added tesseract threads

pkg/scan/scanner.go

@@ -13,11 +13,15 @@ import (
 	"os/exec"
 	"path/filepath"
 	"regexp"
-	"runtime"
 	"time"
 )
 
-const pdfExt = ".pdf"
+const (
+	pdfExt = ".pdf"
+
+	minThreads = 1
+	maxThreads = 4
+)
 
 type PDF struct {
 	cmd  string
@@ -46,7 +50,7 @@ type Scanner struct {
 	p       PDF
 }
 
-func New(base string, langs []string, timeout time.Duration) (s *Scanner, err error) {
+func New(base string, langs []string, threads int, timeout time.Duration) (s *Scanner, err error) {
 	var (
 		tcmd string
 		pcmd string
@@ -77,11 +81,16 @@ func New(base string, langs []string, timeout time.Duration) (s *Scanner, err er
 			lang += "+"
 		}
 	}
+	if threads > maxThreads {
+		threads = maxThreads
+	} else if threads < minThreads {
+		threads = minThreads
+	}
 	args := []string{"-l", lang, "--oem", tesseract_oem}
 	s = &Scanner{
 		base,
 		timeout,
-		Tesseract{tcmd, args, []string{fmt.Sprintf("OMP_THREAD_LIMIT=%d", runtime.NumCPU())}},
+		Tesseract{tcmd, args, []string{fmt.Sprintf("OMP_THREAD_LIMIT=%d", threads)}},
 		PDF{pcmd, []string{"-layout", "-nopgbrk", "-eol", "unix"}},
 	}
 	return