common

package
v1.0.0 Latest Latest
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 Go to latest Published: Apr 12, 2023 License: MIT Imports: 10 Imported by: 0

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Index

Constants

View Source 
const (
	BranchPageFlag   = 0x01
	LeafPageFlag     = 0x02
	MetaPageFlag     = 0x04
	FreelistPageFlag = 0x10
)
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const (
	DefaultMaxBatchSize  int = 1000
	DefaultMaxBatchDelay     = 10 * time.Millisecond
	DefaultAllocSize         = 16 * 1024 * 1024
)

Default values if not set in a DB instance.

View Source 
const (
	// FreelistArrayType indicates backend freelist type is array
	FreelistArrayType = FreelistType("array")
	// FreelistMapType indicates backend freelist type is hashmap
	FreelistMapType = FreelistType("hashmap")
)
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const BranchPageElementSize = unsafe.Sizeof(branchPageElement{})
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const BucketHeaderSize = int(unsafe.Sizeof(InBucket{}))
View Source 
const (
	BucketLeafFlag = 0x01
)
View Source 
const IgnoreNoSync = runtime.GOOS == "openbsd"

IgnoreNoSync specifies whether the NoSync field of a DB is ignored when syncing changes to a file. This is required as some operating systems, such as OpenBSD, do not have a unified buffer cache (UBC) and writes must be synchronized using the msync(2) syscall.

View Source 
const LeafPageElementSize = unsafe.Sizeof(leafPageElement{})
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const Magic uint32 = 0xED0CDAED

Magic represents a marker value to indicate that a file is a Bolt DB.

View Source 
const MaxMmapStep = 1 << 30 // 1GB

MaxMmapStep is the largest step that can be taken when remapping the mmap.

View Source 
const MinKeysPerPage = 2
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const PageHeaderSize = unsafe.Sizeof(Page{})
View Source 
const Version = 2

Version represents the data file format version.

Variables

View Source 
var DefaultPageSize = os.Getpagesize()

DefaultPageSize is the default page size for db which is set to the OS page size.

Functions

func Assert 

func Assert(condition bool, msg string, v ...interface{})

Assert will panic with a given formatted message if the given condition is false.

func CopyFile 

func CopyFile(srcPath, dstPath string) error

func Mergepgids 

func Mergepgids(dst, a, b Pgids)

Mergepgids copies the sorted union of a and b into dst. If dst is too small, it panics.

func NewLeafPageElement 

func NewLeafPageElement(flags, pos, ksize, vsize uint32) *leafPageElement

func UnsafeAdd 

func UnsafeAdd(base unsafe.Pointer, offset uintptr) unsafe.Pointer

func UnsafeByteSlice 

func UnsafeByteSlice(base unsafe.Pointer, offset uintptr, i, j int) []byte

func UnsafeIndex 

func UnsafeIndex(base unsafe.Pointer, offset uintptr, elemsz uintptr, n int) unsafe.Pointer

func UnsafeSlice 

func UnsafeSlice(slice, data unsafe.Pointer, len int)

UnsafeSlice modifies the data, len, and cap of a slice variable pointed to by the slice parameter. This helper should be used over other direct manipulation of reflect.SliceHeader to prevent misuse, namely, converting from reflect.SliceHeader to a Go slice type.

func UsedSpaceInPage 

func UsedSpaceInPage(inodes Inodes, p *Page) uint32

func WriteInodeToPage 

func WriteInodeToPage(inodes Inodes, p *Page) uint32

Types

type FreelistType 

type FreelistType string

FreelistType is the type of the freelist backend

type InBucket 

type InBucket struct {
	// contains filtered or unexported fields
}

InBucket represents the on-file representation of a bucket. This is stored as the "value" of a bucket key. If the bucket is small enough, then its root page can be stored inline in the "value", after the bucket header. In the case of inline buckets, the "root" will be 0.

func LoadBucket 

func LoadBucket(buf []byte) *InBucket

func NewInBucket 

func NewInBucket(root Pgid, seq uint64) InBucket

func (*InBucket) InSequence 

func (b *InBucket) InSequence() uint64

InSequence returns the sequence. The reason why not naming it `Sequence` is to avoid duplicated name as `(*Bucket) Sequence()`

func (*InBucket) IncSequence 

func (b *InBucket) IncSequence()

func (*InBucket) InlinePage 

func (b *InBucket) InlinePage(v []byte) *Page

func (*InBucket) RootPage 

func (b *InBucket) RootPage() Pgid

func (*InBucket) SetInSequence 

func (b *InBucket) SetInSequence(v uint64)

func (*InBucket) SetRootPage 

func (b *InBucket) SetRootPage(id Pgid)

func (*InBucket) String 

func (b *InBucket) String() string

type Inode 

type Inode struct {
	// contains filtered or unexported fields
}

Inode represents an internal node inside of a node. It can be used to point to elements in a page or point to an element which hasn't been added to a page yet.

func (*Inode) Flags 

func (in *Inode) Flags() uint32

func (*Inode) Key 

func (in *Inode) Key() []byte

func (*Inode) Pgid 

func (in *Inode) Pgid() Pgid

func (*Inode) SetFlags 

func (in *Inode) SetFlags(flags uint32)

func (*Inode) SetKey 

func (in *Inode) SetKey(key []byte)

func (*Inode) SetPgid 

func (in *Inode) SetPgid(id Pgid)

func (*Inode) SetValue 

func (in *Inode) SetValue(value []byte)

func (*Inode) Value 

func (in *Inode) Value() []byte

type Inodes 

type Inodes []Inode

func ReadInodeFromPage 

func ReadInodeFromPage(p *Page) Inodes

type Meta 

type Meta struct {
	// contains filtered or unexported fields
}

func LoadPageMeta 

func LoadPageMeta(buf []byte) *Meta

func (*Meta) Copy 

func (m *Meta) Copy(dest *Meta)

Copy copies one meta object to another.

func (*Meta) DecTxid 

func (m *Meta) DecTxid()

func (*Meta) Flags 

func (m *Meta) Flags() uint32

func (*Meta) Freelist 

func (m *Meta) Freelist() Pgid

func (*Meta) IncTxid 

func (m *Meta) IncTxid()

func (*Meta) Magic 

func (m *Meta) Magic() uint32

func (*Meta) PageSize 

func (m *Meta) PageSize() uint32

func (*Meta) Pgid 

func (m *Meta) Pgid() Pgid

func (*Meta) Print 

func (m *Meta) Print(w io.Writer)

func (*Meta) RootBucket 

func (m *Meta) RootBucket() *InBucket

func (*Meta) SetChecksum 

func (m *Meta) SetChecksum(v uint64)

func (*Meta) SetFlags 

func (m *Meta) SetFlags(v uint32)

func (*Meta) SetFreelist 

func (m *Meta) SetFreelist(v Pgid)

func (*Meta) SetMagic 

func (m *Meta) SetMagic(v uint32)

func (*Meta) SetPageSize 

func (m *Meta) SetPageSize(v uint32)

func (*Meta) SetPgid 

func (m *Meta) SetPgid(id Pgid)

func (*Meta) SetRootBucket 

func (m *Meta) SetRootBucket(b InBucket)

func (*Meta) SetTxid 

func (m *Meta) SetTxid(id Txid)

func (*Meta) SetVersion 

func (m *Meta) SetVersion(v uint32)

func (*Meta) Sum64 

func (m *Meta) Sum64() uint64

Sum64 generates the checksum for the meta.

func (*Meta) Txid 

func (m *Meta) Txid() Txid

func (*Meta) Validate 

func (m *Meta) Validate() error

Validate checks the marker bytes and version of the meta page to ensure it matches this binary.

func (*Meta) Write 

func (m *Meta) Write(p *Page)

Write writes the meta onto a page.

type Page 

type Page struct {
	// contains filtered or unexported fields
}

func LoadPage 

func LoadPage(buf []byte) *Page

func NewPage 

func NewPage(id Pgid, flags, count uint16, overflow uint32) *Page

func (*Page) BranchPageElement 

func (p *Page) BranchPageElement(index uint16) *branchPageElement

BranchPageElement retrieves the branch node by index

func (*Page) BranchPageElements 

func (p *Page) BranchPageElements() []branchPageElement

BranchPageElements retrieves a list of branch nodes.

func (*Page) Count 

func (p *Page) Count() uint16

func (*Page) FastCheck 

func (p *Page) FastCheck(id Pgid)

func (*Page) Flags 

func (p *Page) Flags() uint16

func (*Page) FlagsXOR 

func (p *Page) FlagsXOR(v uint16)

func (*Page) FreelistPageCount 

func (p *Page) FreelistPageCount() (int, int)

func (*Page) FreelistPageIds 

func (p *Page) FreelistPageIds() []Pgid

func (*Page) Id 

func (p *Page) Id() Pgid

func (*Page) IsBranchPage 

func (p *Page) IsBranchPage() bool

func (*Page) IsFreelistPage 

func (p *Page) IsFreelistPage() bool

func (*Page) IsLeafPage 

func (p *Page) IsLeafPage() bool

func (*Page) IsMetaPage 

func (p *Page) IsMetaPage() bool

func (*Page) LeafPageElement 

func (p *Page) LeafPageElement(index uint16) *leafPageElement

LeafPageElement retrieves the leaf node by index

func (*Page) LeafPageElements 

func (p *Page) LeafPageElements() []leafPageElement

LeafPageElements retrieves a list of leaf nodes.

func (*Page) Meta 

func (p *Page) Meta() *Meta

Meta returns a pointer to the metadata section of the page.

func (*Page) Overflow 

func (p *Page) Overflow() uint32

func (*Page) PageElementSize 

func (p *Page) PageElementSize() uintptr

func (*Page) SetCount 

func (p *Page) SetCount(target uint16)

func (*Page) SetFlags 

func (p *Page) SetFlags(v uint16)

func (*Page) SetId 

func (p *Page) SetId(target Pgid)

func (*Page) SetOverflow 

func (p *Page) SetOverflow(target uint32)

func (*Page) String 

func (p *Page) String() string

func (*Page) Typ 

func (p *Page) Typ() string

Typ returns a human-readable page type string used for debugging.

type PageInfo 

type PageInfo struct {
	ID            int
	Type          string
	Count         int
	OverflowCount int
}

PageInfo represents human readable information about a page.

type Pages 

type Pages []*Page

func (Pages) Len 

func (s Pages) Len() int

func (Pages) Less 

func (s Pages) Less(i, j int) bool

func (Pages) Swap 

func (s Pages) Swap(i, j int)

type Pgid 

type Pgid uint64
const PgidNoFreelist Pgid = 0xffffffffffffffff

type Pgids 

type Pgids []Pgid

func (Pgids) Len 

func (s Pgids) Len() int

func (Pgids) Less 

func (s Pgids) Less(i, j int) bool

func (Pgids) Merge 

func (a Pgids) Merge(b Pgids) Pgids

Merge returns the sorted union of a and b.

func (Pgids) Swap 

func (s Pgids) Swap(i, j int)

type Txid 

type Txid uint64

Txid represents the internal transaction identifier.

Source Files

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