Function tryCompact

coderd/x/chatd/chatloop/compaction.go:89–181

tryCompact checks whether context usage exceeds the compaction threshold and, if so, generates and persists a summary. Returns (true, nil) when compaction was performed, (false, nil) when not needed, and (false, err) on failure.

(
	ctx context.Context,
	model fantasy.LanguageModel,
	compaction *CompactionOptions,
	contextLimitFallback int64,
	stepUsage fantasy.Usage,
	stepMetadata fantasy.ProviderMetadata,
	allMessages []fantasy.Message,
)

// (true, nil) when compaction was performed, (false, nil) when not
// needed, and (false, err) on failure.
func tryCompact(
	ctx context.Context,
	model fantasy.LanguageModel,
	compaction *CompactionOptions,
	contextLimitFallback int64,
	stepUsage fantasy.Usage,
	stepMetadata fantasy.ProviderMetadata,
	allMessages []fantasy.Message,
) (bool, error) {
	config, ok := normalizedCompactionConfig(compaction)
	if !ok {
		return false, nil
	}

	contextTokens := contextTokensFromUsage(stepUsage)
	if contextTokens <= 0 {
		return false, nil
	}

	metadataLimit := extractContextLimit(stepMetadata)
	contextLimit := resolveContextLimit(
		metadataLimit.Int64,
		config.ContextLimit,
		contextLimitFallback,
	)

	usagePercent, compact := shouldCompact(
		contextTokens, contextLimit, config.ThresholdPercent,
	)
	if !compact {
		return false, nil
	}

	// Publish the "Summarizing..." tool-call indicator so
	// connected clients see activity during summary generation.
	if config.PublishMessagePart != nil && config.ToolCallID != "" {
		config.PublishMessagePart(
			codersdk.ChatMessageRoleAssistant,
			codersdk.ChatMessageToolCall(config.ToolCallID, config.ToolName, nil),
		)
	}

	summary, err := generateCompactionSummary(
		ctx, model, allMessages, config,
	)
	if err != nil {
		return false, err
	}
	if summary == "" {
		// Publish a tool-result error so connected clients
		// see the compaction failure.
		publishCompactionError(config, "compaction produced an empty summary")
		return false, xerrors.New("compaction produced an empty summary")
	}

	systemSummary := strings.TrimSpace(
		config.SystemSummaryPrefix + "\n\n" + summary,
	)