Follows proper autoloading standards (#3123)

* Follows proper autoloading standards
 - Splits PHP classes in descriptor.php into separate files
 - Splits MapFieldIter and RepeatedFieldIter into separate files
 - Moves descriptor.php to Internal/functions.php
 - Moves all namespaced functions into Iternal/functions.php

* fixes Makefile.am for added php files

* [PHP] moves all functions to GPBUtil

* removes description.php from the makefile

1 files changed, 236 insertions, 0 deletions

diff --git a/php/src/Google/Protobuf/Internal/FieldDescriptor.php b/php/src/Google/Protobuf/Internal/FieldDescriptor.php
new file mode 100644
index 00000000..6c91950f
--- /dev/null
+++ b/php/src/Google/Protobuf/Internal/FieldDescriptor.php
@@ -0,0 +1,236 @@
+<?php
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+namespace Google\Protobuf\Internal;
+
+class FieldDescriptor
+{
+
+    private $name;
+    private $setter;
+    private $getter;
+    private $number;
+    private $label;
+    private $type;
+    private $message_type;
+    private $enum_type;
+    private $packed;
+    private $is_map;
+    private $oneof_index = -1;
+
+    public function setOneofIndex($index)
+    {
+        $this->oneof_index = $index;
+    }
+
+    public function getOneofIndex()
+    {
+        return $this->oneof_index;
+    }
+
+    public function setName($name)
+    {
+        $this->name = $name;
+    }
+
+    public function getName()
+    {
+        return $this->name;
+    }
+
+    public function setSetter($setter)
+    {
+        $this->setter = $setter;
+    }
+
+    public function getSetter()
+    {
+        return $this->setter;
+    }
+
+    public function setGetter($getter)
+    {
+        $this->getter = $getter;
+    }
+
+    public function getGetter()
+    {
+        return $this->getter;
+    }
+
+    public function setNumber($number)
+    {
+        $this->number = $number;
+    }
+
+    public function getNumber()
+    {
+        return $this->number;
+    }
+
+    public function setLabel($label)
+    {
+        $this->label = $label;
+    }
+
+    public function getLabel()
+    {
+        return $this->label;
+    }
+
+    public function isRepeated()
+    {
+        return $this->label === GPBLabel::REPEATED;
+    }
+
+    public function setType($type)
+    {
+        $this->type = $type;
+    }
+
+    public function getType()
+    {
+        return $this->type;
+    }
+
+    public function setMessageType($message_type)
+    {
+        $this->message_type = $message_type;
+    }
+
+    public function getMessageType()
+    {
+        return $this->message_type;
+    }
+
+    public function setEnumType($enum_type)
+    {
+        $this->enum_type = $enum_type;
+    }
+
+    public function getEnumType()
+    {
+        return $this->enum_type;
+    }
+
+    public function setPacked($packed)
+    {
+        $this->packed = $packed;
+    }
+
+    public function getPacked()
+    {
+        return $this->packed;
+    }
+
+    public function isPackable()
+    {
+        return $this->isRepeated() && self::isTypePackable($this->type);
+    }
+
+    public function isMap()
+    {
+        return $this->getType() == GPBType::MESSAGE &&
+               !is_null($this->getMessageType()->getOptions()) &&
+               $this->getMessageType()->getOptions()->getMapEntry();
+    }
+
+    private static function isTypePackable($field_type)
+    {
+        return ($field_type !== GPBType::STRING  &&
+            $field_type !== GPBType::GROUP   &&
+            $field_type !== GPBType::MESSAGE &&
+            $field_type !== GPBType::BYTES);
+    }
+
+    public static function getFieldDescriptor(
+        $name,
+        $label,
+        $type,
+        $number,
+        $oneof_index,
+        $packed,
+        $type_name = null)
+    {
+        $field = new FieldDescriptor();
+        $field->setName($name);
+        $camel_name = implode('', array_map('ucwords', explode('_', $name)));
+        $field->setGetter('get' . $camel_name);
+        $field->setSetter('set' . $camel_name);
+        $field->setType($type);
+        $field->setNumber($number);
+        $field->setLabel($label);
+        $field->setPacked($packed);
+        $field->setOneofIndex($oneof_index);
+
+        // At this time, the message/enum type may have not been added to pool.
+        // So we use the type name as place holder and will replace it with the
+        // actual descriptor in cross building.
+        switch ($type) {
+            case GPBType::MESSAGE:
+                $field->setMessageType($type_name);
+                break;
+            case GPBType::ENUM:
+                $field->setEnumType($type_name);
+                break;
+            default:
+                break;
+        }
+
+        return $field;
+    }
+
+    public static function buildFromProto($proto)
+    {
+        $type_name = null;
+        switch ($proto->getType()) {
+            case GPBType::MESSAGE:
+            case GPBType::GROUP:
+            case GPBType::ENUM:
+                $type_name = $proto->getTypeName();
+                break;
+            default:
+                break;
+        }
+
+        $oneof_index = $proto->hasOneofIndex() ? $proto->getOneofIndex() : -1;
+        $packed = false;
+        $options = $proto->getOptions();
+        if ($options !== null) {
+            $packed = $options->getPacked();
+        }
+
+        return FieldDescriptor::getFieldDescriptor(
+            $proto->getName(), $proto->getLabel(), $proto->getType(),
+            $proto->getNumber(), $oneof_index, $packed, $type_name);
+    }
+}