From bd027341be3650dd390911a0feb6184fb409d542 Mon Sep 17 00:00:00 2001
From: Daniele Alessandri <suppakilla@gmail.com>
Date: Tue, 3 May 2011 15:07:56 +0200
Subject: [PATCH 1/6] New command: EVAL (Redis v2.4-dev).

---
 lib/Predis/Commands/ServerEval.php        | 13 +++++++++++++
 lib/Predis/Profiles/ServerVersionNext.php |  1 +
 2 files changed, 14 insertions(+)
 create mode 100644 lib/Predis/Commands/ServerEval.php

diff --git a/lib/Predis/Commands/ServerEval.php b/lib/Predis/Commands/ServerEval.php
new file mode 100644
index 00000000..b214bf67
--- /dev/null
+++ b/lib/Predis/Commands/ServerEval.php
@@ -0,0 +1,13 @@
+<?php
+
+namespace Predis\Commands;
+
+class ServerEval extends Command {
+    public function getId() {
+        return 'EVAL';
+    }
+
+    protected function canBeHashed() {
+        return false;
+    }
+}
diff --git a/lib/Predis/Profiles/ServerVersionNext.php b/lib/Predis/Profiles/ServerVersionNext.php
index e1793d5d..5d7bf45c 100644
--- a/lib/Predis/Profiles/ServerVersionNext.php
+++ b/lib/Predis/Profiles/ServerVersionNext.php
@@ -20,6 +20,7 @@ class ServerVersionNext extends ServerVersion22 {
             /* remote server control commands */
             'info'                      => '\Predis\Commands\ServerInfoV24x',
             'client'                    => '\Predis\Commands\ServerClient',
+            'eval'                      => '\Predis\Commands\ServerEval',
         ));
     }
 }

From 2bdfed5071910e9dd317c9910ef7c6fdf9bb8db3 Mon Sep 17 00:00:00 2001
From: Daniele Alessandri <suppakilla@gmail.com>
Date: Tue, 3 May 2011 15:14:51 +0200
Subject: [PATCH 2/6] Add an abstraction for a virtual command that leverages
 Redis scripting with the new EVAL command.

---
 lib/Predis/Commands/ScriptedCommand.php | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 lib/Predis/Commands/ScriptedCommand.php

diff --git a/lib/Predis/Commands/ScriptedCommand.php b/lib/Predis/Commands/ScriptedCommand.php
new file mode 100644
index 00000000..bb366e18
--- /dev/null
+++ b/lib/Predis/Commands/ScriptedCommand.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Predis\Commands;
+
+abstract class ScriptedCommand extends ServerEval {
+    public abstract function getScript();
+
+    public abstract function keysCount();
+
+    protected function filterArguments(Array $arguments) {
+        if (($keys = $this->keysCount()) === -1) {
+            $keys = count($arguments);
+        }
+        return array_merge(array($this->getScript(), $keys), $arguments);
+    }
+}

From a386263d84982e0e3ef135e62b3a7e89dc0ad4e5 Mon Sep 17 00:00:00 2001
From: Daniele Alessandri <suppakilla@gmail.com>
Date: Tue, 3 May 2011 17:37:39 +0200
Subject: [PATCH 3/6] Add an helper method to get the actual keys from the
 whole argument list.

---
 lib/Predis/Commands/ScriptedCommand.php | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/Predis/Commands/ScriptedCommand.php b/lib/Predis/Commands/ScriptedCommand.php
index bb366e18..69c9ca0c 100644
--- a/lib/Predis/Commands/ScriptedCommand.php
+++ b/lib/Predis/Commands/ScriptedCommand.php
@@ -13,4 +13,12 @@ abstract class ScriptedCommand extends ServerEval {
         }
         return array_merge(array($this->getScript(), $keys), $arguments);
     }
+
+    protected function getKeys() {
+        $arguments = $this->getArguments();
+        if (($keys = $this->keysCount()) === -1) {
+            return array_slice($arguments, 2);
+        }
+        return array_slice($arguments, 2, $keys);
+    }
 }

From ca22208ce87f8bb2e00a40905815a0e48b85540b Mon Sep 17 00:00:00 2001
From: Daniele Alessandri <suppakilla@gmail.com>
Date: Tue, 3 May 2011 18:00:30 +0200
Subject: [PATCH 4/6] Define a default value for the number of values used to
 populate KEYS.

---
 lib/Predis/Commands/ScriptedCommand.php | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/Predis/Commands/ScriptedCommand.php b/lib/Predis/Commands/ScriptedCommand.php
index 69c9ca0c..564b25de 100644
--- a/lib/Predis/Commands/ScriptedCommand.php
+++ b/lib/Predis/Commands/ScriptedCommand.php
@@ -5,7 +5,12 @@ namespace Predis\Commands;
 abstract class ScriptedCommand extends ServerEval {
     public abstract function getScript();
 
-    public abstract function keysCount();
+    protected function keysCount() {
+        // The default behaviour is to use the first argument as the only value
+        // for KEYS and the rest of the arguments (if any) for ARGV. When -1 is
+        // returned, all the arguments are considered as values for KEYS.
+        return 1;
+    }
 
     protected function filterArguments(Array $arguments) {
         if (($keys = $this->keysCount()) === -1) {

From 0e0cd865e7291d2355de60b642e78c9a2d6886fb Mon Sep 17 00:00:00 2001
From: Daniele Alessandri <suppakilla@gmail.com>
Date: Fri, 13 May 2011 19:53:03 +0200
Subject: [PATCH 5/6] Change the default value for the number of arguments used
 to populate KEYS.

---
 lib/Predis/Commands/ScriptedCommand.php | 18 +++++-------------
 1 file changed, 5 insertions(+), 13 deletions(-)

diff --git a/lib/Predis/Commands/ScriptedCommand.php b/lib/Predis/Commands/ScriptedCommand.php
index 564b25de..8224a1cc 100644
--- a/lib/Predis/Commands/ScriptedCommand.php
+++ b/lib/Predis/Commands/ScriptedCommand.php
@@ -6,24 +6,16 @@ abstract class ScriptedCommand extends ServerEval {
     public abstract function getScript();
 
     protected function keysCount() {
-        // The default behaviour is to use the first argument as the only value
-        // for KEYS and the rest of the arguments (if any) for ARGV. When -1 is
-        // returned, all the arguments are considered as values for KEYS.
-        return 1;
+        // The default behaviour for the base class is to use all the arguments
+        // passed to a scripted command to populate the KEYS table in Lua.
+        return count($this->getArguments());
     }
 
     protected function filterArguments(Array $arguments) {
-        if (($keys = $this->keysCount()) === -1) {
-            $keys = count($arguments);
-        }
-        return array_merge(array($this->getScript(), $keys), $arguments);
+        return array_merge(array($this->getScript(), $this->keysCount()), $arguments);
     }
 
     protected function getKeys() {
-        $arguments = $this->getArguments();
-        if (($keys = $this->keysCount()) === -1) {
-            return array_slice($arguments, 2);
-        }
-        return array_slice($arguments, 2, $keys);
+        return array_slice($this->getArguments(), 2, $this->keysCount());
     }
 }

From 092b82203368e13a31dadd1353cacde0a051e585 Mon Sep 17 00:00:00 2001
From: Daniele Alessandri <suppakilla@gmail.com>
Date: Fri, 13 May 2011 20:06:06 +0200
Subject: [PATCH 6/6] Add an example for server-side scripting with Lua using
 Predis abstractions.

---
 examples/ServerSideScripting.php | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)
 create mode 100644 examples/ServerSideScripting.php

diff --git a/examples/ServerSideScripting.php b/examples/ServerSideScripting.php
new file mode 100644
index 00000000..df1599c5
--- /dev/null
+++ b/examples/ServerSideScripting.php
@@ -0,0 +1,32 @@
+<?php
+
+require 'SharedConfigurations.php';
+
+// Additionally to the EVAL command defined in the current development profile, the new
+// Predis\Commands\ScriptedCommand base class can be used to build an higher abstraction
+// for our "scripted" commands so that they will appear just like any other command on
+// the client-side. This is a quick example used to implement INCREX.
+
+use Predis\Commands\ScriptedCommand;
+
+class IncrementExistingKey extends ScriptedCommand {
+    protected function keysCount() {
+        return 1;
+    }
+
+    public function getScript() {
+        return
+<<<LUA
+    if redis('exists', KEYS[1]) == 1 then
+        return redis('incr', KEYS[1])
+    end
+LUA;
+    }
+}
+
+$client = new Predis\Client($single_server, 'dev');
+$client->getProfile()->defineCommand('increx', 'IncrementExistingKey');
+
+$client->set('foo', 10);
+var_dump($client->increx('foo'));       // int(11)
+var_dump($client->increx('bar'));       // NULL