Initial import

Author: jasonbradley

SpeedyDiff.php

@@ -0,0 +1,108 @@
+<?php
+/**
+ * @author Jason Bradley
+ *
+ *  Creates a diff of two files from large files
+ */
+class SpeedyDiff
+{
+    protected $file1;
+    protected $file2;
+    
+    protected $diff_file = '';
+    protected $has_difference = false;
+    
+    public function __construct($file1, $file2))
+    {
+        if (!is_file($file1) || !is_file($file2))
+        {
+            throw new Exception("Provide two files.");
+        }
+
+        
+        $this->file1 = $file1;
+        $this->file2 = $file2;
+        
+        $this->runDiff();
+    }
+    
+    protected function createDiffFile($tmp_file)
+    {
+        if (!is_file($tmp_file))
+        {
+            throw new Exception("No diff file provided.");
+        }
+        
+        $this->diff_file = tempnam('/tmp', 'speeddifffinal');
+
+        $tmp_diff_handle = fopen($tmp_file, 'r');
+        $diff_file_handle = fopen($this->diff_file, 'a');
+
+        while (($line = fgets($tmp_diff_handle)) !== false) 
+        {
+            $first_char = substr($line, 0, 1);
+            
+            if ($first_char == '>')
+            {
+                fwrite($diff_file_handle, substr($line, 2));
+            }
+        }
+        
+        fclose($tmp_diff_handle);
+        fclose($diff_file_handle);
+        
+        //remove the tmp file
+        unlink($tmp_file);
+        
+        if (!is_file($this->diff_file))
+        {
+            throw new Exception("There was a problem writing the new diff file.");
+        }
+        else if (file_get_contents($this->diff_file) == '')
+        {
+            throw new Exception("Nothing was written to the new diff file.");
+        }
+    }
+    
+    protected function runDiff()
+    {
+        $tmp_file = tempnam('/tmp', 'speeddiff');
+        $cmd = "diff {$this->file1} {$this->file2} --speed-large-files -b > $tmp_file";
+        exec($cmd, $output, $return_var);
+        
+        unset($output);
+        
+        if ($return_var > 1)
+        {
+            unlink($tmp_file);
+            throw new Exception("There was an error when calling $cmd");
+        }
+        else if (!is_file($tmp_file))
+        {
+            throw new Exception("Unable to write to tmp file, $tmp_file");
+        }
+        else if (file_get_contents($tmp_file) == '')
+        {
+            return;
+        }
+        
+        $this->has_difference = true;
+        
+        $this->createDiffFile($tmp_file);
+    }
+    
+    /**
+     * Get the file created from the diff
+     * 
+     * @return String|Boolean
+     */
+    public function getDiffFile()
+    {
+        return (is_file($this->diff_file)) ? $this->diff_file : false;
+    }
+    
+    public function getHasDifference()
+    {
+        return $this->has_difference;
+    }
+}