mg_php

A PHP Extension for InterSystems Cache/IRIS and YottaDB.

Chris Munt cmunt@mgateway.com
16 April 2024, MGateway Ltd http://www.mgateway.com

Current Release: Version: 3.3; Revision 62.
Verified to work with PHP versions up to (and including) v8.2.x.
Two connectivity models to the InterSystems or YottaDB database are provided: High performance via the local database API or network based.
Release Notes can be found at the end of this document.

Contents

Overview
Prerequisites
Installing mg_php
PHP Configuration
Connecting to the database
Invocation of database commands
Invocation of database functions
Transaction Processing
Direct access to InterSystems classes (IRIS and Cache)
License

Overview

mg_php is an Open Source PHP extension developed for InterSystems Cache/IRIS and the YottaDB database. It will also work with the GT.M database and other M-like databases.

Prerequisites

PHP installation:

   http://www.php.net/

InterSystems Cache/IRIS or YottaDB (or similar M database):

   https://www.intersystems.com/
   https://yottadb.com/

Installing mg_php

There are three parts to mg_php installation and configuration.

The PHP extension (mg_php.so or mg_php.dll).
The DB Superserver: the %zmgsi routines.
A network configuration to bind the former two elements together.

Building the mg_php extension

mg_php is written in standard C. For Linux systems, the PHP installation procedure can use the freely available GNU C compiler (gcc) which can be installed as follows.

Ubuntu:

   apt-get install gcc

Red Hat and CentOS:

   yum install gcc

Apple OS X can use the freely available Xcode development environment.

There are two options for Windows, both of which are free:

There are built Windows x64 binaries available from:

https://github.com/chrisemunt/mg_php/blob/master/bin/winx64

Having created a suitable development environment, the PHP Extension installer can be used to build and deploy mg_php. You will find the setup scripts in the /src directory of the distribution.

UNIX

Invoke the following commands from the /src directory (i.e. the directory containing config.m4 file).

   phpize
   ./configure
   make
   make install

Windows

Building mg_php for Windows from source is more involved. Having successfully built PHP from source, create a directory called mg_php underneath the /ext directory of PHP distribution. Typically, this will be something like:

   C:\php-sdk\phpdev\vc15\x64\php-8.2.1-src\ext\mg_php\

Now, copy the contents of the mg_php /src directory to that location. The …\ext\mg_php will now contain the mg_php source code together with the config.w32 file. Open the appropriate Visual Studio Developer command Window (i.e. x86 or x64) and change directory to the root of the PHP source tree. For example:

   C:\php-sdk\phpdev\vc15\x64\php-8.2.1-src\

Set the essential variables for the build environment by invoking:

   C:\php-sdk\bin\phpsdk_setvars.bat

Invoke the following commands to build the mg_php.dll extension:

   buildconf
   configure --disable-all --enable-cli --enable-mg_php --with-all-shared
   nmake
   nmake install

Installing the DB Superserver

The DB Superserver is required for:

Network based access to databases.

Two M routines need to be installed (%zmgsi and %zmgsis). These can be found in the Service Integration Gateway (mgsi) GitHub source code repository (https://github.com/chrisemunt/mgsi). Note that it is not necessary to install the whole Service Integration Gateway, just the two M routines held in that repository.

Installation for InterSystems Cache/IRIS

Log in to the %SYS Namespace and install the zmgsi routines held in /isc/zmgsi_isc.ro.

   do $system.OBJ.Load("/isc/zmgsi_isc.ro","ck")

Change to your development Namespace and check the installation:

   do ^%zmgsi

   MGateway Ltd - Service Integration Gateway
   Version: 4.5; Revision 31 (18 November 2023)

Installation for YottaDB

The instructions given here assume a standard ‘out of the box’ installation of YottaDB (version 1.38) deployed in the following location:

   /usr/local/lib/yottadb/r138

The primary default location for routines:

   /root/.yottadb/r1.38_x86_64/r

Copy all the routines (i.e. all files with an ‘m’ extension) held in the GitHub /yottadb directory to:

   /root/.yottadb/r1.38_x86_64/r

Change directory to the following location and start a YottaDB command shell:

   cd /usr/local/lib/yottadb/r138
   ./ydb

Link all the zmgsi routines and check the installation:

   do ylink^%zmgsi

   do ^%zmgsi

   MGateway Ltd - Service Integration Gateway
   Version: 4.5; Revision 31 (18 November 2023)

Note that the version of zmgsi is successfully displayed.

Finally, add the following lines to the interface file (zmgsi.ci in the example used in the db.open() method).

   sqlemg: ydb_string_t * sqlemg^%zmgsis(I:ydb_string_t*, I:ydb_string_t *, I:ydb_string_t *)
   sqlrow: ydb_string_t * sqlrow^%zmgsis(I:ydb_string_t*, I:ydb_string_t *, I:ydb_string_t *)
   sqldel: ydb_string_t * sqldel^%zmgsis(I:ydb_string_t*, I:ydb_string_t *)
   ifc_zmgsis: ydb_string_t * ifc^%zmgsis(I:ydb_string_t*, I:ydb_string_t *, I:ydb_string_t*)

A copy of this file can be downloaded from the /unix directory of the mgsi GitHub repository here

Starting the DB Superserver

The default TCP server port for zmgsi is 7041. If you wish to use an alternative port then modify the following instructions accordingly.

For InterSystems DB servers the concurrent TCP service should be started in the %SYS Namespace.

Start the DB Superserver using the following command:

   do start^%zmgsi(0)

To use a server TCP port other than 7041, specify it in the start-up command (as opposed to using zero to indicate the default port of 7041).

For YottaDB, as an alternative to starting the DB Superserver from the command prompt, Superserver processes can be started via the xinetd daemon. Instructions for configuring this option can be found in the mgsi repository here

PHP code using the mg_php functions will, by default, expect the database server to be listening on port 7041 of the local server (localhost). However, mg_php provides the functionality to modify these default settings at run-time. It is not necessary for the PHP installation to reside on the same host as the database server.

Resources used by the DB Superserver (%zmgsi)

The zmgsi server-side code will write to the following global:

^zmgsi: The event Log.

PHP Configuration

PHP should be configured to recognise the mg_php extension. The PHP configuration file (php.ini) is usually found in the following locations:

UNIX

   /usr/local/lib/php.ini

Add the following line to the extensions section:

   extension=mg_php.so

Finally, install the mg_php.so file in the PHP modules directory, which is usually:

   /usr/local/lib/php/extensions/[version_information]/

Windows

   C:\Windows\php.ini

Add the following line to the extensions section:

   extension=mg_php.dll

Finally, install the mg_php.dll file in the PHP modules directory, which is usually:

   C:\Windows\System32\

Connecting to the database

Before invoking database functionality,the following simple script can be used to check that mg_php is successfully installed.

   <?php
      print(m_ext_version());
   ?>

This should return something like:

   MGateway Ltd. - mg_php: PHP Gateway to M - Version 3.3.61

Connecting the database via the network.

By default, mg_php will connect to the server over TCP - the default parameters for which being the database listening locally on port 7041. This can be modified using the following function.

   m_set_host(<netname>, <port>, <username>, <password>)

If this function is not called, the default server will be used (localhost listening on TCP port 7041).

Example:

   m_set_host("localhost", 7041, "", "");

Connecting to the database via its API.

As an alternative to connecting to the database using TCP based connectivity, mg_php provides the option of high-performance embedded access to a local installation of the database via its API.

InterSystems Caché or IRIS.

Use the following functions to bind to the database API.

   m_set_uci(<namespace>)
   m_bind_server_api(<dbtype>, <path>, <username>, <password>, <envvars>, <params>)

Where:

namespace: Namespace.
dbtype: Database type (“Cache”, or “IRIS”).
path: Path to database manager directory.
username: Database username.
password: Database password.
envvars: List of required environment variables.
params: Reserved for future use.

Example:

   m_set_uci("USER");
   $result = m_bind_server_api("IRIS", "/usr/iris20221/mgr", "_SYSTEM", "SYS", "", "");

The bind function will return ‘1’ for success and ‘0’ for failure.

Before leaving your PHP application, it is good practice to gracefully release the binding to the database:

   m_release_server_api()

Example:

   m_release_server_api();

YottaDB

Use the following function to bind to the database API.

   m_bind_server_api(<dbtype>, <path>, <username>, <password>, <envvars>, <params>)

Where:

dbtype: Database type (“YottaDB”).
path: Path to the YottaDB installation/library.
username: Database username.
password: Database password.
envvars: List of required environment variables.
params: Reserved for future use.

Example:

This example assumes that the YottaDB installation is in: /usr/local/lib/yottadb/r138.
This is where the libyottadb.so library is found.
Also, in this directory, as indicated in the environment variables, the YottaDB routine interface file resides (zmgsi.ci in this example). The interface file must contain the following lines:

   sqlemg: ydb_string_t * sqlemg^%zmgsis(I:ydb_string_t*, I:ydb_string_t *, I:ydb_string_t *)
   sqlrow: ydb_string_t * sqlrow^%zmgsis(I:ydb_string_t*, I:ydb_string_t *, I:ydb_string_t *)
   sqldel: ydb_string_t * sqldel^%zmgsis(I:ydb_string_t*, I:ydb_string_t *)
   ifc_zmgsis: ydb_string_t * ifc^%zmgsis(I:ydb_string_t*, I:ydb_string_t *, I:ydb_string_t*)

Moving on to the PHP code for binding to the YottaDB database. Modify the values of these environment variables in accordance with your own YottaDB installation. Note that each line is terminated with a linefeed character, with a double linefeed at the end of the list.

   $envvars = "";
   $envvars = $envvars . "ydb_dir=/root/.yottadb\n";
   $envvars = $envvars . "ydb_rel=r1.38_x86_64\n";
   $envvars = $envvars . "ydb_gbldir=/root/.yottadb/r1.38_x86_64/g/yottadb.gld\n";
   $envvars = $envvars . "ydb_routines=/root/.yottadb/r1.38_x86_64/o*(/root/.yottadb/r1.38_x86_64/r root/.yottadb/r) /usr/local/lib/yottadb/r138/libyottadbutil.so\n";
   $envvars = $envvars . "ydb_ci=/usr/local/lib/yottadb/r138/zmgsi.ci\n";
   $envvars = $envvars . "\n";

   $result = m_bind_server_api("YottaDB", "/usr/local/lib/yottadb/r138", "", "", envvars, "");

The bind function will return ‘1’ for success and ‘0’ for failure.

Before leaving your PHP application, it is good practice to gracefully release the binding to the database:

   m_release_server_api()

Example:

   m_release_server_api();

Invocation of database commands

Before invoking database functionality,the following simple script can be used to check that mg_php is successfully installed.

   print(m_ext_version());

This should return something like:

   MGateway Ltd. - mg_php: PHP Gateway to M - Version 3.3.61

Now consider the following database script:

   Set ^Person(1)="Chris Munt"
   Set name=$Get(^Person(1))

Equivalent PHP code:

   m_set("^Person", 1, "Chris Munt");
   $name = m_get("^Person", 1);;

mg_php provides functions to invoke all database commands and functions.

Set a record (m_set)

   result = m_set(<global>, <key>, <data>)

Example:

   $result = m_set("^Person", 1, "Chris Munt");

Get a record (m_get)

   result = m_get(<global>, <key>)

Example:

   $result = m_get("^Person", 1);

Delete a record (m_delete or m_kill)

   result = m_delete(<dbhandle>, <global>, <key>)

Example:

   $result = m_delete("^Person", 1);

Check whether a record is defined (m_defined or m_data)

   result = m_defined(<global>, <key>)

Example:

   $result = m_defined("^Person", 1);

Parse a set of records (in order - m_order)

   result = m_order(<global>, <key>)

Example:

   $key = m_order("^Person", "");
   while ($key != "") {
      $name = m_get("^MGWCust", $key);
      print("\n$key = $name");
      $key = m_order("^Person", $key);
   }

Parse a set of records (in reverse order - m_previous)

   result = m_previous(<global>, <key>)

Example:

   $key = m_previous("^Person", "");
   while ($key != "") {
      $name = m_get("^MGWCust", $key);
      print("\n$key = $name");
      $key = m_previous("^Person", $key);
   }

Increment a global node (m_increment)

   result = m_increment(<global>, <key>, <increment_value>)

Example:

   $result = m_increment("^Global", "counter", 1);

This will increment the value of global node ^Global(“counter”) by 1 and return the next value.

Invocation of database functions

Use m_function or m_proc.

 result = m_function(<function>, <parameters>)

Example:

M routine called ‘math’:

   add(a, b) ; Add two numbers together
             quit (a+b)

PHP invocation:

   $result = m_function("add^math", 2, 3);

Transaction Processing

M DB Servers implement Transaction Processing by means of the methods described in this section.

Start a Transaction

   result = m_tstart()

On successful completion this method will return zero, or an error code on failure.

Example:

   $result = m_tstart()

Determine the Transaction Level

   result = m_tlevel()

Transactions can be nested and this method will return the level of nesting. If no Transaction is active this method will return zero. Otherwise a positive integer will be returned to represent the current depth of Transaction nesting.

Example:

   $tlevel = m_tlevel()

Commit a Transaction

   result = m_tcommit()

On successful completion this method will return zero, or an error code on failure.

Example:

   $result = m_tcommit()

Rollback a Transaction

   result = m_trollback()

On successful completion this method will return zero, or an error code on failure.

Example:

   $result = m_trollback()

Direct access to InterSystems classes (IRIS and Cache)

Invocation of a ClassMethod (m_classmethod)

   result = m_classmethod(<class_name>, <classmethod_name>, <parameters>)

Example (Encode a date to internal storage format):

   $result = m_classmethod("%Library.Date", "DisplayToLogical", "10/10/2019");

License

Copyright (c) 2018-2024 MGateway Ltd,
Surrey UK.
All rights reserved.

http://www.mgateway.com
Email: cmunt@mgateway.com

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Release Notes

v3.0.1 (13 June 2019)

Initial Experimental Pre-Release

v3.1.56 (19 February 2020)

Initial Release

v3.1.56a (12 January 2021)

Restructure and update the documentation.

v3.2.57 (18 February 2021)

Introduce support for M transaction processing: tstart, $tlevel, tcommit, trollback.
- Available with DB Superserver v4 and later.
Introduce support for the M increment function.

v3.2.58 (14 March 2021)

Introduce support for YottaDB Transaction Processing over API based connectivity.
- This functionality was previously only available over network-based connectivity to YottaDB.

v3.3.59 (26 January 2023)

Introduce support for PHP v8.0.x, v8.1.x and v8.2.x.

v3.3.60 (26 March 2023)

Properly terminate strings returned from the YottaDB API.

v3.3.60a (23 June 2023)

Documentation update.

v3.3.61 (22 March 2024)

Correct a fault in the m_proc_byref() and m_method_byref() functions.
- It remains the case that the first two arguments to these functions are passed by value (DB Server name and M function name) but subsequent arguments are passed by reference.

v3.3.62 (16 April 2024)

Correct a fault in the management of DB Server connections in multi-process Apache configurations.
- This fault led web requests failing with ‘empty page’ errors.