forgejo/vendor/github.com/RoaringBitmap/roaring/serialization_littleendian.go
6543 30ce3731a1
Vendor Update Go Libs ()
* denisenkom/go-mssqldb untagged -> v0.9.0

* github.com/editorconfig/editorconfig-core-go v2.3.7 -> v2.3.8

* github.com/go-testfixtures/testfixtures v3.4.0 -> v3.4.1

* github.com/mholt/archiver v3.3.2 -> v3.5.0

* github.com/olivere/elastic v7.0.20 -> v7.0.21

* github.com/urfave/cli v1.22.4 -> v1.22.5

* github.com/xanzy/go-gitlab v0.38.1 -> v0.39.0

* github.com/yuin/goldmark-meta untagged -> v1.0.0

* github.com/ethantkoenig/rupture 0a76f03a811a -> c3b3b810dc77

* github.com/jaytaylor/html2text 8fb95d837f7d -> 3577fbdbcff7

* github.com/kballard/go-shellquote cd60e84ee657 -> 95032a82bc51

* github.com/msteinert/pam 02ccfbfaf0cc -> 913b8f8cdf8b

* github.com/unknwon/paginater 7748a72e0141 -> 042474bd0eae

* CI.restart()

Co-authored-by: techknowlogick <techknowlogick@gitea.io>
2020-11-06 13:41:42 -05:00

134 lines
3.8 KiB
Go
Vendored

// +build 386,!appengine amd64,!appengine arm,!appengine arm64,!appengine ppc64le,!appengine mipsle,!appengine mips64le,!appengine mips64p32le,!appengine wasm,!appengine
package roaring
import (
"errors"
"io"
"reflect"
"runtime"
"unsafe"
)
func (ac *arrayContainer) writeTo(stream io.Writer) (int, error) {
buf := uint16SliceAsByteSlice(ac.content)
return stream.Write(buf)
}
func (bc *bitmapContainer) writeTo(stream io.Writer) (int, error) {
if bc.cardinality <= arrayDefaultMaxSize {
return 0, errors.New("refusing to write bitmap container with cardinality of array container")
}
buf := uint64SliceAsByteSlice(bc.bitmap)
return stream.Write(buf)
}
func uint64SliceAsByteSlice(slice []uint64) []byte {
// make a new slice header
header := *(*reflect.SliceHeader)(unsafe.Pointer(&slice))
// update its capacity and length
header.Len *= 8
header.Cap *= 8
// instantiate result and use KeepAlive so data isn't unmapped.
result := *(*[]byte)(unsafe.Pointer(&header))
runtime.KeepAlive(&slice)
// return it
return result
}
func uint16SliceAsByteSlice(slice []uint16) []byte {
// make a new slice header
header := *(*reflect.SliceHeader)(unsafe.Pointer(&slice))
// update its capacity and length
header.Len *= 2
header.Cap *= 2
// instantiate result and use KeepAlive so data isn't unmapped.
result := *(*[]byte)(unsafe.Pointer(&header))
runtime.KeepAlive(&slice)
// return it
return result
}
func (bc *bitmapContainer) asLittleEndianByteSlice() []byte {
return uint64SliceAsByteSlice(bc.bitmap)
}
// Deserialization code follows
////
// These methods (byteSliceAsUint16Slice,...) do not make copies,
// they are pointer-based (unsafe). The caller is responsible to
// ensure that the input slice does not get garbage collected, deleted
// or modified while you hold the returned slince.
////
func byteSliceAsUint16Slice(slice []byte) (result []uint16) { // here we create a new slice holder
if len(slice)%2 != 0 {
panic("Slice size should be divisible by 2")
}
// reference: https://go101.org/article/unsafe.html
// make a new slice header
bHeader := (*reflect.SliceHeader)(unsafe.Pointer(&slice))
rHeader := (*reflect.SliceHeader)(unsafe.Pointer(&result))
// transfer the data from the given slice to a new variable (our result)
rHeader.Data = bHeader.Data
rHeader.Len = bHeader.Len / 2
rHeader.Cap = bHeader.Cap / 2
// instantiate result and use KeepAlive so data isn't unmapped.
runtime.KeepAlive(&slice) // it is still crucial, GC can free it)
// return result
return
}
func byteSliceAsUint64Slice(slice []byte) (result []uint64) {
if len(slice)%8 != 0 {
panic("Slice size should be divisible by 8")
}
// reference: https://go101.org/article/unsafe.html
// make a new slice header
bHeader := (*reflect.SliceHeader)(unsafe.Pointer(&slice))
rHeader := (*reflect.SliceHeader)(unsafe.Pointer(&result))
// transfer the data from the given slice to a new variable (our result)
rHeader.Data = bHeader.Data
rHeader.Len = bHeader.Len / 8
rHeader.Cap = bHeader.Cap / 8
// instantiate result and use KeepAlive so data isn't unmapped.
runtime.KeepAlive(&slice) // it is still crucial, GC can free it)
// return result
return
}
func byteSliceAsInterval16Slice(slice []byte) (result []interval16) {
if len(slice)%4 != 0 {
panic("Slice size should be divisible by 4")
}
// reference: https://go101.org/article/unsafe.html
// make a new slice header
bHeader := (*reflect.SliceHeader)(unsafe.Pointer(&slice))
rHeader := (*reflect.SliceHeader)(unsafe.Pointer(&result))
// transfer the data from the given slice to a new variable (our result)
rHeader.Data = bHeader.Data
rHeader.Len = bHeader.Len / 4
rHeader.Cap = bHeader.Cap / 4
// instantiate result and use KeepAlive so data isn't unmapped.
runtime.KeepAlive(&slice) // it is still crucial, GC can free it)
// return result
return
}