refactor(application): introduce application global state (#2072)

* start breaking up the giant channel refactor now that it's better understood - easier to merge bites

Signed-off-by: Dave Lee <dave@gray101.com>

* add concurrency and base64 back in, along with new base64 tests.

Signed-off-by: Dave Lee <dave@gray101.com>

* Automatic rename of whisper.go's Result to TranscriptResult

Signed-off-by: Dave Lee <dave@gray101.com>

* remove pkg/concurrency - significant changes coming in split 2

Signed-off-by: Dave Lee <dave@gray101.com>

* fix comments

Signed-off-by: Dave Lee <dave@gray101.com>

* add list_model service as another low-risk service to get it out of the way

Signed-off-by: Dave Lee <dave@gray101.com>

* split backend config loader into seperate file from the actual config struct. No changes yet, just reduce cognative load with smaller files of logical blocks

Signed-off-by: Dave Lee <dave@gray101.com>

* rename state.go ==> application.go

Signed-off-by: Dave Lee <dave@gray101.com>

* fix lost import?

Signed-off-by: Dave Lee <dave@gray101.com>

---------

Signed-off-by: Dave Lee <dave@gray101.com>

pkg/utils/base64.go

@@ -0,0 +1,50 @@
+package utils
+
+import (
+	"encoding/base64"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+)
+
+var base64DownloadClient http.Client = http.Client{
+	Timeout: 30 * time.Second,
+}
+
+// this function check if the string is an URL, if it's an URL downloads the image in memory
+// encodes it in base64 and returns the base64 string
+
+// This may look weird down in pkg/utils while it is currently only used in core/config
+//
+//	but I believe it may be useful for MQTT as well in the near future, so I'm
+//	extracting it while I'm thinking of it.
+func GetImageURLAsBase64(s string) (string, error) {
+	if strings.HasPrefix(s, "http") {
+		// download the image
+		resp, err := base64DownloadClient.Get(s)
+		if err != nil {
+			return "", err
+		}
+		defer resp.Body.Close()
+
+		// read the image data into memory
+		data, err := io.ReadAll(resp.Body)
+		if err != nil {
+			return "", err
+		}
+
+		// encode the image data in base64
+		encoded := base64.StdEncoding.EncodeToString(data)
+
+		// return the base64 string
+		return encoded, nil
+	}
+
+	// if the string instead is prefixed with "data:image/jpeg;base64,", drop it
+	if strings.HasPrefix(s, "data:image/jpeg;base64,") {
+		return strings.ReplaceAll(s, "data:image/jpeg;base64,", ""), nil
+	}
+	return "", fmt.Errorf("not valid string")
+}

pkg/utils/base64_test.go

@@ -0,0 +1,31 @@
+package utils_test
+
+import (
+	. "github.com/go-skynet/LocalAI/pkg/utils"
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("utils/base64 tests", func() {
+	It("GetImageURLAsBase64 can strip data url prefixes", func() {
+		// This one doesn't actually _care_ that it's base64, so feed "bad" data in this test in order to catch a change in that behavior for informational purposes.
+		input := "data:image/jpeg;base64,FOO"
+		b64, err := GetImageURLAsBase64(input)
+		Expect(err).To(BeNil())
+		Expect(b64).To(Equal("FOO"))
+	})
+	It("GetImageURLAsBase64 returns an error for bogus data", func() {
+		input := "FOO"
+		b64, err := GetImageURLAsBase64(input)
+		Expect(b64).To(Equal(""))
+		Expect(err).ToNot(BeNil())
+		Expect(err).To(MatchError("not valid string"))
+	})
+	It("GetImageURLAsBase64 can actually download images and calculates something", func() {
+		// This test doesn't actually _check_ the results at this time, which is bad, but there wasn't a test at all before...
+		input := "https://upload.wikimedia.org/wikipedia/en/2/29/Wargames.jpg"
+		b64, err := GetImageURLAsBase64(input)
+		Expect(err).To(BeNil())
+		Expect(b64).ToNot(BeNil())
+	})
+})