Golang Batch.Del方法代码示例

// deleteRow adds to the batch the kv operations necessary to delete a table row
// with the given values.
func (rd *rowDeleter) deleteRow(ctx context.Context, b *client.Batch, values []parser.Datum) error {
	if err := rd.fks.checkAll(values); err != nil {
		return err
	}

	primaryIndexKey, secondaryIndexEntries, err := rd.helper.encodeIndexes(rd.fetchColIDtoRowIndex, values)
	if err != nil {
		return err
	}

	for _, secondaryIndexEntry := range secondaryIndexEntries {
		if log.V(2) {
			log.Infof(ctx, "Del %s", secondaryIndexEntry.Key)
		}
		b.Del(secondaryIndexEntry.Key)
	}

	// Delete the row.
	rd.startKey = roachpb.Key(primaryIndexKey)
	rd.endKey = roachpb.Key(encoding.EncodeNotNullDescending(primaryIndexKey))
	if log.V(2) {
		log.Infof(ctx, "DelRange %s - %s", rd.startKey, rd.endKey)
	}
	b.DelRange(&rd.startKey, &rd.endKey, false)
	rd.startKey, rd.endKey = nil, nil

	return nil
}

// deleteIndexRow adds to the batch the kv operations necessary to delete a
// table row from the given index.
func (rd *rowDeleter) deleteIndexRow(
	ctx context.Context, b *client.Batch, idx *sqlbase.IndexDescriptor, values []parser.Datum,
) error {
	if err := rd.fks.checkAll(values); err != nil {
		return err
	}
	secondaryIndexEntry, err := sqlbase.EncodeSecondaryIndex(
		rd.helper.tableDesc, idx, rd.fetchColIDtoRowIndex, values)
	if err != nil {
		return err
	}
	if log.V(2) {
		log.Infof(ctx, "Del %s", secondaryIndexEntry.Key)
	}
	b.Del(secondaryIndexEntry.Key)
	return nil
}

func delMeta(b *client.Batch, key roachpb.Key, desc *roachpb.RangeDescriptor) {
	b.Del(key)
}

//.........这里部分代码省略.........
			// backwards compatible with the original BaseFormatVersion.

			idx, ok := ru.updateColIDtoRowIndex[family.DefaultColumnID]
			if !ok {
				continue
			}

			ru.key = keys.MakeFamilyKey(primaryIndexKey, uint32(family.ID))
			if log.V(2) {
				log.Infof(ctx, "Put %s -> %v", ru.key, ru.marshalled[idx].PrettyPrint())
			}
			b.Put(&ru.key, &ru.marshalled[idx])
			ru.key = nil

			continue
		}

		ru.key = keys.MakeFamilyKey(primaryIndexKey, uint32(family.ID))
		ru.valueBuf = ru.valueBuf[:0]

		var lastColID sqlbase.ColumnID
		familySortedColumnIDs, ok := ru.helper.sortedColumnFamily(family.ID)
		if !ok {
			panic("invalid family sorted column id map")
		}
		for _, colID := range familySortedColumnIDs {
			if ru.helper.columnInPK(colID) {
				if family.ID != 0 {
					return nil, errors.Errorf("primary index column %d must be in family 0, was %d", colID, family.ID)
				}
				// Skip primary key columns as their values are encoded in the key of
				// each family. Family 0 is guaranteed to exist and acts as a sentinel.
				continue
			}

			idx, ok := ru.fetchColIDtoRowIndex[colID]
			if !ok {
				return nil, errors.Errorf("column %d was expected to be fetched, but wasn't", colID)
			}
			col := ru.fetchCols[idx]

			if ru.newValues[idx].Compare(parser.DNull) == 0 {
				continue
			}

			if lastColID > col.ID {
				panic(fmt.Errorf("cannot write column id %d after %d", col.ID, lastColID))
			}
			colIDDiff := col.ID - lastColID
			lastColID = col.ID
			ru.valueBuf, err = sqlbase.EncodeTableValue(ru.valueBuf, colIDDiff, ru.newValues[idx])
			if err != nil {
				return nil, err
			}
		}

		if family.ID != 0 && len(ru.valueBuf) == 0 {
			// The family might have already existed but every column in it is being
			// set to NULL, so delete it.
			if log.V(2) {
				log.Infof(ctx, "Del %s", ru.key)
			}

			b.Del(&ru.key)
		} else {
			ru.value.SetTuple(ru.valueBuf)
			if log.V(2) {
				log.Infof(ctx, "Put %s -> %v", ru.key, ru.value.PrettyPrint())
			}
			b.Put(&ru.key, &ru.value)
		}

		ru.key = nil
	}

	// Update secondary indexes.
	for i, newSecondaryIndexEntry := range newSecondaryIndexEntries {
		secondaryIndexEntry := secondaryIndexEntries[i]
		secondaryKeyChanged := !bytes.Equal(newSecondaryIndexEntry.Key, secondaryIndexEntry.Key)
		if secondaryKeyChanged {
			if err := ru.fks.checkIdx(ru.helper.indexes[i].ID, oldValues, ru.newValues); err != nil {
				return nil, err
			}

			if log.V(2) {
				log.Infof(ctx, "Del %s", secondaryIndexEntry.Key)
			}
			b.Del(secondaryIndexEntry.Key)
			// Do not update Indexes in the DELETE_ONLY state.
			if _, ok := ru.deleteOnlyIndex[i]; !ok {
				if log.V(2) {
					log.Infof(ctx, "CPut %s -> %v", newSecondaryIndexEntry.Key, newSecondaryIndexEntry.Value.PrettyPrint())
				}
				b.CPut(newSecondaryIndexEntry.Key, &newSecondaryIndexEntry.Value, nil)
			}
		}
	}

	return ru.newValues, nil
}