From 9d6539923e615014189c9281a52fad080f09a64e Mon Sep 17 00:00:00 2001
From: p8p <p8p@users.noreply.github.com>
Date: Sat, 25 Aug 2018 04:16:01 -0700
Subject: [PATCH] is_hdd update

---
 src/blockchain_db/lmdb/db_lmdb.cpp |  8 ++-
 src/common/util.cpp                | 84 +++++++++++++-----------------
 src/common/util.h                  |  2 +-
 tests/unit_tests/CMakeLists.txt    |  3 +-
 tests/unit_tests/is_hdd.cpp        | 17 ++++++
 5 files changed, 61 insertions(+), 53 deletions(-)
 create mode 100644 tests/unit_tests/is_hdd.cpp

diff --git a/src/blockchain_db/lmdb/db_lmdb.cpp b/src/blockchain_db/lmdb/db_lmdb.cpp
index 983a0168a..230fc1d7c 100644
--- a/src/blockchain_db/lmdb/db_lmdb.cpp
+++ b/src/blockchain_db/lmdb/db_lmdb.cpp
@@ -1200,8 +1200,12 @@ void BlockchainLMDB::open(const std::string& filename, const int db_flags)
     throw DB_ERROR("Database could not be opened");
   }
 
-  if (tools::is_hdd(filename.c_str()))
-    MCLOG_RED(el::Level::Warning, "global", "The blockchain is on a rotating drive: this will be very slow, use a SSD if possible");
+  boost::optional<bool> is_hdd_result = tools::is_hdd(filename.c_str());
+  if (is_hdd_result)
+  {
+    if (is_hdd_result.value())
+        MCLOG_RED(el::Level::Warning, "global", "The blockchain is on a rotating drive: this will be very slow, use a SSD if possible");
+  }
 
   m_folder = filename;
 
diff --git a/src/common/util.cpp b/src/common/util.cpp
index 5e0d2726e..151e2b615 100644
--- a/src/common/util.cpp
+++ b/src/common/util.cpp
@@ -46,6 +46,13 @@
 #include <string>
 #endif
 
+//tools::is_hdd
+#ifdef __GLIBC__
+  #include <sstream>
+  #include <sys/sysmacros.h>
+  #include <fstream>
+#endif
+
 #include "unbound.h"
 
 #include "include_base_utils.h"
@@ -733,62 +740,41 @@ std::string get_nix_version_display_string()
 #endif
   }
 
-  bool is_hdd(const char *path)
+  boost::optional<bool> is_hdd(const char *file_path)
   {
 #ifdef __GLIBC__
-    std::string device = "";
-    struct stat st, dst;
-    if (stat(path, &st) < 0)
-      return 0;
-
-    DIR *dir = opendir("/dev/block");
-    if (!dir)
-      return 0;
-    struct dirent *de;
-    while ((de = readdir(dir)))
+    struct stat st;
+    std::string prefix;
+    if(stat(file_path, &st) == 0)
     {
-      if (strcmp(de->d_name, ".") && strcmp(de->d_name, ".."))
+      std::ostringstream s;
+      s << "/sys/dev/block/" << major(st.st_dev) << ":" << minor(st.st_dev);
+      prefix = s.str();
+    }
+    else
+    {
+      return boost::none;
+    }
+    std::string attr_path = prefix + "/queue/rotational";
+    std::ifstream f(attr_path, std::ios_base::in);
+    if(not f.is_open())
+    {
+      attr_path = prefix + "/../queue/rotational";
+      f.open(attr_path, std::ios_base::in);
+      if(not f.is_open())
       {
-        std::string dev_path = std::string("/dev/block/") + de->d_name;
-        char resolved[PATH_MAX];
-        if (realpath(dev_path.c_str(), resolved) && !strncmp(resolved, "/dev/", 5))
-        {
-          if (stat(resolved, &dst) == 0)
-          {
-            if (dst.st_rdev == st.st_dev)
-            {
-              // take out trailing digits (eg, sda1 -> sda)
-              char *ptr = resolved;
-              while (*ptr)
-                ++ptr;
-              while (ptr > resolved && isdigit(*--ptr))
-                *ptr = 0;
-              device = resolved + 5;
-              break;
-            }
-          }
-        }
+          return boost::none;
       }
     }
-    closedir(dir);
-
-    if (device.empty())
-      return 0;
-
-    std::string sys_path = "/sys/block/" + device + "/queue/rotational";
-    FILE *f = fopen(sys_path.c_str(), "r");
-    if (!f)
-      return false;
-    char s[8];
-    char *ptr = fgets(s, sizeof(s), f);
-    fclose(f);
-    if (!ptr)
-      return 0;
-    s[sizeof(s) - 1] = 0;
-    int n = atoi(s); // returns 0 on parse error
-    return n == 1;
+    unsigned short val = 0xdead;
+    f >> val;
+    if(not f.fail())
+    {
+      return (val == 1);
+    }
+    return boost::none;
 #else
-    return 0;
+    return boost::none;
 #endif
   }
 
diff --git a/src/common/util.h b/src/common/util.h
index 8815232e2..0e0b50520 100644
--- a/src/common/util.h
+++ b/src/common/util.h
@@ -230,7 +230,7 @@ namespace tools
   bool sha256sum(const uint8_t *data, size_t len, crypto::hash &hash);
   bool sha256sum(const std::string &filename, crypto::hash &hash);
 
-  bool is_hdd(const char *path);
+  boost::optional<bool> is_hdd(const char *path);
 
   boost::optional<std::pair<uint32_t, uint32_t>> parse_subaddress_lookahead(const std::string& str);
 
diff --git a/tests/unit_tests/CMakeLists.txt b/tests/unit_tests/CMakeLists.txt
index 145e3820e..7cbf38424 100644
--- a/tests/unit_tests/CMakeLists.txt
+++ b/tests/unit_tests/CMakeLists.txt
@@ -76,7 +76,8 @@ set(unit_tests_sources
   output_selection.cpp
   vercmp.cpp
   ringdb.cpp
-  wipeable_string.cpp)
+  wipeable_string.cpp
+  is_hdd.cpp)
 
 set(unit_tests_headers
   unit_tests_utils.h)
diff --git a/tests/unit_tests/is_hdd.cpp b/tests/unit_tests/is_hdd.cpp
new file mode 100644
index 000000000..1be670e5e
--- /dev/null
+++ b/tests/unit_tests/is_hdd.cpp
@@ -0,0 +1,17 @@
+#include "common/util.h"
+#include <string>
+#include <gtest/gtest.h>
+
+#if defined(__GLIBC__)
+TEST(is_hdd, linux_os_root)
+{
+  std::string path = "/";
+  EXPECT_TRUE(tools::is_hdd(path.c_str()));
+}
+#else
+TEST(is_hdd, unknown_os)
+{
+  std::string path = "";
+  EXPECT_FALSE(tools::is_hdd(path.c_str()));
+}
+#endif