Merge pull request #136 from green-ponies/master

Memory calculation adjustments

README.txt

@@ -1,11 +1,14 @@
 
      _________.__     .__                   .__         ________   
     /   _____/|  |__  |__|  _____    _____  |__|  ____  \_____  \  
-         \_____  \ |  |  \|  |/     \ /     \|  |/ __ \ /  ____/ 
-         /        \|   Y  \  |  Y Y  \  Y Y  \  \  ___//       \ 
-        /_______  /|___|  /__|__|_|  /__|_|  /__|\___  >_______ \
+    \_____  \ |  |  \ |  | /     \  /     \ |  |_/ __ \  /  ____/  
+    /        \|   Y  \|  ||  Y Y  \|  Y Y  \|  |\  ___/ /       \  
+   /_______  /|___|  /|__||__|_|  /|__|_|  /|__| \___  >\_______ \ 
            \/      \/           \/       \/          \/         \/ 
                                                                 
+_________________________________________________________________________
+
+
 Shimmie Alpha
 ~~~~~~~~~~~~~
 If you're reading this on github and looking for the stable version, go
@@ -58,6 +61,15 @@ database and file formats haven't changed *completely*, it's different
 enough to be a pain.
 
 
+Custom Configuration
+~~~~~~~~~~~~~~~~~~~~
+
+Various aspects of Shimmie can be configured to suit your site specific
+needs via the file "config.php" (created after installation).
+Take a look at "core/default_config.inc.php" for the available options
+that can used.
+
+
 Development Info
 ~~~~~~~~~~~~~~~~
 http://shimmie.shishnet.org/doc/
@@ -70,7 +82,7 @@ Contact
 ~~~~~~~
 #shimmie on Freenode -- IRC
 webmaster at shishnet.org -- email
-https://github.com/shish/shimmie2 -- bug tracker
+https://github.com/shish/shimmie2/issues -- bug tracker
 
 
 Licence

contrib/resize/main.php

@@ -172,8 +172,19 @@ class ResizeImage extends Extension {
 			throw new ImageResizeException("The image size does not match what is in the database! - Aborting Resize.");
 		}
 		
-		/* Check memory usage limits */
-		$memory_use = (filesize($image_filename)*2) + ($width*$height*4) + (4*1024*1024);
+		/*
+			Check Memory usage limits
+		
+			Old check:   $memory_use = (filesize($image_filename)*2) + ($width*$height*4) + (4*1024*1024);
+			New check:    memory_use = width * height * (bits per channel) * channels * 2.5
+			
+			It didn't make sense to compute the memory usage based on the NEW size for the image. ($width*$height*4)
+			We need to consider the size that we are GOING TO instead.
+			
+			The factor of 2.5 is simply a rough guideline.
+			http://stackoverflow.com/questions/527532/reasonable-php-memory-limit-for-image-resize
+		*/
+		$memory_use = ($info[0] * $info[1] * ($info['bits'] / 8) * $info['channels'] * 2.5) / 1024;
 		$memory_limit = get_memory_limit();
 		
 		if ($memory_use > $memory_limit) {

core/default_config.inc.php

@@ -1,4 +1,16 @@
 <?php
+/**
+ * These are the default configuration options for Shimmie.
+ *
+ * All of these can be over-ridden by placing a 'define' in config.php
+ *
+ * Do NOT change them in this file. These are the defaults only!
+ *
+ * Example:
+ *  define("SPEED_HAX", true);
+ *
+ */
+
 // to change these system-level settings, do define("FOO", 123); in config.php
 function _d($name, $value) {if(!defined($name)) define($name, $value);}
 _d("DATABASE_DSN", null);    // string   PDO database connection details
@@ -18,4 +30,5 @@ _d("WH_SPLITS", 1);          // int      how many levels of subfolders to put in
 _d("VERSION", 'trunk');      // string   shimmie version
 _d("SCORE_VERSION", 's2hack/'.VERSION); // string SCore version
 _d("TIMEZONE", null);        // string   timezone
+
 ?>

core/util.inc.php

@@ -547,24 +547,48 @@ function get_memory_limit() {
 	global $config;
 
 	// thumbnail generation requires lots of memory
-	$default_limit = 8*1024*1024;
+	$default_limit = 8*1024*1024;	// 8 MB of memory is PHP's default.
 	$shimmie_limit = parse_shorthand_int($config->get_int("thumb_mem_limit"));
+	
 	if($shimmie_limit < 3*1024*1024) {
 		// we aren't going to fit, override
 		$shimmie_limit = $default_limit;
 	}
 	
-	ini_set("memory_limit", $shimmie_limit);
+	/*
+	Get PHP's configured memory limit.
+	Note that this is set to -1 for NO memory limit.
+	
+	http://ca2.php.net/manual/en/ini.core.php#ini.memory-limit
+	*/
 	$memory = parse_shorthand_int(ini_get("memory_limit"));
 	
-	// changing of memory limit is disabled / failed
 	if ($memory == -1) {
-		$memory = $default_limit;
+		// No memory limit.
+		
+		// Return the larger of the set limits.
+		if ($shimmie_limit > $default_limit) {
+			return $shimmie_limit;
+		} else {
+			return $default_limit; // return the default memory limit
+		}
+	} else {
+		// PHP has a memory limit set.
+		
+		if ($shimmie_limit > $memory) {
+			// Shimmie wants more memory than what PHP is currently set for.
+			
+			// Attempt to set PHP's memory limit.
+			if ( ini_set("memory_limit", $shimmie_limit) === FALSE ) {
+				/*  We can't change PHP's limit, oh well, return whatever its currently set to */
+				return $memory;
+			}
+			$memory = parse_shorthand_int(ini_get("memory_limit"));
 		}
 		
-	assert($memory > 0);
-
-	return $memory;
+		// PHP's memory limit is more than Shimmie needs.
+		return $memory; // return the current setting
+	}
 }
 
 /**