Merge pull request #331 from caleb-artifact/gcp-speedup

Increased the performance of GCP segment

segment-gcp.go

@@ -1,20 +1,126 @@
 package main
 
 import (
+	"bytes"
+	"fmt"
 	"log"
+	"os"
 	"os/exec"
+	"runtime"
 	"strings"
 
 	pwl "github.com/justjanne/powerline-go/powerline"
 )
 
-func segmentGCP(p *powerline) []pwl.Segment {
+const gcloudCoreSectionHeader = "\n[core]\n"
+
+func getCloudConfigDir() (string, error) {
+	p, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	if runtime.GOOS != "windows" {
+		p += "/.config"
+	}
+	p += "/gcloud"
+	return p, nil
+}
+
+func getActiveGCloudConfig(configDir string) (string, error) {
+	activeConfigPath := configDir + "/active_config"
+
+	stat, err := os.Stat(activeConfigPath)
+	if (err == nil && os.IsNotExist(err)) || (err == nil && stat.IsDir()) {
+		return "default", nil
+	} else if err != nil {
+		return "", err
+	}
+
+	contents, err := os.ReadFile(activeConfigPath)
+	if err != nil {
+		return "", err
+	}
+
+	config := strings.TrimSpace(string(contents))
+	if config == "" {
+		config = "default"
+	}
+
+	return config, nil
+}
+
+func getGCPProjectFromGCloud() (string, error) {
 	out, err := exec.Command("gcloud", "config", "list", "project", "--format", "value(core.project)").Output()
+	if err != nil {
+		return "", err
+	}
+
+	return strings.TrimSuffix(string(out), "\n"), nil
+}
+
+func getGCPProjectFromFile() (string, error) {
+	configDir, err := getCloudConfigDir()
+	if err != nil {
+		return "", err
+	}
+
+	activeConfig, err := getActiveGCloudConfig(configDir)
+	if err != nil {
+		return "", err
+	}
+
+	configPath := configDir + "/configurations/config_" + activeConfig
+	stat, err := os.Stat(configPath)
+	if err != nil {
+		return "", err
+	} else if stat.IsDir() {
+		return "", fmt.Errorf("%s is a directory", configPath)
+	}
+
+	b, err := os.ReadFile(configPath)
+	if err != nil {
+		return "", err
+	}
+	b = append([]byte("\n"), b...)
+
+	coreStart := bytes.Index(b, []byte(gcloudCoreSectionHeader))
+	if coreStart == -1 {
+		return "", fmt.Errorf("could not find [core] section in %s", configPath)
+	}
+	b = b[coreStart+len(gcloudCoreSectionHeader):]
+
+	coreEnd := bytes.Index(b, []byte("\n["))
+	if coreEnd != -1 {
+		b = b[:coreEnd]
+	}
+
+	lines := bytes.Split(b[coreStart+len(gcloudCoreSectionHeader):coreEnd], []byte("\n"))
+	for _, line := range lines {
+		parts := bytes.Split(line, []byte("="))
+		if len(parts) == 2 {
+			if strings.TrimSpace(string(parts[0])) == "project" {
+				return strings.TrimSpace(string(parts[1])), nil
+			}
+		}
+	}
+
+	return "", nil
+}
+
+func getGCPProject() (string, error) {
+	if project, err := getGCPProjectFromFile(); err == nil {
+		return project, nil
+	} else {
+		return getGCPProjectFromGCloud()
+	}
+}
+
+func segmentGCP(p *powerline) []pwl.Segment {
+	project, err := getGCPProject()
 	if err != nil {
 		log.Fatal(err)
 	}
 
-	project := strings.TrimSuffix(string(out), "\n")
 	if project == "" {
 		return []pwl.Segment{}
 	}