0ca2bbaeb3
This provides a way to create a CID without having to read all data into memory before passing it into Sum. Instead, call SumStream passing in an io.Reader.
97 lines
1.6 KiB
Go
97 lines
1.6 KiB
Go
package cid
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import (
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"io"
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mh "github.com/multiformats/go-multihash"
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)
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type Builder interface {
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Sum(data []byte) (Cid, error)
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GetCodec() uint64
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WithCodec(uint64) Builder
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}
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type V0Builder struct{}
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type V1Builder struct {
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Codec uint64
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MhType uint64
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MhLength int // MhLength <= 0 means the default length
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}
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func (p Prefix) GetCodec() uint64 {
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return p.Codec
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}
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func (p Prefix) WithCodec(c uint64) Builder {
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if c == p.Codec {
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return p
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}
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p.Codec = c
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if c != DagProtobuf {
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p.Version = 1
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}
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return p
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}
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func (p V0Builder) Sum(data []byte) (Cid, error) {
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hash, err := mh.Sum(data, mh.SHA2_256, -1)
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if err != nil {
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return Undef, err
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}
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return Cid{string(hash)}, nil
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}
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func (p V0Builder) SumStream(r io.Reader) (Cid, error) {
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hash, err := mh.SumStream(r, mh.SHA2_256, -1)
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if err != nil {
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return Undef, err
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}
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return Cid{string(hash)}, nil
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}
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func (p V0Builder) GetCodec() uint64 {
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return DagProtobuf
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}
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func (p V0Builder) WithCodec(c uint64) Builder {
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if c == DagProtobuf {
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return p
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}
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return V1Builder{Codec: c, MhType: mh.SHA2_256}
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}
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func (p V1Builder) Sum(data []byte) (Cid, error) {
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mhLen := p.MhLength
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if mhLen <= 0 {
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mhLen = -1
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}
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hash, err := mh.Sum(data, p.MhType, mhLen)
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if err != nil {
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return Undef, err
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}
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return NewCidV1(p.Codec, hash), nil
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}
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func (p V1Builder) SumStream(r io.Reader) (Cid, error) {
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mhLen := p.MhLength
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if mhLen <= 0 {
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mhLen = -1
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}
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hash, err := mh.SumStream(r, p.MhType, mhLen)
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if err != nil {
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return Undef, err
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}
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return NewCidV1(p.Codec, hash), nil
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}
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func (p V1Builder) GetCodec() uint64 {
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return p.Codec
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}
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func (p V1Builder) WithCodec(c uint64) Builder {
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p.Codec = c
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return p
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}
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