googleai: move downloadImageData to separate file (#530)

.golangci.yaml

@@ -20,6 +20,7 @@ linters:
     - exhaustruct
     - varnamelen
     - nlreturn
+    - gomnd
     - wrapcheck # TODO: we should probably enable this one (at least for new code).
     - testpackage
     - nolintlint # see https://github.com/golangci/golangci-lint/issues/3228.

llms/googleai/download.go

@@ -0,0 +1,33 @@
+package googleai
+
+import (
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+)
+
+// downloadImageData downloads the content from the given URL and returns the
+// image type and data. The image type is the second part of the response's
+// MIME (e.g. "png" from "image/png").
+func downloadImageData(url string) (string, []byte, error) {
+	resp, err := http.Get(url) //nolint
+	if err != nil {
+		return "", nil, fmt.Errorf("failed to fetch image from url: %w", err)
+	}
+	defer resp.Body.Close()
+
+	urlData, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return "", nil, fmt.Errorf("failed to read image bytes: %w", err)
+	}
+
+	mimeType := resp.Header.Get("Content-Type")
+
+	parts := strings.Split(mimeType, "/")
+	if len(parts) != 2 {
+		return "", nil, ErrInvalidMimeType
+	}
+
+	return parts[1], urlData, nil
+}

llms/googleai/googleai_llm.go

@@ -8,9 +8,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io"
 	"log"
-	"net/http"
 	"strings"
 
 	"github.com/google/generative-ai-go/genai"
@@ -115,35 +113,6 @@ func (g *GoogleAI) GenerateContent(ctx context.Context, messages []llms.MessageC
 	return response, nil
 }
 
-// downloadImageData downloads the content from the given URL and returns it as
-// a *genai.Blob.
-func downloadImageData(url string) (*genai.Blob, error) {
-	resp, err := http.Get(url) //nolint
-	if err != nil {
-		return nil, fmt.Errorf("failed to fetch image from url: %w", err)
-	}
-	defer resp.Body.Close()
-
-	urlData, err := io.ReadAll(resp.Body)
-	if err != nil {
-		return nil, fmt.Errorf("failed to read image bytes: %w", err)
-	}
-
-	mimeType := resp.Header.Get("Content-Type")
-
-	// The convenience function genai.ImageData requires just the right part of
-	// the mime type, so we need to parse it
-	parts := strings.Split(mimeType, "/")
-
-	if len(parts) != 2 { //nolint
-		return nil, ErrInvalidMimeType
-	}
-
-	blob := genai.ImageData(parts[1], urlData)
-
-	return &blob, nil
-}
-
 // convertCandidates converts a sequence of genai.Candidate to a response.
 func convertCandidates(candidates []*genai.Candidate) (*llms.ContentResponse, error) {
 	var contentResponse llms.ContentResponse
@@ -197,18 +166,18 @@ func convertParts(parts []llms.ContentPart) ([]genai.Part, error) {
 	convertedParts := make([]genai.Part, 0, len(parts))
 	for _, part := range parts {
 		var out genai.Part
-		var err error
 
 		switch p := part.(type) {
 		case llms.TextContent:
 			out = genai.Text(p.Text)
 		case llms.BinaryContent:
 			out = genai.Blob{MIMEType: p.MIMEType, Data: p.Data}
 		case llms.ImageURLContent:
-			out, err = downloadImageData(p.URL)
-		}
-		if err != nil {
-			return nil, err
+			typ, data, err := downloadImageData(p.URL)
+			if err != nil {
+				return nil, err
+			}
+			out = genai.ImageData(typ, data)
 		}
 
 		convertedParts = append(convertedParts, out)

llms/googleai/googleai_option.go

@@ -1,4 +1,3 @@
-//nolint:gomnd
 package googleai
 
 // options is a set of options for GoogleAI clients.