dashboard, p2p, vendor: visualize peers (#19247)

* dashboard, p2p: visualize peers

* dashboard: change scale to green to red

vendor/github.com/oschwald/maxminddb-golang/reader_other.go

@@ -0,0 +1,63 @@
+// +build !appengine
+
+package maxminddb
+
+import (
+	"os"
+	"runtime"
+)
+
+// Open takes a string path to a MaxMind DB file and returns a Reader
+// structure or an error. The database file is opened using a memory map,
+// except on Google App Engine where mmap is not supported; there the database
+// is loaded into memory. Use the Close method on the Reader object to return
+// the resources to the system.
+func Open(file string) (*Reader, error) {
+	mapFile, err := os.Open(file)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		if rerr := mapFile.Close(); rerr != nil {
+			err = rerr
+		}
+	}()
+
+	stats, err := mapFile.Stat()
+	if err != nil {
+		return nil, err
+	}
+
+	fileSize := int(stats.Size())
+	mmap, err := mmap(int(mapFile.Fd()), fileSize)
+	if err != nil {
+		return nil, err
+	}
+
+	reader, err := FromBytes(mmap)
+	if err != nil {
+		if err2 := munmap(mmap); err2 != nil {
+			// failing to unmap the file is probably the more severe error
+			return nil, err2
+		}
+		return nil, err
+	}
+
+	reader.hasMappedFile = true
+	runtime.SetFinalizer(reader, (*Reader).Close)
+	return reader, err
+}
+
+// Close unmaps the database file from virtual memory and returns the
+// resources to the system. If called on a Reader opened using FromBytes
+// or Open on Google App Engine, this method does nothing.
+func (r *Reader) Close() error {
+	var err error
+	if r.hasMappedFile {
+		runtime.SetFinalizer(r, nil)
+		r.hasMappedFile = false
+		err = munmap(r.buffer)
+	}
+	r.buffer = nil
+	return err
+}