github.com/cloudwego/frugal@v0.1.15/pretouch.go (about)

     1  /*
     2   * Copyright 2022 ByteDance Inc.
     3   *
     4   * Licensed under the Apache License, Version 2.0 (the "License");
     5   * you may not use this file except in compliance with the License.
     6   * You may obtain a copy of the License at
     7   *
     8   *     http://www.apache.org/licenses/LICENSE-2.0
     9   *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS,
    12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13   * See the License for the specific language governing permissions and
    14   * limitations under the License.
    15   */
    16  
    17  package frugal
    18  
    19  import (
    20      `reflect`
    21      `sync`
    22  
    23      `github.com/cloudwego/frugal/internal/binary/decoder`
    24      `github.com/cloudwego/frugal/internal/binary/encoder`
    25      `github.com/cloudwego/frugal/internal/opts`
    26      `github.com/cloudwego/frugal/internal/rt`
    27      `github.com/oleiade/lane`
    28  )
    29  
    30  type _Ty struct {
    31      d  int
    32      ty *rt.GoType
    33  }
    34  
    35  var (
    36      typool sync.Pool
    37  )
    38  
    39  func newty(ty *rt.GoType, d int) *_Ty {
    40      if v := typool.Get(); v == nil {
    41          return &_Ty { d, ty }
    42      } else {
    43          r := v.(*_Ty)
    44          r.d, r.ty = d, ty
    45          return r
    46      }
    47  }
    48  
    49  // Pretouch compiles vt ahead-of-time to avoid JIT compilation on-the-fly, in
    50  // order to reduce the first-hit latency.
    51  func Pretouch(vt reflect.Type, options ...Option) error {
    52      d := 0
    53      o := opts.GetDefaultOptions()
    54  
    55      /* apply all the options */
    56      for _, fn := range options {
    57          fn(&o)
    58      }
    59  
    60      /* unpack the type */
    61      v := make(map[*rt.GoType]bool)
    62      t := rt.Dereference(rt.UnpackType(vt))
    63  
    64      /* add the root type */
    65      q := lane.NewQueue()
    66      q.Enqueue(newty(t, 1))
    67  
    68      /* BFS the type tree */
    69      for !q.Empty() {
    70          ty := q.Pop().(*_Ty)
    71          tv, err := decoder.Pretouch(ty.ty, o)
    72  
    73          /* also pretouch the encoder */
    74          if err == nil {
    75              err = encoder.Pretouch(ty.ty, o)
    76          }
    77  
    78          /* mark the type as been visited */
    79          d, v[ty.ty] = ty.d, true
    80          typool.Put(ty)
    81  
    82          /* check for errors */
    83          if err != nil {
    84              return err
    85          }
    86  
    87          /* check for cutoff conditions */
    88          if !o.CanPretouch(d) {
    89              continue
    90          }
    91  
    92          /* add all the not visited sub-types */
    93          for s := range tv {
    94              if t = rt.UnpackType(s); !v[t] {
    95                  q.Enqueue(newty(t, d + 1))
    96              }
    97          }
    98      }
    99  
   100      /* completed with no errors */
   101      return nil
   102  }