github.com/cloudwego/frugal@v0.1.15/internal/binary/defs/sizes.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 defs
    18  
    19  import (
    20      `reflect`
    21  )
    22  
    23  const (
    24      IntSize   = 4 << (^uint(0) >> 63)
    25      StackSize = 1024
    26  )
    27  
    28  func GetSize(vt reflect.Type) int {
    29      switch vt.Kind() {
    30          case reflect.Bool    : return 1
    31          case reflect.Int     : return IntSize
    32          case reflect.Int8    : return 1
    33          case reflect.Int16   : return 2
    34          case reflect.Int32   : return 4
    35          case reflect.Int64   : return measureInt64(vt)
    36          case reflect.Float64 : return 8
    37          case reflect.Map     : return -1
    38          case reflect.Ptr     : return -1
    39          case reflect.Slice   : return -1
    40          case reflect.String  : return -1
    41          case reflect.Struct  : return measureStruct(vt)
    42          default              : panic("unsupported type by Thrift")
    43      }
    44  }
    45  
    46  func measureInt64(vt reflect.Type) int {
    47      if vt == i64type {
    48          return 8
    49      } else {
    50          return 4
    51      }
    52  }
    53  
    54  func measureStruct(vt reflect.Type) int {
    55      var fs int
    56      var rs int
    57  
    58      /* measure each field, plus the 3-byte field header */
    59      for i := 0; i < vt.NumField(); i++ {
    60          if fs = GetSize(vt.Field(i).Type); fs > 0 {
    61              rs += fs + 3
    62          } else {
    63              return -1
    64          }
    65      }
    66  
    67      /* all fields have fixed size, plus the STOP field */
    68      return rs + 1
    69  }