content: /*
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.github.pgasync.io.frontend;
  
  import com.github.pgasync.io.IO;
  import com.github.pgasync.message.frontend.Bind;
  
  import java.nio.ByteBuffer;
  import java.nio.charset.Charset;
  
  /**
   * See <a href="https://www.postgresql.org/docs/11/protocol-message-formats.html">Postgres message formats</a>
   *
   * <pre>
   * Bind (F)
   *   Byte1('B')
   *       Identifies the message as a Bind command.
   *
   *   Int32
   *       Length of message contents in bytes, including self.
   *
   *   String
   *       The name of the destination portal (an empty string selects the unnamed portal).
   *
   *   String
   *       The name of the source prepared statement (an empty string selects the unnamed prepared statement).
   *
   *   Int16
   *       The number of parameter format codes that follow (denoted C below). This can be zero to indicate that there are no parameters or that the parameters all use the default format (text); or one, in which case the specified format code is applied to all parameters; or it can equal the actual number of parameters.
   *
   *   Int16[C]
   *       The parameter format codes. Each must presently be zero (text) or one (binary).
   *
   *   Int16
   *       The number of parameter values that follow (possibly zero). This must match the number of parameters needed by the query.
   *
   *   Next, the following pair of fields appear for each parameter:
   *
   *   Int32
   *       The length of the parameter value, in bytes (this count does not include itself). Can be zero. As a special case, -1 indicates a NULL parameter value. No value bytes follow in the NULL case.
   *
   *   Byten
   *       The value of the parameter, in the format indicated by the associated format code. n is the above length.
   *
   *   After the last parameter, the following fields appear:
   *
   *   Int16
   *       The number of result-column format codes that follow (denoted R below). This can be zero to indicate that there are no result columns or that the result columns should all use the default format (text); or one, in which case the specified format code is applied to all result columns (if any); or it can equal the actual number of result columns of the query.
   *
   *   Int16[R]
   *       The result-column format codes. Each must presently be zero (text) or one (binary).
   * </pre>
   *
   * @author Antti Laisi
   */
  public class BindEncoder extends ExtendedQueryEncoder<Bind> {
  
      @Override
      public Class<Bind> getMessageType() {
          return Bind.class;
      }
  
      @Override
      protected byte getMessageId() {
          return (byte) 'B';
      }
  
      @Override
      public void writeBody(Bind msg, ByteBuffer buffer, Charset encoding) {
          IO.putCString(buffer, "", encoding); // portal
          IO.putCString(buffer, msg.getSname(), encoding); // prepared statement
          buffer.putShort((short) 0); // number of format codes
          buffer.putShort((short) msg.getParams().length); // number of parameters
          for (byte[] param : msg.getParams()) {
              writeParameter(buffer, param);
          }
          buffer.putShort((short) 0);
      }
  
      void writeParameter(ByteBuffer buffer, byte[] param) {
          if (param == null) {
              buffer.putInt(-1);
          } else {
              buffer.putInt(param.length);
              buffer.put(param);
          }
      }
  }
  