Support for bytea datatype for node-postgres

node-postgres_types_bytea.fragment.js

// types.js
// ...

var parseByteA = function(val) {
  // Step 1: Find binary data length (and validate data)
  var length = 0;
  for (var i = 0; i < val.length; i++) {
    if (val[i] == "\\") {
      if (i >= val.length - 1)
        throw "Invalid bytea encoding: '\\' at the end";
      if (val[i + 1] == "\\") {
        length += 1;
        i += 1;
      } else {
        if (i >= val.length - 3)
          throw "Invalid bytea encoding: not enough space for 3 octal digits after '\\' near the end";
        if (!val.substr(i + 1, 3).match(/^[0-7]{3}$/))
          throw "Invalid bytea encoding: '\\' is not followed by 3 octal digits at "+ I
        length += 1;
        i += 3;
      }
    } else {
      if (val.charCodeAt(i) > 255)
        throw "Invalid bytea encoding: multi-byte character at position " + i
      length += 1;
    }
  }

  // Step 2: Allocate buffer and fill it decoding the data
  var buf = new Buffer(length),
      pos = 0;
  for (var i = 0; i < val.length; i++) {
    if (val[i] == "\\") {
      // No need for correctness checks as they were done in step 1
      if (val[i + 1] == "\\") {
        buf[pos] = 92; // 92 == "\\".charCodeAt(0) == val.charCodeAt(i + 1)
        pos += 1;
        i += 1;
      } else {
        buf[pos] = parseInt(val.substr(i + 1, 3), 8);
        pos += 1;
        i += 3;
      }
    } else {
      buf[pos] = val.charCodeAt(i);
      pos += 1;
    }
  }
  return buf;

  /*
  // Alternate implementation (lacks error checking and probably more resource-hungry):
  return new Buffer(val.replace(/\\([0-7]{3})/g, function (full_match, code) {
    return String.fromCharCode(parseInt(code, 8));
  }).replace(/\\\\/g, "\\"));
  */
};

// ...

registerStringTypeParser(17, parseByteA);