| khenaidoo | 2672188 | 2021-08-11 17:42:52 -0400 | [diff] [blame] | 1 | // Copyright 2019 The Prometheus Authors |
| 2 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 3 | // you may not use this file except in compliance with the License. |
| 4 | // You may obtain a copy of the License at |
| 5 | // |
| 6 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 7 | // |
| 8 | // Unless required by applicable law or agreed to in writing, software |
| 9 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 10 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 11 | // See the License for the specific language governing permissions and |
| 12 | // limitations under the License. |
| 13 | |
| 14 | package util |
| 15 | |
| 16 | import ( |
| 17 | "io" |
| 18 | "io/ioutil" |
| 19 | "os" |
| 20 | ) |
| 21 | |
| 22 | // ReadFileNoStat uses ioutil.ReadAll to read contents of entire file. |
| 23 | // This is similar to ioutil.ReadFile but without the call to os.Stat, because |
| 24 | // many files in /proc and /sys report incorrect file sizes (either 0 or 4096). |
| 25 | // Reads a max file size of 512kB. For files larger than this, a scanner |
| 26 | // should be used. |
| 27 | func ReadFileNoStat(filename string) ([]byte, error) { |
| 28 | const maxBufferSize = 1024 * 512 |
| 29 | |
| 30 | f, err := os.Open(filename) |
| 31 | if err != nil { |
| 32 | return nil, err |
| 33 | } |
| 34 | defer f.Close() |
| 35 | |
| 36 | reader := io.LimitReader(f, maxBufferSize) |
| 37 | return ioutil.ReadAll(reader) |
| 38 | } |