Call ffmpeg in batches

utils/strings.go

@@ -38,3 +38,17 @@ func MoveString(array []string, srcIndex int, dstIndex int) []string {
 	value := array[srcIndex]
 	return InsertString(RemoveString(array, srcIndex), value, dstIndex)
 }
+
+func BreakUpStringSlice(mediaFileIds []string, chunkSize int) [][]string {
+	numTracks := len(mediaFileIds)
+	var chunks [][]string
+	for i := 0; i < numTracks; i += chunkSize {
+		end := i + chunkSize
+		if end > numTracks {
+			end = numTracks
+		}
+
+		chunks = append(chunks, mediaFileIds[i:end])
+	}
+	return chunks
+}

utils/strings_test.go

@@ -60,4 +60,25 @@ var _ = Describe("Strings", func() {
 			Expect(MoveString([]string{"1", "2", "3"}, 1, 1)).To(ConsistOf("1", "2", "3"))
 		})
 	})
+
+	Describe("BreakUpStringSlice", func() {
+		It("returns no chunks if slice is empty", func() {
+			var slice []string
+			chunks := BreakUpStringSlice(slice, 10)
+			Expect(chunks).To(HaveLen(0))
+		})
+		It("returns the slice in one chunk if len < chunkSize", func() {
+			slice := []string{"a", "b", "c"}
+			chunks := BreakUpStringSlice(slice, 10)
+			Expect(chunks).To(HaveLen(1))
+			Expect(chunks[0]).To(ConsistOf("a", "b", "c"))
+		})
+		It("breaks up the slice if len > chunkSize", func() {
+			slice := []string{"a", "b", "c", "d", "e"}
+			chunks := BreakUpStringSlice(slice, 3)
+			Expect(chunks).To(HaveLen(2))
+			Expect(chunks[0]).To(ConsistOf("a", "b", "c"))
+			Expect(chunks[1]).To(ConsistOf("d", "e"))
+		})
+	})
 })