staticweb package for easier static web server hosting

pkg/server/staticweb/policies/cache.go

@@ -0,0 +1,103 @@
+package policies
+
+import (
+	"fmt"
+	"path"
+	"strings"
+)
+
+// SimpleCachePolicy implements a basic cache policy with a single TTL for all files.
+type SimpleCachePolicy struct {
+	cacheTime int // Cache duration in seconds
+}
+
+// NewSimpleCachePolicy creates a new SimpleCachePolicy with the given cache time in seconds.
+func NewSimpleCachePolicy(cacheTimeSeconds int) *SimpleCachePolicy {
+	return &SimpleCachePolicy{
+		cacheTime: cacheTimeSeconds,
+	}
+}
+
+// GetCacheTime returns the cache duration for any file.
+func (p *SimpleCachePolicy) GetCacheTime(filePath string) int {
+	return p.cacheTime
+}
+
+// GetCacheHeaders returns the Cache-Control header for the given file.
+func (p *SimpleCachePolicy) GetCacheHeaders(filePath string) map[string]string {
+	if p.cacheTime <= 0 {
+		return map[string]string{
+			"Cache-Control": "no-cache, no-store, must-revalidate",
+			"Pragma":        "no-cache",
+			"Expires":       "0",
+		}
+	}
+
+	return map[string]string{
+		"Cache-Control": fmt.Sprintf("public, max-age=%d", p.cacheTime),
+	}
+}
+
+// ExtensionBasedCachePolicy implements a cache policy that varies by file extension.
+type ExtensionBasedCachePolicy struct {
+	rules       map[string]int // Extension -> cache time in seconds
+	defaultTime int            // Default cache time for unmatched extensions
+}
+
+// NewExtensionBasedCachePolicy creates a new ExtensionBasedCachePolicy.
+// rules maps file extensions (with leading dot, e.g., ".js") to cache times in seconds.
+// defaultTime is used for files that don't match any rule.
+func NewExtensionBasedCachePolicy(rules map[string]int, defaultTime int) *ExtensionBasedCachePolicy {
+	return &ExtensionBasedCachePolicy{
+		rules:       rules,
+		defaultTime: defaultTime,
+	}
+}
+
+// GetCacheTime returns the cache duration based on the file extension.
+func (p *ExtensionBasedCachePolicy) GetCacheTime(filePath string) int {
+	ext := strings.ToLower(path.Ext(filePath))
+	if cacheTime, ok := p.rules[ext]; ok {
+		return cacheTime
+	}
+	return p.defaultTime
+}
+
+// GetCacheHeaders returns cache headers based on the file extension.
+func (p *ExtensionBasedCachePolicy) GetCacheHeaders(filePath string) map[string]string {
+	cacheTime := p.GetCacheTime(filePath)
+
+	if cacheTime <= 0 {
+		return map[string]string{
+			"Cache-Control": "no-cache, no-store, must-revalidate",
+			"Pragma":        "no-cache",
+			"Expires":       "0",
+		}
+	}
+
+	return map[string]string{
+		"Cache-Control": fmt.Sprintf("public, max-age=%d", cacheTime),
+	}
+}
+
+// NoCachePolicy implements a cache policy that disables all caching.
+type NoCachePolicy struct{}
+
+// NewNoCachePolicy creates a new NoCachePolicy.
+func NewNoCachePolicy() *NoCachePolicy {
+	return &NoCachePolicy{}
+}
+
+// GetCacheTime always returns 0 (no caching).
+func (p *NoCachePolicy) GetCacheTime(filePath string) int {
+	return 0
+}
+
+// GetCacheHeaders returns headers that disable caching.
+func (p *NoCachePolicy) GetCacheHeaders(filePath string) map[string]string {
+	return map[string]string{
+		"Cache-Control": "no-cache, no-store, must-revalidate",
+		"Pragma":        "no-cache",
+		"Expires":       "0",
+	}
+}