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55 lines
1.7 KiB
Go
55 lines
1.7 KiB
Go
// Copyright 2017 Pilosa Corp.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package syswrap
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import (
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"os"
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"sync"
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"sync/atomic"
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)
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var fileCount uint64
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// maxFileCount is the soft limit on the number of open files. syswrap.OpenFile
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// will warn when this limit is passed.
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var maxFileCount uint64 = 500000
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var fileMu sync.RWMutex
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func SetMaxFileCount(max uint64) {
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fileMu.Lock()
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maxFileCount = max
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fileMu.Unlock()
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}
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// OpenFile passes the arguments along to os.OpenFile while incrementing a
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// counter. If the counter is above the maximum, it returns mustClose true to
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// signal the calling function that it should not keep the file open
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// indefinitely. Files opened with this function should be closed by
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// syswrap.CloseFile.
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func OpenFile(name string, flag int, perm os.FileMode) (file *os.File, mustClose bool, err error) {
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file, err = os.OpenFile(name, flag, perm)
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fileMu.RLock()
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defer fileMu.RUnlock()
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if newCount := atomic.AddUint64(&fileCount, 1); newCount > maxFileCount {
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mustClose = true
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}
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return file, mustClose, err
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}
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// CloseFile decrements the global count of open files and closes the file.
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func CloseFile(f *os.File) error {
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atomic.AddUint64(&fileCount, ^uint64(0)) // decrement
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return f.Close()
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}
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