From c6fbd2e710bb0f0949d12d1d489c59d942fa0886 Mon Sep 17 00:00:00 2001
From: Lizan Zhou <zlizan@google.com>
Date: Tue, 29 Aug 2017 16:45:51 -0700
Subject: [PATCH] escape bytes attributes in DebugString (#103)

---
 mixerclient/src/attribute.cc | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/mixerclient/src/attribute.cc b/mixerclient/src/attribute.cc
index 0f888a7e2c50..6f104f51365f 100644
--- a/mixerclient/src/attribute.cc
+++ b/mixerclient/src/attribute.cc
@@ -14,11 +14,31 @@
  */
 
 #include "include/attribute.h"
+#include <iomanip>
+#include <locale>
 #include <sstream>
 
 namespace istio {
 namespace mixer_client {
 
+namespace {
+
+std::string escape(const std::string& source) {
+  std::stringstream ss;
+  static const std::locale& loc = std::locale::classic();
+
+  for (const auto& c : source) {
+    if (std::isprint(c, loc)) {
+      ss << c;
+    } else {
+      ss << "\\x" << std::setfill('0') << std::setw(2) << std::hex
+         << static_cast<uint16_t>(c);
+    }
+  }
+  return ss.str();
+}
+}
+
 const std::string Attributes::kQuotaName = "quota.name";
 const std::string Attributes::kQuotaAmount = "quota.amount";
 
@@ -120,7 +140,7 @@ std::string Attributes::DebugString() const {
         ss << "(STRING): " << it.second.str_v;
         break;
       case Attributes::Value::ValueType::BYTES:
-        ss << "(BYTES): " << it.second.str_v;
+        ss << "(BYTES): " << escape(it.second.str_v);
         break;
       case Attributes::Value::ValueType::INT64:
         ss << "(INT64): " << it.second.value.int64_v;