Add support for other systems

Signed-off-by: Gavin Halliday <[email protected]>

system/jlib/jdebug.cpp

@@ -835,24 +835,28 @@ static const char * queryCGroup()
             {
                 auto processLine = [](size_t len, const char * ln)
                 {
+                    //Note ln points at the start of the line, but the line is not null terminated
                     switch (*ln)
                     {
                     case '0':
                         if (strncmp(ln, "0::/", 4) == 0)
                         {
-                            //Format is 0::/<cgroup>.  Note ln points at the start of the line, but the line is not terminated
-                            cgroup.set(ln+4, len-4);
+                            //Format is 0::/<cgroup>
+                            //If not running in a container the "cgroup" may be something like user.slice/user-1000.slice/[email protected]/....
+                            //If so ignore because it is not a real cgroup
+                            if (!memchr(ln+4, '/', len-4))
+                                cgroup.set(ln+4, len-4);
                         }
                         break;
                     }
+                    //Some systems with version 1 cgroups have <n>:cpu,cpuacct:/<cgroup>
+                    const char  * match = (const char *)jmemmem(len, ln, 14, ":cpu,cpuacct:/");
+                    if (match)
+                        cgroup.set(match+14, (ln + len) - (match + 14));
                 };
 
                 processLines(contents, processLine);
             }
-            //If not running in a container the "cgroup" may be something like user.slice/user-1000.slice/[email protected]/....
-            //If so clear the cached value because it is not a real cgroup
-            if (cgroup && strchr(cgroup, '/'))
-                cgroup.clear();
             gatheredGroup = true;
         }
     }

system/jlib/jstring.cpp

@@ -2955,3 +2955,31 @@ const char * stristr (const char *haystack, const char *needle)
     }
     return nullptr;
 }
+
+
+const void * jmemmem(size_t lenHaystack, const void * haystack, size_t lenNeedle, const void *needle)
+{
+    if (lenNeedle == 0)
+        return haystack;
+
+    if (lenHaystack < lenNeedle)
+        return nullptr;
+
+    const char * search = (const char *)needle;
+    char first = *search;
+    if (lenNeedle == 1)
+        return memchr(haystack, first, lenHaystack);
+
+    const char * buffer = (const char *)haystack;
+    for (size_t i = 0; i <= lenHaystack - lenNeedle; i++)
+    {
+        //Special case the first character to avoid a function call each iteration.
+        if (buffer[i] == first)
+        {
+            if (memcmp(buffer + i + 1, search + 1, lenNeedle-1) == 0)
+                return buffer + i;
+        }
+    }
+
+    return nullptr;
+}

system/jlib/jstring.hpp

@@ -656,4 +656,7 @@ extern jlib_decl void getSnakeCase(StringBuffer & out, const char * camelValue);
 //If the string has any characters, ensure the last character matches the separator
 extern jlib_decl void ensureSeparator(StringBuffer & out, char separator);
 
+//Search for one block of bytes within another block of bytes - memmem is not standard, so we provide our own
+extern jlib_decl const void * jmemmem(size_t lenHaystack, const void * haystack, size_t lenNeedle, const void *needle);
+
 #endif

testing/unittests/jlibtests.cpp

@@ -4631,6 +4631,7 @@ class JLibStringTest : public CppUnit::TestFixture
 public:
     CPPUNIT_TEST_SUITE(JLibStringTest);
         CPPUNIT_TEST(testStristr);
+        CPPUNIT_TEST(testMemMem);
     CPPUNIT_TEST_SUITE_END();
 
     void testStristr()
@@ -4648,6 +4649,21 @@ class JLibStringTest : public CppUnit::TestFixture
         CPPUNIT_ASSERT_EQUAL_STR(stristr("", "ABC"), "");
         CPPUNIT_ASSERT_EQUAL_STR(stristr("ABC", ""), "");
     }
+
+    void testMemMem()
+    {
+        constexpr const char * haystack = "abcdefghijklmnopqrstuvwxyz";
+        CPPUNIT_ASSERT_EQUAL((const void*)(haystack), jmemmem(10, haystack, 0, nullptr));
+        CPPUNIT_ASSERT_EQUAL((const void*)(haystack), jmemmem(10, haystack, 3, "abc"));
+        CPPUNIT_ASSERT_EQUAL((const void*)(haystack), jmemmem(3, haystack, 3, "abc"));
+        CPPUNIT_ASSERT_EQUAL((const void*)nullptr, jmemmem(2, haystack, 3, "abc"));
+        CPPUNIT_ASSERT_EQUAL((const void*)(haystack+7), jmemmem(10, haystack, 3, "hij"));
+        CPPUNIT_ASSERT_EQUAL((const void*)nullptr, jmemmem(10, haystack, 3, "ijk"));
+        CPPUNIT_ASSERT_EQUAL((const void*)(haystack+8), jmemmem(10, haystack, 1, "i"));
+        CPPUNIT_ASSERT_EQUAL((const void*)(nullptr), jmemmem(8, haystack, 1, "i"));
+        CPPUNIT_ASSERT_EQUAL((const void*)(nullptr), jmemmem(9, haystack, 2, "ij"));
+        CPPUNIT_ASSERT_EQUAL((const void*)(haystack+8), jmemmem(10, haystack, 2, "ij"));
+    }
 };
 
 CPPUNIT_TEST_SUITE_REGISTRATION( JLibStringTest );