From d5f87c81befcbe51c47e0ae67e2df6346908bce7 Mon Sep 17 00:00:00 2001
From: Jan De Dobbeleer <jan.de.dobbeleer@gmail.com>
Date: Wed, 3 Aug 2022 07:25:42 +0200
Subject: [PATCH] feat: store template cache and reuse for extra prompts

resolves #2605
---
 src/engine/engine.go     |  2 ++
 src/environment/shell.go | 25 ++++++++++++++++++++++++-
 src/mock/environment.go  |  4 ++++
 3 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/src/engine/engine.go b/src/engine/engine.go
index ded15381..177ace3c 100644
--- a/src/engine/engine.go
+++ b/src/engine/engine.go
@@ -354,6 +354,8 @@ const (
 )
 
 func (e *Engine) PrintExtraPrompt(promptType ExtraPromptType) string {
+	// populate env with latest context
+	e.Env.LoadTemplateCache()
 	var prompt *Segment
 	switch promptType {
 	case Debug:
diff --git a/src/environment/shell.go b/src/environment/shell.go
index 984f1eef..6e375c5e 100644
--- a/src/environment/shell.go
+++ b/src/environment/shell.go
@@ -3,6 +3,7 @@ package environment
 import (
 	"bytes"
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -35,7 +36,8 @@ const (
 )
 
 var (
-	lock = sync.RWMutex{}
+	lock          = sync.RWMutex{}
+	TEMPLATECACHE = fmt.Sprintf("template_cache_%d", os.Getppid())
 )
 
 type Flags struct {
@@ -181,6 +183,7 @@ type Environment interface {
 	ConvertToWindowsPath(path string) string
 	WifiNetwork() (*WifiInfo, error)
 	TemplateCache() *TemplateCache
+	LoadTemplateCache()
 	Log(logType LogType, funcName, message string)
 	Trace(start time.Time, function string, args ...string)
 }
@@ -659,9 +662,29 @@ func (env *ShellEnvironment) Cache() Cache {
 }
 
 func (env *ShellEnvironment) Close() {
+	defer env.Trace(time.Now(), "Close")
+	templateCache, err := json.Marshal(env.TemplateCache())
+	if err == nil {
+		env.fileCache.Set(TEMPLATECACHE, string(templateCache), 1440)
+	}
 	env.fileCache.Close()
 }
 
+func (env *ShellEnvironment) LoadTemplateCache() {
+	defer env.Trace(time.Now(), "LoadTemplateCache")
+	val, OK := env.fileCache.Get(TEMPLATECACHE)
+	if !OK {
+		return
+	}
+	var templateCache TemplateCache
+	err := json.Unmarshal([]byte(val), &templateCache)
+	if err != nil {
+		env.Log(Error, "LoadTemplateCache", err.Error())
+		return
+	}
+	env.tmplCache = &templateCache
+}
+
 func (env *ShellEnvironment) Logs() string {
 	return env.logBuilder.String()
 }
diff --git a/src/mock/environment.go b/src/mock/environment.go
index ae0fa510..344ca870 100644
--- a/src/mock/environment.go
+++ b/src/mock/environment.go
@@ -218,6 +218,10 @@ func (env *MockedEnvironment) TemplateCache() *environment.TemplateCache {
 	return args.Get(0).(*environment.TemplateCache)
 }
 
+func (env *MockedEnvironment) LoadTemplateCache() {
+	_ = env.Called()
+}
+
 func (env *MockedEnvironment) MockGitCommand(dir, returnValue string, args ...string) {
 	args = append([]string{"-C", dir, "--no-optional-locks", "-c", "core.quotepath=false", "-c", "color.status=false"}, args...)
 	env.On("RunCommand", "git", args).Return(returnValue, nil)