Examples with RelationInfo io.crate.metadata.RelationInfo used on opensource projects

Example 1 with RelationInfo

use of io.crate.metadata.RelationInfo in project crate by crate.

the class Messages method sendRowDescription.

/**
 * RowDescription (B)
 * <p>
 * | 'T' | int32 len | int16 numCols
 * <p>
 * For each field:
 * <p>
 * | string name | int32 table_oid | int16 attr_num | int32 oid | int16 typlen | int32 type_modifier | int16 format_code
 * <p>
 * See https://www.postgresql.org/docs/current/static/protocol-message-formats.html
 */
static void sendRowDescription(Channel channel, Collection<Symbol> columns, @Nullable FormatCodes.FormatCode[] formatCodes, @Nullable RelationInfo relation) {
    int length = 4 + 2;
    int columnSize = 4 + 2 + 4 + 2 + 4 + 2;
    ByteBuf buffer = channel.alloc().buffer(// use 10 as an estimate for columnName length
    length + (columns.size() * (10 + columnSize)));
    buffer.writeByte('T');
    // will be set at the end
    buffer.writeInt(0);
    buffer.writeShort(columns.size());
    int tableOid = 0;
    if (relation != null && columns.stream().allMatch(Messages::isRefWithPosition)) {
        tableOid = OidHash.relationOid(relation);
    }
    int idx = 0;
    for (Symbol column : columns) {
        byte[] nameBytes = Symbols.pathFromSymbol(column).sqlFqn().getBytes(StandardCharsets.UTF_8);
        length += nameBytes.length + 1;
        length += columnSize;
        writeCString(buffer, nameBytes);
        buffer.writeInt(tableOid);
        // attr_num
        if (column instanceof Reference) {
            Integer position = ((Reference) column).position();
            buffer.writeShort(position == null ? 0 : position);
        } else {
            buffer.writeShort(0);
        }
        PGType<?> pgType = PGTypes.get(column.valueType());
        buffer.writeInt(pgType.oid());
        buffer.writeShort(pgType.typeLen());
        buffer.writeInt(pgType.typeMod());
        buffer.writeShort(FormatCodes.getFormatCode(formatCodes, idx).ordinal());
        idx++;
    }
    buffer.setInt(1, length);
    ChannelFuture channelFuture = channel.write(buffer);
    if (LOGGER.isTraceEnabled()) {
        channelFuture.addListener((ChannelFutureListener) future -> LOGGER.trace("sentRowDescription"));
    }
}