func (pl PostingList) readBlock(idx uint, lastDoc match.DocId) (uint, Block) {
bytes := pl.Raw[idx:]
if bytes[0]&blockTypeDoc == blockTypeDoc {
docSize, docOffset := varint.Read(bytes)
doc := match.DocId(docOffset) + lastDoc
data := Block{idx, false, 1, doc, 0}
return docSize, data
}
nextBlockOffset := readUInt(bytes[1:])
nextDocOffset := readUInt64(bytes[5:])
data := Block{idx, true, nextBlockOffset, lastDoc, match.DocId(uint64(lastDoc) + nextDocOffset)}
return 1 + SKIP_PAYLOAD, data
}
func FromBytes(raw []byte) *PostingList {
maxId := readUInt64(raw)
raw = raw[8:]
n, rawLen := varint.Read(raw)
raw = raw[n:]
raw = raw[:rawLen]
return &PostingList{raw, match.DocId(maxId)}
}
func (pl PostingList) blocks(visit func(Block)) {
i := uint(0)
lastDoc := match.DocId(0)
// walk through the blocks
numBlocks := uint(len(pl.Raw))
for i < numBlocks {
r, block := pl.readBlock(i, lastDoc)
lastDoc = block.doc
visit(block)
i += r
}
}
func docId(block, bit uint) (doc match.DocId) {
return match.DocId(block*32 + bit)
}