includes/utils/AvroValidator.php

   1 <?php
   2 /**
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2 of the License, or
   6  * (at your option) any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License along
  14  * with this program; if not, write to the Free Software Foundation, Inc.,
  15  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  16  * http://www.gnu.org/copyleft/gpl.html
  17  *
  18  * @file
  19  */
  20
  21 /**
  22  * Generate error strings for data that doesn't match the specified
  23  * Avro schema. This is very similar to AvroSchema::is_valid_datum(),
  24  * but returns error messages instead of a boolean.
  25  *
  26  * @since 1.26
  27  * @author Erik Bernhardson <ebernhardson@wikimedia.org>
  28  * @copyright © 2015 Erik Bernhardson and Wikimedia Foundation.
  29  */
  30 class AvroValidator {
  31         /**
  32          * @param AvroSchema $schema The rules to conform to.
  33          * @param mixed $datum The value to validate against $schema.
  34          * @return string|string[] An error or list of errors in the
  35          *  provided $datum. When no errors exist the empty array is
  36          *  returned.
  37          */
  38         public static function getErrors( AvroSchema $schema, $datum ) {
  39                 switch ( $schema->type ) {
  40                         case AvroSchema::NULL_TYPE:
  41                                 if ( !is_null( $datum ) ) {
  42                                         return self::wrongType( 'null', $datum );
  43                                 }
  44                                 return [];
  45                         case AvroSchema::BOOLEAN_TYPE:
  46                                 if ( !is_bool( $datum ) ) {
  47                                         return self::wrongType( 'boolean', $datum );
  48                                 }
  49                                 return [];
  50                         case AvroSchema::STRING_TYPE:
  51                         case AvroSchema::BYTES_TYPE:
  52                                 if ( !is_string( $datum ) ) {
  53                                         return self::wrongType( 'string', $datum );
  54                                 }
  55                                 return [];
  56                         case AvroSchema::INT_TYPE:
  57                                 if ( !is_int( $datum ) ) {
  58                                         return self::wrongType( 'integer', $datum );
  59                                 }
  60                                 if ( AvroSchema::INT_MIN_VALUE > $datum
  61                                         || $datum > AvroSchema::INT_MAX_VALUE
  62                                 ) {
  63                                         return self::outOfRange(
  64                                                 AvroSchema::INT_MIN_VALUE,
  65                                                 AvroSchema::INT_MAX_VALUE,
  66                                                 $datum
  67                                         );
  68                                 }
  69                                 return [];
  70                         case AvroSchema::LONG_TYPE:
  71                                 if ( !is_int( $datum ) ) {
  72                                         return self::wrongType( 'integer', $datum );
  73                                 }
  74                                 if ( AvroSchema::LONG_MIN_VALUE > $datum
  75                                         || $datum > AvroSchema::LONG_MAX_VALUE
  76                                 ) {
  77                                         return self::outOfRange(
  78                                                 AvroSchema::LONG_MIN_VALUE,
  79                                                 AvroSchema::LONG_MAX_VALUE,
  80                                                 $datum
  81                                         );
  82                                 }
  83                                 return [];
  84                         case AvroSchema::FLOAT_TYPE:
  85                         case AvroSchema::DOUBLE_TYPE:
  86                                 if ( !is_float( $datum ) && !is_int( $datum ) ) {
  87                                         return self::wrongType( 'float or integer', $datum );
  88                                 }
  89                                 return [];
  90                         case AvroSchema::ARRAY_SCHEMA:
  91                                 if ( !is_array( $datum ) ) {
  92                                         return self::wrongType( 'array', $datum );
  93                                 }
  94                                 $errors = [];
  95                                 foreach ( $datum as $d ) {
  96                                         $result = self::getErrors( $schema->items(), $d );
  97                                         if ( $result ) {
  98                                                 $errors[] = $result;
  99                                         }
 100                                 }
 101                                 return $errors;
 102                         case AvroSchema::MAP_SCHEMA:
 103                                 if ( !is_array( $datum ) ) {
 104                                         return self::wrongType( 'array', $datum );
 105                                 }
 106                                 $errors = [];
 107                                 foreach ( $datum as $k => $v ) {
 108                                         if ( !is_string( $k ) ) {
 109                                                 $errors[] = self::wrongType( 'string key', $k );
 110                                         }
 111                                         $result = self::getErrors( $schema->values(), $v );
 112                                         if ( $result ) {
 113                                                 $errors[$k] = $result;
 114                                         }
 115                                 }
 116                                 return $errors;
 117                         case AvroSchema::UNION_SCHEMA:
 118                                 $errors = [];
 119                                 foreach ( $schema->schemas() as $schema ) {
 120                                         $result = self::getErrors( $schema, $datum );
 121                                         if ( !$result ) {
 122                                                 return [];
 123                                         }
 124                                         $errors[] = $result;
 125                                 }
 126                                 if ( $errors ) {
 127                                         return [ "Expected any one of these to be true", $errors ];
 128                                 }
 129                                 return "No schemas provided to union";
 130                         case AvroSchema::ENUM_SCHEMA:
 131                                 if ( !in_array( $datum, $schema->symbols() ) ) {
 132                                         $symbols = implode( ', ', $schema->symbols );
 133                                         return "Expected one of $symbols but recieved $datum";
 134                                 }
 135                                 return [];
 136                         case AvroSchema::FIXED_SCHEMA:
 137                                 if ( !is_string( $datum ) ) {
 138                                         return self::wrongType( 'string', $datum );
 139                                 }
 140                                 $len = strlen( $datum );
 141                                 if ( $len !== $schema->size() ) {
 142                                         return "Expected string of length {$schema->size()}, "
 143                                                 . "but recieved one of length $len";
 144                                 }
 145                                 return [];
 146                         case AvroSchema::RECORD_SCHEMA:
 147                         case AvroSchema::ERROR_SCHEMA:
 148                         case AvroSchema::REQUEST_SCHEMA:
 149                                 if ( !is_array( $datum ) ) {
 150                                         return self::wrongType( 'array', $datum );
 151                                 }
 152                                 $errors = [];
 153                                 foreach ( $schema->fields() as $field ) {
 154                                         $name = $field->name();
 155                                         if ( !array_key_exists( $name, $datum ) ) {
 156                                                 $errors[$name] = 'Missing expected field';
 157                                                 continue;
 158                                         }
 159                                         $result = self::getErrors( $field->type(), $datum[$name] );
 160                                         if ( $result ) {
 161                                                 $errors[$name] = $result;
 162                                         }
 163                                 }
 164                                 return $errors;
 165                         default:
 166                                 return "Unknown avro schema type: {$schema->type}";
 167                 }
 168         }
 169
 170         public static function typeOf( $datum ) {
 171                 return is_object( $datum ) ? get_class( $datum ) : gettype( $datum );
 172         }
 173
 174         public static function wrongType( $expected, $datum ) {
 175                 return "Expected $expected, but recieved " . self::typeOf( $datum );
 176         }
 177
 178         public static function outOfRange( $min, $max, $datum ) {
 179                 return "Expected value between $min and $max, but recieved $datum";
 180         }
 181 }