section

Documentation

Overview

Package section contains binary stream manipulation utilities.

Index

• Constants
• func CopyStandardSection(w io.Writer, r Reader, id ID, ...) (length int64, err error)
• func CustomLoader(loaders map[string]CustomContentLoader) func(Reader, uint32) error
• func SkipCustomSections(r Reader, customLoader func(Reader, uint32) error) (err error)
• type ByteRange
• type CustomContentLoader
• type CustomMapping
  • func (target *CustomMapping) Loader(sectionMap *Map) CustomContentLoader
• type CustomSections
  • func (cs *CustomSections) Load(name string, r Reader, length uint32) (err error)
• type FuncName
• type ID
• type Map
  • func MakeMap() (m Map)
  • func NewMap() *Map
  • func (m *Map) Mapper() func(byte, Reader) (uint32, error)
• type MappedNameSection
  • func (ns *MappedNameSection) Loader(sectionMap *Map) func(string, Reader, uint32) error
• type NameSection
  • func (ns *NameSection) Load(_ string, r Reader, length uint32) (err error)
• type Reader

Constants

const (
	Custom   = module.SectionCustom
	Type     = module.SectionType
	Import   = module.SectionImport
	Function = module.SectionFunction
	Table    = module.SectionTable
	Memory   = module.SectionMemory
	Global   = module.SectionGlobal
	Export   = module.SectionExport
	Start    = module.SectionStart
	Element  = module.SectionElement
	Code     = module.SectionCode
	Data     = module.SectionData
)

const CustomName = "name"

Functions

func CopyStandardSection

func CopyStandardSection(w io.Writer, r Reader, id ID, customLoader func(r Reader, payloadLen uint32) error) (length int64, err error)

CopyStandardSection with the given type if one is found. The returned length includes the copied section's header and payload (everything that was written). Custom sections preceding the standard section are processed by customLoader (or discarded if it's nil) - they are not included in the returned length. If another standard section type is found, it is left untouched (the reader will be backed up before the section id) and zero length is returned. If no standard section is encountered, zero length and io.EOF are returned. io.EOF is returned only when it occurs between sections.

func CustomLoader

func CustomLoader(loaders map[string]CustomContentLoader) func(Reader, uint32) error

func SkipCustomSections

func SkipCustomSections(r Reader, customLoader func(Reader, uint32) error) (err error)

SkipCustomSections until the next standard section. The skipped sections are processed by customLoader (or discarded if it's nil). If no standard section is encountered, io.EOF is returned. io.EOF is returned only when it occurs between sections.

Types

type ByteRange

type ByteRange struct {
	Offset int64
	Length int64
}

type CustomContentLoader

type CustomContentLoader func(sectionName string, r Reader, payloadLen uint32) error

type CustomMapping

type CustomMapping ByteRange

func (*CustomMapping) Loader

func (target *CustomMapping) Loader(sectionMap *Map) CustomContentLoader

Loader of arbitrary custom section. Remembers position, discards content.

type CustomSections

type CustomSections struct {
	Sections map[string][]byte
}

func (*CustomSections) Load

func (cs *CustomSections) Load(name string, r Reader, length uint32) (err error)

type FuncName

type FuncName struct {
	FuncName   string
	LocalNames []string
}

type ID

type ID = module.SectionID

type Map

type Map struct {
	Sections [module.NumSections]ByteRange
}

Map of section positions within the WebAssebly binary module. Map must me initialied with MakeMap or NewMap.

Section offset is always nonzero for standard sections; if the section is missing, it's the position where it would be. Section length is nonzero if the section is present.

Sections[Custom] holds information about the last (or latest) custom section. Its offset is zero if there are no custom sections.

func MakeMap

func MakeMap() (m Map)

MakeMap which represents an empty module.

func NewMap

func NewMap() *Map

NewMap which represents an empty module.

func (*Map) Mapper

func (m *Map) Mapper() func(byte, Reader) (uint32, error)

type MappedNameSection

type MappedNameSection struct {
	NameSection
	Mapping ByteRange
}

func (*MappedNameSection) Loader

func (ns *MappedNameSection) Loader(sectionMap *Map) func(string, Reader, uint32) error

Loader of "name" section. Remembers position.

type NameSection

type NameSection struct {
	ModuleName string
	FuncNames  []FuncName
}

func (*NameSection) Load

func (ns *NameSection) Load(_ string, r Reader, length uint32) (err error)

Load "name" section.

type Reader

type Reader = binary.Reader