fastmem.go raw

   1  /*
   2   * Copyright 2021 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  	"reflect"
  21  	"unsafe"
  22  
  23  	"github.com/bytedance/sonic/option"
  24  )
  25  
  26  //go:nosplit
  27  func Get16(v []byte) int16 {
  28      return *(*int16)((*GoSlice)(unsafe.Pointer(&v)).Ptr)
  29  }
  30  
  31  //go:nosplit
  32  func Get32(v []byte) int32 {
  33      return *(*int32)((*GoSlice)(unsafe.Pointer(&v)).Ptr)
  34  }
  35  
  36  //go:nosplit
  37  func Get64(v []byte) int64 {
  38      return *(*int64)((*GoSlice)(unsafe.Pointer(&v)).Ptr)
  39  }
  40  
  41  //go:nosplit
  42  func Mem2Str(v []byte) (s string) {
  43      (*GoString)(unsafe.Pointer(&s)).Len = (*GoSlice)(unsafe.Pointer(&v)).Len
  44      (*GoString)(unsafe.Pointer(&s)).Ptr = (*GoSlice)(unsafe.Pointer(&v)).Ptr
  45      return
  46  }
  47  
  48  //go:nosplit
  49  func Str2Mem(s string) (v []byte) {
  50      (*GoSlice)(unsafe.Pointer(&v)).Cap = (*GoString)(unsafe.Pointer(&s)).Len
  51      (*GoSlice)(unsafe.Pointer(&v)).Len = (*GoString)(unsafe.Pointer(&s)).Len
  52      (*GoSlice)(unsafe.Pointer(&v)).Ptr = (*GoString)(unsafe.Pointer(&s)).Ptr
  53      return
  54  }
  55  
  56  func BytesFrom(p unsafe.Pointer, n int, c int) (r []byte) {
  57      (*GoSlice)(unsafe.Pointer(&r)).Ptr = p
  58      (*GoSlice)(unsafe.Pointer(&r)).Len = n
  59      (*GoSlice)(unsafe.Pointer(&r)).Cap = c
  60      return
  61  }
  62  
  63  func FuncAddr(f interface{}) unsafe.Pointer {
  64      if vv := UnpackEface(f); vv.Type.Kind() != reflect.Func {
  65          panic("f is not a function")
  66      } else {
  67          return *(*unsafe.Pointer)(vv.Value)
  68      }
  69  }
  70  
  71  //go:nocheckptr
  72  func IndexChar(src string, index int) unsafe.Pointer {
  73  	return unsafe.Pointer(uintptr((*GoString)(unsafe.Pointer(&src)).Ptr) + uintptr(index))
  74  }
  75  
  76  //go:nocheckptr
  77  func IndexByte(ptr []byte, index int) unsafe.Pointer {
  78  	return unsafe.Pointer(uintptr((*GoSlice)(unsafe.Pointer(&ptr)).Ptr) + uintptr(index))
  79  }
  80  
  81  func GuardSlice(buf *[]byte, n int) {
  82  	c := cap(*buf)
  83  	l := len(*buf)
  84  	if c-l < n {
  85  		c = c>>1 + n + l
  86  		if c < 32 {
  87  			c = 32
  88  		}
  89  		tmp := make([]byte, l, c)
  90  		copy(tmp, *buf)
  91  		*buf = tmp
  92  	}
  93  }
  94  
  95  func GuardSlice2(buf []byte, n int) []byte {
  96  	c := cap(buf)
  97  	l := len(buf)
  98  	if c-l < n {
  99  		c = c>>1 + n + l
 100  		if c < 32 {
 101  			c = 32
 102  		}
 103  		tmp := make([]byte, l, c)
 104  		copy(tmp, buf)
 105  		buf = tmp
 106  	}
 107      return buf
 108  }
 109  
 110  //go:nosplit
 111  func Ptr2SlicePtr(s unsafe.Pointer, l int, c int) unsafe.Pointer {
 112      slice := &GoSlice{
 113          Ptr: s,
 114          Len: l,
 115          Cap: c,
 116      }
 117      return unsafe.Pointer(slice)
 118  }
 119  
 120  //go:nosplit
 121  func StrPtr(s string) unsafe.Pointer {
 122      return (*GoString)(unsafe.Pointer(&s)).Ptr
 123  }
 124  
 125  //go:nosplit
 126  func StrFrom(p unsafe.Pointer, n int64) (s string) {
 127      (*GoString)(unsafe.Pointer(&s)).Ptr = p
 128      (*GoString)(unsafe.Pointer(&s)).Len = int(n)
 129      return
 130  }
 131  
 132  // NoEscape hides a pointer from escape analysis. NoEscape is
 133  // the identity function but escape analysis doesn't think the
 134  // output depends on the input. NoEscape is inlined and currently
 135  // compiles down to zero instructions.
 136  // USE CAREFULLY!
 137  //go:nosplit
 138  //goland:noinspection GoVetUnsafePointer
 139  func NoEscape(p unsafe.Pointer) unsafe.Pointer {
 140      x := uintptr(p)
 141      return unsafe.Pointer(x ^ 0)
 142  }
 143  
 144  //go:nosplit
 145  func MoreStack(size uintptr)
 146  
 147  //go:nosplit
 148  func Add(ptr unsafe.Pointer, off uintptr) unsafe.Pointer {
 149      return unsafe.Pointer(uintptr(ptr) + off)
 150  }
 151  
 152  // CanSizeResue
 153  func CanSizeResue(cap int) bool {
 154      return cap <= int(option.LimitBufferSize)
 155  }
 156