Add mergeFrom method on Message (#2766)

This method merges the contents of the specified message into the
current message. Singular fields that are set in the specified message
overwrite the corresponding fields in the current message.  Repeated
fields are appended. Map fields key-value pairs are overritten.
Singular/Oneof sub-messages are recursively merged. All overritten
sub-messages are deep-copied.

1 files changed, 68 insertions, 0 deletions

diff --git a/php/src/Google/Protobuf/Internal/Message.php b/php/src/Google/Protobuf/Internal/Message.php
index 9e162a22..17ef8536 100644
--- a/php/src/Google/Protobuf/Internal/Message.php
+++ b/php/src/Google/Protobuf/Internal/Message.php
@@ -491,6 +491,74 @@ class Message
     }
 
     /**
+     * Merges the contents of the specified message into current message.
+     *
+     * This method merges the contents of the specified message into the
+     * current message. Singular fields that are set in the specified message
+     * overwrite the corresponding fields in the current message.  Repeated
+     * fields are appended. Map fields key-value pairs are overritten.
+     * Singular/Oneof sub-messages are recursively merged. All overritten
+     * sub-messages are deep-copied.
+     *
+     * @param object $msg Protobuf message to be merged from.
+     * @return null.
+     */
+    public function mergeFrom($msg)
+    {
+      if (get_class($this) !== get_class($msg)) {
+          user_error("Cannot merge messages with different class.");
+          return;
+      }
+
+      foreach ($this->desc->getField() as $field) {
+          $setter = $field->getSetter();
+          $getter = $field->getGetter();
+          if ($field->isMap()) {
+              if (count($msg->$getter()) != 0) {
+                  $value_field = $field->getMessageType()->getFieldByNumber(2);
+                  foreach ($msg->$getter() as $key => $value) {
+                      if ($value_field->getType() == GPBType::MESSAGE) {
+                          $klass = $value_field->getMessageType()->getClass();
+                          $copy = new $klass;
+                          $copy->mergeFrom($value);
+                          $this->$getter()[$key] = $copy;
+                      } else {
+                          $this->$getter()[$key] = $value;
+                      }
+                  }
+              }
+          } else if ($field->getLabel() === GPBLabel::REPEATED) {
+              if (count($msg->$getter()) != 0) {
+                  foreach ($msg->$getter() as $tmp) {
+                      if ($field->getType() == GPBType::MESSAGE) {
+                          $klass = $field->getMessageType()->getClass();
+                          $copy = new $klass;
+                          $copy->mergeFrom($tmp);
+                          $this->$getter()[] = $copy;
+                      } else {
+                          $this->$getter()[] = $tmp;
+                      }
+                  }
+              }
+          } else if ($field->getLabel() === GPBLabel::OPTIONAL) {
+              if($msg->$getter() !== $this->defaultValue($field)) {
+                  $tmp = $msg->$getter();
+                  if ($field->getType() == GPBType::MESSAGE) {
+                      if (is_null($this->$getter())) {
+                          $klass = $field->getMessageType()->getClass();
+                          $new_msg = new $klass;
+                          $this->$setter($new_msg);
+                      }
+                      $this->$getter()->mergeFrom($tmp);
+                  } else {
+                      $this->$setter($tmp);
+                  }
+              }
+          }
+      }
+    }
+
+    /**
      * Parses a protocol buffer contained in a string.
      *
      * This function takes a string in the (non-human-readable) binary wire