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author | Matthew Heon <matthew.heon@gmail.com> | 2018-08-22 10:59:53 -0400 |
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committer | Atomic Bot <atomic-devel@projectatomic.io> | 2018-08-24 19:19:43 +0000 |
commit | 20a625ba776aee115b872d092a61313fbc8240be (patch) | |
tree | 61d57b261445769987a9215e26db678334b98327 /vendor/github.com/mailru/easyjson/buffer/pool.go | |
parent | 714dbbda9e1f3ec98d75a07ed4c5442ea6540680 (diff) | |
download | podman-20a625ba776aee115b872d092a61313fbc8240be.tar.gz podman-20a625ba776aee115b872d092a61313fbc8240be.tar.bz2 podman-20a625ba776aee115b872d092a61313fbc8240be.zip |
Vendor easyjson code to fix build
To ensure we can build without easyjson installed, vendor the
easyjson repository as the generated files use the easyjson
library.
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Closes: #1322
Approved by: mheon
Diffstat (limited to 'vendor/github.com/mailru/easyjson/buffer/pool.go')
-rw-r--r-- | vendor/github.com/mailru/easyjson/buffer/pool.go | 270 |
1 files changed, 270 insertions, 0 deletions
diff --git a/vendor/github.com/mailru/easyjson/buffer/pool.go b/vendor/github.com/mailru/easyjson/buffer/pool.go new file mode 100644 index 000000000..07fb4bc1f --- /dev/null +++ b/vendor/github.com/mailru/easyjson/buffer/pool.go @@ -0,0 +1,270 @@ +// Package buffer implements a buffer for serialization, consisting of a chain of []byte-s to +// reduce copying and to allow reuse of individual chunks. +package buffer + +import ( + "io" + "sync" +) + +// PoolConfig contains configuration for the allocation and reuse strategy. +type PoolConfig struct { + StartSize int // Minimum chunk size that is allocated. + PooledSize int // Minimum chunk size that is reused, reusing chunks too small will result in overhead. + MaxSize int // Maximum chunk size that will be allocated. +} + +var config = PoolConfig{ + StartSize: 128, + PooledSize: 512, + MaxSize: 32768, +} + +// Reuse pool: chunk size -> pool. +var buffers = map[int]*sync.Pool{} + +func initBuffers() { + for l := config.PooledSize; l <= config.MaxSize; l *= 2 { + buffers[l] = new(sync.Pool) + } +} + +func init() { + initBuffers() +} + +// Init sets up a non-default pooling and allocation strategy. Should be run before serialization is done. +func Init(cfg PoolConfig) { + config = cfg + initBuffers() +} + +// putBuf puts a chunk to reuse pool if it can be reused. +func putBuf(buf []byte) { + size := cap(buf) + if size < config.PooledSize { + return + } + if c := buffers[size]; c != nil { + c.Put(buf[:0]) + } +} + +// getBuf gets a chunk from reuse pool or creates a new one if reuse failed. +func getBuf(size int) []byte { + if size < config.PooledSize { + return make([]byte, 0, size) + } + + if c := buffers[size]; c != nil { + v := c.Get() + if v != nil { + return v.([]byte) + } + } + return make([]byte, 0, size) +} + +// Buffer is a buffer optimized for serialization without extra copying. +type Buffer struct { + + // Buf is the current chunk that can be used for serialization. + Buf []byte + + toPool []byte + bufs [][]byte +} + +// EnsureSpace makes sure that the current chunk contains at least s free bytes, +// possibly creating a new chunk. +func (b *Buffer) EnsureSpace(s int) { + if cap(b.Buf)-len(b.Buf) >= s { + return + } + l := len(b.Buf) + if l > 0 { + if cap(b.toPool) != cap(b.Buf) { + // Chunk was reallocated, toPool can be pooled. + putBuf(b.toPool) + } + if cap(b.bufs) == 0 { + b.bufs = make([][]byte, 0, 8) + } + b.bufs = append(b.bufs, b.Buf) + l = cap(b.toPool) * 2 + } else { + l = config.StartSize + } + + if l > config.MaxSize { + l = config.MaxSize + } + b.Buf = getBuf(l) + b.toPool = b.Buf +} + +// AppendByte appends a single byte to buffer. +func (b *Buffer) AppendByte(data byte) { + if cap(b.Buf) == len(b.Buf) { // EnsureSpace won't be inlined. + b.EnsureSpace(1) + } + b.Buf = append(b.Buf, data) +} + +// AppendBytes appends a byte slice to buffer. +func (b *Buffer) AppendBytes(data []byte) { + for len(data) > 0 { + if cap(b.Buf) == len(b.Buf) { // EnsureSpace won't be inlined. + b.EnsureSpace(1) + } + + sz := cap(b.Buf) - len(b.Buf) + if sz > len(data) { + sz = len(data) + } + + b.Buf = append(b.Buf, data[:sz]...) + data = data[sz:] + } +} + +// AppendBytes appends a string to buffer. +func (b *Buffer) AppendString(data string) { + for len(data) > 0 { + if cap(b.Buf) == len(b.Buf) { // EnsureSpace won't be inlined. + b.EnsureSpace(1) + } + + sz := cap(b.Buf) - len(b.Buf) + if sz > len(data) { + sz = len(data) + } + + b.Buf = append(b.Buf, data[:sz]...) + data = data[sz:] + } +} + +// Size computes the size of a buffer by adding sizes of every chunk. +func (b *Buffer) Size() int { + size := len(b.Buf) + for _, buf := range b.bufs { + size += len(buf) + } + return size +} + +// DumpTo outputs the contents of a buffer to a writer and resets the buffer. +func (b *Buffer) DumpTo(w io.Writer) (written int, err error) { + var n int + for _, buf := range b.bufs { + if err == nil { + n, err = w.Write(buf) + written += n + } + putBuf(buf) + } + + if err == nil { + n, err = w.Write(b.Buf) + written += n + } + putBuf(b.toPool) + + b.bufs = nil + b.Buf = nil + b.toPool = nil + + return +} + +// BuildBytes creates a single byte slice with all the contents of the buffer. Data is +// copied if it does not fit in a single chunk. You can optionally provide one byte +// slice as argument that it will try to reuse. +func (b *Buffer) BuildBytes(reuse ...[]byte) []byte { + if len(b.bufs) == 0 { + ret := b.Buf + b.toPool = nil + b.Buf = nil + return ret + } + + var ret []byte + size := b.Size() + + // If we got a buffer as argument and it is big enought, reuse it. + if len(reuse) == 1 && cap(reuse[0]) >= size { + ret = reuse[0][:0] + } else { + ret = make([]byte, 0, size) + } + for _, buf := range b.bufs { + ret = append(ret, buf...) + putBuf(buf) + } + + ret = append(ret, b.Buf...) + putBuf(b.toPool) + + b.bufs = nil + b.toPool = nil + b.Buf = nil + + return ret +} + +type readCloser struct { + offset int + bufs [][]byte +} + +func (r *readCloser) Read(p []byte) (n int, err error) { + for _, buf := range r.bufs { + // Copy as much as we can. + x := copy(p[n:], buf[r.offset:]) + n += x // Increment how much we filled. + + // Did we empty the whole buffer? + if r.offset+x == len(buf) { + // On to the next buffer. + r.offset = 0 + r.bufs = r.bufs[1:] + + // We can release this buffer. + putBuf(buf) + } else { + r.offset += x + } + + if n == len(p) { + break + } + } + // No buffers left or nothing read? + if len(r.bufs) == 0 { + err = io.EOF + } + return +} + +func (r *readCloser) Close() error { + // Release all remaining buffers. + for _, buf := range r.bufs { + putBuf(buf) + } + // In case Close gets called multiple times. + r.bufs = nil + + return nil +} + +// ReadCloser creates an io.ReadCloser with all the contents of the buffer. +func (b *Buffer) ReadCloser() io.ReadCloser { + ret := &readCloser{0, append(b.bufs, b.Buf)} + + b.bufs = nil + b.toPool = nil + b.Buf = nil + + return ret +} |