platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/resolver_dns_attempt_policy.go

@@ -0,0 +1,97 @@
+package app
+
+import (
+	"os"
+	"strings"
+	"time"
+)
+
+func defaultDNSAttemptPolicy(dnsCount int) dnsAttemptPolicy {
+	tryLimit := envInt("RESOLVE_DNS_TRY_LIMIT", 2)
+	if tryLimit < 1 {
+		tryLimit = 1
+	}
+	if dnsCount > 0 && tryLimit > dnsCount {
+		tryLimit = dnsCount
+	}
+	budgetMS := envInt("RESOLVE_DNS_DOMAIN_BUDGET_MS", 1200)
+	if budgetMS < 200 {
+		budgetMS = 200
+	}
+	if budgetMS > 15000 {
+		budgetMS = 15000
+	}
+	return dnsAttemptPolicy{
+		TryLimit:     tryLimit,
+		DomainBudget: time.Duration(budgetMS) * time.Millisecond,
+		StopOnNX:     resolveNXEarlyStopEnabled(),
+	}
+}
+
+func directDNSAttemptPolicy(dnsCount int) dnsAttemptPolicy {
+	tryLimit := envInt("RESOLVE_DIRECT_TRY_LIMIT", 2)
+	if tryLimit < 1 {
+		tryLimit = 1
+	}
+	if tryLimit > 3 {
+		tryLimit = 3
+	}
+	if dnsCount > 0 && tryLimit > dnsCount {
+		tryLimit = dnsCount
+	}
+	budgetMS := envInt("RESOLVE_DIRECT_BUDGET_MS", 1200)
+	if budgetMS < 200 {
+		budgetMS = 200
+	}
+	if budgetMS > 15000 {
+		budgetMS = 15000
+	}
+	return dnsAttemptPolicy{
+		TryLimit:     tryLimit,
+		DomainBudget: time.Duration(budgetMS) * time.Millisecond,
+		StopOnNX:     resolveNXEarlyStopEnabled(),
+	}
+}
+
+func wildcardDNSAttemptPolicy(dnsCount int) dnsAttemptPolicy {
+	tryLimit := envInt("RESOLVE_WILDCARD_TRY_LIMIT", 1)
+	if tryLimit < 1 {
+		tryLimit = 1
+	}
+	if tryLimit > 2 {
+		tryLimit = 2
+	}
+	if dnsCount > 0 && tryLimit > dnsCount {
+		tryLimit = dnsCount
+	}
+	budgetMS := envInt("RESOLVE_WILDCARD_BUDGET_MS", 1200)
+	if budgetMS < 200 {
+		budgetMS = 200
+	}
+	if budgetMS > 15000 {
+		budgetMS = 15000
+	}
+	return dnsAttemptPolicy{
+		TryLimit:     tryLimit,
+		DomainBudget: time.Duration(budgetMS) * time.Millisecond,
+		StopOnNX:     resolveNXEarlyStopEnabled(),
+	}
+}
+
+func resolveNXEarlyStopEnabled() bool {
+	switch strings.ToLower(strings.TrimSpace(os.Getenv("RESOLVE_NX_EARLY_STOP"))) {
+	case "0", "false", "no", "off":
+		return false
+	default:
+		return true
+	}
+}
+
+func resolveNXHardQuarantineEnabled() bool {
+	switch strings.ToLower(strings.TrimSpace(os.Getenv("RESOLVE_NX_HARD_QUARANTINE"))) {
+	case "1", "true", "yes", "on":
+		return true
+	default:
+		return false
+	}
+}