock()
	581	+	if sess == nil {
	582	+	return
	583	+	}
	584	+	if err := sess.AppendCompaction(messages); err == nil {
	585	+	sessBaselineMsgs = len(messages)
	586	+	}
	587	+	}
578	588		wireAgentPersist := func(a core.Agent) core.Agent {
579	589		if a == nil {
580	590		return a
581	591		}
582	592		a.OnMessageAppended = persistMessage
583	593		a.OnUsage = persistUsage
	594	+	a.OnTranscriptCompacted = persistCompaction
584	595		return a
585	596		}
586	597		wireAgentPersist(ag)


@@ -575,12 +575,23 @@ func runInteractive(ctx context.Context, args Args, version string) error {
575	}	575		}
576	_ = sess.AppendUsage(cum, cum)	576		_ = sess.AppendUsage(cum, cum)
577	}	577		}
		578	+	persistCompaction := func(messages []provider.Message) {
		579	+	persistMu.Lock()
		580	+	defer persistMu.Unlock()
		581	+	if sess == nil {
		582	+	return
		583	+	}
		584	+	if err := sess.AppendCompaction(messages); err == nil {
		585	+	sessBaselineMsgs = len(messages)
		586	+	}
		587	+	}
578	wireAgentPersist := func(a core.Agent) core.Agent {	588		wireAgentPersist := func(a core.Agent) core.Agent {
579	if a == nil {	589		if a == nil {
580	return a	590		return a
581	}	591		}
582	a.OnMessageAppended = persistMessage	592		a.OnMessageAppended = persistMessage
583	a.OnUsage = persistUsage	593		a.OnUsage = persistUsage
		594	+	a.OnTranscriptCompacted = persistCompaction
584	return a	595		return a
585	}	596		}
586	wireAgentPersist(ag)	597		wireAgentPersist(ag)

M internal/core/agent.go +7 -0


@@ -66,6 +66,13 @@ type Agent struct {
66	66		// current and a crash recovers the right cost figure.
67	67		OnUsage func(cumulative provider.Usage)
68	68
	69	+	// OnTranscriptCompacted, if set, fires after Compact replaces the
	70	+	// in-memory transcript with the synthetic summary plus kept tail.
	71	+	// Hosts wire this to append an explicit compaction checkpoint to
	72	+	// the session log; per-message append hooks do not fire for this
	73	+	// wholesale transcript replacement.
	74	+	OnTranscriptCompacted func(messages []provider.Message)
	75	+
69	76		mu sync.Mutex
70	77		messages []provider.Message
71	78		// rev increments whenever the transcript slice is replaced or a


@@ -66,6 +66,13 @@ type Agent struct {
66	// current and a crash recovers the right cost figure.	66		// current and a crash recovers the right cost figure.
67	OnUsage func(cumulative provider.Usage)	67		OnUsage func(cumulative provider.Usage)
68		68
		69	+	// OnTranscriptCompacted, if set, fires after Compact replaces the
		70	+	// in-memory transcript with the synthetic summary plus kept tail.
		71	+	// Hosts wire this to append an explicit compaction checkpoint to
		72	+	// the session log; per-message append hooks do not fire for this
		73	+	// wholesale transcript replacement.
		74	+	OnTranscriptCompacted func(messages []provider.Message)
		75	+
69	mu sync.Mutex	76		mu sync.Mutex
70	messages []provider.Message	77		messages []provider.Message
71	// rev increments whenever the transcript slice is replaced or a	78		// rev increments whenever the transcript slice is replaced or a

M internal/core/compact.go +7 -0


@@ -113,8 +113,15 @@ func (a *Agent) Compact(ctx context.Context, keepTail int, sink func(delta strin
113	113
114	114		a.mu.Lock()
115	115		a.messages = next
	116	+	a.rev++
	117	+	onCompacted := a.OnTranscriptCompacted
	118	+	persisted := append([]provider.Message(nil), next...)
116	119		a.mu.Unlock()
117	120
	121	+	if onCompacted != nil {
	122	+	onCompacted(persisted)
	123	+	}
	124	+
118	125		return summary, nil
119	126		}
120	127


@@ -113,8 +113,15 @@ func (a *Agent) Compact(ctx context.Context, keepTail int, sink func(delta strin
113		113
114	a.mu.Lock()	114		a.mu.Lock()
115	a.messages = next	115		a.messages = next
		116	+	a.rev++
		117	+	onCompacted := a.OnTranscriptCompacted
		118	+	persisted := append([]provider.Message(nil), next...)
116	a.mu.Unlock()	119		a.mu.Unlock()
117		120
		121	+	if onCompacted != nil {
		122	+	onCompacted(persisted)
		123	+	}
		124	+
118	return summary, nil	125		return summary, nil
119	}	126		}
120		127

M internal/core/session.go +74 -12


@@ -66,11 +66,12 @@ type SessionMeta struct {
66	66		// the default unmarshaler cannot reconstruct); it is written with a
67	67		// regular provider.Message value.
68	68		type sessionLine struct {
69		-	Type string `json:"type"`
70		-	Meta *SessionMeta `json:"meta,omitempty"`
71		-	Message *provider.Message `json:"message,omitempty"`
72		-	Usage *provider.Usage `json:"usage,omitempty"`
73		-	Cumulative *provider.Usage `json:"cumulative,omitempty"`
	69	+	Type string `json:"type"`
	70	+	Meta *SessionMeta `json:"meta,omitempty"`
	71	+	Message *provider.Message `json:"message,omitempty"`
	72	+	Messages []provider.Message `json:"messages,omitempty"`
	73	+	Usage *provider.Usage `json:"usage,omitempty"`
	74	+	Cumulative *provider.Usage `json:"cumulative,omitempty"`
74	75		}
75	76
76	77		type sessionLineHead struct {

@@ -190,6 +191,10 @@ func OpenSession(path string) (*Session, []provider.Message, error) {
190	191		if msg, err := hydrateMessage(line); err == nil && len(msg.Content) > 0 {
191	192		messages = append(messages, msg)
192	193		}
	194	+	case "compaction":
	195	+	if compacted, err := hydrateCompaction(line); err == nil {
	196	+	messages = compacted
	197	+	}
193	198		}
194	199		return nil
195	200		}); err != nil {

@@ -373,6 +378,13 @@ func describeSession(path string) SessionSummary {
373	378		if s.FirstUserText == "" {
374	379		s.FirstUserText = firstUserText(line)
375	380		}
	381	+	case "compaction":
	382	+	if compacted, err := hydrateCompaction(line); err == nil {
	383	+	s.MessageCount = len(compacted)
	384	+	if s.FirstUserText == "" && len(compacted) > 0 {
	385	+	s.FirstUserText = firstTextFromMessage(compacted[0])
	386	+	}
	387	+	}
376	388		case "rename":
377	389		var row struct {
378	390		Title string `json:"title"`

@@ -416,6 +428,15 @@ func firstUserText(line []byte) string {
416	428		return ""
417	429		}
418	430
	431	+	func firstTextFromMessage(msg provider.Message) string {
	432	+	for _, c := range msg.Content {
	433	+	if tb, ok := c.(provider.TextBlock); ok && tb.Text != "" {
	434	+	return tb.Text
	435	+	}
	436	+	}
	437	+	return ""
	438	+	}
	439	+
419	440		// PruneEmptySessions deletes session files in cwd's session directory
420	441		// that contain only a meta line (no messages were ever appended).
421	442		// Cleans up the backlog of empty stubs created by old zot versions

@@ -517,6 +538,21 @@ func (s *Session) AppendMessage(m provider.Message) error {
517	538		return nil
518	539		}
519	540
	541	+	// AppendCompaction writes a checkpoint that replaces all earlier
	542	+	// transcript rows when the session is resumed. The old rows remain in
	543	+	// the JSONL file for audit/export, while loaders use the latest
	544	+	// compaction row as the effective transcript.
	545	+	func (s *Session) AppendCompaction(messages []provider.Message) error {
	546	+	if s == nil {
	547	+	return nil
	548	+	}
	549	+	if err := s.writeLine(sessionLine{Type: "compaction", Messages: messages}); err != nil {
	550	+	return err
	551	+	}
	552	+	s.messagesAppended = len(messages)
	553	+	return nil
	554	+	}
	555	+
520	556		// UpdateModel records a provider/model switch in the session file.
521	557		// The reader keeps the most recent meta entry, so the session resumes
522	558		// with the updated model.

@@ -580,19 +616,45 @@ func (s *Session) writeLine(row sessionLine) error {
580	616		// We persist messages by reading the raw "message" object back and
581	617		// rebuilding Content from discriminated fields.
582	618
	619	+	func hydrateCompaction(lineBytes []byte) ([]provider.Message, error) {
	620	+	var row struct {
	621	+	Messages []json.RawMessage `json:"messages"`
	622	+	}
	623	+	if err := json.Unmarshal(lineBytes, &row); err != nil {
	624	+	return nil, err
	625	+	}
	626	+	messages := make([]provider.Message, 0, len(row.Messages))
	627	+	for _, raw := range row.Messages {
	628	+	msg, err := hydrateMessageObject(raw)
	629	+	if err == nil && len(msg.Content) > 0 {
	630	+	messages = append(messages, msg)
	631	+	}
	632	+	}
	633	+	return messages, nil
	634	+	}
	635	+
583	636		func hydrateMessage(lineBytes []byte) (provider.Message, error) {
584	637		var row struct {
585		-	Message struct {
586		-	Role provider.Role `json:"role"`
587		-	Content []json.RawMessage `json:"content"`
588		-	Time time.Time `json:"time"`
589		-	} `json:"message"`
	638	+	Message json.RawMessage `json:"message"`
590	639		}
591	640		if err := json.Unmarshal(lineBytes, &row); err != nil {
592	641		return provider.Message{}, err
593	642		}
594		-	msg := provider.Message{Role: row.Message.Role, Time: row.Message.Time}
595		-	for _, raw := range row.Message.Content {
	643	+	return hydrateMessageObject(row.Message)
	644	+	}
	645	+
	646	+	func hydrateMessageObject(rawMessage []byte) (provider.Message, error) {
	647	+	var row struct {
	648	+	Role provider.Role `json:"role"`
	649	+	Content []json.RawMessage `json:"content"`
	650	+	Time time.Time `json:"time"`
	651	+	Meta map[string]string `json:"meta,omitempty"`
	652	+	}
	653	+	if err := json.Unmarshal(rawMessage, &row); err != nil {
	654	+	return provider.Message{}, err
	655	+	}
	656	+	msg := provider.Message{Role: row.Role, Time: row.Time, Meta: row.Meta}
	657	+	for _, raw := range row.Content {
596	658		var head struct {
597	659		Text string `json:"text"`
598	660		MimeType string `json:"mime_type"`


@@ -66,11 +66,12 @@ type SessionMeta struct {
66		// the default unmarshaler cannot reconstruct); it is written with a	66		// the default unmarshaler cannot reconstruct); it is written with a
67		// regular provider.Message value.	67		// regular provider.Message value.
68		type sessionLine struct {	68		type sessionLine struct {
69	-	Type string `json:"type"`	69	+	Type string `json:"type"`
70	-	Meta *SessionMeta `json:"meta,omitempty"`	70	+	Meta *SessionMeta `json:"meta,omitempty"`
71	-	Message *provider.Message `json:"message,omitempty"`	71	+	Message *provider.Message `json:"message,omitempty"`
72	-	Usage *provider.Usage `json:"usage,omitempty"`	72	+	Messages []provider.Message `json:"messages,omitempty"`
73	-	Cumulative *provider.Usage `json:"cumulative,omitempty"`	73	+	Usage *provider.Usage `json:"usage,omitempty"`
			74	+	Cumulative *provider.Usage `json:"cumulative,omitempty"`
74		}	75		}
75			76
76		type sessionLineHead struct {	77		type sessionLineHead struct {

@@ -190,6 +191,10 @@ func OpenSession(path string) (*Session, []provider.Message, error) {
190		if msg, err := hydrateMessage(line); err == nil && len(msg.Content) > 0 {	191		if msg, err := hydrateMessage(line); err == nil && len(msg.Content) > 0 {
191		messages = append(messages, msg)	192		messages = append(messages, msg)
192		}	193		}
			194	+	case "compaction":
			195	+	if compacted, err := hydrateCompaction(line); err == nil {
			196	+	messages = compacted
			197	+	}
193		}	198		}
194		return nil	199		return nil
195		}); err != nil {	200		}); err != nil {

@@ -373,6 +378,13 @@ func describeSession(path string) SessionSummary {
373		if s.FirstUserText == "" {	378		if s.FirstUserText == "" {
374		s.FirstUserText = firstUserText(line)	379		s.FirstUserText = firstUserText(line)
375		}	380		}
			381	+	case "compaction":
			382	+	if compacted, err := hydrateCompaction(line); err == nil {
			383	+	s.MessageCount = len(compacted)
			384	+	if s.FirstUserText == "" && len(compacted) > 0 {
			385	+	s.FirstUserText = firstTextFromMessage(compacted[0])
			386	+	}
			387	+	}
376		case "rename":	388		case "rename":
377		var row struct {	389		var row struct {
378		Title string `json:"title"`	390		Title string `json:"title"`

@@ -416,6 +428,15 @@ func firstUserText(line []byte) string {
416		return ""	428		return ""
417		}	429		}
418			430
			431	+	func firstTextFromMessage(msg provider.Message) string {
			432	+	for _, c := range msg.Content {
			433	+	if tb, ok := c.(provider.TextBlock); ok && tb.Text != "" {
			434	+	return tb.Text
			435	+	}
			436	+	}
			437	+	return ""
			438	+	}
			439	+
419		// PruneEmptySessions deletes session files in cwd's session directory	440		// PruneEmptySessions deletes session files in cwd's session directory
420		// that contain only a meta line (no messages were ever appended).	441		// that contain only a meta line (no messages were ever appended).
421		// Cleans up the backlog of empty stubs created by old zot versions	442		// Cleans up the backlog of empty stubs created by old zot versions

@@ -517,6 +538,21 @@ func (s *Session) AppendMessage(m provider.Message) error {
517		return nil	538		return nil
518		}	539		}
519			540
			541	+	// AppendCompaction writes a checkpoint that replaces all earlier
			542	+	// transcript rows when the session is resumed. The old rows remain in
			543	+	// the JSONL file for audit/export, while loaders use the latest
			544	+	// compaction row as the effective transcript.
			545	+	func (s *Session) AppendCompaction(messages []provider.Message) error {
			546	+	if s == nil {
			547	+	return nil
			548	+	}
			549	+	if err := s.writeLine(sessionLine{Type: "compaction", Messages: messages}); err != nil {
			550	+	return err
			551	+	}
			552	+	s.messagesAppended = len(messages)
			553	+	return nil
			554	+	}
			555	+
520		// UpdateModel records a provider/model switch in the session file.	556		// UpdateModel records a provider/model switch in the session file.
521		// The reader keeps the most recent meta entry, so the session resumes	557		// The reader keeps the most recent meta entry, so the session resumes
522		// with the updated model.	558		// with the updated model.

@@ -580,19 +616,45 @@ func (s *Session) writeLine(row sessionLine) error {
580		// We persist messages by reading the raw "message" object back and	616		// We persist messages by reading the raw "message" object back and
581		// rebuilding Content from discriminated fields.	617		// rebuilding Content from discriminated fields.
582			618
			619	+	func hydrateCompaction(lineBytes []byte) ([]provider.Message, error) {
			620	+	var row struct {
			621	+	Messages []json.RawMessage `json:"messages"`
			622	+	}
			623	+	if err := json.Unmarshal(lineBytes, &row); err != nil {
			624	+	return nil, err
			625	+	}
			626	+	messages := make([]provider.Message, 0, len(row.Messages))
			627	+	for _, raw := range row.Messages {
			628	+	msg, err := hydrateMessageObject(raw)
			629	+	if err == nil && len(msg.Content) > 0 {
			630	+	messages = append(messages, msg)
			631	+	}
			632	+	}
			633	+	return messages, nil
			634	+	}
			635	+
583		func hydrateMessage(lineBytes []byte) (provider.Message, error) {	636		func hydrateMessage(lineBytes []byte) (provider.Message, error) {
584		var row struct {	637		var row struct {
585	-	Message struct {	638	+	Message json.RawMessage `json:"message"`
586	-	Role provider.Role `json:"role"`
587	-	Content []json.RawMessage `json:"content"`
588	-	Time time.Time `json:"time"`
589	-	} `json:"message"`
590		}	639		}
591		if err := json.Unmarshal(lineBytes, &row); err != nil {	640		if err := json.Unmarshal(lineBytes, &row); err != nil {
592		return provider.Message{}, err	641		return provider.Message{}, err
593		}	642		}
594	-	msg := provider.Message{Role: row.Message.Role, Time: row.Message.Time}	643	+	return hydrateMessageObject(row.Message)
595	-	for _, raw := range row.Message.Content {	644	+	}
			645	+
			646	+	func hydrateMessageObject(rawMessage []byte) (provider.Message, error) {
			647	+	var row struct {
			648	+	Role provider.Role `json:"role"`
			649	+	Content []json.RawMessage `json:"content"`
			650	+	Time time.Time `json:"time"`
			651	+	Meta map[string]string `json:"meta,omitempty"`
			652	+	}
			653	+	if err := json.Unmarshal(rawMessage, &row); err != nil {
			654	+	return provider.Message{}, err
			655	+	}
			656	+	msg := provider.Message{Role: row.Role, Time: row.Time, Meta: row.Meta}
			657	+	for _, raw := range row.Content {
596		var head struct {	658		var head struct {
597		Text string `json:"text"`	659		Text string `json:"text"`
598		MimeType string `json:"mime_type"`	660		MimeType string `json:"mime_type"`