feat(model): LLM token 预算可配置化 — models.json每模型maxTokens + LLM_FALLBACK_MAX_TOKENS回退兜底
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- config.go: LLMConfig.FallbackMaxTokens(LLM_FALLBACK_MAX_TOKENS, 默认8192)
- runtimeconfig/models.go: Group.MaxTokens(models.json每模型独立预算, 负值拒绝)
- model/fallback.go: Chain.WithTokenBudget + applyBudget; runtime.go buildSnapshot接入(active.MaxTokens, env.FallbackMaxTokens)
- 优先级: 显式Request.MaxTokens > 组maxTokens > 仅多步链末端的LLM_FALLBACK_MAX_TOKENS > 适配器默认8192; 单步链不动env兜底(避免OpenAI主模型行为回归)
- gateway admin: AdminLlmProvider.MaxTokens 透传/回显/负值400
- .env.example + .env(LLM_FALLBACK_MAX_TOKENS=8192); Docs/api-client v0.27 + api-reference + design/04
- 新增测试(config/runtimeconfig/budget_test/admin_write), build/vet/test绿+3平台交叉编译
This commit is contained in:
AskaEth committed 2026-09-08 22:42:27 +08:00
1 parent f347681034
commit 53002f1e11
13 files changed
+384 -15

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+185
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@@ -0,0 +1,185 @@
package model
import (
"context"
"encoding/json"
"io"
"net/http"
"net/http/httptest"
"path/filepath"
"testing"
"git.yeij.top/AskaEth/Cyrene_v2/internal/config"
"git.yeij.top/AskaEth/Cyrene_v2/internal/config/runtimeconfig"
)
// newFallbackDispatchServer serves two chain steps from one endpoint: the
// "main" model fails so the chain moves on, every other model succeeds.
func newFallbackDispatchServer(t *testing.T, ch chan<- capturedRequest) *httptest.Server {
t.Helper()
srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
var body map[string]any
_ = json.NewDecoder(r.Body).Decode(&body)
ch <- capturedRequest{method: r.Method, path: r.URL.Path, body: body}
if body["model"] == "main" {
w.WriteHeader(http.StatusInternalServerError)
_, _ = io.WriteString(w, `{"error":"down"}`)
return
}
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(http.StatusOK)
_, _ = io.WriteString(w, okCompletion)
}))
t.Cleanup(srv.Close)
return srv
}
func chatOnce(t *testing.T, chain *Chain) {
t.Helper()
if _, err := chain.Chat(context.Background(),
Request{Messages: []Message{TextMessage(RoleUser, "hi")}}, Options{}); err != nil {
t.Fatalf("Chain.Chat error: %v", err)
}
}
// TestChain_Chat_GroupBudgetAppliesToPrimary asserts the active group's own
// maxTokens is applied to a request that carries no explicit budget.
func TestChain_Chat_GroupBudgetAppliesToPrimary(t *testing.T) {
t.Parallel()
ch := make(chan capturedRequest, 1)
srv := newCompletionServer(t, http.StatusOK, "application/json", okCompletion, ch)
chain := NewChain(Step{Model: "m", Adapter: NewOpenAIChat(config.LLMConfig{BaseURL: srv.URL, Model: "m"})}).
WithTokenBudget(4096, 8192)
chatOnce(t, chain)
if got := (<-ch).body["max_tokens"]; got != float64(4096) {
t.Errorf("body.max_tokens = %v, want the group budget 4096", got)
}
}
// TestChain_Chat_ExplicitRequestWinsOverGroupBudget asserts an explicit
// Request.MaxTokens is never overridden (the small review/judge budgets).
func TestChain_Chat_ExplicitRequestWinsOverGroupBudget(t *testing.T) {
t.Parallel()
ch := make(chan capturedRequest, 1)
srv := newCompletionServer(t, http.StatusOK, "application/json", okCompletion, ch)
chain := NewChain(Step{Model: "m", Adapter: NewOpenAIChat(config.LLMConfig{BaseURL: srv.URL, Model: "m"})}).
WithTokenBudget(4096, 8192)
if _, err := chain.Chat(context.Background(),
Request{Messages: []Message{TextMessage(RoleUser, "hi")}, MaxTokens: 64}, Options{}); err != nil {
t.Fatalf("Chain.Chat error: %v", err)
}
if got := (<-ch).body["max_tokens"]; got != float64(64) {
t.Errorf("body.max_tokens = %v, want the explicit 64", got)
}
}
// TestChain_Chat_FallbackEndAppliesEnvBudget asserts the last-resort budget only
// reaches the final fallback step, never the primary.
func TestChain_Chat_FallbackEndAppliesEnvBudget(t *testing.T) {
t.Parallel()
primaryCh := make(chan capturedRequest, 1)
primary := newCompletionServer(t, http.StatusInternalServerError, "application/json", `{"error":"down"}`, primaryCh)
backupCh := make(chan capturedRequest, 1)
backup := newCompletionServer(t, http.StatusOK, "application/json", okCompletion, backupCh)
chain := NewChain(
Step{Model: "main", Adapter: NewOpenAIChat(config.LLMConfig{BaseURL: primary.URL, Model: "main"})},
Step{Model: "backup", Adapter: NewOpenAIChat(config.LLMConfig{BaseURL: backup.URL, Model: "backup"})},
).WithTokenBudget(0, 3000)
chatOnce(t, chain)
if got := (<-primaryCh).body["max_tokens"]; got != nil {
t.Errorf("primary body.max_tokens = %v, want omitted (no budget on the primary)", got)
}
if got := (<-backupCh).body["max_tokens"]; got != float64(3000) {
t.Errorf("fallback body.max_tokens = %v, want the env fallback budget 3000", got)
}
}
// TestChain_Chat_GroupBudgetWinsOverFallbackEnv asserts a group maxTokens beats
// the last-resort env budget even on the final fallback step.
func TestChain_Chat_GroupBudgetWinsOverFallbackEnv(t *testing.T) {
t.Parallel()
primaryCh := make(chan capturedRequest, 1)
primary := newCompletionServer(t, http.StatusInternalServerError, "application/json", `{"error":"down"}`, primaryCh)
backupCh := make(chan capturedRequest, 1)
backup := newCompletionServer(t, http.StatusOK, "application/json", okCompletion, backupCh)
chain := NewChain(
Step{Model: "main", Adapter: NewOpenAIChat(config.LLMConfig{BaseURL: primary.URL, Model: "main"})},
Step{Model: "backup", Adapter: NewOpenAIChat(config.LLMConfig{BaseURL: backup.URL, Model: "backup"})},
).WithTokenBudget(2000, 999)
chatOnce(t, chain)
if got := (<-backupCh).body["max_tokens"]; got != float64(2000) {
t.Errorf("fallback body.max_tokens = %v, want the group budget 2000", got)
}
}
// TestChain_Chat_SingleStepIgnoresFallbackEnv asserts a chain with no fallback
// model (one step = the primary) never gets the last-resort budget, so the
// adapter default is preserved.
func TestChain_Chat_SingleStepIgnoresFallbackEnv(t *testing.T) {
t.Parallel()
ch := make(chan capturedRequest, 1)
srv := newCompletionServer(t, http.StatusOK, "application/json", okCompletion, ch)
chain := NewChain(Step{Model: "m", Adapter: NewOpenAIChat(config.LLMConfig{BaseURL: srv.URL, Model: "m"})}).
WithTokenBudget(0, 3000)
chatOnce(t, chain)
if got := (<-ch).body["max_tokens"]; got != nil {
t.Errorf("body.max_tokens = %v, want omitted (single-step chain is not a fallback)", got)
}
}
// TestRuntimeLLM_GroupMaxTokensEndToEnd proves the models.json maxTokens field
// reaches the provider request body through the real runtime stack.
func TestRuntimeLLM_GroupMaxTokensEndToEnd(t *testing.T) {
ch := make(chan capturedRequest, 1)
srv := newCompletionServer(t, http.StatusOK, "application/json", okCompletion, ch)
path := filepath.Join(t.TempDir(), "models.json")
if err := runtimeconfig.SaveModels(path, []runtimeconfig.Group{
{ID: "openai", Provider: ProviderOpenAI, BaseURL: srv.URL, APIKey: "sk-1", Model: "m", MaxTokens: 1234},
}); err != nil {
t.Fatalf("SaveModels: %v", err)
}
m := NewRuntimeLLM(path, rtEnv(), nil)
if got := m.Groups()[0].MaxTokens; got != 1234 {
t.Fatalf("Groups()[0].MaxTokens = %d, want 1234", got)
}
if _, err := m.Chat(context.Background(),
Request{Messages: []Message{TextMessage(RoleUser, "hi")}}, Options{}); err != nil {
t.Fatalf("RuntimeLLM.Chat error: %v", err)
}
if got := (<-ch).body["max_tokens"]; got != float64(1234) {
t.Errorf("body.max_tokens = %v, want the group budget 1234", got)
}
}
// TestRuntimeLLM_FallbackEndAppliesEnvBudget proves LLM_FALLBACK_MAX_TOKENS is
// wired from config through buildSnapshot into the final fallback step.
func TestRuntimeLLM_FallbackEndAppliesEnvBudget(t *testing.T) {
ch := make(chan capturedRequest, 2)
srv := newFallbackDispatchServer(t, ch)
path := filepath.Join(t.TempDir(), "models.json")
if err := runtimeconfig.SaveModels(path, []runtimeconfig.Group{
{ID: "openai", Provider: ProviderOpenAI, BaseURL: srv.URL, APIKey: "sk-1", Model: "main", Fallback: "backup"},
}); err != nil {
t.Fatalf("SaveModels: %v", err)
}
env := rtEnv()
env.FallbackMaxTokens = 2500
m := NewRuntimeLLM(path, env, nil)
if _, err := m.Chat(context.Background(),
Request{Messages: []Message{TextMessage(RoleUser, "hi")}}, Options{}); err != nil {
t.Fatalf("RuntimeLLM.Chat error: %v", err)
}
primary := <-ch
backup := <-ch
if got := primary.body["max_tokens"]; got != nil {
t.Errorf("primary body.max_tokens = %v, want omitted", got)
}
if got := backup.body["max_tokens"]; got != float64(2500) {
t.Errorf("fallback body.max_tokens = %v, want LLM_FALLBACK_MAX_TOKENS 2500", got)
}
}
+42 -4
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@@ -19,6 +19,13 @@ type Step struct {
// single provider is expected.
type Chain struct {
steps []Step
// groupMaxTokens is the active model group's own budget (models.json
// maxTokens). When > 0 it applies to every step of the group's chain and
// wins over fallbackMaxTokens.
groupMaxTokens int
// fallbackMaxTokens is the last-resort budget (LLM_FALLBACK_MAX_TOKENS). It
// only applies to the final step of a chain that actually has a fallback.
fallbackMaxTokens int
}
// NewChain builds a fallback chain from the given steps.
@@ -26,6 +33,37 @@ func NewChain(steps ...Step) *Chain {
return &Chain{steps: steps}
}
// WithTokenBudget sets the chain's token budgets: the active group's own budget
// and the last-resort fallback budget. It must be called before the chain is
// published to concurrent callers (the runtime builds a fresh chain per
// snapshot and swaps it in atomically), so the fields are never mutated in
// flight.
func (c *Chain) WithTokenBudget(groupMaxTokens, fallbackMaxTokens int) *Chain {
c.groupMaxTokens = groupMaxTokens
c.fallbackMaxTokens = fallbackMaxTokens
return c
}
// applyBudget resolves the effective MaxTokens for step idx, honoring the
// precedence: an explicit Request.MaxTokens > the group's MaxTokens > the
// last-resort LLM_FALLBACK_MAX_TOKENS > the adapter default. The last-resort
// budget only applies when the chain really has a fallback step (len > 1) and
// only to that final step; a single-step chain is a primary model, not a
// fallback, so its adapter default is left untouched.
func (c *Chain) applyBudget(req Request, idx int) Request {
if req.MaxTokens != 0 {
return req
}
if c.groupMaxTokens > 0 {
req.MaxTokens = c.groupMaxTokens
return req
}
if c.fallbackMaxTokens > 0 && len(c.steps) > 1 && idx == len(c.steps)-1 {
req.MaxTokens = c.fallbackMaxTokens
}
return req
}
// NewOpenAIChatChain builds a fallback chain from a single supplier config: the
// primary model first, then cfg.Fallback (when set and distinct), both served
// by an OpenAIChatAdapter against the same OpenAI-compatible endpoint. It
@@ -45,8 +83,8 @@ func (c *Chain) Chat(ctx context.Context, req Request, opts Options) (Response,
return Response{}, ErrNoSteps
}
var lastErr error
for _, s := range c.steps {
stepReq := req
for i, s := range c.steps {
stepReq := c.applyBudget(req, i)
if s.Model != "" {
stepReq.Model = s.Model
}
@@ -68,8 +106,8 @@ func (c *Chain) ChatStream(ctx context.Context, req Request, onEvent func(Stream
return Response{}, ErrNoSteps
}
var lastErr error
for _, s := range c.steps {
stepReq := req
for i, s := range c.steps {
stepReq := c.applyBudget(req, i)
if s.Model != "" {
stepReq.Model = s.Model
}
+6
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@@ -169,6 +169,12 @@ func buildSnapshot(groups []runtimeconfig.Group, env config.LLMConfig) (*runtime
if err != nil && !errors.Is(err, ErrNoModel) {
return nil, err
}
if chain != nil {
// Budgets are resolved inside the chain: the active group's own
// maxTokens (models.json) wins, and env.FallbackMaxTokens only caps the
// last step of a chain that really has a fallback (design/04 §3.1).
chain = chain.WithTokenBudget(active.MaxTokens, env.FallbackMaxTokens)
}
router := NewRouter(DefaultModelForProvider(cfg),
WithVisionModel(env.VisionModel),
WithDefaultProvider(cfg.Provider),