route-update: cache non-volatile domain status for 7 days

router/route-update.sh

@@ -156,10 +156,13 @@ detect_volatile_domains()
     local state="$1" name="$2" label="$3" rtype="$4"
     shift 4
     local volatile_file="$STATE_DIR/$state/volatile_domains"
+    local nonvolatile_cache="$STATE_DIR/$state/nonvolatile_cache_${rtype}"
     local ttl_threshold=120
+    local cache_max_age=$((7 * 86400))  # 7 days
     local domains=$(mktemp)
+    local uncached=$(mktemp)
     local checker=$(mktemp)
-    trap "rm -f $domains $checker" RETURN
+    trap "rm -f $domains $uncached $checker" RETURN
 
     # Extract unique domain names from list files
     for f in "$@" ; do
@@ -168,6 +171,22 @@ detect_volatile_domains()
 
     [ -s "$domains" ] || { rm -f "$volatile_file" ; return 0 ; }
 
+    # Filter out domains cached as non-volatile (cache valid for cache_max_age)
+    if [ -f "$nonvolatile_cache" ] && [ -z "$FORCE" ] ; then
+        local cache_age=$(( $(date +%s) - $(stat -c %Y "$nonvolatile_cache") ))
+        if [ "$cache_age" -lt "$cache_max_age" ] ; then
+            # Only check domains not in the non-volatile cache
+            grep -Fxv -f "$nonvolatile_cache" "$domains" > "$uncached" || true
+            local total=$(wc -l < "$domains")
+            local skipped=$(( total - $(wc -l < "$uncached") ))
+            [ "$skipped" -gt 0 ] && vlog "[$name]$label skipped $skipped cached non-volatile domains" || true
+        else
+            cp "$domains" "$uncached"
+        fi
+    else
+        cp "$domains" "$uncached"
+    fi
+
     # Parallel dig via temp script (avoids quoting issues with xargs)
     # Volatile = low TTL OR different IPs from local vs extra DNS resolver
     cat > "$checker" << 'CHECKER'
@@ -189,7 +208,28 @@ fi
 [ -n "$reason" ] && printf "%s\t%s records=%s\n" "$domain" "$reason" "$count"
 CHECKER
     chmod +x "$checker"
-    xargs -P 10 -I{} "$checker" "$rtype" "$ttl_threshold" {} "$EXTRA_DNS" < "$domains" > "$volatile_file"
+
+    if [ -s "$uncached" ] ; then
+        xargs -P 10 -I{} "$checker" "$rtype" "$ttl_threshold" {} "$EXTRA_DNS" < "$uncached" > "$volatile_file"
+    else
+        : > "$volatile_file"
+    fi
+
+    # Rebuild non-volatile cache: all checked domains minus volatile ones
+    local volatile_names=$(mktemp)
+    [ -s "$volatile_file" ] && awk -F'	' '{print $1}' "$volatile_file" > "$volatile_names" || : > "$volatile_names"
+    # Merge previous cache (if valid) with newly confirmed non-volatile domains
+    local new_nonvolatile=$(mktemp)
+    if [ -s "$uncached" ] ; then
+        grep -Fxv -f "$volatile_names" "$uncached" > "$new_nonvolatile" || true
+    fi
+    {
+        [ -f "$nonvolatile_cache" ] && [ -z "$FORCE" ] && cat "$nonvolatile_cache"
+        cat "$new_nonvolatile"
+    } | sort -u > "$nonvolatile_cache.tmp"
+    # Keep only domains still in current list
+    grep -Fx -f "$domains" "$nonvolatile_cache.tmp" > "$nonvolatile_cache" || true
+    rm -f "$nonvolatile_cache.tmp" "$volatile_names" "$new_nonvolatile"
 
     if [ -s "$volatile_file" ] ; then
         vlog "[$name]$label volatile domains (TTL≤${ttl_threshold}s or diff resolvers): $(wc -l < "$volatile_file")"