optional graph, xh-tool mentioned

Dockerfile

@@ -19,4 +19,6 @@ COPY ./php.ini /usr/local/etc/php/
 
 COPY ./xhprof/xhprof_lib/utils /utils
 
+ENV SVG=$SVG
+
 WORKDIR /code

README.md

@@ -10,16 +10,34 @@ Profiling is started automatically with `auto_prepend_file` configuration.
 docker run --rm -v $(pwd):/code phperf/php-profiler php test_me.php
 ```
 
+You can also generate SVG call graph adding `SVG=1` ENV var (may take long time for big profiles)
+
+```
+docker run --rm -e SVG=1 -v $(pwd):/code phperf/php-profiler php test_me.php
+```
+
 After your script is finished `xhprof` report and SVG graph will be saved:
 ```
+Performance index: 0.00037335238456726
 Nodes in report: 33
-Saving report to xhprof_report.1517989322.4259.serialized
+Saving report to xhprof_report.1518411787.448.serialized
 Generating dot script
 Generating dot image
-Saving graph to xhprof_report.1517989322.4259.serialized.svg
+Saving graph to xhprof_report.1518411787.448.serialized.svg
+```
+
+You can analyze profiling report with [`xh-tool`](https://github.com/phperf/xh-tool)
+```
+xh-tool top xhprof_report.1518411787.448.serialized --limit 5 --strip-nesting
+name                           wallTime   wallTime%   wallTime1   ownTime    ownTime%   ownTime1   count
+PerformanceIndex::euler        1.22s      65.55       9.1us       1.22s      65.55      9.1us      135K 
+PerformanceIndex::measure      1.87s      99.94       1.87s       427.62ms   22.89      427.62ms   1    
+PerformanceIndex::checkParts   62.24ms    3.33        4.1us       62.24ms    3.33       4.1us      15K  
+md5                            43.53ms    2.33        4.4us       43.53ms    2.33       4.4us      10K  
+preg_match                     23.71ms    1.27        4.7us       23.71ms    1.27       4.7us      5K   
 ```
 
-You can upload report to https://blackfire.io (cli tool needed) for analysis
+Or you can upload report to https://blackfire.io (`blackfire` cli tool needed) for analysis
 ```
 blackfire upload xhprof_report.1517989322.4259.serialized
 ```

prepend_v4.php

@@ -10,22 +10,23 @@ register_shutdown_function(
             file_put_contents('/code/' . $name,
                 serialize($data));
 
-            include_once "/utils/callgraph_utils.php";
-            include_once "/utils/xhprof_lib.php";
-            include_once "/utils/xhprof_runs.php";
+            if (getenv('SVG')) {
+                include_once "/utils/callgraph_utils.php";
+                include_once "/utils/xhprof_lib.php";
+                include_once "/utils/xhprof_runs.php";
 
-            echo "Generating dot script\n";
-            $threshold = 0;
-            if (count($data) > 1000) {
-                $threshold = 0.001;
+                echo "Generating dot script\n";
+                $threshold = 0;
+                if (count($data) > 1000) {
+                    $threshold = 0.001;
+                }
+                $script = xhprof_generate_dot_script($data, $threshold, null, null, null, null);
+                echo "Generating dot image\n";
+                $content = xhprof_generate_image_by_dot($script, 'svg');
+                echo 'Saving graph to ' . $name . '.svg', "\n";
+                file_put_contents('/code/' . $name . '.svg',
+                    $content);
             }
-            $script = xhprof_generate_dot_script($data, $threshold, null, null, null, null);
-            echo "Generating dot image\n";
-            $content = xhprof_generate_image_by_dot($script, 'svg');
-            echo 'Saving graph to ' . $name . '.svg', "\n";
-            file_put_contents('/code/' . $name . '.svg',
-                $content);
-
         });
     }
 );