[Glacier] Add proper string formatting for ErrorCodes.

lib/glacier/status/error.cpp

@@ -0,0 +1,44 @@
+#include "glacier/status/error.h"
+
+namespace glcr {
+
+StringView ErrorCodeToStr(ErrorCode code) {
+  switch (code) {
+    case OK:
+      return "OK";
+    case INVALID_ARGUMENT:
+      return "INVALID_ARGUMENT";
+    case NOT_FOUND:
+      return "NOT_FOUND";
+    case PERMISSION_DENIED:
+      return "PERMISSION_DENIED";
+    case NULL_PTR:
+      return "NULL_PTR";
+    case EMPTY:
+      return "EMPTY";
+    case ALREADY_EXISTS:
+      return "ALREADY_EXISTS";
+    case BUFFER_SIZE:
+      return "BUFFER_SIZE";
+    case FAILED_PRECONDITION:
+      return "FAILED_PRECONDITION";
+    case INTERNAL:
+      return "INTERNAL";
+    case UNIMPLEMENTED:
+      return "UNIMPLEMENTED";
+    case EXHAUSTED:
+      return "EXHAUSTED";
+    case INVALID_RESPONSE:
+      return "INVALID_RESPONSE";
+    case CAP_NOT_FOUND:
+      return "CAP_NOT_FOUND";
+    case CAP_WRONG_TYPE:
+      return "CAP_WRONG_TYPE";
+    case CAP_PERMISSION_DENIED:
+      return "CAP_PERMISSION_DENIED";
+    default:
+      return "UNKNOWN";
+  }
+}
+
+}  // namespace glcr

lib/glacier/status/error.h

@@ -2,6 +2,8 @@
 
 #include <stdint.h>
 
+#include "glacier/string/string_view.h"
+
 namespace glcr {
 
 enum ErrorCode : uint64_t {
@@ -29,6 +31,8 @@ enum ErrorCode : uint64_t {
 
 };
 
+StringView ErrorCodeToStr(ErrorCode code);
+
 #define RET_ERR(expr)                                              \
   {                                                                \
     glcr::ErrorCode _tmp_err = static_cast<glcr::ErrorCode>(expr); \