perf: cache document root resolution when possible

caddy/caddy.go

@@ -6,9 +6,11 @@ package caddy
 import (
 	"encoding/json"
 	"errors"
+	"fmt"
 	"net/http"
 	"path/filepath"
 	"strconv"
+	"strings"
 
 	"github.com/caddyserver/caddy/v2"
 	"github.com/caddyserver/caddy/v2/caddyconfig"
@@ -212,8 +214,10 @@ type FrankenPHPModule struct {
 	// Env sets an extra environment variable to the given value. Can be specified more than once for multiple environment variables.
 	Env map[string]string `json:"env,omitempty"`
 
-	preparedEnv frankenphp.PreparedEnv
-	logger      *zap.Logger
+	resolvedDocumentRoot        string
+	preparedEnv                 frankenphp.PreparedEnv
+	preparedEnvNeedsReplacement bool
+	logger                      *zap.Logger
 }
 
 // CaddyModule returns the Caddy module information.
@@ -251,30 +255,69 @@ func (f *FrankenPHPModule) Provision(ctx caddy.Context) error {
 		f.ResolveRootSymlink = &rrs
 	}
 
+	if !needReplacement(f.Root) {
+		root, err := filepath.Abs(f.Root)
+		if err != nil {
+			return fmt.Errorf("unable to make the root path absolute: %w", err)
+		}
+		f.resolvedDocumentRoot = root
+
+		if *f.ResolveRootSymlink {
+			root, err := filepath.EvalSymlinks(root)
+			if err != nil {
+				return fmt.Errorf("unable to resolve root symlink: %w", err)
+			}
+
+			f.resolvedDocumentRoot = root
+		}
+	}
+
 	if f.preparedEnv == nil {
 		f.preparedEnv = frankenphp.PrepareEnv(f.Env)
+
+		for e := range f.preparedEnv {
+			if needReplacement(e) {
+				f.preparedEnvNeedsReplacement = true
+
+				break
+			}
+		}
 	}
 
 	return nil
 }
 
+// needReplacement checks if a string contains placeholdes.
+func needReplacement(s string) bool {
+	return strings.Contains(s, "{") || strings.Contains(s, "}")
+}
+
 // ServeHTTP implements caddyhttp.MiddlewareHandler.
 // TODO: Expose TLS versions as env vars, as Apache's mod_ssl: https://github.com/caddyserver/caddy/blob/master/modules/caddyhttp/reverseproxy/fastcgi/fastcgi.go#L298
 func (f FrankenPHPModule) ServeHTTP(w http.ResponseWriter, r *http.Request, _ caddyhttp.Handler) error {
 	origReq := r.Context().Value(caddyhttp.OriginalRequestCtxKey).(http.Request)
 	repl := r.Context().Value(caddy.ReplacerCtxKey).(*caddy.Replacer)
 
-	documentRoot := repl.ReplaceKnown(f.Root, "")
+	var documentRootOption frankenphp.RequestOption
+	if f.resolvedDocumentRoot == "" {
+		documentRootOption = frankenphp.WithRequestDocumentRoot(repl.ReplaceKnown(f.Root, ""), *f.ResolveRootSymlink)
+	} else {
+		documentRootOption = frankenphp.WithRequestResolvedDocumentRoot(f.resolvedDocumentRoot)
+	}
 
 	env := make(map[string]string, len(f.preparedEnv)+1)
 	env["REQUEST_URI\x00"] = origReq.URL.RequestURI()
 	for k, v := range f.preparedEnv {
-		env[k] = repl.ReplaceKnown(v, "")
+		if f.preparedEnvNeedsReplacement {
+			env[k] = repl.ReplaceKnown(v, "")
+		} else {
+			env[k] = v
+		}
 	}
 
 	fr, err := frankenphp.NewRequestWithContext(
 		r,
-		frankenphp.WithRequestDocumentRoot(documentRoot, *f.ResolveRootSymlink),
+		documentRootOption,
 		frankenphp.WithRequestSplitPath(f.SplitPath),
 		frankenphp.WithRequestPreparedEnv(env),
 	)

request_options.go

@@ -36,6 +36,16 @@ func WithRequestDocumentRoot(documentRoot string, resolveSymlink bool) RequestOp
 	}
 }
 
+// WithRequestResolvedDocumentRoot is similar to WithRequestDocumentRoot
+// but doesn't does any checks or resolving on the path to improve performance.
+func WithRequestResolvedDocumentRoot(documentRoot string) RequestOption {
+	return func(o *FrankenPHPContext) error {
+		o.documentRoot = documentRoot
+
+		return nil
+	}
+}
+
 // The path in the URL will be split into two, with the first piece ending
 // with the value of SplitPath. The first piece will be assumed as the
 // actual resource (CGI script) name, and the second piece will be set to