stackmap.go

Documentation: github.com/bytedance/sonic/internal/rt

     1  /**
     2   * Copyright 2023 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 rt
    18  
    19  import (
    20      `fmt`
    21      `strings`
    22      `unsafe`
    23  
    24  )
    25  
    26  type Bitmap struct {
    27      N int
    28      B []byte
    29  }
    30  
    31  func (self *Bitmap) grow() {
    32      if self.N >= len(self.B) * 8 {
    33          self.B = append(self.B, 0)
    34      }
    35  }
    36  
    37  func (self *Bitmap) mark(i int, bv int) {
    38      if bv != 0 {
    39          self.B[i / 8] |= 1 << (i % 8)
    40      } else {
    41          self.B[i / 8] &^= 1 << (i % 8)
    42      }
    43  }
    44  
    45  func (self *Bitmap) Set(i int, bv int) {
    46      if i >= self.N {
    47          panic("bitmap: invalid bit position")
    48      } else {
    49          self.mark(i, bv)
    50      }
    51  }
    52  
    53  func (self *Bitmap) Append(bv int) {
    54      self.grow()
    55      self.mark(self.N, bv)
    56      self.N++
    57  }
    58  
    59  func (self *Bitmap) AppendMany(n int, bv int) {
    60      for i := 0; i < n; i++ {
    61          self.Append(bv)
    62      }
    63  }
    64  
    65  // var (
    66  //     _stackMapLock  = sync.Mutex{}
    67  //     _stackMapCache = make(map[*StackMap]struct{})
    68  // )
    69  
    70  type BitVec struct {
    71      N uintptr
    72      B unsafe.Pointer
    73  }
    74  
    75  func (self BitVec) Bit(i uintptr) byte {
    76      return (*(*byte)(unsafe.Pointer(uintptr(self.B) + i / 8)) >> (i % 8)) & 1
    77  }
    78  
    79  func (self BitVec) String() string {
    80      var i uintptr
    81      var v []string
    82  
    83      /* add each bit */
    84      for i = 0; i < self.N; i++ {
    85          v = append(v, fmt.Sprintf("%d", self.Bit(i)))
    86      }
    87  
    88      /* join them together */
    89      return fmt.Sprintf(
    90          "BitVec { %s }",
    91          strings.Join(v, ", "),
    92      )
    93  }
    94  
    95  type StackMap struct {
    96      N int32
    97      L int32
    98      B [1]byte
    99  }
   100  
   101  // func (self *StackMap) add() {
   102  //     _stackMapLock.Lock()
   103  //     _stackMapCache[self] = struct{}{}
   104  //     _stackMapLock.Unlock()
   105  // }
   106  
   107  func (self *StackMap) Pin() uintptr {
   108      // self.add()
   109      return uintptr(unsafe.Pointer(self))
   110  }
   111  
   112  func (self *StackMap) Get(i int32) BitVec {
   113      return BitVec {
   114          N: uintptr(self.L),
   115          B: unsafe.Pointer(uintptr(unsafe.Pointer(&self.B)) + uintptr(i * ((self.L + 7) >> 3))),
   116      }
   117  }
   118  
   119  func (self *StackMap) String() string {
   120      sb := strings.Builder{}
   121      sb.WriteString("StackMap {")
   122  
   123      /* dump every stack map */
   124      for i := int32(0); i < self.N; i++ {
   125          sb.WriteRune('\n')
   126          sb.WriteString("    " + self.Get(i).String())
   127      }
   128  
   129      /* close the stackmap */
   130      sb.WriteString("\n}")
   131      return sb.String()
   132  }
   133  
   134  func (self *StackMap) MarshalBinary() ([]byte, error) {
   135      size := int(self.N) * int(self.L) + int(unsafe.Sizeof(self.L)) + int(unsafe.Sizeof(self.N))
   136      return BytesFrom(unsafe.Pointer(self), size, size), nil
   137  }
   138  
   139  var (
   140      byteType = UnpackEface(byte(0)).Type
   141  )
   142  
   143  const (
   144      _StackMapSize = unsafe.Sizeof(StackMap{})
   145  )
   146  
   147  //go:linkname mallocgc runtime.mallocgc
   148  //goland:noinspection GoUnusedParameter
   149  func mallocgc(nb uintptr, vt *GoType, zero bool) unsafe.Pointer
   150  
   151  type StackMapBuilder struct {
   152      b Bitmap
   153  }
   154  
   155  //go:nocheckptr
   156  func (self *StackMapBuilder) Build() (p *StackMap) {
   157      nb := len(self.b.B)
   158      bm := mallocgc(_StackMapSize + uintptr(nb) - 1, byteType, false)
   159  
   160      /* initialize as 1 bitmap of N bits */
   161      p = (*StackMap)(bm)
   162      p.N, p.L = 1, int32(self.b.N)
   163      copy(BytesFrom(unsafe.Pointer(&p.B), nb, nb), self.b.B)
   164      return
   165  }
   166  
   167  func (self *StackMapBuilder) AddField(ptr bool) {
   168      if ptr {
   169          self.b.Append(1)
   170      } else {
   171          self.b.Append(0)
   172      }
   173  }
   174  
   175  func (self *StackMapBuilder) AddFields(n int, ptr bool) {
   176      if ptr {
   177          self.b.AppendMany(n, 1)
   178      } else {
   179          self.b.AppendMany(n, 0)
   180      }
   181  }
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