diff options
Diffstat (limited to 'vendor/github.com/bytedance/sonic/internal/caching/pcache.go')
-rw-r--r-- | vendor/github.com/bytedance/sonic/internal/caching/pcache.go | 173 |
1 files changed, 0 insertions, 173 deletions
diff --git a/vendor/github.com/bytedance/sonic/internal/caching/pcache.go b/vendor/github.com/bytedance/sonic/internal/caching/pcache.go deleted file mode 100644 index 8c1224d9c..000000000 --- a/vendor/github.com/bytedance/sonic/internal/caching/pcache.go +++ /dev/null @@ -1,173 +0,0 @@ -/* - * Copyright 2021 ByteDance Inc. - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - -package caching - -import ( - `sync` - `sync/atomic` - `unsafe` - - `github.com/bytedance/sonic/internal/rt` -) - -/** Program Map **/ - -const ( - _LoadFactor = 0.5 - _InitCapacity = 4096 // must be a power of 2 -) - -type _ProgramMap struct { - n uint64 - m uint32 - b []_ProgramEntry -} - -type _ProgramEntry struct { - vt *rt.GoType - fn interface{} -} - -func newProgramMap() *_ProgramMap { - return &_ProgramMap { - n: 0, - m: _InitCapacity - 1, - b: make([]_ProgramEntry, _InitCapacity), - } -} - -func (self *_ProgramMap) copy() *_ProgramMap { - fork := &_ProgramMap{ - n: self.n, - m: self.m, - b: make([]_ProgramEntry, len(self.b)), - } - for i, f := range self.b { - fork.b[i] = f - } - return fork -} - -func (self *_ProgramMap) get(vt *rt.GoType) interface{} { - i := self.m + 1 - p := vt.Hash & self.m - - /* linear probing */ - for ; i > 0; i-- { - if b := self.b[p]; b.vt == vt { - return b.fn - } else if b.vt == nil { - break - } else { - p = (p + 1) & self.m - } - } - - /* not found */ - return nil -} - -func (self *_ProgramMap) add(vt *rt.GoType, fn interface{}) *_ProgramMap { - p := self.copy() - f := float64(atomic.LoadUint64(&p.n) + 1) / float64(p.m + 1) - - /* check for load factor */ - if f > _LoadFactor { - p = p.rehash() - } - - /* insert the value */ - p.insert(vt, fn) - return p -} - -func (self *_ProgramMap) rehash() *_ProgramMap { - c := (self.m + 1) << 1 - r := &_ProgramMap{m: c - 1, b: make([]_ProgramEntry, int(c))} - - /* rehash every entry */ - for i := uint32(0); i <= self.m; i++ { - if b := self.b[i]; b.vt != nil { - r.insert(b.vt, b.fn) - } - } - - /* rebuild successful */ - return r -} - -func (self *_ProgramMap) insert(vt *rt.GoType, fn interface{}) { - h := vt.Hash - p := h & self.m - - /* linear probing */ - for i := uint32(0); i <= self.m; i++ { - if b := &self.b[p]; b.vt != nil { - p += 1 - p &= self.m - } else { - b.vt = vt - b.fn = fn - atomic.AddUint64(&self.n, 1) - return - } - } - - /* should never happens */ - panic("no available slots") -} - -/** RCU Program Cache **/ - -type ProgramCache struct { - m sync.Mutex - p unsafe.Pointer -} - -func CreateProgramCache() *ProgramCache { - return &ProgramCache { - m: sync.Mutex{}, - p: unsafe.Pointer(newProgramMap()), - } -} - -func (self *ProgramCache) Get(vt *rt.GoType) interface{} { - return (*_ProgramMap)(atomic.LoadPointer(&self.p)).get(vt) -} - -func (self *ProgramCache) Compute(vt *rt.GoType, compute func(*rt.GoType, ... interface{}) (interface{}, error), ex ...interface{}) (interface{}, error) { - var err error - var val interface{} - - /* use defer to prevent inlining of this function */ - self.m.Lock() - defer self.m.Unlock() - - /* double check with write lock held */ - if val = self.Get(vt); val != nil { - return val, nil - } - - /* compute the value */ - if val, err = compute(vt, ex...); err != nil { - return nil, err - } - - /* update the RCU cache */ - atomic.StorePointer(&self.p, unsafe.Pointer((*_ProgramMap)(atomic.LoadPointer(&self.p)).add(vt, val))) - return val, nil -} |