LocalAI/api/openai/chat.go

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package openai
import (
"bufio"
"bytes"
"encoding/json"
"fmt"
"strings"
"github.com/go-skynet/LocalAI/api/backend"
config "github.com/go-skynet/LocalAI/api/config"
"github.com/go-skynet/LocalAI/api/options"
"github.com/go-skynet/LocalAI/pkg/grammar"
model "github.com/go-skynet/LocalAI/pkg/model"
"github.com/gofiber/fiber/v2"
"github.com/rs/zerolog/log"
"github.com/valyala/fasthttp"
)
func ChatEndpoint(cm *config.ConfigLoader, o *options.Option) func(c *fiber.Ctx) error {
emptyMessage := ""
process := func(s string, req *OpenAIRequest, config *config.Config, loader *model.ModelLoader, responses chan OpenAIResponse) {
initialMessage := OpenAIResponse{
Model: req.Model, // we have to return what the user sent here, due to OpenAI spec.
Choices: []Choice{{Delta: &Message{Role: "assistant", Content: &emptyMessage}}},
Object: "chat.completion.chunk",
}
responses <- initialMessage
ComputeChoices(s, req.N, config, o, loader, func(s string, c *[]Choice) {}, func(s string) bool {
resp := OpenAIResponse{
Model: req.Model, // we have to return what the user sent here, due to OpenAI spec.
Choices: []Choice{{Delta: &Message{Content: &s}, Index: 0}},
Object: "chat.completion.chunk",
}
responses <- resp
return true
})
close(responses)
}
return func(c *fiber.Ctx) error {
processFunctions := false
funcs := grammar.Functions{}
model, input, err := readInput(c, o.Loader, true)
if err != nil {
return fmt.Errorf("failed reading parameters from request:%w", err)
}
config, input, err := readConfig(model, input, cm, o.Loader, o.Debug, o.Threads, o.ContextSize, o.F16)
if err != nil {
return fmt.Errorf("failed reading parameters from request:%w", err)
}
log.Debug().Msgf("Configuration read: %+v", config)
// Allow the user to set custom actions via config file
// to be "embedded" in each model
noActionName := "answer"
noActionDescription := "use this action to answer without performing any action"
if config.FunctionsConfig.NoActionFunctionName != "" {
noActionName = config.FunctionsConfig.NoActionFunctionName
}
if config.FunctionsConfig.NoActionDescriptionName != "" {
noActionDescription = config.FunctionsConfig.NoActionDescriptionName
}
// process functions if we have any defined or if we have a function call string
if len(input.Functions) > 0 && config.ShouldUseFunctions() {
log.Debug().Msgf("Response needs to process functions")
processFunctions = true
noActionGrammar := grammar.Function{
Name: noActionName,
Description: noActionDescription,
Parameters: map[string]interface{}{
"properties": map[string]interface{}{
"message": map[string]interface{}{
"type": "string",
"description": "The message to reply the user with",
}},
},
}
// Append the no action function
funcs = append(funcs, input.Functions...)
if !config.FunctionsConfig.DisableNoAction {
funcs = append(funcs, noActionGrammar)
}
// Force picking one of the functions by the request
if config.FunctionToCall() != "" {
funcs = funcs.Select(config.FunctionToCall())
}
// Update input grammar
jsStruct := funcs.ToJSONStructure()
config.Grammar = jsStruct.Grammar("")
} else if input.JSONFunctionGrammarObject != nil {
config.Grammar = input.JSONFunctionGrammarObject.Grammar("")
}
// functions are not supported in stream mode (yet?)
toStream := input.Stream && !processFunctions
log.Debug().Msgf("Parameters: %+v", config)
var predInput string
mess := []string{}
for _, i := range input.Messages {
var content string
role := i.Role
// if function call, we might want to customize the role so we can display better that the "assistant called a json action"
// if an "assistant_function_call" role is defined, we use it, otherwise we use the role that is passed by in the request
if i.FunctionCall != nil && i.Role == "assistant" {
roleFn := "assistant_function_call"
r := config.Roles[roleFn]
if r != "" {
role = roleFn
}
}
r := config.Roles[role]
contentExists := i.Content != nil && *i.Content != ""
if r != "" {
if contentExists {
content = fmt.Sprint(r, " ", *i.Content)
}
if i.FunctionCall != nil {
j, err := json.Marshal(i.FunctionCall)
if err == nil {
if contentExists {
content += "\n" + fmt.Sprint(r, " ", string(j))
} else {
content = fmt.Sprint(r, " ", string(j))
}
}
}
} else {
if contentExists {
content = fmt.Sprint(*i.Content)
}
if i.FunctionCall != nil {
j, err := json.Marshal(i.FunctionCall)
if err == nil {
if contentExists {
content += "\n" + string(j)
} else {
content = string(j)
}
}
}
}
mess = append(mess, content)
}
predInput = strings.Join(mess, "\n")
log.Debug().Msgf("Prompt (before templating): %s", predInput)
if toStream {
log.Debug().Msgf("Stream request received")
c.Context().SetContentType("text/event-stream")
//c.Response().Header.SetContentType(fiber.MIMETextHTMLCharsetUTF8)
// c.Set("Content-Type", "text/event-stream")
c.Set("Cache-Control", "no-cache")
c.Set("Connection", "keep-alive")
c.Set("Transfer-Encoding", "chunked")
}
templateFile := config.Model
if config.TemplateConfig.Chat != "" && !processFunctions {
templateFile = config.TemplateConfig.Chat
}
if config.TemplateConfig.Functions != "" && processFunctions {
templateFile = config.TemplateConfig.Functions
}
// A model can have a "file.bin.tmpl" file associated with a prompt template prefix
templatedInput, err := o.Loader.TemplatePrefix(templateFile, struct {
Input string
Functions []grammar.Function
}{
Input: predInput,
Functions: funcs,
})
if err == nil {
predInput = templatedInput
log.Debug().Msgf("Template found, input modified to: %s", predInput)
} else {
log.Debug().Msgf("Template failed loading: %s", err.Error())
}
log.Debug().Msgf("Prompt (after templating): %s", predInput)
if processFunctions {
log.Debug().Msgf("Grammar: %+v", config.Grammar)
}
if toStream {
responses := make(chan OpenAIResponse)
go process(predInput, input, config, o.Loader, responses)
c.Context().SetBodyStreamWriter(fasthttp.StreamWriter(func(w *bufio.Writer) {
for ev := range responses {
var buf bytes.Buffer
enc := json.NewEncoder(&buf)
enc.Encode(ev)
log.Debug().Msgf("Sending chunk: %s", buf.String())
fmt.Fprintf(w, "data: %v\n", buf.String())
w.Flush()
}
resp := &OpenAIResponse{
Model: input.Model, // we have to return what the user sent here, due to OpenAI spec.
Choices: []Choice{
{
FinishReason: "stop",
Index: 0,
Delta: &Message{Content: &emptyMessage},
}},
Object: "chat.completion.chunk",
}
respData, _ := json.Marshal(resp)
w.WriteString(fmt.Sprintf("data: %s\n\n", respData))
w.WriteString("data: [DONE]\n\n")
w.Flush()
}))
return nil
}
result, err := ComputeChoices(predInput, input.N, config, o, o.Loader, func(s string, c *[]Choice) {
if processFunctions {
// As we have to change the result before processing, we can't stream the answer (yet?)
ss := map[string]interface{}{}
json.Unmarshal([]byte(s), &ss)
log.Debug().Msgf("Function return: %s %+v", s, ss)
// The grammar defines the function name as "function", while OpenAI returns "name"
func_name := ss["function"]
// Similarly, while here arguments is a map[string]interface{}, OpenAI actually want a stringified object
args := ss["arguments"] // arguments needs to be a string, but we return an object from the grammar result (TODO: fix)
d, _ := json.Marshal(args)
ss["arguments"] = string(d)
ss["name"] = func_name
// if do nothing, reply with a message
if func_name == noActionName {
log.Debug().Msgf("nothing to do, computing a reply")
// If there is a message that the LLM already sends as part of the JSON reply, use it
arguments := map[string]interface{}{}
json.Unmarshal([]byte(d), &arguments)
m, exists := arguments["message"]
if exists {
switch message := m.(type) {
case string:
if message != "" {
log.Debug().Msgf("Reply received from LLM: %s", message)
message = backend.Finetune(*config, predInput, message)
log.Debug().Msgf("Reply received from LLM(finetuned): %s", message)
*c = append(*c, Choice{Message: &Message{Role: "assistant", Content: &message}})
return
}
}
}
log.Debug().Msgf("No action received from LLM, without a message, computing a reply")
// Otherwise ask the LLM to understand the JSON output and the context, and return a message
// Note: This costs (in term of CPU) another computation
config.Grammar = ""
predFunc, err := backend.ModelInference(predInput, o.Loader, *config, o, nil)
if err != nil {
log.Error().Msgf("inference error: %s", err.Error())
return
}
prediction, err := predFunc()
if err != nil {
log.Error().Msgf("inference error: %s", err.Error())
return
}
prediction = backend.Finetune(*config, predInput, prediction)
*c = append(*c, Choice{Message: &Message{Role: "assistant", Content: &prediction}})
} else {
// otherwise reply with the function call
*c = append(*c, Choice{
FinishReason: "function_call",
Message: &Message{Role: "assistant", FunctionCall: ss},
})
}
return
}
*c = append(*c, Choice{FinishReason: "stop", Index: 0, Message: &Message{Role: "assistant", Content: &s}})
}, nil)
if err != nil {
return err
}
resp := &OpenAIResponse{
Model: input.Model, // we have to return what the user sent here, due to OpenAI spec.
Choices: result,
Object: "chat.completion",
}
respData, _ := json.Marshal(resp)
log.Debug().Msgf("Response: %s", respData)
// Return the prediction in the response body
return c.JSON(resp)
}
}