Auto cache shutdown based on memory consumption

Question

I want to implement an efficient LRU cache that automatically preempts elements based on free memory.

Now only 2 things come to mind:

• Poll with gosigar
• or set a fixed maximum and periodically check runtime.ReadMemStats .

Are there any other ways? How to do memcached ?

Answer 1

I carried out his survey of system memory statistics every 1 second.

See: https://github.com/eaigner/last

Reading memory statistics on Linux:

 import ( "syscall" ) func ReadSysMemStats(s *MemStats) error { if s == nil { return nil } var info syscall.Sysinfo_t err := syscall.Sysinfo(&info) if err != nil { return err } s.Total = info.Totalram s.Free = info.Freeram s.Used = s.Total - s.Free return nil } 

And on Darwin / OSX

 /* #include <mach/mach.h> #include <mach/mach_host.h> */ import "C" import ( "fmt" "unsafe" ) func readSysMemStats(s *SysMemStats) error { if s == nil { return nil } var vm_pagesize C.vm_size_t var vm_stat C.vm_statistics_data_t var count C.mach_msg_type_number_t = C.HOST_VM_INFO_COUNT host_port := C.host_t(C.mach_host_self()) C.host_page_size(host_port, &vm_pagesize) status := C.host_statistics( host_port, C.HOST_VM_INFO, C.host_info_t(unsafe.Pointer(&vm_stat)), &count) if status != C.KERN_SUCCESS { return fmt.Errorf("could not get vm statistics: %d", status) } // Stats in bytes free := uint64(vm_stat.free_count) active := uint64(vm_stat.active_count) inactive := uint64(vm_stat.inactive_count) wired := uint64(vm_stat.wire_count) pagesize := uint64(vm_pagesize) s.Used = (active + inactive + wired) * pagesize s.Free = free * pagesize s.Total = s.Used + s.Free return nil }