obuf
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Byte buffer specialized for data in chunks with special cases for dropping bytes in the front, merging bytes in to various integer types and abandoning buffer without penalty for previous chunk merges.
269 lines (239 loc) • 8.32 kB
JavaScript
var assert = require('assert');
var OffsetBuffer = require('../');
describe('OffsetBuffer', function() {
var o;
beforeEach(function() {
o = new OffsetBuffer();
});
describe('.take()', function() {
it('should return empty buffer', function() {
var b = new Buffer('hello world');
o.push(b);
var r = o.take(0);
assert.equal(r.length, 0);
assert.equal(o.size, b.length);
});
it('should return the first buffer itself', function() {
var b = new Buffer('hello world');
o.push(b);
var r = o.take(b.length);
assert(r === b);
assert(o.isEmpty());
});
it('should return the slice of the buffer ', function() {
var b = new Buffer('hello world');
o.push(b);
assert.equal(o.take(5).toString(), 'hello');
assert.equal(o.take(1).toString(), ' ');
assert.equal(o.take(5).toString(), 'world');
assert(o.isEmpty());
});
it('should concat buffers', function() {
o.push(new Buffer('hello'));
o.push(new Buffer(' '));
o.push(new Buffer('world!'));
assert.equal(o.take(11).toString(), 'hello world');
assert.equal(o.take(1).toString(), '!');
assert(o.isEmpty());
});
});
describe('.skip', function() {
it('should skip bytes', function() {
o.push(new Buffer('hello '));
o.push(new Buffer('world'));
o.push(new Buffer(' oh gosh'));
assert.equal(o.take(2).toString(), 'he');
o.skip(1);
assert.equal(o.take(2).toString(), 'lo');
o.skip(1);
assert.equal(o.take(2).toString(), 'wo');
o.skip(4);
assert.equal(o.take(7).toString(), 'oh gosh');
assert(o.isEmpty());
});
});
describe('.peekUInt8', function() {
it('should return and not move by one byte', function() {
o.push(new Buffer([ 0x1, 0x2 ]));
assert.equal(o.peekUInt8(), 1);
assert.equal(o.readUInt8(), 1);
assert.equal(o.peekUInt8(), 2);
assert.equal(o.readUInt8(), 2);
assert(o.isEmpty());
});
});
describe('.peekInt8', function() {
it('should return signed number', function() {
o.push(new Buffer([ 0x80 ]));
assert.equal(o.peekInt8(), -128);
assert.equal(o.readInt8(), -128);
assert(o.isEmpty());
});
});
describe('.readUInt8', function() {
it('should return and move by one byte', function() {
o.push(new Buffer([ 0x1, 0x2 ]));
o.push(new Buffer([ 0x3, 0x4 ]));
assert.equal(o.readUInt8(), 1);
assert.equal(o.readUInt8(), 2);
assert.equal(o.readUInt8(), 3);
assert.equal(o.readUInt8(), 4);
assert(o.isEmpty());
});
});
describe('.readInt8', function() {
it('should return signed number', function() {
o.push(new Buffer([ 0x8f, 0x7f ]));
assert.equal(o.readInt8(), -113);
assert.equal(o.readInt8(), 127);
assert(o.isEmpty());
});
});
describe('.readUInt16LE', function() {
it('should return and move by two bytes', function() {
o.push(new Buffer([ 0x1, 0x2, 0x3 ]));
o.push(new Buffer([ 0x4, 0x5, 0x6 ]));
assert.equal(o.readUInt16LE(), 0x0201);
assert.equal(o.readUInt16LE(), 0x0403);
assert.equal(o.readUInt16LE(), 0x0605);
assert(o.isEmpty());
});
it('should return and move by two bytes (regression #1)', function() {
o.push(new Buffer([ 0x1 ]));
o.push(new Buffer([ 0x2, 0x3, 0x4 ]));
assert.equal(o.readUInt16LE(), 0x0201);
assert.equal(o.readUInt16LE(), 0x0403);
assert(o.isEmpty());
});
});
describe('.readInt16LE', function() {
it('should return signed number', function() {
o.push(new Buffer([ 0x23, 0x81 ]));
assert.equal(o.readInt16LE(), -32477);
assert(o.isEmpty());
});
});
describe('.readUInt24LE', function() {
it('should return and move by three bytes', function() {
o.push(new Buffer([ 0x1, 0x2, 0x3, 0x4, 0x5 ]));
o.push(new Buffer([ 0x6, 0x7 ]));
o.push(new Buffer([ 0x8, 0x9 ]));
assert.equal(o.readUInt24LE(), 0x030201);
assert.equal(o.readUInt24LE(), 0x060504);
assert.equal(o.readUInt24LE(), 0x090807);
assert(o.isEmpty());
});
it('should return and move by three bytes (regression #1)', function() {
o.push(new Buffer([ 0x1, 0x2 ]));
o.push(new Buffer([ 0x3 ]));
assert.equal(o.readUInt24LE(), 0x030201);
assert.equal(o.buffers.length, 0);
assert(o.isEmpty());
});
});
describe('.readInt24LE', function() {
it('should return signed number', function() {
o.push(new Buffer([ 0x23, 0x45, 0x81 ]));
assert.equal(o.readInt24LE(), -8305373);
assert(o.isEmpty());
});
});
describe('.readUInt32LE', function() {
it('should return and move by four bytes', function() {
o.push(new Buffer([ 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7 ]));
o.push(new Buffer([ 0x8, 0x9, 0xa ]));
o.push(new Buffer([ 0xb, 0xc, 0xd ]));
o.push(new Buffer([ 0xe, 0xf, 0x10 ]));
assert.equal(o.readUInt32LE(), 0x04030201);
assert.equal(o.readUInt32LE(), 0x08070605);
assert.equal(o.readUInt32LE(), 0x0c0b0a09);
assert.equal(o.readUInt32LE(), 0x100f0e0d);
assert(o.isEmpty());
});
it('should return and move by four bytes (regression #1)', function() {
o.push(new Buffer([ 0x1, 0x2, 0x3 ]));
o.push(new Buffer([ 0x4 ]));
assert.equal(o.readUInt32LE(), 0x04030201);
assert.equal(o.buffers.length, 0);
assert(o.isEmpty());
});
});
describe('.readInt32LE', function() {
it('should return signed number', function() {
o.push(new Buffer([ 0xff, 0xff, 0xff, 0xff ]));
assert.equal(o.readInt32LE(), -1);
assert(o.isEmpty());
});
});
describe('.readUInt16BE', function() {
it('should return and move by two bytes', function() {
o.push(new Buffer([ 0x1, 0x2, 0x3 ]));
o.push(new Buffer([ 0x4, 0x5, 0x6 ]));
assert.equal(o.readUInt16BE(), 0x0102);
assert.equal(o.readUInt16BE(), 0x0304);
assert.equal(o.readUInt16BE(), 0x0506);
assert(o.isEmpty());
});
});
describe('.readInt16BE', function() {
it('should return signed number', function() {
o.push(new Buffer([ 0x81, 0x23 ]));
assert.equal(o.readInt16BE(), -32477);
assert(o.isEmpty());
});
});
describe('.readUInt24BE', function() {
it('should return and move by three bytes', function() {
o.push(new Buffer([ 0x1, 0x2, 0x3, 0x4, 0x5 ]));
o.push(new Buffer([ 0x6, 0x7 ]));
o.push(new Buffer([ 0x8, 0x9 ]));
assert.equal(o.readUInt24BE(), 0x010203);
assert.equal(o.readUInt24BE(), 0x040506);
assert.equal(o.readUInt24BE(), 0x070809);
assert(o.isEmpty());
});
});
describe('.readInt24BE', function() {
it('should return signed number', function() {
o.push(new Buffer([ 0x81, 0x45, 0x23 ]));
assert.equal(o.readInt24BE(), -8305373);
assert(o.isEmpty());
});
});
describe('.readUInt32BE', function() {
it('should return and move by four bytes', function() {
o.push(new Buffer([ 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7 ]));
o.push(new Buffer([ 0x8, 0x9, 0xa ]));
o.push(new Buffer([ 0xb, 0xc, 0xd ]));
o.push(new Buffer([ 0xe, 0xf, 0x10 ]));
assert.equal(o.readUInt32BE(), 0x01020304);
assert.equal(o.readUInt32BE(), 0x05060708);
assert.equal(o.readUInt32BE(), 0x090a0b0c);
assert.equal(o.readUInt32BE(), 0x0d0e0f10);
assert(o.isEmpty());
});
it('should return positive values', function() {
o.push(new Buffer([ 0xff, 0xff, 0xff, 0xff ]));
assert.equal(o.readUInt32BE(), 0xffffffff);
assert(o.isEmpty());
});
});
describe('.readInt32BE', function() {
it('should return signed number', function() {
o.push(new Buffer([ 0xff, 0xff, 0xff, 0xff ]));
assert.equal(o.readInt32BE(), -1);
assert(o.isEmpty());
});
});
describe('.has', function() {
it('should properly check the amount of the remaining bytes', function() {
o.push(new Buffer([ 1, 2, 3 ]));
assert(o.has(3));
assert.equal(o.readUInt8(), 0x01);
assert(!o.has(3));
assert(o.has(2));
assert.equal(o.readUInt16BE(), 0x0203);
assert(!o.has(1));
});
});
});