chore: simplify GetMemoryInfo in darwin

component/memory/memory_darwin.go

@@ -6,9 +6,7 @@ import (
 	"github.com/ebitengine/purego"
 )
 
-const (
-	PROC_PIDTASKINFO = 4
-)
+const PROC_PIDTASKINFO = 4
 
 type ProcTaskInfo struct {
 	Virtual_size      uint64
@@ -31,89 +29,24 @@ type ProcTaskInfo struct {
 	Priority          int32
 }
 
-// Library represents a dynamic library loaded by purego.
-type Library struct {
-	addr  uintptr
-	path  string
-	close func()
-}
+const System = "/usr/lib/libSystem.B.dylib"
 
-func NewLibrary(path string) (*Library, error) {
-	lib, err := purego.Dlopen(path, purego.RTLD_LAZY|purego.RTLD_GLOBAL)
-	if err != nil {
-		return nil, err
-	}
+type ProcPidInfoFunc func(pid, flavor int32, arg uint64, buffer uintptr, bufferSize int32) int32
 
-	closeFunc := func() {
-		purego.Dlclose(lib)
-	}
-
-	return &Library{
-		addr:  lib,
-		path:  path,
-		close: closeFunc,
-	}, nil
-}
-
-func (lib *Library) Dlsym(symbol string) (uintptr, error) {
-	return purego.Dlsym(lib.addr, symbol)
-}
-
-func GetFunc[T any](lib *Library, symbol string) T {
-	var fptr T
-	purego.RegisterLibFunc(&fptr, lib.addr, symbol)
-	return fptr
-}
-
-func (lib *Library) Close() {
-	lib.close()
-}
-
-// library paths
-const (
-	System = "/usr/lib/libSystem.B.dylib"
-)
-
-// System functions and symbols.
-type (
-	ProcPidInfoFunc func(pid, flavor int32, arg uint64, buffer uintptr, bufferSize int32) int32
-)
-
-const (
-	ProcPidInfoSym = "proc_pidinfo"
-)
-
-type dlFuncs struct {
-	lib *Library
-
-	procPidInfo ProcPidInfoFunc
-}
-
-func loadProcFuncs() (*dlFuncs, error) {
-	lib, err := NewLibrary(System)
-	if err != nil {
-		return nil, err
-	}
-
-	return &dlFuncs{
-		lib:         lib,
-		procPidInfo: GetFunc[ProcPidInfoFunc](lib, ProcPidInfoSym),
-	}, nil
-}
-
-func (f *dlFuncs) Close() {
-	f.lib.Close()
-}
+const ProcPidInfoSym = "proc_pidinfo"
 
 func GetMemoryInfo(pid int32) (*MemoryInfoStat, error) {
-	funcs, err := loadProcFuncs()
+	lib, err := purego.Dlopen(System, purego.RTLD_LAZY|purego.RTLD_GLOBAL)
 	if err != nil {
 		return nil, err
 	}
-	defer funcs.Close()
+	defer purego.Dlclose(lib)
+
+	var procPidInfo ProcPidInfoFunc
+	purego.RegisterLibFunc(&procPidInfo, lib, ProcPidInfoSym)
 
 	var ti ProcTaskInfo
-	funcs.procPidInfo(pid, PROC_PIDTASKINFO, 0, uintptr(unsafe.Pointer(&ti)), int32(unsafe.Sizeof(ti)))
+	procPidInfo(pid, PROC_PIDTASKINFO, 0, uintptr(unsafe.Pointer(&ti)), int32(unsafe.Sizeof(ti)))
 
 	ret := &MemoryInfoStat{
 		RSS: uint64(ti.Resident_size),