- Modified patch by Jeremy: throttle module improvements and fixes:

   + throttle module: flush cache when the throttle enables/disables
   + throttle module: prevent throttle being enabled by 0 users or guests when disabled
   + system module: remove requirement for statistics.module
   + block module: update help text to reflect access log is no longer required
   + statistics module: throttle is now enabled/disabled, not using levels 0-5

8 files changed, 42 insertions, 20 deletions

diff --git a/modules/block.module b/modules/block.module
index 406b0ef19..c004ca158 100644
--- a/modules/block.module
+++ b/modules/block.module
@@ -33,7 +33,7 @@ function block_help($section) {
       return t("
 <p>Blocks are the boxes in the left and right side bars of the web site. They are made available by modules or created manually.</p>
 <p>Only enabled blocks are shown. You can position the blocks by deciding which side of the page they will show up on (region) and in which order they appear (weight).</p>
-<p>If you want certain blocks to disable themselves temporarily during high server loads, check the 'Throttle' box. You will need to enable the auto-throttle on the <a href=\"%throttle\">throttle configuration page</a> after having enabled the throttle module.
+<p>If you want certain blocks to disable themselves temporarily during high server loads, check the 'Throttle' box. You can configure the auto-throttle on the <a href=\"%throttle\">throttle configuration page</a> after having enabled the throttle module.
 ", array('%throttle' => url('admin/settings/throttle')));
     case 'admin/block/add':
       return t("Here you can create a new block. Once you have created this block you must make it active and give it a place on the page using <a href=\"%overview\">blocks</a>. The title is used when displaying the block. The description is used in the \"block\" column on the <a href=\"%overview\">blocks</a> page.", array('%overview' => url('admin/block')));
diff --git a/modules/block/block.module b/modules/block/block.module
index 406b0ef19..c004ca158 100644
--- a/modules/block/block.module
+++ b/modules/block/block.module
@@ -33,7 +33,7 @@ function block_help($section) {
       return t("
 <p>Blocks are the boxes in the left and right side bars of the web site. They are made available by modules or created manually.</p>
 <p>Only enabled blocks are shown. You can position the blocks by deciding which side of the page they will show up on (region) and in which order they appear (weight).</p>
-<p>If you want certain blocks to disable themselves temporarily during high server loads, check the 'Throttle' box. You will need to enable the auto-throttle on the <a href=\"%throttle\">throttle configuration page</a> after having enabled the throttle module.
+<p>If you want certain blocks to disable themselves temporarily during high server loads, check the 'Throttle' box. You can configure the auto-throttle on the <a href=\"%throttle\">throttle configuration page</a> after having enabled the throttle module.
 ", array('%throttle' => url('admin/settings/throttle')));
     case 'admin/block/add':
       return t("Here you can create a new block. Once you have created this block you must make it active and give it a place on the page using <a href=\"%overview\">blocks</a>. The title is used when displaying the block. The description is used in the \"block\" column on the <a href=\"%overview\">blocks</a> page.", array('%overview' => url('admin/block')));
diff --git a/modules/statistics.module b/modules/statistics.module
index c2645d434..0ad65b778 100644
--- a/modules/statistics.module
+++ b/modules/statistics.module
@@ -94,7 +94,7 @@ function statistics_exit() {
       }
     }
   }
-  if ((variable_get('statistics_enable_access_log', 0)) && (module_invoke('throttle', 'status') < 5)) {
+  if ((variable_get('statistics_enable_access_log', 0)) && (module_invoke('throttle', 'status') == 0)) {
     // Statistical logs are enabled.
     $referrer = referer_uri();
     $hostname = $_SERVER['REMOTE_ADDR'];
diff --git a/modules/statistics/statistics.module b/modules/statistics/statistics.module
index c2645d434..0ad65b778 100644
--- a/modules/statistics/statistics.module
+++ b/modules/statistics/statistics.module
@@ -94,7 +94,7 @@ function statistics_exit() {
       }
     }
   }
-  if ((variable_get('statistics_enable_access_log', 0)) && (module_invoke('throttle', 'status') < 5)) {
+  if ((variable_get('statistics_enable_access_log', 0)) && (module_invoke('throttle', 'status') == 0)) {
     // Statistical logs are enabled.
     $referrer = referer_uri();
     $hostname = $_SERVER['REMOTE_ADDR'];
diff --git a/modules/system.module b/modules/system.module
index 556cdb2e2..de83f63c3 100644
--- a/modules/system.module
+++ b/modules/system.module
@@ -470,8 +470,7 @@ function system_module_listing() {
   ksort($files);
 
   $required = array('modules/admin.module', 'modules/block.module', 'modules/filter.module', 'modules/system.module', 'modules/user.module', 'modules/watchdog.module');
-  // the throttle mechanism requires additional modules always be enabled
-  $throttle_required = array_merge($required, array('modules/statistics.module', 'modules/throttle.module'));
+  $throttle_required = array_merge($required, array('modules/throttle.module'));
 
   $header = array(t('Name'), t('Description'), t('Enabled'), t('Throttle'));
 
diff --git a/modules/system/system.module b/modules/system/system.module
index 556cdb2e2..de83f63c3 100644
--- a/modules/system/system.module
+++ b/modules/system/system.module
@@ -470,8 +470,7 @@ function system_module_listing() {
   ksort($files);
 
   $required = array('modules/admin.module', 'modules/block.module', 'modules/filter.module', 'modules/system.module', 'modules/user.module', 'modules/watchdog.module');
-  // the throttle mechanism requires additional modules always be enabled
-  $throttle_required = array_merge($required, array('modules/statistics.module', 'modules/throttle.module'));
+  $throttle_required = array_merge($required, array('modules/throttle.module'));
 
   $header = array(t('Name'), t('Description'), t('Enabled'), t('Throttle'));
 
diff --git a/modules/throttle.module b/modules/throttle.module
index 631aed155..46062f917 100644
--- a/modules/throttle.module
+++ b/modules/throttle.module
@@ -63,27 +63,38 @@ function throttle_exit() {
     }
 
     // update the throttle status
-    if ($users > $max_users) {
+    if ($max_users && $users > $max_users) {
       if (!$throttle) {
         variable_set('throttle_level', 1);
+        cache_clear_all();
         watchdog('special', t('Throttle: %users %user accessing site; throttle enabled.', array('%users' => "<em>$users</em>", '%user' => format_plural($users, 'user', 'users'))));
       }
     }
-    elseif ($guests >= $max_guests) {
+    elseif ($max_guests && $guests > $max_guests) {
       if (!$throttle) {
         variable_set('throttle_level', 1);
+        cache_clear_all();
         watchdog('special', t('Throttle: %guests %guest accessing site; throttle enabled.', array('%guests' => "<em>$guests</em>", '%guest' => format_plural($guests, 'guest', 'guests'))));
       }
     }
     else {
       if ($throttle) {
         variable_set('throttle_level', 0);
+        cache_clear_all();
         watchdog('special', t('Throttle: %users %user, %guests %guest accessing site; throttle disabled.', array('%users' => "<em>$users</em>", '%user' => format_plural($users, 'user', 'users'), '%guests' => "<em>$guests</em>", '%guest' => format_plural($guests, 'guest', 'guests'))));
       }
     }
   }
 }
 
+function _throttle_validate($value, $form) {
+  if ($value != NULL) {
+    if (!is_numeric($value) || $value < 0) {
+      form_set_error($form, t("'%value' is not a valid auto-throttle setting.  Please enter a positive numeric value.", array('%value' => $value)));
+    }
+  }
+}
+
 /**
  * Implementation of hook_perm().
  */
@@ -99,7 +110,7 @@ function throttle_help($section) {
     case 'admin/modules#description':
       return t('Allows configuration of congestion control auto-throttle mechanism.');
     case 'admin/settings/throttle':
-      return t('If your site gets linked to by a popular website, or otherwise comes under a "Denial of Service" (DoS) attack, your webserver might become overwhelmed.  This module provides a mechanism for automatically detecting a surge in incoming traffic.  This mechanism is utilized by other Drupal models to automatically optimize their performance by temporarily disabling CPU-intensive functionality.  To use the auto-throttle, the statistics module\'s <a href="%access">access log</a> must be enabled.', array('%access' => url('admin/settings/statistics')));
+      return t('If your site gets linked to by a popular website, or otherwise comes under a "Denial of Service" (DoS) attack, your webserver might become overwhelmed.  This module provides a congestion control throttling mechanism for automatically detecting a surge in incoming traffic.  This mechanism is utilized by other Drupal models to automatically optimize their performance by temporarily disabling CPU-intensive functionality.');
   }
 }
 
@@ -108,9 +119,10 @@ function throttle_help($section) {
  */
 function throttle_settings() {
   // Tune auto-throttle.
-  $numbers = array(0 => t('disabled')) + drupal_map_assoc(array(25, 50, 75, 100, 125, 150, 175, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000));
-  $group = form_select(t('Auto-throttle on anonymous users'), 'throttle_anonymous', variable_get('throttle_anonymous', 0), $numbers, t('The congestion control throttle can be automatically enabled when the selected number of anonymous users currently visiting your site exceeds the specified threshold.  You can inspect the number of anonymous users using the "Who\'s online" block.'));
-  $group .= form_select(t('Auto-throttle on authenticated users'), 'throttle_user', variable_get('throttle_user', 0), $numbers, t('The congestion control throttle can be automatically enabled when the selected number of authenticated users currently visiting your site exceeds the specified threshold.  You can inspect the number of authenticated users using the "Who\'s online" block.'));
+  _throttle_validate(variable_get('throttle_anonymous', ''), 'throttle_anonymous');
+  _throttle_validate(variable_get('throttle_user', ''), 'throttle_user');
+  $group = form_textfield(t('Auto-throttle on anonymous users'), 'throttle_anonymous', variable_get('throttle_anonymous', ''), 5, 6, t('The congestion control throttle can be automatically enabled when the number of anonymous users currently visiting your site exceeds the specified threshold.  Leave this value blank or set to "0" if you do not wish to auto-throttle on anonymous users.  You can inspect the current number of anonymous users using the "Who\'s online" block.'));
+  $group .= form_textfield(t('Auto-throttle on authenticated users'), 'throttle_user', variable_get('throttle_user', ''), 5, 6, t('The congestion control throttle can be automatically enabled when the number of authenticated users currently visiting your site exceeds the specified threshold.  Leave this value blank or set to "0" if you do not wish to auto-throttle on authenticated users.  You can inspect the current number of authenticated users using the "Who\'s online" block.'));
   $probabilities = array(0 => '100%', 1 => '50%', 2 => '33.3%', 3 => '25%', 4 => '20%', 5 => '16.6%', 7 => '12.5%', 9 => '10%', 19 => '5%', 99 => '1%', 199 => '.5%', 399 => '.25%', 989 => '.1%');
   $group .= form_select(t('Auto-throttle probability limiter'), 'throttle_probability_limiter', variable_get('throttle_probability_limiter', 9), $probabilities, t('The auto-throttle probability limiter is an efficiency mechanism to statistically reduce the overhead of the auto-throttle.  The limiter is expressed as a percentage of page views, so for example if set to the default of 10% we only perform the extra database queries to update the throttle status 1 out of every 10 page views.  The busier your site, the lower you should set the limiter value.'));
   $period = drupal_map_assoc(array(1800, 3600, 7200, 10800, 14400, 18000, 21600, 43200, 64800, 86400, 172800, 259200, 604800), 'format_interval');
diff --git a/modules/throttle/throttle.module b/modules/throttle/throttle.module
index 631aed155..46062f917 100644
--- a/modules/throttle/throttle.module
+++ b/modules/throttle/throttle.module
@@ -63,27 +63,38 @@ function throttle_exit() {
     }
 
     // update the throttle status
-    if ($users > $max_users) {
+    if ($max_users && $users > $max_users) {
       if (!$throttle) {
         variable_set('throttle_level', 1);
+        cache_clear_all();
         watchdog('special', t('Throttle: %users %user accessing site; throttle enabled.', array('%users' => "<em>$users</em>", '%user' => format_plural($users, 'user', 'users'))));
       }
     }
-    elseif ($guests >= $max_guests) {
+    elseif ($max_guests && $guests > $max_guests) {
       if (!$throttle) {
         variable_set('throttle_level', 1);
+        cache_clear_all();
         watchdog('special', t('Throttle: %guests %guest accessing site; throttle enabled.', array('%guests' => "<em>$guests</em>", '%guest' => format_plural($guests, 'guest', 'guests'))));
       }
     }
     else {
       if ($throttle) {
         variable_set('throttle_level', 0);
+        cache_clear_all();
         watchdog('special', t('Throttle: %users %user, %guests %guest accessing site; throttle disabled.', array('%users' => "<em>$users</em>", '%user' => format_plural($users, 'user', 'users'), '%guests' => "<em>$guests</em>", '%guest' => format_plural($guests, 'guest', 'guests'))));
       }
     }
   }
 }
 
+function _throttle_validate($value, $form) {
+  if ($value != NULL) {
+    if (!is_numeric($value) || $value < 0) {
+      form_set_error($form, t("'%value' is not a valid auto-throttle setting.  Please enter a positive numeric value.", array('%value' => $value)));
+    }
+  }
+}
+
 /**
  * Implementation of hook_perm().
  */
@@ -99,7 +110,7 @@ function throttle_help($section) {
     case 'admin/modules#description':
       return t('Allows configuration of congestion control auto-throttle mechanism.');
     case 'admin/settings/throttle':
-      return t('If your site gets linked to by a popular website, or otherwise comes under a "Denial of Service" (DoS) attack, your webserver might become overwhelmed.  This module provides a mechanism for automatically detecting a surge in incoming traffic.  This mechanism is utilized by other Drupal models to automatically optimize their performance by temporarily disabling CPU-intensive functionality.  To use the auto-throttle, the statistics module\'s <a href="%access">access log</a> must be enabled.', array('%access' => url('admin/settings/statistics')));
+      return t('If your site gets linked to by a popular website, or otherwise comes under a "Denial of Service" (DoS) attack, your webserver might become overwhelmed.  This module provides a congestion control throttling mechanism for automatically detecting a surge in incoming traffic.  This mechanism is utilized by other Drupal models to automatically optimize their performance by temporarily disabling CPU-intensive functionality.');
   }
 }
 
@@ -108,9 +119,10 @@ function throttle_help($section) {
  */
 function throttle_settings() {
   // Tune auto-throttle.
-  $numbers = array(0 => t('disabled')) + drupal_map_assoc(array(25, 50, 75, 100, 125, 150, 175, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000));
-  $group = form_select(t('Auto-throttle on anonymous users'), 'throttle_anonymous', variable_get('throttle_anonymous', 0), $numbers, t('The congestion control throttle can be automatically enabled when the selected number of anonymous users currently visiting your site exceeds the specified threshold.  You can inspect the number of anonymous users using the "Who\'s online" block.'));
-  $group .= form_select(t('Auto-throttle on authenticated users'), 'throttle_user', variable_get('throttle_user', 0), $numbers, t('The congestion control throttle can be automatically enabled when the selected number of authenticated users currently visiting your site exceeds the specified threshold.  You can inspect the number of authenticated users using the "Who\'s online" block.'));
+  _throttle_validate(variable_get('throttle_anonymous', ''), 'throttle_anonymous');
+  _throttle_validate(variable_get('throttle_user', ''), 'throttle_user');
+  $group = form_textfield(t('Auto-throttle on anonymous users'), 'throttle_anonymous', variable_get('throttle_anonymous', ''), 5, 6, t('The congestion control throttle can be automatically enabled when the number of anonymous users currently visiting your site exceeds the specified threshold.  Leave this value blank or set to "0" if you do not wish to auto-throttle on anonymous users.  You can inspect the current number of anonymous users using the "Who\'s online" block.'));
+  $group .= form_textfield(t('Auto-throttle on authenticated users'), 'throttle_user', variable_get('throttle_user', ''), 5, 6, t('The congestion control throttle can be automatically enabled when the number of authenticated users currently visiting your site exceeds the specified threshold.  Leave this value blank or set to "0" if you do not wish to auto-throttle on authenticated users.  You can inspect the current number of authenticated users using the "Who\'s online" block.'));
   $probabilities = array(0 => '100%', 1 => '50%', 2 => '33.3%', 3 => '25%', 4 => '20%', 5 => '16.6%', 7 => '12.5%', 9 => '10%', 19 => '5%', 99 => '1%', 199 => '.5%', 399 => '.25%', 989 => '.1%');
   $group .= form_select(t('Auto-throttle probability limiter'), 'throttle_probability_limiter', variable_get('throttle_probability_limiter', 9), $probabilities, t('The auto-throttle probability limiter is an efficiency mechanism to statistically reduce the overhead of the auto-throttle.  The limiter is expressed as a percentage of page views, so for example if set to the default of 10% we only perform the extra database queries to update the throttle status 1 out of every 10 page views.  The busier your site, the lower you should set the limiter value.'));
   $period = drupal_map_assoc(array(1800, 3600, 7200, 10800, 14400, 18000, 21600, 43200, 64800, 86400, 172800, 259200, 604800), 'format_interval');