Protobuf implementations

Page Summary

Two PHP implementations for Protobuf are available: C (better performance, requires extension) and PHP (easier implementation, uses a package).
The C implementation is recommended when possible, but the PHP implementation can be used when necessary.
The PHP implementation is used automatically if the C implementation is not installed and configured.
Instructions are provided for installing and configuring both the C and PHP implementations.
A command is available to determine which Protobuf implementation is currently in use.

There are two Protobuf implementations available for PHP:

C: Uses the Protobuf PHP C extension, which provides significantly better runtime performance.
PHP: Uses the google/protobuf PHP package, which requires no additional system extensions.

Use the C implementation when possible, though the pure PHP implementation can be used when security or environment constraints prevent installing C extensions.

The PHP implementation is automatically installed as a dependency of googleapis/gax-php in Composer, and is used at runtime only if the C implementation is not installed and enabled.

C implementation

To install and configure the Protobuf PHP C extension:

Install the extension using PECL:
```
sudo pecl install protobuf
```
Enable the extension in your active php.ini file (for both CLI and web server environments such as PHP-FPM or Apache; run php --ini to locate the CLI configuration file):
```
extension=protobuf.so
```
Note: On Windows, add extension=php_protobuf.dll to php.ini instead.

PHP implementation

To use the pure PHP implementation, ensure that the C implementation is disabled and all dependencies of googleapis/gax-php are installed:

Comment out or remove any extension=protobuf.so (or extension=php_protobuf.dll) line in your php.ini files.
Run composer install from the directory that contains the composer.json file of your project. The composer.json file should specify googleads/google-ads-php as a dependency.

Key Point: Typically, the Protobuf version that this PHP library relies on is transitively specified in the composer.json file of google/gax. For performance or compatibility reasons, a minimum Protobuf version may also be specified directly in the PHP client library's composer.json.

Determine which implementation is being used

Run the following command in your terminal to check whether the C extension is enabled in your PHP CLI environment:

php -i | grep protobuf

If the output is not empty (for example, protobuf support => enabled), you are using the C implementation.
Otherwise, you are not using the C implementation, and the Google Ads API PHP library automatically falls back to the pure PHP implementation installed by Composer.