metadata

Documentation

Overview

 Package metadata implements protocols for publishing content claims on IPNI

  The goal is to enable partial publishing of content claims to IPNI

	The rules for publishing content claims records to IPNI are as follows:

	Content claims should be published to IPNI by the original issuer of the content claim.

	The ContextID for the content claim should be the cid of the content the claim is about,
	except in the case of a location commitment, where the content ID should be:
		hash(audience public key, content cid multihash)

	The claim record MUST be able to be looked up on IPNI from the content cid multihash (or double encryption thereof)

	The claim MAY be able to be looked up by additional multihashes, particularly in the case of the IndexClaim, where
	the record should be accessible from any multihash inside the index

	The metadata for the claim is structured to maximize utility of the record while minimizing size

	To generally respect the 100 byte maximum size for IPNI records, we do not encode the claim itself, but rather its CID.

	The full claim must be retrievable through an http multiaddr of the provider which contains path segments of the form `{claim}`.
	To retrieve the claim, replace every `{claim}` with the string encoding of the claim CID

	For a location commitment, the content must retrievable through an http multiaddr of the provider
	which contains path segments of the form `{shard}`. To retrieve the claim, replace every `{shard}` with the string encoding
	of the shard cid in the metadata, or if not present, the CIDv1 encoding using RAW codec of the multihash used to lookup the record
	Additionally, if a Range parameter is present in the metadata, it should be translated into a range HTTP header when retrieving
	content

	However, in order to enable faster chaining of requests and general processing, we add additional fields to encode
	specific information from the full claim.

	This enables a client to quickly read the record and take action based on information in the claim before it has retrieved the full claim

Index

• Constants
• Variables
• type EqualsClaimMetadata
  • func (e *EqualsClaimMetadata) GetClaim() cid.Cid
  • func (e *EqualsClaimMetadata) ID() multicodec.Code
  • func (e *EqualsClaimMetadata) MarshalBinary() ([]byte, error)
  • func (e *EqualsClaimMetadata) ReadFrom(r io.Reader) (n int64, err error)
  • func (e *EqualsClaimMetadata) UnmarshalBinary(data []byte) error
• type HasClaim
• type IndexClaimMetadata
  • func (i *IndexClaimMetadata) GetClaim() cid.Cid
  • func (i *IndexClaimMetadata) ID() multicodec.Code
  • func (i *IndexClaimMetadata) MarshalBinary() ([]byte, error)
  • func (i *IndexClaimMetadata) ReadFrom(r io.Reader) (n int64, err error)
  • func (i *IndexClaimMetadata) UnmarshalBinary(data []byte) error
• type LocationCommitmentMetadata
  • func (l *LocationCommitmentMetadata) GetClaim() cid.Cid
  • func (l *LocationCommitmentMetadata) ID() multicodec.Code
  • func (l *LocationCommitmentMetadata) MarshalBinary() ([]byte, error)
  • func (l *LocationCommitmentMetadata) ReadFrom(r io.Reader) (n int64, err error)
  • func (l *LocationCommitmentMetadata) UnmarshalBinary(data []byte) error
• type Range

Constants

const EqualsClaimID = 0x3E0001

EqualsClaimID is the multicodec for equals claims

const IndexClaimID = 0x3E0000

IndexClaimID is the multicodec for index claims

const LocationCommitmentID = 0x3E0002

LocationCommitmentID is the multicodec for location commitments

Variables

var MetadataContext ipnimd.MetadataContext

Types

type EqualsClaimMetadata

type EqualsClaimMetadata struct {
	// Equals represents an equivalent cid to the content cid that was used for lookup
	Equals cid.Cid
	// Expiration as unix epoch in seconds
	Expiration int64
	// Claim indicates the cid of the claim - the claim should be fetchable by combining the http multiaddr of the provider with the claim cid
	Claim cid.Cid
}

EqualsClaimMetadata represents metadata for an equals claim

func (*EqualsClaimMetadata) GetClaim

func (e *EqualsClaimMetadata) GetClaim() cid.Cid

func (*EqualsClaimMetadata) ID

func (e *EqualsClaimMetadata) ID() multicodec.Code

func (*EqualsClaimMetadata) MarshalBinary

func (e *EqualsClaimMetadata) MarshalBinary() ([]byte, error)

func (*EqualsClaimMetadata) ReadFrom

func (e *EqualsClaimMetadata) ReadFrom(r io.Reader) (n int64, err error)

func (*EqualsClaimMetadata) UnmarshalBinary

func (e *EqualsClaimMetadata) UnmarshalBinary(data []byte) error

type HasClaim

type HasClaim interface {
	GetClaim() cid.Cid
}

type IndexClaimMetadata

type IndexClaimMetadata struct {
	// Index represents the cid of the index for this claim
	Index cid.Cid
	// Expiration as unix epoch in seconds
	Expiration int64
	// Claim indicates the cid of the claim - the claim should be fetchable by combining the http multiaddr of the provider with the claim cid
	Claim cid.Cid
}

 IndexClaimMetadata represents metadata for an index claim
	Index claim metadata

func (*IndexClaimMetadata) GetClaim

func (i *IndexClaimMetadata) GetClaim() cid.Cid

func (*IndexClaimMetadata) ID

func (i *IndexClaimMetadata) ID() multicodec.Code

func (*IndexClaimMetadata) MarshalBinary

func (i *IndexClaimMetadata) MarshalBinary() ([]byte, error)

func (*IndexClaimMetadata) ReadFrom

func (i *IndexClaimMetadata) ReadFrom(r io.Reader) (n int64, err error)

func (*IndexClaimMetadata) UnmarshalBinary

func (i *IndexClaimMetadata) UnmarshalBinary(data []byte) error

type LocationCommitmentMetadata

type LocationCommitmentMetadata struct {
	// Shard is an optional alternate cid to use to lookup this location -- if the looked up shard is part of a larger shard
	Shard *cid.Cid
	// Range is an optional byte range within a shard
	Range *Range
	// Expiration as unix epoch in seconds
	Expiration int64
	// Claim indicates the cid of the claim - the claim should be fetchable by combining the http multiaddr of the provider with the claim cid
	Claim cid.Cid
}

LocationCommitmentMetadata represents metadata for an equals claim

func (*LocationCommitmentMetadata) GetClaim

func (l *LocationCommitmentMetadata) GetClaim() cid.Cid

func (*LocationCommitmentMetadata) ID

func (l *LocationCommitmentMetadata) ID() multicodec.Code

func (*LocationCommitmentMetadata) MarshalBinary

func (l *LocationCommitmentMetadata) MarshalBinary() ([]byte, error)

func (*LocationCommitmentMetadata) ReadFrom

func (l *LocationCommitmentMetadata) ReadFrom(r io.Reader) (n int64, err error)

func (*LocationCommitmentMetadata) UnmarshalBinary

func (l *LocationCommitmentMetadata) UnmarshalBinary(data []byte) error

type Range

type Range struct {
	Offset uint64
	Length *uint64
}