feat(rerankers): Add new backend, support jina rerankers API (#2121)

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

core/http/endpoints/jina/rerank.go

@@ -0,0 +1,84 @@
+package jina
+
+import (
+	"github.com/go-skynet/LocalAI/core/backend"
+	"github.com/go-skynet/LocalAI/core/config"
+
+	fiberContext "github.com/go-skynet/LocalAI/core/http/ctx"
+	"github.com/go-skynet/LocalAI/core/schema"
+	"github.com/go-skynet/LocalAI/pkg/grpc/proto"
+	"github.com/go-skynet/LocalAI/pkg/model"
+	"github.com/gofiber/fiber/v2"
+	"github.com/rs/zerolog/log"
+)
+
+func JINARerankEndpoint(cl *config.BackendConfigLoader, ml *model.ModelLoader, appConfig *config.ApplicationConfig) func(c *fiber.Ctx) error {
+	return func(c *fiber.Ctx) error {
+		req := new(schema.JINARerankRequest)
+		if err := c.BodyParser(req); err != nil {
+			return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
+				"error": "Cannot parse JSON",
+			})
+		}
+
+		input := new(schema.TTSRequest)
+
+		// Get input data from the request body
+		if err := c.BodyParser(input); err != nil {
+			return err
+		}
+
+		modelFile, err := fiberContext.ModelFromContext(c, ml, input.Model, false)
+		if err != nil {
+			modelFile = input.Model
+			log.Warn().Msgf("Model not found in context: %s", input.Model)
+		}
+
+		cfg, err := cl.LoadBackendConfigFileByName(modelFile, appConfig.ModelPath,
+			config.LoadOptionDebug(appConfig.Debug),
+			config.LoadOptionThreads(appConfig.Threads),
+			config.LoadOptionContextSize(appConfig.ContextSize),
+			config.LoadOptionF16(appConfig.F16),
+		)
+
+		if err != nil {
+			modelFile = input.Model
+			log.Warn().Msgf("Model not found in context: %s", input.Model)
+		} else {
+			modelFile = cfg.Model
+		}
+		log.Debug().Msgf("Request for model: %s", modelFile)
+
+		if input.Backend != "" {
+			cfg.Backend = input.Backend
+		}
+
+		request := &proto.RerankRequest{
+			Query:     req.Query,
+			TopN:      int32(req.TopN),
+			Documents: req.Documents,
+		}
+
+		results, err := backend.Rerank(cfg.Backend, modelFile, request, ml, appConfig, *cfg)
+		if err != nil {
+			return err
+		}
+
+		response := &schema.JINARerankResponse{
+			Model: req.Model,
+		}
+
+		for _, r := range results.Results {
+			response.Results = append(response.Results, schema.JINADocumentResult{
+				Index:          int(r.Index),
+				Document:       schema.JINAText{Text: r.Text},
+				RelevanceScore: float64(r.RelevanceScore),
+			})
+		}
+
+		response.Usage.TotalTokens = int(results.Usage.TotalTokens)
+		response.Usage.PromptTokens = int(results.Usage.PromptTokens)
+
+		return c.Status(fiber.StatusOK).JSON(response)
+	}
+}