1// Copyright 2019 Google Inc. All rights reserved. 2// 3// Licensed under the Apache License, Version 2.0 (the "License"); 4// you may not use this file except in compliance with the License. 5// You may obtain a copy of the License at 6// 7// http://www.apache.org/licenses/LICENSE-2.0 8// 9// Unless required by applicable law or agreed to in writing, software 10// distributed under the License is distributed on an "AS IS" BASIS, 11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12// See the License for the specific language governing permissions and 13// limitations under the License. 14 15package build 16 17import ( 18 "encoding/binary" 19 "syscall" 20) 21 22func detectTotalRAM(ctx Context) uint64 { 23 s, err := syscall.Sysctl("hw.memsize") 24 if err != nil { 25 ctx.Printf("Failed to get system memory size: %v", err) 26 return 0 27 } 28 29 // syscall.Sysctl assumes that the return value is a string and trims the last byte if it is 0. 30 if len(s) == 7 { 31 s += "\x00" 32 } 33 34 if len(s) != 8 { 35 ctx.Printf("Failed to get system memory size, returned %d bytes, expecting 8 bytes", len(s)) 36 return 0 37 } 38 39 return binary.LittleEndian.Uint64([]byte(s)) 40} 41