bufferutils: add PUSHDATA implementation
This commit is contained in:
Daniel Cousens
parent
36a1d579f8
commit
d18f2dba00
3 changed files with 157 additions and 22 deletions
|
|
@ -1,4 +1,46 @@
|
|||
var assert = require('assert')
|
||||
var opcodes = require('./opcodes')
|
||||
|
||||
function pushDataSize(i) {
|
||||
return i < opcodes.OP_PUSHDATA1 ? 1
|
||||
: i < 0xff ? 2
|
||||
: i < 0xffff ? 3
|
||||
: 5
|
||||
}
|
||||
|
||||
function readPushDataInt(buffer, offset) {
|
||||
var opcode = buffer.readUInt8(offset)
|
||||
var number, size
|
||||
|
||||
// ~6 bit
|
||||
if (opcode < opcodes.OP_PUSHDATA1) {
|
||||
number = opcode
|
||||
size = 1
|
||||
|
||||
// 8 bit
|
||||
} else if (opcode === opcodes.OP_PUSHDATA1) {
|
||||
number = buffer.readUInt8(offset + 1)
|
||||
size = 2
|
||||
|
||||
// 16 bit
|
||||
} else if (opcode === opcodes.OP_PUSHDATA2) {
|
||||
number = buffer.readUInt16LE(offset + 1)
|
||||
size = 3
|
||||
|
||||
// 32 bit
|
||||
} else {
|
||||
assert.equal(opcode, opcodes.OP_PUSHDATA4, 'Unexpected opcode')
|
||||
|
||||
number = buffer.readUInt32LE(offset + 1)
|
||||
size = 5
|
||||
|
||||
}
|
||||
|
||||
return {
|
||||
number: number,
|
||||
size: size
|
||||
}
|
||||
}
|
||||
|
||||
function readUInt64LE(buffer, offset) {
|
||||
var a = buffer.readUInt32LE(offset)
|
||||
|
|
@ -16,17 +58,17 @@ function readVarInt(buffer, offset) {
|
|||
var t = buffer.readUInt8(offset)
|
||||
var number, size
|
||||
|
||||
// 8-bit
|
||||
// 8 bit
|
||||
if (t < 253) {
|
||||
number = t
|
||||
size = 1
|
||||
|
||||
// 16-bit
|
||||
// 16 bit
|
||||
} else if (t < 254) {
|
||||
number = buffer.readUInt16LE(offset + 1)
|
||||
size = 3
|
||||
|
||||
// 32-bit
|
||||
// 32 bit
|
||||
} else if (t < 255) {
|
||||
number = buffer.readUInt32LE(offset + 1)
|
||||
size = 5
|
||||
|
|
@ -43,6 +85,37 @@ function readVarInt(buffer, offset) {
|
|||
}
|
||||
}
|
||||
|
||||
function writePushDataInt(buffer, number, offset) {
|
||||
var size = pushDataSize(number)
|
||||
|
||||
// ~6 bit
|
||||
if (size === 1) {
|
||||
buffer.writeUInt8(number, offset)
|
||||
|
||||
// 8 bit
|
||||
} else if (size === 2) {
|
||||
buffer.writeUInt8(opcodes.OP_PUSHDATA1, offset)
|
||||
buffer.writeUInt8(number, offset + 1)
|
||||
|
||||
// 16 bit
|
||||
} else if (size === 3) {
|
||||
buffer.writeUInt8(opcodes.OP_PUSHDATA2, offset)
|
||||
buffer.writeUInt16LE(number, offset + 1)
|
||||
|
||||
// 32 bit
|
||||
} else {
|
||||
// Javascript Safe Integer limitation
|
||||
// assert(Number.isSafeInteger(value), 'value must be < 2^53')
|
||||
assert(number < 0x0020000000000000, 'value must be < 2^53')
|
||||
|
||||
buffer.writeUInt8(opcodes.OP_PUSHDATA4, offset)
|
||||
buffer.writeUInt32LE(number, offset + 1)
|
||||
|
||||
}
|
||||
|
||||
return size
|
||||
}
|
||||
|
||||
function writeUInt64LE(buffer, value, offset) {
|
||||
// Javascript Safe Integer limitation
|
||||
// assert(Number.isSafeInteger(value), 'value must be < 2^53')
|
||||
|
|
@ -86,9 +159,12 @@ function writeVarInt(buffer, number, offset) {
|
|||
}
|
||||
|
||||
module.exports = {
|
||||
pushDataSize: pushDataSize,
|
||||
readPushDataInt: readPushDataInt,
|
||||
readUInt64LE: readUInt64LE,
|
||||
readVarInt: readVarInt,
|
||||
varIntSize: varIntSize,
|
||||
writePushDataInt: writePushDataInt,
|
||||
writeUInt64LE: writeUInt64LE,
|
||||
writeVarInt: writeVarInt
|
||||
}
|
||||
|
|
|
|||
|
|
@ -4,6 +4,32 @@ var bufferutils = require('../src/bufferutils')
|
|||
var fixtures = require('./fixtures/buffer.json')
|
||||
|
||||
describe('bufferutils', function() {
|
||||
describe('pushDataSize', function() {
|
||||
it('matches test vectors', function() {
|
||||
fixtures.valid.forEach(function(f) {
|
||||
if (!f.hexPD) return
|
||||
|
||||
var size = bufferutils.pushDataSize(f.dec)
|
||||
|
||||
assert.equal(size, f.hexPD.length / 2)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
describe('readPushDataInt', function() {
|
||||
it('matches test vectors', function() {
|
||||
fixtures.valid.forEach(function(f) {
|
||||
if (!f.hexPD) return
|
||||
|
||||
var buffer = new Buffer(f.hexPD, 'hex')
|
||||
var d = bufferutils.readPushDataInt(buffer, 0)
|
||||
|
||||
assert.equal(d.number, f.dec)
|
||||
assert.equal(d.size, buffer.length)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
describe('readUInt64LE', function() {
|
||||
it('matches test vectors', function() {
|
||||
fixtures.valid.forEach(function(f) {
|
||||
|
|
@ -30,14 +56,38 @@ describe('bufferutils', function() {
|
|||
describe('varIntSize', function() {
|
||||
it('matches test vectors', function() {
|
||||
fixtures.valid.forEach(function(f) {
|
||||
var number = parseInt(f.dec)
|
||||
var size = bufferutils.varIntSize(number)
|
||||
var size = bufferutils.varIntSize(f.dec)
|
||||
|
||||
assert.equal(size, f.hexVI.length / 2)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
describe('writePushDataInt', function() {
|
||||
it('matches test vectors', function() {
|
||||
fixtures.valid.forEach(function(f, i) {
|
||||
if (!f.hexPD) return
|
||||
|
||||
var buffer = new Buffer(5)
|
||||
buffer.fill(0)
|
||||
|
||||
var n = bufferutils.writePushDataInt(buffer, f.dec, 0)
|
||||
assert.equal(buffer.slice(0, n).toString('hex'), f.hexPD)
|
||||
})
|
||||
})
|
||||
|
||||
fixtures.invalid.forEach(function(f) {
|
||||
it('throws on ' + f.description, function() {
|
||||
var buffer = new Buffer(5)
|
||||
buffer.fill(0)
|
||||
|
||||
assert.throws(function() {
|
||||
bufferutils.writePushDataInt(buffer, f.dec, 0)
|
||||
}, /value must be < 2\^53/)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
||||
describe('writeUInt64LE', function() {
|
||||
it('matches test vectors', function() {
|
||||
fixtures.valid.forEach(function(f) {
|
||||
|
|
@ -51,12 +101,12 @@ describe('bufferutils', function() {
|
|||
|
||||
fixtures.invalid.forEach(function(f) {
|
||||
it('throws on ' + f.description, function() {
|
||||
assert.throws(function() {
|
||||
var buffer = new Buffer(8)
|
||||
buffer.fill(0)
|
||||
var buffer = new Buffer(8)
|
||||
buffer.fill(0)
|
||||
|
||||
assert.throws(function() {
|
||||
bufferutils.writeUInt64LE(buffer, f.dec, 0)
|
||||
})
|
||||
}, /value must be < 2\^53/)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
|
@ -74,12 +124,12 @@ describe('bufferutils', function() {
|
|||
|
||||
fixtures.invalid.forEach(function(f) {
|
||||
it('throws on ' + f.description, function() {
|
||||
assert.throws(function() {
|
||||
var buffer = new Buffer(9)
|
||||
buffer.fill(0)
|
||||
var buffer = new Buffer(9)
|
||||
buffer.fill(0)
|
||||
|
||||
assert.throws(function() {
|
||||
bufferutils.writeVarInt(buffer, f.dec, 0)
|
||||
})
|
||||
}, /value must be < 2\^53/)
|
||||
})
|
||||
})
|
||||
})
|
||||
|
|
|
|||
27
test/fixtures/buffer.json
vendored
27
test/fixtures/buffer.json
vendored
|
|
@ -3,47 +3,56 @@
|
|||
{
|
||||
"dec": 0,
|
||||
"hex64": "0000000000000000",
|
||||
"hexVI": "00"
|
||||
"hexVI": "00",
|
||||
"hexPD": "00"
|
||||
},
|
||||
{
|
||||
"dec": 1,
|
||||
"hex64": "0100000000000000",
|
||||
"hexVI": "01"
|
||||
"hexVI": "01",
|
||||
"hexPD": "01"
|
||||
},
|
||||
{
|
||||
"dec": 252,
|
||||
"hex64": "fc00000000000000",
|
||||
"hexVI": "fc"
|
||||
"hexVI": "fc",
|
||||
"hexPD": "4cfc"
|
||||
},
|
||||
{
|
||||
"dec": 253,
|
||||
"hex64": "fd00000000000000",
|
||||
"hexVI": "fdfd00"
|
||||
"hexVI": "fdfd00",
|
||||
"hexPD": "4cfd"
|
||||
},
|
||||
{
|
||||
"dec": 254,
|
||||
"hex64": "fe00000000000000",
|
||||
"hexVI": "fdfe00"
|
||||
"hexVI": "fdfe00",
|
||||
"hexPD": "4cfe"
|
||||
},
|
||||
{
|
||||
"dec": 65535,
|
||||
"hex64": "ffff000000000000",
|
||||
"hexVI": "fdffff"
|
||||
"hexVI": "fdffff",
|
||||
"hexPD": "4effff0000"
|
||||
},
|
||||
{
|
||||
"dec": 65536,
|
||||
"hex64": "0000010000000000",
|
||||
"hexVI": "fe00000100"
|
||||
"hexVI": "fe00000100",
|
||||
"hexPD": "4e00000100"
|
||||
},
|
||||
{
|
||||
"dec": 65537,
|
||||
"hex64": "0100010000000000",
|
||||
"hexVI": "fe01000100"
|
||||
"hexVI": "fe01000100",
|
||||
"hexPD": "4e01000100"
|
||||
},
|
||||
{
|
||||
"dec": 4294967295,
|
||||
"hex64": "ffffffff00000000",
|
||||
"hexVI": "feffffffff"
|
||||
"hexVI": "feffffffff",
|
||||
"hexPD": "4effffffff"
|
||||
},
|
||||
{
|
||||
"dec": 4294967296,
|
||||
|
|
|
|||
Loading…
Add table
Reference in a new issue