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package types
import (
"bytes"
"errors"
"fmt"
"io"
"sync"
"golang.org/x/crypto/ripemd160"
cmn "github.com/tendermint/tmlibs/common"
"github.com/tendermint/tmlibs/merkle"
)
var (
ErrPartSetUnexpectedIndex = errors.New("Error part set unexpected index")
ErrPartSetInvalidProof = errors.New("Error part set invalid proof")
)
type Part struct {
Index int `json:"index"`
Bytes cmn.HexBytes `json:"bytes"`
Proof merkle.SimpleProof `json:"proof"`
// Cache
hash []byte
}
func (part *Part) Hash() []byte {
if part.hash != nil {
return part.hash
}
hasher := ripemd160.New()
hasher.Write(part.Bytes) // nolint: errcheck, gas
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{#%v
%s Bytes: %X...
%s Proof: %v
%s}`,
part.Index,
indent, cmn.Fingerprint(part.Bytes),
indent, part.Proof.StringIndented(indent+" "),
indent)
}
//-------------------------------------
type PartSetHeader struct {
Total int `json:"total"`
Hash cmn.HexBytes `json:"hash"`
}
func (psh PartSetHeader) String() string {
return fmt.Sprintf("%v:%X", psh.Total, cmn.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)
}
//-------------------------------------
type PartSet struct {
total int
hash []byte
mtx sync.Mutex
parts []*Part
partsBitArray *cmn.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, partSize int) *PartSet {
// divide data into 4kb parts.
total := (len(data) + partSize - 1) / partSize
parts := make([]*Part, total)
parts_ := make([]merkle.Hasher, total)
partsBitArray := cmn.NewBitArray(total)
for i := 0; i < total; i++ {
part := &Part{
Index: i,
Bytes: data[i*partSize : cmn.MinInt(len(data), (i+1)*partSize)],
}
parts[i] = part
parts_[i] = part
partsBitArray.SetIndex(i, true)
}
// Compute merkle proofs
root, proofs := merkle.SimpleProofsFromHashers(parts_)
for i := 0; i < total; i++ {
parts[i].Proof = *proofs[i]
}
return &PartSet{
total: total,
hash: root,
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: cmn.NewBitArray(header.Total),
count: 0,
}
}
func (ps *PartSet) Header() PartSetHeader {
if ps == nil {
return PartSetHeader{}
}
return PartSetHeader{
Total: ps.total,
Hash: ps.hash,
}
}
func (ps *PartSet) HasHeader(header PartSetHeader) bool {
if ps == nil {
return false
}
return ps.Header().Equals(header)
}
func (ps *PartSet) BitArray() *cmn.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, verify bool) (bool, error) {
ps.mtx.Lock()
defer ps.mtx.Unlock()
// Invalid part index
if part.Index >= ps.total {
return false, ErrPartSetUnexpectedIndex
}
// If part already exists, return false.
if ps.parts[part.Index] != nil {
return false, nil
}
// Check hash proof
if verify {
if !part.Proof.Verify(part.Index, ps.total, part.Hash(), ps.Hash()) {
return false, ErrPartSetInvalidProof
}
}
// Add part
ps.parts[part.Index] = part
ps.partsBitArray.SetIndex(part.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() {
cmn.PanicSanity("Cannot GetReader() on incomplete PartSet")
}
return NewPartSetReader(ps.parts)
}
type PartSetReader struct {
i int
parts []*Part
reader *bytes.Reader
}
func NewPartSetReader(parts []*Part) *PartSetReader {
return &PartSetReader{
i: 0,
parts: parts,
reader: bytes.NewReader(parts[0].Bytes),
}
}
func (psr *PartSetReader) Read(p []byte) (n int, err error) {
readerLen := psr.reader.Len()
if readerLen >= len(p) {
return psr.reader.Read(p)
} else if readerLen > 0 {
n1, err := psr.Read(p[:readerLen])
if err != nil {
return n1, err
}
n2, err := psr.Read(p[readerLen:])
return n1 + n2, err
}
psr.i++
if psr.i >= len(psr.parts) {
return 0, io.EOF
}
psr.reader = bytes.NewReader(psr.parts[psr.i].Bytes)
return psr.Read(p)
}
func (ps *PartSet) StringShort() string {
if ps == nil {
return "nil-PartSet"
}
ps.mtx.Lock()
defer ps.mtx.Unlock()
return fmt.Sprintf("(%v of %v)", ps.Count(), ps.Total())
}