/*!
* staticwriter.js - buffer writer for bcoin
* Copyright (c) 2014-2017, Christopher Jeffrey (MIT License).
* https://github.com/bcoin-org/bcoin
*/
'use strict';
var assert = require('assert');
var encoding = require('./encoding');
var crypto = require('../crypto/crypto');
/**
* Statically allocated buffer writer.
* @alias module:utils.StaticWriter
* @constructor
* @param {Number} size
*/
function StaticWriter(size) {
if (!(this instanceof StaticWriter))
return new StaticWriter(size);
this.data = new Buffer(size);
this.written = 0;
}
/**
* Allocate and render the final buffer.
* @param {Boolean?} keep - Do not destroy the writer.
* @returns {Buffer} Rendered buffer.
*/
StaticWriter.prototype.render = function render(keep) {
var data = this.data;
assert(this.written === data.length);
if (!keep)
this.destroy();
return data;
};
/**
* Get size of data written so far.
* @returns {Number}
*/
StaticWriter.prototype.getSize = function getSize() {
return this.written;
};
/**
* Seek to relative offset.
* @param {Number} offset
*/
StaticWriter.prototype.seek = function seek(offset) {
this.written += offset;
};
/**
* Destroy the buffer writer.
*/
StaticWriter.prototype.destroy = function destroy() {
this.data = null;
this.written = null;
};
/**
* Write uint8.
* @param {Number} value
*/
StaticWriter.prototype.writeU8 = function writeU8(value) {
this.written = this.data.writeUInt8(value, this.written, true);
};
/**
* Write uint16le.
* @param {Number} value
*/
StaticWriter.prototype.writeU16 = function writeU16(value) {
this.written = this.data.writeUInt16LE(value, this.written, true);
};
/**
* Write uint16be.
* @param {Number} value
*/
StaticWriter.prototype.writeU16BE = function writeU16BE(value) {
this.written = this.data.writeUInt16BE(value, this.written, true);
};
/**
* Write uint32le.
* @param {Number} value
*/
StaticWriter.prototype.writeU32 = function writeU32(value) {
this.written = this.data.writeUInt32LE(value, this.written, true);
};
/**
* Write uint32be.
* @param {Number} value
*/
StaticWriter.prototype.writeU32BE = function writeU32BE(value) {
this.written = this.data.writeUInt32BE(value, this.written, true);
};
/**
* Write uint64le.
* @param {Number} value
*/
StaticWriter.prototype.writeU64 = function writeU64(value) {
this.written = encoding.writeU64(this.data, value, this.written);
};
/**
* Write uint64be.
* @param {Number} value
*/
StaticWriter.prototype.writeU64BE = function writeU64BE(value) {
this.written = encoding.writeU64BE(this.data, value, this.written);
};
/**
* Write uint64le.
* @param {BN} value
*/
StaticWriter.prototype.writeU64BN = function writeU64BN(value) {
assert(false, 'Not implemented.');
};
/**
* Write uint64be.
* @param {BN} value
*/
StaticWriter.prototype.writeU64BEBN = function writeU64BEBN(value) {
assert(false, 'Not implemented.');
};
/**
* Write int8.
* @param {Number} value
*/
StaticWriter.prototype.write8 = function write8(value) {
this.written = this.data.writeInt8(value, this.written, true);
};
/**
* Write int16le.
* @param {Number} value
*/
StaticWriter.prototype.write16 = function write16(value) {
this.written = this.data.writeInt16LE(value, this.written, true);
};
/**
* Write int16be.
* @param {Number} value
*/
StaticWriter.prototype.write16BE = function write16BE(value) {
this.written = this.data.writeInt16BE(value, this.written, true);
};
/**
* Write int32le.
* @param {Number} value
*/
StaticWriter.prototype.write32 = function write32(value) {
this.written = this.data.writeInt32LE(value, this.written, true);
};
/**
* Write int32be.
* @param {Number} value
*/
StaticWriter.prototype.write32BE = function write32BE(value) {
this.written = this.data.writeInt32BE(value, this.written, true);
};
/**
* Write int64le.
* @param {Number} value
*/
StaticWriter.prototype.write64 = function write64(value) {
this.written = encoding.write64(this.data, value, this.written);
};
/**
* Write int64be.
* @param {Number} value
*/
StaticWriter.prototype.write64BE = function write64BE(value) {
this.written = encoding.write64BE(this.data, value, this.written);
};
/**
* Write int64le.
* @param {BN} value
*/
StaticWriter.prototype.write64BN = function write64BN(value) {
assert(false, 'Not implemented.');
};
/**
* Write int64be.
* @param {BN} value
*/
StaticWriter.prototype.write64BEBN = function write64BEBN(value) {
assert(false, 'Not implemented.');
};
/**
* Write float le.
* @param {Number} value
*/
StaticWriter.prototype.writeFloat = function writeFloat(value) {
this.written = this.data.writeFloatLE(value, this.written, true);
};
/**
* Write float be.
* @param {Number} value
*/
StaticWriter.prototype.writeFloatBE = function writeFloatBE(value) {
this.written = this.data.writeFloatBE(value, this.written, true);
};
/**
* Write double le.
* @param {Number} value
*/
StaticWriter.prototype.writeDouble = function writeDouble(value) {
this.written = this.data.writeDoubleLE(value, this.written, true);
};
/**
* Write double be.
* @param {Number} value
*/
StaticWriter.prototype.writeDoubleBE = function writeDoubleBE(value) {
this.written = this.data.writeDoubleBE(value, this.written, true);
};
/**
* Write a varint.
* @param {Number} value
*/
StaticWriter.prototype.writeVarint = function writeVarint(value) {
this.written = encoding.writeVarint(this.data, value, this.written);
};
/**
* Write a varint.
* @param {BN} value
*/
StaticWriter.prototype.writeVarintBN = function writeVarintBN(value) {
assert(false, 'Not implemented.');
};
/**
* Write a varint (type 2).
* @param {Number} value
*/
StaticWriter.prototype.writeVarint2 = function writeVarint2(value) {
this.written = encoding.writeVarint2(this.data, value, this.written);
};
/**
* Write a varint (type 2).
* @param {BN} value
*/
StaticWriter.prototype.writeVarint2BN = function writeVarint2BN(value) {
assert(false, 'Not implemented.');
};
/**
* Write bytes.
* @param {Buffer} value
*/
StaticWriter.prototype.writeBytes = function writeBytes(value) {
if (value.length === 0)
return;
value.copy(this.data, this.written);
this.written += value.length;
};
/**
* Write bytes with a varint length before them.
* @param {Buffer} value
*/
StaticWriter.prototype.writeVarBytes = function writeVarBytes(value) {
this.writeVarint(value.length);
this.writeBytes(value);
};
/**
* Copy bytes.
* @param {Buffer} value
* @param {Number} start
* @param {Number} end
*/
StaticWriter.prototype.copy = function copy(value, start, end) {
var len = end - start;
if (len === 0)
return;
value.copy(this.data, this.written, start, end);
this.written += len;
};
/**
* Write string to buffer.
* @param {String} value
* @param {String?} enc - Any buffer-supported encoding.
*/
StaticWriter.prototype.writeString = function writeString(value, enc) {
var size;
if (value.length === 0)
return;
size = Buffer.byteLength(value, enc);
this.data.write(value, this.written, enc);
this.written += size;
};
/**
* Write a 32 byte hash.
* @param {Hash} value
*/
StaticWriter.prototype.writeHash = function writeHash(value) {
if (typeof value !== 'string') {
assert(value.length === 32);
return this.writeBytes(value);
}
assert(value.length === 64);
this.data.write(value, this.written, 'hex');
this.written += 32;
};
/**
* Write a string with a varint length before it.
* @param {String}
* @param {String?} enc - Any buffer-supported encoding.
*/
StaticWriter.prototype.writeVarString = function writeVarString(value, enc) {
var size;
if (value.length === 0) {
this.writeVarint(0);
return;
}
size = Buffer.byteLength(value, enc);
this.writeVarint(size);
this.data.write(value, this.written, enc);
this.written += size;
};
/**
* Write a null-terminated string.
* @param {String|Buffer}
* @param {String?} enc - Any buffer-supported encoding.
*/
StaticWriter.prototype.writeNullString = function writeNullString(value, enc) {
this.writeString(value, enc);
this.writeU8(0);
};
/**
* Calculate and write a checksum for the data written so far.
*/
StaticWriter.prototype.writeChecksum = function writeChecksum() {
var data = this.data.slice(0, this.written);
var hash = crypto.hash256(data);
hash.copy(this.data, this.written, 0, 4);
this.written += 4;
};
/**
* Fill N bytes with value.
* @param {Number} value
* @param {Number} size
*/
StaticWriter.prototype.fill = function fill(value, size) {
assert(size >= 0);
if (size === 0)
return;
this.data.fill(value, this.written, this.written + size);
this.written += size;
};
/*
* Expose
*/
module.exports = StaticWriter;