shrinkray-redacted.php

<?php

/*
date: 2013-dec/2014-jan
beasmaster: REDACTED
help: REDACTED
svn: http://REDACTED/hrinkray/?root=svn
readme: http://REDACTED/README.md?root=svn&view=log
overview: given a file, try progressive steps to reduce the information
*/

// derived
$how = $_SERVER['REQUEST_METHOD'];

// steped in as needed
$ax=isset($_REQUEST['ax']) ? $_REQUEST['ax'] : null;
$mode=isset($_REQUEST['mode']) ? $_REQUEST['mode'] : null;
$srpath=isset($_REQUEST['srpath']) ? $_REQUEST['srpath'] : null;
$max=isset($_REQUEST['max']) ? $_REQUEST['max'] : null;

// target size
$shrinkray_max_size=7340032;


// response codes
$shrinkray_status_ok='HTTP/1.1 200 OK';
$shrinkray_status_shrunk_tags='HTTP/1.1 230 Shrunk via tags';
$shrinkray_status_shrunk_dedup='HTTP/1.1 235 Shurnk via duplication';
$shrinkray_status_shrunk_punctuation='HTTP/1.1 239 Shrunk via punctuation';
$shrinkray_status_shrunk_numbers='HTTP/1.1 240 Shrunk via numbers';
$shrinkray_status_shrunk_lowercase='HTTP/1.1 245 Shrunk via lowercase';
$shrinkray_status_shrunk_header='HTTP/1.1 250 Shrunk via header';
$shrinkray_status_error='HTTP/1.1 400 Bad Request';
$shrinkray_status_gone='HTTP/1.1 410 Gone';
$shrinkray_status_precondition_failed='HTTP/1.1 412 Precondition Failed';
$shrinkray_status_too_large='HTTP/1.1 413 Request Entity Too Large';
$shrinkray_status_internal_error='HTTP/1.1 500 Internal Server Error';
$shrinkray_status_redirect='Location: /shrinkray/';

// array magic to find uniq values
function shrinkray_dedup($input_string) {
    $start_array=explode(" ", $input_string);
    # $dedup_array=array_flip(array_merge(array_flip($start_array))); // faster than array_unique
    $dedup_array=array_merge(array_flip(array_flip($start_array))); // faster than array_unique
    $output_string=implode(" ", $dedup_array);
    return $output_string;
}

// evaluate the string, did it work? if so, output
function shrinkray_eval($input_string, $response_status) {
    global $shrinkray_max_size;
    if (strlen($input_string) < $shrinkray_max_size ) {
        shrinkray_response($response_status); // set HTTP headers before delivering data!
        print $input_string;
        exit;
    }
}


// handle all HTTP headers
function shrinkray_response($shrinkray_status, $shrinkray_message, $shrinkray_exit = NULL) {
    header($shrinkray_status);
    if (!empty($shrinkray_message)) {
         echo $shrinkray_message;
    }
    if (!empty($shrinkray_exit)){
         exit($shrinkray_exit);
    }
}

switch ($ax) {
    case "help":
        print "This is a webservice for shrinking documents.  It accepts the ax of help, lim, uq, ht, sr.  Find out more http://REDACTED/docs/README.md?root=svn&view=log";
        exit;
        break;
    case "lim":
        print $shrinkray_max_size;
        exit;
        break;
    case "sr":
        if (empty($srpath)) {
           shrinkray_response($shrinkray_status_error, "did not recieve GET with srpath", 1);
           exit;
        }
        if (is_readable($srpath)) {
            $source_string=file_get_contents($srpath, true);
        } else {
            shrinkray_response($shrinkray_status_gone, "document does not exist", 0);
            exit;
        }
        if (strlen($source_string) > $shrinkray_max_size) {
            // step - strip HTML
            $working_string=strip_tags($source_string);
            shrinkray_eval($working_string, $shrinkray_status_shrunk_tags);

            // step - remove duplicate tokens
            shrinkray_eval(shrinkray_dedup($working_string), $shrinkray_status_shrunk_dedup);

            // step - strip punctuation
            $working_string=preg_replace("/[\p{P}\p{S}\p{Zp}]/", " ", $working_string);
            $working_string=preg_replace("/\s\s+/", " ", $working_string);
                // reference: http://us1.php.net/manual/en/regexp.reference.unicode.php
                // \p{P}    punctuation class
                // \p{S}    symbol class
                // \p{N}    number class
                // was $working_string=preg_replace("/[^a-zA-Z0-9\s]+/", " ", $working_string);
            shrinkray_eval(shrinkray_dedup($working_string), $shrinkray_status_shrunk_punctuation);

            // step - strip numbers
            $working_string=preg_replace("/\p{N}/", " ", $working_string);
            $working_string=preg_replace("/\s\s+/", " ", $working_string);
            shrinkray_eval(shrinkray_dedup($working_string), $shrinkray_status_shrunk_numbers);

            // step - lower case
            shrinkray_eval(shrinkray_dedup(strtolower($working_string)), $shrinkray_status_shrunk_lowercase);

            // step - head, switch back to source string, remove HTML tags again
            $working_string=substr(strip_tags($source_string), 0, ($shrinkray_max_size - 100));
            $working_string=preg_replace("/\s\s+/", " ", $working_string);
            shrinkray_eval($working_string.'...', $shrinkray_status_shrunk_header);

            // Ugh, it didn't work and really there's not a lot of ways to get to this step
            shrinkray_response($shrinkray_status_too_large, "tried all the tricks, still too large", 1);

        } else {
            shrinkray_response($shrinkray_status_precondition_failed, "document does not need shrinking", 0);
        }
        break;
    default:
        shrinkray_response($shrinkray_status_redirect, "bye bye", 0);
        break;
}
?>