1 files changed, 89 insertions, 0 deletions
diff --git a/rgxp/regx.go b/rgxp/regx.go
new file mode 100644
index 0000000..e647533
--- /dev/null
+++ b/rgxp/regx.go
@@ -0,0 +1,89 @@
+// Copyright 2021 SNIX LLC sina@snix.ir
+//
+// This program is free software; you can redistribute it and/or
+// modify it under the terms of the GNU General Public License
+// version 2 as published by the Free Software Foundation.
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+
+package rgxp
+
+import (
+	"context"
+	"goshkan/opts"
+	"goshkan/rgdb"
+	"regexp"
+	"strings"
+)
+
+// used from ntcp package (TLS or HTTP connections)
+var regexComp *regexp.Regexp
+
+func RegexpCompiled() *regexp.Regexp { return regexComp }
+
+func compileReg(rwRegex *string) error {
+	tempReg, err := regexp.Compile(*rwRegex)
+	if err == nil {
+		regexComp = tempReg
+	}
+	return err
+}
+
+// load all regex from mysql database and compile them
+func LoadRegexpInit(db *rgdb.MariaSQLDB) {
+	ctx, cancel := context.WithTimeout(context.Background(), databaseCtxTime)
+	defer cancel()
+	allReg, err := db.LoadAllRegex(ctx)
+	if err != nil {
+		opts.MYSQLD(err)
+	}
+
+	opts.SYSLOG(readRegex)
+	allReg = append(allReg, &rgdb.RegStruct{Regex: regMatchN})
+
+	for i, rg := range allReg {
+		allReg[i].Regex = "(" + rg.Regex + ")"
+	}
+	ppstr := joinRegexTo(allReg, "|")
+	if err := compileReg(&ppstr); err != nil {
+		opts.OSEXIT(err)
+	}
+}
+
+// recompile regexp , when new regex string applied by user
+func AddRecompileReg(new *string) error {
+	regtext := regexComp.String() + "|(" + *new + ")"
+	return compileReg(&regtext)
+}
+
+func DelRecompileReg(ptrn *string) error {
+	cutd := strings.TrimPrefix(
+		strings.TrimSuffix(strings.ReplaceAll(
+			strings.ReplaceAll(regexComp.String(),
+				"("+*ptrn+")", ""), "||", "|"), "|"), "|")
+	return compileReg(&cutd)
+}
+
+func joinRegexTo(elems rgdb.RegexList, sep string) string {
+	switch len(elems) {
+	case 0:
+		return ""
+	case 1:
+		return elems[0].Regex
+	}
+	n := len(sep) * (len(elems) - 1)
+	for i := 0; i < len(elems); i++ {
+		n += len(elems[i].Regex)
+	}
+
+	var b strings.Builder
+	b.Grow(n)
+	b.WriteString(elems[0].Regex)
+	for _, s := range elems[1:] {
+		b.WriteString(sep)
+		b.WriteString(s.Regex)
+	}
+	return b.String()
+}