From e62b5bedae9c604f044aa27d12e42e289446f46e Mon Sep 17 00:00:00 2001
From: axtloss <axtlos@getcryst.al>
Date: Sun, 21 Apr 2024 15:09:19 +0200
Subject: [PATCH] feat: Migrate plugins to c-shared

This migrates plugins from using go/plugin to ebitengine/purego and c-shared.
With this change vib and plugins do not need to be built against the exact same api version anymore, which makes the deployment of vib with plugins much easier.
---
 core/plugins.go | 34 ++++++++++++++++++++++++----------
 core/structs.go | 10 +++-------
 go.mod          |  5 +++++
 go.sum          |  4 ++++
 4 files changed, 36 insertions(+), 17 deletions(-)

diff --git a/core/plugins.go b/core/plugins.go
index 4d6a4fa..fd66d1b 100644
--- a/core/plugins.go
+++ b/core/plugins.go
@@ -1,9 +1,12 @@
 package core
 
 import (
+	"C"
+	"encoding/json"
 	"fmt"
-	"plugin"
+	"strings"
 
+	"github.com/ebitengine/purego"
 	"github.com/vanilla-os/vib/api"
 )
 
@@ -19,20 +22,31 @@ func LoadPlugin(name string, module interface{}, recipe *api.Recipe) (string, er
 	if !pluginOpened {
 		fmt.Println("Loading new plugin")
 		buildModule = Plugin{Name: name}
-		var err error
-		loadedPlugin, err := plugin.Open(fmt.Sprintf("%s/%s.so", recipe.PluginPath, name))
-		if err != nil {
-			panic(err)
-		}
-		buildFunction, err := loadedPlugin.Lookup("BuildModule")
+
+		loadedPlugin, err := purego.Dlopen(fmt.Sprintf("%s/%s.so", recipe.PluginPath, name), purego.RTLD_NOW|purego.RTLD_GLOBAL)
 		if err != nil {
 			panic(err)
 		}
-		buildModule.BuildFunc = buildFunction.(func(interface{}, *api.Recipe) (string, error))
+		var buildFunction func(*C.char, *C.char) string
+		purego.RegisterLibFunc(&buildFunction, loadedPlugin, "BuildModule")
+		buildModule.BuildFunc = buildFunction
 		buildModule.LoadedPlugin = loadedPlugin
-
 		openedPlugins[name] = buildModule
 	}
 	fmt.Printf("Using plugin: %s\n", buildModule.Name)
-	return buildModule.BuildFunc(module, recipe)
+	moduleJson, err := json.Marshal(module)
+	if err != nil {
+		return "", err
+	}
+	recipeJson, err := json.Marshal(recipe)
+	if err != nil {
+		return "", err
+	}
+
+	res := buildModule.BuildFunc(C.CString(string(moduleJson)), C.CString(string(recipeJson)))
+	if strings.HasPrefix(res, "ERROR:") {
+		return "", fmt.Errorf("%s", strings.Replace(res, "ERROR: ", "", 1))
+	} else {
+		return res, nil
+	}
 }
diff --git a/core/structs.go b/core/structs.go
index 4edbd10..10f1f09 100644
--- a/core/structs.go
+++ b/core/structs.go
@@ -1,10 +1,6 @@
 package core
 
-import (
-	"plugin"
-
-	"github.com/vanilla-os/vib/api"
-)
+import "C"
 
 type Module struct {
 	Name    string `json:"name"`
@@ -26,6 +22,6 @@ type ModuleCommand struct {
 
 type Plugin struct {
 	Name         string
-	BuildFunc    func(interface{}, *api.Recipe) (string, error)
-	LoadedPlugin *plugin.Plugin
+	BuildFunc    func(*C.char, *C.char) string
+	LoadedPlugin uintptr
 }
diff --git a/go.mod b/go.mod
index 39a5e9c..4595a35 100644
--- a/go.mod
+++ b/go.mod
@@ -6,6 +6,11 @@ require github.com/spf13/cobra v1.7.0
 
 require github.com/mitchellh/mapstructure v1.5.0
 
+require (
+	github.com/ebitengine/purego v0.7.1 // indirect
+	golang.org/x/sys v0.7.0 // indirect
+)
+
 require (
 	github.com/google/uuid v1.3.0
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
diff --git a/go.sum b/go.sum
index 3ac7eea..55decbd 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,6 @@
 github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/ebitengine/purego v0.7.1 h1:6/55d26lG3o9VCZX8lping+bZcmShseiqlh2bnUDiPA=
+github.com/ebitengine/purego v0.7.1/go.mod h1:ah1In8AOtksoNK6yk5z1HTJeUkC1Ez4Wk2idgGslMwQ=
 github.com/google/uuid v1.3.0 h1:t6JiXgmwXMjEs8VusXIJk2BXHsn+wx8BZdTaoZ5fu7I=
 github.com/google/uuid v1.3.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
@@ -14,6 +16,8 @@ github.com/vanilla-os/vib/api v0.0.0-20240212085722-f163a19e5a63 h1:WwnKmkEFT0nQ
 github.com/vanilla-os/vib/api v0.0.0-20240212085722-f163a19e5a63/go.mod h1:vjJzDfFxfFHN5O2hcMwGM9De3+H9gGa00Pr3Um6EmCA=
 github.com/vanilla-os/vib/api v0.0.0-20240331150207-852011e4d96f h1:sRPpotRlyj3Qx4ftt5oYf7JQuIYTQwwPq93xomWaIKQ=
 github.com/vanilla-os/vib/api v0.0.0-20240331150207-852011e4d96f/go.mod h1:vjJzDfFxfFHN5O2hcMwGM9De3+H9gGa00Pr3Um6EmCA=
+golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
+golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=