package types import ( "bytes" "errors" "fmt" "io" "sync" "code.google.com/p/go.crypto/ripemd160" . "github.com/tendermint/go-common" "github.com/tendermint/go-merkle" "github.com/tendermint/go-wire" ) const ( partSize = 4096 // 4KB ) var ( ErrPartSetUnexpectedIndex = errors.New("Error part set unexpected index") ErrPartSetInvalidProof = errors.New("Error part set invalid proof") ) type Part struct { Proof merkle.SimpleProof `json:"proof"` Bytes []byte `json:"bytes"` // Cache hash []byte } func (part *Part) Hash() []byte { if part.hash != nil { return part.hash } else { hasher := ripemd160.New() hasher.Write(part.Bytes) // doesn't err part.hash = hasher.Sum(nil) return part.hash } } func (part *Part) String() string { return part.StringIndented("") } func (part *Part) StringIndented(indent string) string { return fmt.Sprintf(`Part{ %s Proof: %v %s Bytes: %X %s}`, indent, part.Proof.StringIndented(indent+" "), indent, part.Bytes, indent) } //------------------------------------- type PartSetHeader struct { Total int `json:"total"` Hash []byte `json:"hash"` } func (psh PartSetHeader) String() string { return fmt.Sprintf("PartSet{T:%v %X}", psh.Total, Fingerprint(psh.Hash)) } func (psh PartSetHeader) IsZero() bool { return psh.Total == 0 } func (psh PartSetHeader) Equals(other PartSetHeader) bool { return psh.Total == other.Total && bytes.Equal(psh.Hash, other.Hash) } func (psh PartSetHeader) WriteSignBytes(w io.Writer, n *int, err *error) { wire.WriteTo([]byte(Fmt(`{"hash":"%X","total":%v}`, psh.Hash, psh.Total)), w, n, err) } //------------------------------------- type PartSet struct { total int hash []byte mtx sync.Mutex parts []*Part partsBitArray *BitArray count int } // Returns an immutable, full PartSet from the data bytes. // The data bytes are split into "partSize" chunks, and merkle tree computed. func NewPartSetFromData(data []byte) *PartSet { // divide data into 4kb parts. total := (len(data) + partSize - 1) / partSize parts := make([]*Part, total) parts_ := make([]merkle.Hashable, total) partsBitArray := NewBitArray(total) for i := 0; i < total; i++ { part := &Part{ Bytes: data[i*partSize : MinInt(len(data), (i+1)*partSize)], } parts[i] = part parts_[i] = part partsBitArray.SetIndex(i, true) } // Compute merkle proofs proofs := merkle.SimpleProofsFromHashables(parts_) for i := 0; i < total; i++ { parts[i].Proof = *proofs[i] } return &PartSet{ total: total, hash: proofs[0].RootHash, parts: parts, partsBitArray: partsBitArray, count: total, } } // Returns an empty PartSet ready to be populated. func NewPartSetFromHeader(header PartSetHeader) *PartSet { return &PartSet{ total: header.Total, hash: header.Hash, parts: make([]*Part, header.Total), partsBitArray: NewBitArray(header.Total), count: 0, } } func (ps *PartSet) Header() PartSetHeader { if ps == nil { return PartSetHeader{} } else { return PartSetHeader{ Total: ps.total, Hash: ps.hash, } } } func (ps *PartSet) HasHeader(header PartSetHeader) bool { if ps == nil { return false } else { return ps.Header().Equals(header) } } func (ps *PartSet) BitArray() *BitArray { ps.mtx.Lock() defer ps.mtx.Unlock() return ps.partsBitArray.Copy() } func (ps *PartSet) Hash() []byte { if ps == nil { return nil } return ps.hash } func (ps *PartSet) HashesTo(hash []byte) bool { if ps == nil { return false } return bytes.Equal(ps.hash, hash) } func (ps *PartSet) Count() int { if ps == nil { return 0 } return ps.count } func (ps *PartSet) Total() int { if ps == nil { return 0 } return ps.total } func (ps *PartSet) AddPart(part *Part) (bool, error) { ps.mtx.Lock() defer ps.mtx.Unlock() // Invalid part index if part.Proof.Index >= ps.total { return false, ErrPartSetUnexpectedIndex } // If part already exists, return false. if ps.parts[part.Proof.Index] != nil { return false, nil } // Check hash proof if !part.Proof.Verify(part.Hash(), ps.Hash()) { return false, ErrPartSetInvalidProof } // Add part ps.parts[part.Proof.Index] = part ps.partsBitArray.SetIndex(part.Proof.Index, true) ps.count++ return true, nil } func (ps *PartSet) GetPart(index int) *Part { ps.mtx.Lock() defer ps.mtx.Unlock() return ps.parts[index] } func (ps *PartSet) IsComplete() bool { return ps.count == ps.total } func (ps *PartSet) GetReader() io.Reader { if !ps.IsComplete() { PanicSanity("Cannot GetReader() on incomplete PartSet") } buf := []byte{} for _, part := range ps.parts { buf = append(buf, part.Bytes...) } return bytes.NewReader(buf) } func (ps *PartSet) StringShort() string { if ps == nil { return "nil-PartSet" } else { return fmt.Sprintf("(%v of %v)", ps.Count(), ps.Total()) } }