Add support for systems w/o swap

Suggested-by: Mikko Rantalainen <mikko.rantalainen@gmail.com>

OOMAnalyser.html

@@ -69,6 +69,13 @@
             /* empty - used to show sections for manually triggered OOMs */
         }
 
+        .js-swap-active--show {
+            /* empty - used to show if the swap space is activated */
+        }
+        .js-swap-inactive--show {
+            /* empty - used to show if the swap space is not activated */
+        }
+
         .result__table {
             border-collapse: collapse;
             padding: 10px;
@@ -317,15 +324,26 @@ window.onerror = function (msg, url, lineNo, columnNo, error) {
             has been terminated. It uses <span class="killed_proc_rss_percent"></span>
             (<span class="killed_proc_total_rss_kb"></span>) of the resident memory.
         </p>
+
+        <div class="js-text--default-show js-swap-active--show">
             <p>
                 The system has <span class="system_total_ram_kb"></span> physical memory and
-            <span class="swap_total_kb"></span> swap space. That's <span class="system_total_ramswap_kb"></span> total.
+                <span class="swap_total_kb"></span> swap space. That's <span class="system_total_ramswap_kb"></span>
-            <span class="system_total_used_percent"></span>
+                total. <span class="system_total_used_percent"></span>
-            (<span class="system_total_ram_used_kb"></span> out of <span class="system_total_ram_kb"></span>) physical
+                (<span class="system_total_ram_used_kb"></span> out of <span class="system_total_ram_kb"></span>)
-            memory and <span class="system_swap_used_percent"></span>
+                physical memory and <span class="system_swap_used_percent"></span>
                 (<span class="swap_used_kb"></span> out of <span class="swap_total_kb"></span>) swap space are in use.
             </p>
         </div>
+        <div class="js-text--default-show js-swap-inactive--show">
+            <p>
+                The system has <span class="system_total_ram_kb"></span> physical memory and no swap space.
+                <span class="system_total_used_percent"></span>
+                (<span class="system_total_ram_used_kb"></span> out of <span class="system_total_ram_kb"></span>)
+                physical memory are in use.
+            </p>
+        </div>
+    </div>
 
     <h3>Details of analysis</h3>
     <p>
@@ -445,31 +463,34 @@ window.onerror = function (msg, url, lineNo, columnNo, error) {
             <td>RAM Summary</td>
             <td class="result__table--border" colspan="2"><div id="svg_ram"></div></td>
         </tr>
-        <tr>
+        <tr class="js-text--default-show js-swap-active--show">>
             <td>Swap Summary</td>
             <td class="result__table--border" colspan="2"><div id="svg_swap"></div></td>
         </tr>
 
         <!-- Swap Usage -->
 
-        <tr>
+        <tr class="js-text--default-show">
             <th class="table__sub-section--bold" colspan="3" scope="row">Swap Usage</th>
         </tr>
-        <tr>
+        <tr class="js-text--default-show js-swap-inactive--show">
+            <td colspan="3">No swap space available</td>
+        </tr>
+        <tr class="js-text--default-show js-swap-active--show">
             <td>Swap Total</td>
             <td class="swap_total_kb text--align-right"></td>
             <td>Total amount of swap space available.
                 <a class="a__footnote" href="#footnote-proc5">[1]</a>
             </td>
         </tr>
-        <tr>
+        <tr class="js-text--default-show js-swap-active--show">
             <td>Swap Free</td>
             <td class="swap_free_kb text--align-right"></td>
             <td>Amount of swap space that is currently unused.
                 <a class="a__footnote" href="#footnote-proc5">[1]</a>
             </td>
         </tr>
-        <tr>
+        <tr class="js-text--default-show js-swap-active--show">
             <td>Swap Cached</td>
             <td class="swap_cache_kb text--align-right"></td>
             <td>Memory that once was swapped out, is swapped back in
@@ -480,7 +501,7 @@ window.onerror = function (msg, url, lineNo, columnNo, error) {
                 <a class="a__footnote" href="#footnote-proc5">[1]</a>
             </td>
         </tr>
-        <tr>
+        <tr class="js-text--default-show js-swap-active--show">
             <td>Swap Used</td>
             <td class="swap_used_kb text--align-right"></td>
             <td>Amount of used swap space w/o cached swap <br>
@@ -862,6 +883,7 @@ window.onerror = function (msg, url, lineNo, columnNo, error) {
         <li>Rework removal of unused information</li>
         <li>Report uncaught errors to the user</li>
         <li>Add support for manually triggered OOM (suggested by Mikko Rantalainen)</li>
+        <li>Add support for systems w/o swap (suggested by Mikko Rantalainen)</li>
         <li>...</li>
     </ol>
 

OOMAnalyser.py

@@ -467,6 +467,13 @@ class OOMResult:
     @type: str
     """
 
+    swap_active = False
+    """
+    Swap space active or inactive
+    
+    @type: bool
+    """
+
 
 class OOMAnalyser:
     """Analyse an OOM object and calculate additional values"""
@@ -531,7 +538,7 @@ class OOMAnalyser:
             r'^Free swap  = (?P<swap_free_kb>\d+)kB'
             r'(?:\n)'
             r'^Total swap = (?P<swap_total_kb>\d+)kB',
-            True,
+            False,
         ),
         'Page information': (
             r'^(?P<ram_pages>\d+) pages RAM'
@@ -697,7 +704,7 @@ class OOMAnalyser:
                 self.oom_result.details.update(match.groupdict())
             elif is_mandatory:
                 error('Failed to extract information from OOM text. The regular expression "{}" (pattern "{}") '
-                      'does not find anything. This will cause subsequent errors.'.format(k, pattern))
+                      'does not find anything. This can lead to errors later on.'.format(k, pattern))
         # __pragma__ ('nojsiter')
 
         if self.oom_result.details['trigger_proc_order'] == "-1":
@@ -891,6 +898,14 @@ class OOMAnalyser:
 
     def _calc_swap_values(self):
         """Calculate all swap related values"""
+        try:
+            self.oom_result.swap_active = self.oom_result.details['swap_total_kb'] > 0
+        except KeyError:
+            self.oom_result.swap_active = False
+
+        if not self.oom_result.swap_active:
+            return
+
         self.oom_result.details['swap_cache_kb'] = self.oom_result.details['swap_cache_pages'] * self.oom_result.details['page_size_kb']
         del self.oom_result.details['swap_cache_pages']
 
@@ -909,7 +924,11 @@ class OOMAnalyser:
 
         # calculate remaining explanation values
         self.oom_result.details['system_total_ram_kb'] = self.oom_result.details['ram_pages'] * self.oom_result.details['page_size_kb']
-        self.oom_result.details['system_total_ramswap_kb'] = self.oom_result.details['system_total_ram_kb'] + self.oom_result.details['swap_total_kb']
+        if self.oom_result.swap_active:
+            self.oom_result.details['system_total_ramswap_kb'] = self.oom_result.details['system_total_ram_kb'] + \
+                                                                 self.oom_result.details['swap_total_kb']
+        else:
+            self.oom_result.details['system_total_ramswap_kb'] = self.oom_result.details['system_total_ram_kb']
         total_rss_pages = 0
         for pid in self.oom_result.details['_ps'].keys():
             total_rss_pages += self.oom_result.details['_ps'][pid]['rss_pages']
@@ -1534,6 +1553,8 @@ Killed process 6576 (mysqld) total-vm:33914892kB, anon-rss:20629004kB, file-rss:
         # generate process table
         self.update_process_table()
 
+        # show/hide swap space
+        if self.oom_result.swap_active:
             # generate swap usage diagram
             svg_swap = self.svg_generate_bar_chart(
                 self.svg_colors_swap,
@@ -1543,6 +1564,11 @@ Killed process 6576 (mysqld) total-vm:33914892kB, anon-rss:20629004kB, file-rss:
             )
             elem_svg_swap = document.getElementById('svg_swap')
             elem_svg_swap.appendChild(svg_swap)
+            show_elements('.js-swap-active--show')
+            hide_elements('.js-swap-inactive--show')
+        else:
+            hide_elements('.js-swap-active--show')
+            show_elements('.js-swap-inactive--show')
 
         # generate RAM usage diagram
         svg_ram = self.svg_generate_bar_chart(

test.py

@@ -193,6 +193,8 @@ class TestInBrowser(TestBase):
         explanation = self.driver.find_element_by_id('explanation')
         self.assertTrue('OOM killer was automatically triggered' in explanation.text,
                         'Missing text "OOM killer was automatically triggered"')
+        self.assertTrue('swap space are in use' in explanation.text,
+                        'Missing text "swap space are in use"')
 
     def test_010_load_page(self):
         """Test if the page is loading"""
@@ -306,6 +308,32 @@ Killed process 6576 (java) total-vm:33914892kB, anon-rss:20629004kB, file-rss:0k
         self.assertTrue('OOM killer was manually triggered' in explanation.text,
                         'Missing text "OOM killer was manually triggered"')
 
+    def test_080_swap_deactivated(self):
+        """Test w/o swap or with deactivated swap"""
+        example = OOMAnalyser.OOMDisplay.example
+        example = example.replace('Total swap = 8388604kB', 'Total swap = 0kB')
+        self.analyse_oom(example)
+        self.assert_on_warn_error()
+
+        explanation = self.driver.find_element_by_id('explanation')
+        self.assertFalse('swap space are in use' in explanation.text,
+                         'No swap space but text "swap space are in use"')
+
+        self.click_reset()
+
+        example = OOMAnalyser.OOMDisplay.example
+        example = re.sub(r'\d+ pages in swap cac.*\n*', '', example, re.MULTILINE)
+        example = re.sub(r'Swap cache stats.*\n*', '', example)
+        example = re.sub(r'Free swap.*\n*', '', example)
+        example = re.sub(r'Total swap.*\n*', '', example)
+
+        self.analyse_oom(example)
+        self.assert_on_warn_error()
+
+        explanation = self.driver.find_element_by_id('explanation')
+        self.assertFalse('swap space are in use' in explanation.text,
+                         'No swap space but text "swap space are in use"')
+
 
 class TestPython(TestBase):