/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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.
 */

var log = require("./log");
var Int64 = require("node-int64");
var Thrift = require("./thrift");
var Type = Thrift.Type;

const { parse: uuidParse, stringify: uuidStringify } = require("uuid");

module.exports = TCompactProtocol;

var POW_8 = Math.pow(2, 8);
var POW_24 = Math.pow(2, 24);
var POW_32 = Math.pow(2, 32);
var POW_40 = Math.pow(2, 40);
var POW_48 = Math.pow(2, 48);
var POW_52 = Math.pow(2, 52);
var POW_1022 = Math.pow(2, 1022);

/**
 * Constructor Function for the Compact Protocol.
 * @constructor
 * @param {object} [trans] - The underlying transport to read/write.
 * @classdesc The Apache Thrift Protocol layer performs serialization
 *     of base types, the compact protocol serializes data in binary
 *     form with minimal space used for scalar values.
 */
function TCompactProtocol(trans) {
  this.trans = trans;
  this.lastField_ = [];
  this.lastFieldId_ = 0;
  this.string_limit_ = 0;
  this.string_buf_ = null;
  this.string_buf_size_ = 0;
  this.container_limit_ = 0;
  this.booleanField_ = {
    name: null,
    hasBoolValue: false,
  };
  this.boolValue_ = {
    hasBoolValue: false,
    boolValue: false,
  };
}

//
// Compact Protocol Constants
//

/**
 * Compact Protocol ID number.
 * @readonly
 * @const {number} PROTOCOL_ID
 */
TCompactProtocol.PROTOCOL_ID = -126; //1000 0010

/**
 * Compact Protocol version number.
 * @readonly
 * @const {number} VERSION_N
 */
TCompactProtocol.VERSION_N = 1;

/**
 * Compact Protocol version mask for combining protocol version and message type in one byte.
 * @readonly
 * @const {number} VERSION_MASK
 */
TCompactProtocol.VERSION_MASK = 0x1f; //0001 1111

/**
 * Compact Protocol message type mask for combining protocol version and message type in one byte.
 * @readonly
 * @const {number} TYPE_MASK
 */
TCompactProtocol.TYPE_MASK = -32; //1110 0000

/**
 * Compact Protocol message type bits for ensuring message type bit size.
 * @readonly
 * @const {number} TYPE_BITS
 */
TCompactProtocol.TYPE_BITS = 7; //0000 0111

/**
 * Compact Protocol message type shift amount for combining protocol version and message type in one byte.
 * @readonly
 * @const {number} TYPE_SHIFT_AMOUNT
 */
TCompactProtocol.TYPE_SHIFT_AMOUNT = 5;

/**
 * Compact Protocol type IDs used to keep type data within one nibble.
 * @readonly
 * @property {number}  CT_STOP          - End of a set of fields.
 * @property {number}  CT_BOOLEAN_TRUE  - Flag for Boolean field with true value (packed field and value).
 * @property {number}  CT_BOOLEAN_FALSE - Flag for Boolean field with false value (packed field and value).
 * @property {number}  CT_BYTE          - Signed 8 bit integer.
 * @property {number}  CT_I16           - Signed 16 bit integer.
 * @property {number}  CT_I32           - Signed 32 bit integer.
 * @property {number}  CT_I64           - Signed 64 bit integer (2^53 max in JavaScript).
 * @property {number}  CT_DOUBLE        - 64 bit IEEE 854 floating point.
 * @property {number}  CT_BINARY        - Array of bytes (used for strings also).
 * @property {number}  CT_LIST          - A collection type (unordered).
 * @property {number}  CT_SET           - A collection type (unordered and without repeated values).
 * @property {number}  CT_MAP           - A collection type (map/associative-array/dictionary).
 * @property {number}  CT_STRUCT        - A multifield type.
 * @property {number}  CT_UUID          - A UUID type.
 */
TCompactProtocol.Types = {
  CT_STOP: 0x00,
  CT_BOOLEAN_TRUE: 0x01,
  CT_BOOLEAN_FALSE: 0x02,
  CT_BYTE: 0x03,
  CT_I16: 0x04,
  CT_I32: 0x05,
  CT_I64: 0x06,
  CT_DOUBLE: 0x07,
  CT_BINARY: 0x08,
  CT_LIST: 0x09,
  CT_SET: 0x0a,
  CT_MAP: 0x0b,
  CT_STRUCT: 0x0c,
  CT_UUID: 0x0d,
};

/**
 * Array mapping Compact type IDs to standard Thrift type IDs.
 * @readonly
 */
TCompactProtocol.TTypeToCType = [
  TCompactProtocol.Types.CT_STOP, // T_STOP
  0, // unused
  TCompactProtocol.Types.CT_BOOLEAN_TRUE, // T_BOOL
  TCompactProtocol.Types.CT_BYTE, // T_BYTE
  TCompactProtocol.Types.CT_DOUBLE, // T_DOUBLE
  0, // unused
  TCompactProtocol.Types.CT_I16, // T_I16
  0, // unused
  TCompactProtocol.Types.CT_I32, // T_I32
  0, // unused
  TCompactProtocol.Types.CT_I64, // T_I64
  TCompactProtocol.Types.CT_BINARY, // T_STRING
  TCompactProtocol.Types.CT_STRUCT, // T_STRUCT
  TCompactProtocol.Types.CT_MAP, // T_MAP
  TCompactProtocol.Types.CT_SET, // T_SET
  TCompactProtocol.Types.CT_LIST, // T_LIST
  TCompactProtocol.Types.CT_UUID, // T_UUID
];

//
// Compact Protocol Utilities
//

/**
 * Returns the underlying transport layer.
 * @return {object} The underlying transport layer.
 */ TCompactProtocol.prototype.getTransport = function () {
  return this.trans;
};

/**
 * Lookup a Compact Protocol Type value for a given Thrift Type value.
 * N.B. Used only internally.
 * @param {number} ttype - Thrift type value
 * @returns {number} Compact protocol type value
 */
TCompactProtocol.prototype.getCompactType = function (ttype) {
  return TCompactProtocol.TTypeToCType[ttype];
};

/**
 * Lookup a Thrift Type value for a given Compact Protocol Type value.
 * N.B. Used only internally.
 * @param {number} type - Compact Protocol type value
 * @returns {number} Thrift Type value
 */
TCompactProtocol.prototype.getTType = function (type) {
  switch (type) {
    case Type.STOP:
      return Type.STOP;
    case TCompactProtocol.Types.CT_BOOLEAN_FALSE:
    case TCompactProtocol.Types.CT_BOOLEAN_TRUE:
      return Type.BOOL;
    case TCompactProtocol.Types.CT_BYTE:
      return Type.BYTE;
    case TCompactProtocol.Types.CT_I16:
      return Type.I16;
    case TCompactProtocol.Types.CT_I32:
      return Type.I32;
    case TCompactProtocol.Types.CT_I64:
      return Type.I64;
    case TCompactProtocol.Types.CT_DOUBLE:
      return Type.DOUBLE;
    case TCompactProtocol.Types.CT_BINARY:
      return Type.STRING;
    case TCompactProtocol.Types.CT_LIST:
      return Type.LIST;
    case TCompactProtocol.Types.CT_SET:
      return Type.SET;
    case TCompactProtocol.Types.CT_MAP:
      return Type.MAP;
    case TCompactProtocol.Types.CT_STRUCT:
      return Type.STRUCT;
    case TCompactProtocol.Types.CT_UUID:
      return Type.UUID;
    default:
      throw new Thrift.TProtocolException(
        Thrift.TProtocolExceptionType.INVALID_DATA,
        "Unknown type: " + type,
      );
  }
  return Type.STOP;
};

//
// Compact Protocol write operations
//

/**
 * Send any buffered bytes to the end point.
 */
TCompactProtocol.prototype.flush = function () {
  return this.trans.flush();
};

/**
 * Writes an RPC message header
 * @param {string} name - The method name for the message.
 * @param {number} type - The type of message (CALL, REPLY, EXCEPTION, ONEWAY).
 * @param {number} seqid - The call sequence number (if any).
 */
TCompactProtocol.prototype.writeMessageBegin = function (name, type, seqid) {
  this.writeByte(TCompactProtocol.PROTOCOL_ID);
  this.writeByte(
    (TCompactProtocol.VERSION_N & TCompactProtocol.VERSION_MASK) |
      ((type << TCompactProtocol.TYPE_SHIFT_AMOUNT) &
        TCompactProtocol.TYPE_MASK),
  );
  this.writeVarint32(seqid);
  this.writeString(name);

  // Record client seqid to find callback again
  if (this._seqid) {
    log.warning("SeqId already set", { name: name });
  } else {
    this._seqid = seqid;
    this.trans.setCurrSeqId(seqid);
  }
};

TCompactProtocol.prototype.writeMessageEnd = function () {};

TCompactProtocol.prototype.writeStructBegin = function (name) {
  this.lastField_.push(this.lastFieldId_);
  this.lastFieldId_ = 0;
};

TCompactProtocol.prototype.writeStructEnd = function () {
  this.lastFieldId_ = this.lastField_.pop();
};

/**
 * Writes a struct field header
 * @param {string} name - The field name (not written with the compact protocol).
 * @param {number} type - The field data type (a normal Thrift field Type).
 * @param {number} id - The IDL field Id.
 */
TCompactProtocol.prototype.writeFieldBegin = function (name, type, id) {
  if (type != Type.BOOL) {
    return this.writeFieldBeginInternal(name, type, id, -1);
  }

  this.booleanField_.name = name;
  this.booleanField_.fieldType = type;
  this.booleanField_.fieldId = id;
};

TCompactProtocol.prototype.writeFieldEnd = function () {};

TCompactProtocol.prototype.writeFieldStop = function () {
  this.writeByte(TCompactProtocol.Types.CT_STOP);
};

/**
 * Writes a map collection header
 * @param {number} keyType - The Thrift type of the map keys.
 * @param {number} valType - The Thrift type of the map values.
 * @param {number} size - The number of k/v pairs in the map.
 */
TCompactProtocol.prototype.writeMapBegin = function (keyType, valType, size) {
  if (size === 0) {
    this.writeByte(0);
  } else {
    this.writeVarint32(size);
    this.writeByte(
      (this.getCompactType(keyType) << 4) | this.getCompactType(valType),
    );
  }
};

TCompactProtocol.prototype.writeMapEnd = function () {};

/**
 * Writes a list collection header
 * @param {number} elemType - The Thrift type of the list elements.
 * @param {number} size - The number of elements in the list.
 */
TCompactProtocol.prototype.writeListBegin = function (elemType, size) {
  this.writeCollectionBegin(elemType, size);
};

TCompactProtocol.prototype.writeListEnd = function () {};

/**
 * Writes a set collection header
 * @param {number} elemType - The Thrift type of the set elements.
 * @param {number} size - The number of elements in the set.
 */
TCompactProtocol.prototype.writeSetBegin = function (elemType, size) {
  this.writeCollectionBegin(elemType, size);
};

TCompactProtocol.prototype.writeSetEnd = function () {};

TCompactProtocol.prototype.writeBool = function (value) {
  if (this.booleanField_.name !== null) {
    // we haven't written the field header yet
    this.writeFieldBeginInternal(
      this.booleanField_.name,
      this.booleanField_.fieldType,
      this.booleanField_.fieldId,
      value
        ? TCompactProtocol.Types.CT_BOOLEAN_TRUE
        : TCompactProtocol.Types.CT_BOOLEAN_FALSE,
    );
    this.booleanField_.name = null;
  } else {
    // we're not part of a field, so just write the value
    this.writeByte(
      value
        ? TCompactProtocol.Types.CT_BOOLEAN_TRUE
        : TCompactProtocol.Types.CT_BOOLEAN_FALSE,
    );
  }
};

TCompactProtocol.prototype.writeByte = function (b) {
  this.trans.write(new Buffer([b]));
};

TCompactProtocol.prototype.writeI16 = function (i16) {
  this.writeVarint32(this.i32ToZigzag(i16));
};

TCompactProtocol.prototype.writeI32 = function (i32) {
  this.writeVarint32(this.i32ToZigzag(i32));
};

TCompactProtocol.prototype.writeI64 = function (i64) {
  this.writeVarint64(this.i64ToZigzag(i64));
};

// Little-endian, unlike TBinaryProtocol
TCompactProtocol.prototype.writeDouble = function (v) {
  var buff = new Buffer(8);
  var m, e, c;

  buff[7] = v < 0 ? 0x80 : 0x00;

  v = Math.abs(v);
  if (v !== v) {
    // NaN, use QNaN IEEE format
    m = 2251799813685248;
    e = 2047;
  } else if (v === Infinity) {
    m = 0;
    e = 2047;
  } else {
    e = Math.floor(Math.log(v) / Math.LN2);
    c = Math.pow(2, -e);
    if (v * c < 1) {
      e--;
      c *= 2;
    }

    if (e + 1023 >= 2047) {
      // Overflow
      m = 0;
      e = 2047;
    } else if (e + 1023 >= 1) {
      // Normalized - term order matters, as Math.pow(2, 52-e) and v*Math.pow(2, 52) can overflow
      m = (v * c - 1) * POW_52;
      e += 1023;
    } else {
      // Denormalized - also catches the '0' case, somewhat by chance
      m = v * POW_1022 * POW_52;
      e = 0;
    }
  }

  buff[6] = (e << 4) & 0xf0;
  buff[7] |= (e >> 4) & 0x7f;

  buff[0] = m & 0xff;
  m = Math.floor(m / POW_8);
  buff[1] = m & 0xff;
  m = Math.floor(m / POW_8);
  buff[2] = m & 0xff;
  m = Math.floor(m / POW_8);
  buff[3] = m & 0xff;
  m >>= 8;
  buff[4] = m & 0xff;
  m >>= 8;
  buff[5] = m & 0xff;
  m >>= 8;
  buff[6] |= m & 0x0f;

  this.trans.write(buff);
};

TCompactProtocol.prototype.writeStringOrBinary = function (
  name,
  encoding,
  arg,
) {
  if (typeof arg === "string") {
    this.writeVarint32(Buffer.byteLength(arg, encoding));
    this.trans.write(new Buffer(arg, encoding));
  } else if (
    arg instanceof Buffer ||
    Object.prototype.toString.call(arg) == "[object Uint8Array]"
  ) {
    // Buffers in Node.js under Browserify may extend UInt8Array instead of
    // defining a new object. We detect them here so we can write them
    // correctly
    this.writeVarint32(arg.length);
    this.trans.write(arg);
  } else {
    throw new Error(name + " called without a string/Buffer argument: " + arg);
  }
};

TCompactProtocol.prototype.writeString = function (arg) {
  this.writeStringOrBinary("writeString", "utf8", arg);
};

TCompactProtocol.prototype.writeBinary = function (arg) {
  this.writeStringOrBinary("writeBinary", "binary", arg);
};

TCompactProtocol.prototype.writeUuid = function (arg) {
  this.trans.write(Buffer.from(uuidParse(arg)));
};

//
// Compact Protocol internal write methods
//

TCompactProtocol.prototype.writeFieldBeginInternal = function (
  name,
  fieldType,
  fieldId,
  typeOverride,
) {
  //If there's a type override, use that.
  var typeToWrite =
    typeOverride == -1 ? this.getCompactType(fieldType) : typeOverride;
  //Check if we can delta encode the field id
  if (fieldId > this.lastFieldId_ && fieldId - this.lastFieldId_ <= 15) {
    //Include the type delta with the field ID
    this.writeByte(((fieldId - this.lastFieldId_) << 4) | typeToWrite);
  } else {
    //Write separate type and ID values
    this.writeByte(typeToWrite);
    this.writeI16(fieldId);
  }
  this.lastFieldId_ = fieldId;
};

TCompactProtocol.prototype.writeCollectionBegin = function (elemType, size) {
  if (size <= 14) {
    //Combine size and type in one byte if possible
    this.writeByte((size << 4) | this.getCompactType(elemType));
  } else {
    this.writeByte(0xf0 | this.getCompactType(elemType));
    this.writeVarint32(size);
  }
};

/**
 * Write an i32 as a varint. Results in 1-5 bytes on the wire.
 */
TCompactProtocol.prototype.writeVarint32 = function (n) {
  var buf = new Buffer(5);
  var wsize = 0;
  while (true) {
    if ((n & ~0x7f) === 0) {
      buf[wsize++] = n;
      break;
    } else {
      buf[wsize++] = (n & 0x7f) | 0x80;
      n = n >>> 7;
    }
  }
  var wbuf = new Buffer(wsize);
  buf.copy(wbuf, 0, 0, wsize);
  this.trans.write(wbuf);
};

/**
 * Write an i64 as a varint. Results in 1-10 bytes on the wire.
 * N.B. node-int64 is always big endian
 */
TCompactProtocol.prototype.writeVarint64 = function (n) {
  if (typeof n === "number") {
    n = new Int64(n);
  }
  if (!(n instanceof Int64)) {
    throw new Thrift.TProtocolException(
      Thrift.TProtocolExceptionType.INVALID_DATA,
      "Expected Int64 or Number, found: " + n,
    );
  }

  var buf = new Buffer(10);
  var wsize = 0;
  var hi = n.buffer.readUInt32BE(0, true);
  var lo = n.buffer.readUInt32BE(4, true);
  var mask = 0;
  while (true) {
    if ((lo & ~0x7f) === 0 && hi === 0) {
      buf[wsize++] = lo;
      break;
    } else {
      buf[wsize++] = (lo & 0x7f) | 0x80;
      mask = hi << 25;
      lo = lo >>> 7;
      hi = hi >>> 7;
      lo = lo | mask;
    }
  }
  var wbuf = new Buffer(wsize);
  buf.copy(wbuf, 0, 0, wsize);
  this.trans.write(wbuf);
};

/**
 * Convert l into a zigzag long. This allows negative numbers to be
 * represented compactly as a varint.
 */
TCompactProtocol.prototype.i64ToZigzag = function (l) {
  if (typeof l === "string") {
    l = new Int64(parseInt(l, 10));
  } else if (typeof l === "number") {
    l = new Int64(l);
  }
  if (!(l instanceof Int64)) {
    throw new Thrift.TProtocolException(
      Thrift.TProtocolExceptionType.INVALID_DATA,
      "Expected Int64 or Number, found: " + l,
    );
  }
  var hi = l.buffer.readUInt32BE(0, true);
  var lo = l.buffer.readUInt32BE(4, true);
  var sign = hi >>> 31;
  hi = ((hi << 1) | (lo >>> 31)) ^ (!!sign ? 0xffffffff : 0);
  lo = (lo << 1) ^ (!!sign ? 0xffffffff : 0);
  return new Int64(hi, lo);
};

/**
 * Convert n into a zigzag int. This allows negative numbers to be
 * represented compactly as a varint.
 */
TCompactProtocol.prototype.i32ToZigzag = function (n) {
  return (n << 1) ^ (n & 0x80000000 ? 0xffffffff : 0);
};

//
// Compact Protocol read operations
//

TCompactProtocol.prototype.readMessageBegin = function () {
  //Read protocol ID
  var protocolId = this.trans.readByte();
  if (protocolId != TCompactProtocol.PROTOCOL_ID) {
    throw new Thrift.TProtocolException(
      Thrift.TProtocolExceptionType.BAD_VERSION,
      "Bad protocol identifier " + protocolId,
    );
  }

  //Read Version and Type
  var versionAndType = this.trans.readByte();
  var version = versionAndType & TCompactProtocol.VERSION_MASK;
  if (version != TCompactProtocol.VERSION_N) {
    throw new Thrift.TProtocolException(
      Thrift.TProtocolExceptionType.BAD_VERSION,
      "Bad protocol version " + version,
    );
  }
  var type =
    (versionAndType >> TCompactProtocol.TYPE_SHIFT_AMOUNT) &
    TCompactProtocol.TYPE_BITS;

  //Read SeqId
  var seqid = this.readVarint32();

  //Read name
  var name = this.readString();

  return { fname: name, mtype: type, rseqid: seqid };
};

TCompactProtocol.prototype.readMessageEnd = function () {};

TCompactProtocol.prototype.readStructBegin = function () {
  this.lastField_.push(this.lastFieldId_);
  this.lastFieldId_ = 0;
  return { fname: "" };
};

TCompactProtocol.prototype.readStructEnd = function () {
  this.lastFieldId_ = this.lastField_.pop();
};

TCompactProtocol.prototype.readFieldBegin = function () {
  var fieldId = 0;
  var b = this.trans.readByte(b);
  var type = b & 0x0f;

  if (type == TCompactProtocol.Types.CT_STOP) {
    return { fname: null, ftype: Thrift.Type.STOP, fid: 0 };
  }

  //Mask off the 4 MSB of the type header to check for field id delta.
  var modifier = (b & 0x000000f0) >>> 4;
  if (modifier === 0) {
    //If not a delta read the field id.
    fieldId = this.readI16();
  } else {
    //Recover the field id from the delta
    fieldId = this.lastFieldId_ + modifier;
  }
  var fieldType = this.getTType(type);

  //Boolean are encoded with the type
  if (
    type == TCompactProtocol.Types.CT_BOOLEAN_TRUE ||
    type == TCompactProtocol.Types.CT_BOOLEAN_FALSE
  ) {
    this.boolValue_.hasBoolValue = true;
    this.boolValue_.boolValue =
      type == TCompactProtocol.Types.CT_BOOLEAN_TRUE ? true : false;
  }

  //Save the new field for the next delta computation.
  this.lastFieldId_ = fieldId;
  return { fname: null, ftype: fieldType, fid: fieldId };
};

TCompactProtocol.prototype.readFieldEnd = function () {};

TCompactProtocol.prototype.readMapBegin = function () {
  var msize = this.readVarint32();
  if (msize < 0) {
    throw new Thrift.TProtocolException(
      Thrift.TProtocolExceptionType.NEGATIVE_SIZE,
      "Negative map size",
    );
  }

  var kvType = 0;
  if (msize !== 0) {
    kvType = this.trans.readByte();
  }

  var keyType = this.getTType((kvType & 0xf0) >>> 4);
  var valType = this.getTType(kvType & 0xf);
  return { ktype: keyType, vtype: valType, size: msize };
};

TCompactProtocol.prototype.readMapEnd = function () {};

TCompactProtocol.prototype.readListBegin = function () {
  var size_and_type = this.trans.readByte();

  var lsize = (size_and_type >>> 4) & 0x0000000f;
  if (lsize == 15) {
    lsize = this.readVarint32();
  }

  if (lsize < 0) {
    throw new Thrift.TProtocolException(
      Thrift.TProtocolExceptionType.NEGATIVE_SIZE,
      "Negative list size",
    );
  }

  var elemType = this.getTType(size_and_type & 0x0000000f);

  return { etype: elemType, size: lsize };
};

TCompactProtocol.prototype.readListEnd = function () {};

TCompactProtocol.prototype.readSetBegin = function () {
  return this.readListBegin();
};

TCompactProtocol.prototype.readSetEnd = function () {};

TCompactProtocol.prototype.readBool = function () {
  var value = false;
  var rsize = 0;
  if (this.boolValue_.hasBoolValue === true) {
    value = this.boolValue_.boolValue;
    this.boolValue_.hasBoolValue = false;
  } else {
    var res = this.trans.readByte();
    rsize = res.rsize;
    value = res.value == TCompactProtocol.Types.CT_BOOLEAN_TRUE;
  }
  return value;
};

TCompactProtocol.prototype.readByte = function () {
  return this.trans.readByte();
};

TCompactProtocol.prototype.readUuid = function () {
  const buf = this.trans.read(16);
  return uuidStringify(new Uint8Array(buf));
};

TCompactProtocol.prototype.readI16 = function () {
  return this.readI32();
};

TCompactProtocol.prototype.readI32 = function () {
  return this.zigzagToI32(this.readVarint32());
};

TCompactProtocol.prototype.readI64 = function () {
  return this.zigzagToI64(this.readVarint64());
};

// Little-endian, unlike TBinaryProtocol
TCompactProtocol.prototype.readDouble = function () {
  var buff = this.trans.read(8);
  var off = 0;

  var signed = buff[off + 7] & 0x80;
  var e = (buff[off + 6] & 0xf0) >> 4;
  e += (buff[off + 7] & 0x7f) << 4;

  var m = buff[off];
  m += buff[off + 1] << 8;
  m += buff[off + 2] << 16;
  m += buff[off + 3] * POW_24;
  m += buff[off + 4] * POW_32;
  m += buff[off + 5] * POW_40;
  m += (buff[off + 6] & 0x0f) * POW_48;

  switch (e) {
    case 0:
      e = -1022;
      break;
    case 2047:
      return m ? NaN : signed ? -Infinity : Infinity;
    default:
      m += POW_52;
      e -= 1023;
  }

  if (signed) {
    m *= -1;
  }

  return m * Math.pow(2, e - 52);
};

TCompactProtocol.prototype.readBinary = function () {
  var size = this.readVarint32();
  if (size === 0) {
    return new Buffer(0);
  }

  if (size < 0) {
    throw new Thrift.TProtocolException(
      Thrift.TProtocolExceptionType.NEGATIVE_SIZE,
      "Negative binary size",
    );
  }
  return this.trans.read(size);
};

TCompactProtocol.prototype.readString = function () {
  var size = this.readVarint32();
  // Catch empty string case
  if (size === 0) {
    return "";
  }

  // Catch error cases
  if (size < 0) {
    throw new Thrift.TProtocolException(
      Thrift.TProtocolExceptionType.NEGATIVE_SIZE,
      "Negative string size",
    );
  }
  return this.trans.readString(size);
};

//
// Compact Protocol internal read operations
//

/**
 * Read an i32 from the wire as a varint. The MSB of each byte is set
 * if there is another byte to follow. This can read up to 5 bytes.
 */
TCompactProtocol.prototype.readVarint32 = function () {
  return this.readVarint64().toNumber();
};

/**
 * Read an i64 from the wire as a proper varint. The MSB of each byte is set
 * if there is another byte to follow. This can read up to 10 bytes.
 */
TCompactProtocol.prototype.readVarint64 = function () {
  var rsize = 0;
  var lo = 0;
  var hi = 0;
  var shift = 0;
  while (true) {
    var b = this.trans.readByte();
    rsize++;
    if (shift <= 25) {
      lo = lo | ((b & 0x7f) << shift);
    } else if (25 < shift && shift < 32) {
      lo = lo | ((b & 0x7f) << shift);
      hi = hi | ((b & 0x7f) >>> (32 - shift));
    } else {
      hi = hi | ((b & 0x7f) << (shift - 32));
    }
    shift += 7;
    if (!(b & 0x80)) {
      break;
    }
    if (rsize >= 10) {
      throw new Thrift.TProtocolException(
        Thrift.TProtocolExceptionType.INVALID_DATA,
        "Variable-length int over 10 bytes.",
      );
    }
  }
  return new Int64(hi, lo);
};

/**
 * Convert from zigzag int to int.
 */
TCompactProtocol.prototype.zigzagToI32 = function (n) {
  return (n >>> 1) ^ (-1 * (n & 1));
};

/**
 * Convert from zigzag long to long.
 */
TCompactProtocol.prototype.zigzagToI64 = function (n) {
  var hi = n.buffer.readUInt32BE(0, true);
  var lo = n.buffer.readUInt32BE(4, true);

  var neg = new Int64(hi & 0, lo & 1);
  neg._2scomp();
  var hi_neg = neg.buffer.readUInt32BE(0, true);
  var lo_neg = neg.buffer.readUInt32BE(4, true);

  var hi_lo = hi << 31;
  hi = (hi >>> 1) ^ hi_neg;
  lo = ((lo >>> 1) | hi_lo) ^ lo_neg;
  return new Int64(hi, lo);
};

TCompactProtocol.prototype.skip = function (type, depth) {
  depth = (depth || 0) + 1;
  if (depth > 64) {
    throw new Thrift.TProtocolException(
      Thrift.TProtocolExceptionType.DEPTH_LIMIT,
      "Maximum skip depth exceeded"
    );
  }
  switch (type) {
    case Type.BOOL:
      this.readBool();
      break;
    case Type.BYTE:
      this.readByte();
      break;
    case Type.I16:
      this.readI16();
      break;
    case Type.I32:
      this.readI32();
      break;
    case Type.I64:
      this.readI64();
      break;
    case Type.DOUBLE:
      this.readDouble();
      break;
    case Type.STRING:
      this.readString();
      break;
    case Type.UUID:
      this.readUuid();
      break;
    case Type.STRUCT:
      this.readStructBegin();
      while (true) {
        var r = this.readFieldBegin();
        if (r.ftype === Type.STOP) {
          break;
        }
        this.skip(r.ftype, depth);
        this.readFieldEnd();
      }
      this.readStructEnd();
      break;
    case Type.MAP:
      var mapBegin = this.readMapBegin();
      for (var i = 0; i < mapBegin.size; ++i) {
        this.skip(mapBegin.ktype, depth);
        this.skip(mapBegin.vtype, depth);
      }
      this.readMapEnd();
      break;
    case Type.SET:
      var setBegin = this.readSetBegin();
      for (var i2 = 0; i2 < setBegin.size; ++i2) {
        this.skip(setBegin.etype, depth);
      }
      this.readSetEnd();
      break;
    case Type.LIST:
      var listBegin = this.readListBegin();
      for (var i3 = 0; i3 < listBegin.size; ++i3) {
        this.skip(listBegin.etype, depth);
      }
      this.readListEnd();
      break;
    default:
      throw new Error("Invalid type: " + type);
  }
};
