diff options
author | Kali Kaneko (leap communications) <kali@leap.se> | 2019-01-12 18:39:45 +0100 |
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committer | Ruben Pollan <meskio@sindominio.net> | 2019-01-17 12:30:32 +0100 |
commit | b1247d2d0d51108c910a73891ff3116e5f032ab1 (patch) | |
tree | e9948964f0bfb1ad2df3bc7bad02aa1f41ccfbd8 /vendor/github.com/oxtoacart/bpool/sizedbufferpool.go | |
parent | efcb8312e31b5c2261b1a1e95ace55b322cfcc27 (diff) |
[pkg] all your deps are vendored to us
Diffstat (limited to 'vendor/github.com/oxtoacart/bpool/sizedbufferpool.go')
-rw-r--r-- | vendor/github.com/oxtoacart/bpool/sizedbufferpool.go | 60 |
1 files changed, 60 insertions, 0 deletions
diff --git a/vendor/github.com/oxtoacart/bpool/sizedbufferpool.go b/vendor/github.com/oxtoacart/bpool/sizedbufferpool.go new file mode 100644 index 0000000..8519aca --- /dev/null +++ b/vendor/github.com/oxtoacart/bpool/sizedbufferpool.go @@ -0,0 +1,60 @@ +package bpool + +import ( + "bytes" +) + +// SizedBufferPool implements a pool of bytes.Buffers in the form of a bounded +// channel. Buffers are pre-allocated to the requested size. +type SizedBufferPool struct { + c chan *bytes.Buffer + a int +} + +// SizedBufferPool creates a new BufferPool bounded to the given size. +// size defines the number of buffers to be retained in the pool and alloc sets +// the initial capacity of new buffers to minimize calls to make(). +// +// The value of alloc should seek to provide a buffer that is representative of +// most data written to the the buffer (i.e. 95th percentile) without being +// overly large (which will increase static memory consumption). You may wish to +// track the capacity of your last N buffers (i.e. using an []int) prior to +// returning them to the pool as input into calculating a suitable alloc value. +func NewSizedBufferPool(size int, alloc int) (bp *SizedBufferPool) { + return &SizedBufferPool{ + c: make(chan *bytes.Buffer, size), + a: alloc, + } +} + +// Get gets a Buffer from the SizedBufferPool, or creates a new one if none are +// available in the pool. Buffers have a pre-allocated capacity. +func (bp *SizedBufferPool) Get() (b *bytes.Buffer) { + select { + case b = <-bp.c: + // reuse existing buffer + default: + // create new buffer + b = bytes.NewBuffer(make([]byte, 0, bp.a)) + } + return +} + +// Put returns the given Buffer to the SizedBufferPool. +func (bp *SizedBufferPool) Put(b *bytes.Buffer) { + b.Reset() + + // Release buffers over our maximum capacity and re-create a pre-sized + // buffer to replace it. + // Note that the cap(b.Bytes()) provides the capacity from the read off-set + // only, but as we've called b.Reset() the full capacity of the underlying + // byte slice is returned. + if cap(b.Bytes()) > bp.a { + b = bytes.NewBuffer(make([]byte, 0, bp.a)) + } + + select { + case bp.c <- b: + default: // Discard the buffer if the pool is full. + } +} |