perf(plugins/image-to-txt): use logical core count

.env.template

@@ -167,8 +167,8 @@ AUTH_BEARER_TOKEN_ARRAY=
 OCR_ENABLED=
 
 # The number of Tesseract workers to create.
-# Defaults to counting the number of physical cores on the machine
-# and creating an equal number of workers
+# Defaults to using number of logical CPUs on the system
+# (-1 to account for the main thread) and creating an equal number of workers
 OCR_WORKERS=
 
 # Languages to load trained data for for the `ocr` query string param

package.json

@@ -16,7 +16,7 @@
 	"author": "Frazer Smith <frazer.dev@outlook.com>",
 	"funding": "https://github.com/sponsors/Fdawgs",
 	"engines": {
-		"node": ">=18.12.1"
+		"node": ">=18.14.0"
 	},
 	"scripts": {
 		"benchmark:html": "autocannon -a 100 -m POST -i \"./test_resources/test_files/pdf_1.3_NHS_Constitution.pdf\" -H \"Content-Type:application/pdf\" \"http://0.0.0.0:3000/pdf/html?lastPageToConvert=1\"",

src/config/index.js

@@ -1,14 +1,14 @@
 "use strict";
 
 const { readFile } = require("node:fs/promises");
+const { availableParallelism } = require("node:os");
 const envSchema = require("env-schema");
 const { getStream } = require("file-stream-rotator");
 const S = require("fluent-json-schema").default;
 const { stdSerializers, stdTimeFunctions } = require("pino");
 const { parse: secureParse } = require("secure-json-parse");
 const { dirname, joinSafe, normalizeTrim } = require("upath");
 
-const coreCount = require("../utils/core-count");
 const { description, license, version } = require("../../package.json");
 
 /**
@@ -330,8 +330,8 @@ async function getConfig() {
 		tesseract: {
 			enabled: env.OCR_ENABLED === true,
 			languages: env.OCR_LANGUAGES || "eng",
-			// Use number of physical CPU cores available if ENV variable not specified
-			workers: env.OCR_WORKERS || coreCount(),
+			// Use all but one core for OCR workers to prevent blocking the event loop if ENV variable not specified
+			workers: env.OCR_WORKERS || availableParallelism() - 1,
 		},
 		unrtf: {
 			tempDir,