github.com/matrixorigin/matrixone@v1.2.0/pkg/container/types/bytes.go (about)

     1  // Copyright 2021 Matrix Origin
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package types
    16  
    17  import (
    18  	"bytes"
    19  	"unsafe"
    20  
    21  	"github.com/matrixorigin/matrixone/pkg/common/mpool"
    22  	"github.com/matrixorigin/matrixone/pkg/common/util"
    23  )
    24  
    25  const (
    26  	VarlenaInlineSize = 23
    27  	VarlenaSize       = 24
    28  	MaxStringSize     = 10485760
    29  	VarlenaBigHdr     = 0xffffffff
    30  	MaxVarcharLen     = 65535
    31  	MaxCharLen        = 255
    32  	MaxBinaryLen      = 255
    33  	MaxVarBinaryLen   = 65535
    34  	MaxEnumLen        = 65535
    35  	MaxBitLen         = 64
    36  )
    37  
    38  func (v *Varlena) UnsafePtr() unsafe.Pointer {
    39  	return unsafe.Pointer(&v[0])
    40  }
    41  
    42  func (v *Varlena) ByteSlice() []byte {
    43  	svlen := (*v)[0]
    44  	ptr := unsafe.Add(unsafe.Pointer(&v[0]), 1)
    45  	return unsafe.Slice((*byte)(ptr), svlen)
    46  }
    47  
    48  func (v *Varlena) U32Slice() []uint32 {
    49  	ptr := (*uint32)(v.UnsafePtr())
    50  	return unsafe.Slice(ptr, 6)
    51  }
    52  
    53  func (v *Varlena) OffsetLen() (uint32, uint32) {
    54  	s := v.U32Slice()
    55  	return s[1], s[2]
    56  }
    57  
    58  func (v *Varlena) SetOffsetLen(voff, vlen uint32) {
    59  	s := v.U32Slice()
    60  	s[0] = VarlenaBigHdr
    61  	s[1] = voff
    62  	s[2] = vlen
    63  }
    64  
    65  // do not use this function, will be deleted in the future
    66  // use BuildVarlenaFromValena or BuildVarlenaFromByteSlice instead
    67  func BuildVarlena(bs []byte, area []byte, m *mpool.MPool) (Varlena, []byte, error) {
    68  	var err error
    69  	var v Varlena
    70  	vlen := len(bs)
    71  	if vlen <= VarlenaInlineSize {
    72  		v[0] = byte(vlen)
    73  		copy(v[1:1+vlen], bs)
    74  		return v, area, nil
    75  	} else {
    76  		voff := len(area)
    77  		if voff+vlen < cap(area) || m == nil {
    78  			area = append(area, bs...)
    79  		} else {
    80  			area, err = m.Grow2(area, bs, voff+vlen)
    81  			if err != nil {
    82  				return v, nil, err
    83  			}
    84  		}
    85  		v.SetOffsetLen(uint32(voff), uint32(vlen))
    86  		return v, area, nil
    87  	}
    88  }
    89  
    90  func (v *Varlena) IsSmall() bool {
    91  	return (*v)[0] <= VarlenaInlineSize
    92  }
    93  
    94  // For short slice, this one will return a slice stored internal
    95  // in the varlena.   Caller must ensure that v has a longer life
    96  // span than the returned byte slice.
    97  //
    98  // Main user of Varlena is vector.  v that comes from vector.Data
    99  // will be fine.
   100  func (v *Varlena) GetByteSlice(area []byte) []byte {
   101  	svlen := (*v)[0]
   102  	if svlen <= VarlenaInlineSize {
   103  		return v.ByteSlice()
   104  	}
   105  	voff, vlen := v.OffsetLen()
   106  	return area[voff : voff+vlen]
   107  }
   108  
   109  // GetArray Returns []T from Varlena. If the Varlena size is less than Inline size,
   110  // it returns the value from the Varlena header.
   111  // Else, it returns the value from the area.
   112  func GetArray[T RealNumbers](v *Varlena, area []byte) []T {
   113  	svlen := (*v)[0]
   114  	if svlen <= VarlenaInlineSize {
   115  		return BytesToArray[T](v.ByteSlice())
   116  	}
   117  	voff, vlen := v.OffsetLen()
   118  	return BytesToArray[T](area[voff : voff+vlen])
   119  }
   120  
   121  // See the lifespan comment above.
   122  func (v *Varlena) GetString(area []byte) string {
   123  	return util.UnsafeBytesToString(v.GetByteSlice(area))
   124  }
   125  
   126  func (v *Varlena) Reset() {
   127  	var vzero Varlena
   128  	*v = vzero
   129  }
   130  
   131  func PrefixCompare(lhs, rhs []byte) int {
   132  	if len(lhs) > len(rhs) {
   133  		lhs = lhs[:len(rhs)]
   134  	}
   135  
   136  	return bytes.Compare(lhs, rhs)
   137  }