Celestino Amoroso
29bc2c62a3
Module organization requires a better structure to decouple definitions and implementations
103 lines
2.0 KiB
Go
103 lines
2.0 KiB
Go
// Copyright (c) 2024 Celestino Amoroso (celestino.amoroso@gmail.com).
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// All rights reserved.
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// operator-plugin.go
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package expr
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import (
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"fmt"
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"io"
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"plugin"
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)
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//-------- plugin term
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func newPluginTerm(tk *Token) (inst *term) {
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return &term{
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tk: *tk,
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children: make([]*term, 0, 1),
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position: posPrefix,
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priority: priSign,
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evalFunc: evalPlugin,
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}
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}
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func importPlugin(ctx ExprContext, dirList []string, name string) (err error) {
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var filePath string
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var p *plugin.Plugin
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var sym plugin.Symbol
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var moduleName string
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var importFunc func(ctx ExprContext)
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var ok bool
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decoratedName := fmt.Sprintf("expr-%s-plugin.so", name)
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if filePath, err = makeFilepath(decoratedName, dirList); err != nil {
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return
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}
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if p, err = plugin.Open(filePath); err != nil {
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return
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}
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if sym, err = p.Lookup("MODULE_NAME"); err != nil {
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return
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}
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if moduleName = *sym.(*string); moduleName == "" {
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err = fmt.Errorf("plugin %q does not provide a valid module name", decoratedName)
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return
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}
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if sym, err = p.Lookup("ImportFuncs"); err != nil {
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return
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}
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if importFunc, ok = sym.(func(ExprContext)); !ok {
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err = fmt.Errorf("plugin %q does not provide a valid import function", decoratedName)
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return
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}
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registerPlugin(moduleName, p)
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importFunc(globalCtx)
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return
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}
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func evalPlugin(ctx ExprContext, self *term) (v any, err error) {
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var childValue any
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var moduleSpec any
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if childValue, err = self.evalPrefix(ctx); err != nil {
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return
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}
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dirList := buildSearchDirList("plugin", ENV_EXPR_PLUGIN_PATH)
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count := 0
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it := NewAnyIterator(childValue)
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for moduleSpec, err = it.Next(); err == nil; moduleSpec, err = it.Next() {
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if module, ok := moduleSpec.(string); ok {
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if err = importPlugin(ctx, dirList, module); err != nil {
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break
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}
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count++
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} else {
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err = self.Errorf("expected string as item nr %d, got %s", it.Index()+1, typeName(moduleSpec))
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break
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}
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}
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if err == io.EOF {
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err = nil
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}
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if err == nil {
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v = int64(count)
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}
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return
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}
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// init
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func init() {
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registerTermConstructor(SymKwPlugin, newPluginTerm)
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}
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