146 lines
3.6 KiB
Go
146 lines
3.6 KiB
Go
// Copyright (c) 2017 Couchbase, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package zap
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import (
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"encoding/binary"
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"io"
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"github.com/RoaringBitmap/roaring"
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)
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// writes out the length of the roaring bitmap in bytes as varint
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// then writes out the roaring bitmap itself
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func writeRoaringWithLen(r *roaring.Bitmap, w io.Writer,
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reuseBufVarint []byte) (int, error) {
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buf, err := r.ToBytes()
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if err != nil {
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return 0, err
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}
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var tw int
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// write out the length
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n := binary.PutUvarint(reuseBufVarint, uint64(len(buf)))
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nw, err := w.Write(reuseBufVarint[:n])
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tw += nw
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if err != nil {
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return tw, err
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}
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// write out the roaring bytes
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nw, err = w.Write(buf)
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tw += nw
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if err != nil {
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return tw, err
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}
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return tw, nil
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}
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func persistFields(fieldsInv []string, w *CountHashWriter, dictLocs []uint64) (uint64, error) {
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var rv uint64
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var fieldsOffsets []uint64
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for fieldID, fieldName := range fieldsInv {
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// record start of this field
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fieldsOffsets = append(fieldsOffsets, uint64(w.Count()))
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// write out the dict location and field name length
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_, err := writeUvarints(w, dictLocs[fieldID], uint64(len(fieldName)))
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if err != nil {
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return 0, err
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}
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// write out the field name
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_, err = w.Write([]byte(fieldName))
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if err != nil {
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return 0, err
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}
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}
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// now write out the fields index
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rv = uint64(w.Count())
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for fieldID := range fieldsInv {
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err := binary.Write(w, binary.BigEndian, fieldsOffsets[fieldID])
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if err != nil {
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return 0, err
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}
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}
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return rv, nil
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}
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// FooterSize is the size of the footer record in bytes
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// crc + ver + chunk + field offset + stored offset + num docs + docValueOffset
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const FooterSize = 4 + 4 + 4 + 8 + 8 + 8 + 8
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func persistFooter(numDocs, storedIndexOffset, fieldsIndexOffset, docValueOffset uint64,
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chunkMode uint32, crcBeforeFooter uint32, writerIn io.Writer) error {
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w := NewCountHashWriter(writerIn)
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w.crc = crcBeforeFooter
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// write out the number of docs
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err := binary.Write(w, binary.BigEndian, numDocs)
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if err != nil {
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return err
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}
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// write out the stored field index location:
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err = binary.Write(w, binary.BigEndian, storedIndexOffset)
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if err != nil {
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return err
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}
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// write out the field index location
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err = binary.Write(w, binary.BigEndian, fieldsIndexOffset)
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if err != nil {
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return err
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}
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// write out the fieldDocValue location
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err = binary.Write(w, binary.BigEndian, docValueOffset)
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if err != nil {
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return err
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}
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// write out 32-bit chunk factor
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err = binary.Write(w, binary.BigEndian, chunkMode)
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if err != nil {
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return err
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}
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// write out 32-bit version
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err = binary.Write(w, binary.BigEndian, Version)
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if err != nil {
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return err
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}
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// write out CRC-32 of everything upto but not including this CRC
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err = binary.Write(w, binary.BigEndian, w.crc)
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if err != nil {
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return err
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}
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return nil
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}
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func writeUvarints(w io.Writer, vals ...uint64) (tw int, err error) {
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buf := make([]byte, binary.MaxVarintLen64)
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for _, val := range vals {
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n := binary.PutUvarint(buf, val)
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var nw int
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nw, err = w.Write(buf[:n])
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tw += nw
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if err != nil {
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return tw, err
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}
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}
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return tw, err
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}
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