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Fix Long bugs, and represent Longs as Numbers when possible.
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Before, any JS Number which was an integer would be serialized as an INT
if it fit in 32 bits, and as a LONG otherwise.  This broke when integral
Numbers were larger than 2^63.  Now such numbers are represented as
DOUBLEs.

Before, any Long was deserialized as a Long, which was awkward because
you'd serialize a Number and get back a Long, which is awkward to deal
with.  Now, any Long which is in [-2^53, 2^53] (a range that can be
precisely represented by a JS Number) is deserialized as a Number.
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@sethml
sethml committed Jul 29, 2011
1 parent 8068cfc commit ba88962
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Showing 2 changed files with 75 additions and 26 deletions.
63 changes: 39 additions & 24 deletions lib/mongodb/bson/bson.js
View file
Expand Up @@ -19,8 +19,12 @@ var BinaryParser = require('./binary_parser').BinaryParser
function BSON () {};

// BSON MAX VALUES
BSON.BSON_INT32_MAX = 2147483648;
BSON.BSON_INT32_MIN = -2147483648;
BSON.BSON_INT32_MAX = 0x80000000;
BSON.BSON_INT32_MIN = -0x80000000;

// JS MAX PRECISE VALUES
BSON.JS_INT_MAX = 0x20000000000000; // Any integer up to 2^53 can be precisely represented by a double.
BSON.JS_INT_MIN = -0x20000000000000; // Any integer down to -2^53 can be precisely represented by a double.

// BSON DATA TYPES
BSON.BSON_DATA_NUMBER = 1;
Expand Down Expand Up @@ -85,14 +89,14 @@ BSON.calculateObjectSize = function(object) {
stack.push({keys:keys, object:currentObject});
currentObject = value;
keys = Object.keys(value)
} else if(typeof value == 'number' && value === parseInt(value, 10)) {
if(value >= BSON.BSON_INT32_MAX || value < BSON.BSON_INT32_MIN) {
} else if(typeof value == 'number' || toString.call(value) === '[object Number]') {
if(value >= BSON.BSON_INT32_MAX || value < BSON.BSON_INT32_MIN ||
value !== parseInt(value, 10)) {
// Long and Number take same number of bytes.
totalLength += (name != null ? (Buffer.byteLength(name) + 1) : 0) + (8 + 1);
} else {
totalLength += (name != null ? (Buffer.byteLength(name) + 1) : 0) + (4 + 1);
}
} else if(typeof value == 'number' || toString.call(value) === '[object Number]') {
totalLength += (name != null ? (Buffer.byteLength(name) + 1) : 0) + (8 + 1);
} else if(typeof value == 'boolean' || toString.call(value) === '[object Boolean]') {
totalLength += (name != null ? (Buffer.byteLength(name) + 1) : 0) + (1 + 1);
} else if(value instanceof Date) {
Expand Down Expand Up @@ -246,28 +250,27 @@ BSON.serializeWithBufferAndIndex = function serializeWithBufferAndIndex(object,
index = index + size - 1;
// Write zero
buffer[index++] = 0;
} else if(typeof value == 'number' && value === parseInt(value, 10)) {
} else if((typeof value == 'number' || toString.call(value) === '[object Number]') &&
value === parseInt(value, 10) &&
value >= BSON.JS_INT_MIN && value <= BSON.JS_INT_MAX) {
// Write the type
buffer[index++] = value >= BSON.BSON_INT32_MAX || value < BSON.BSON_INT32_MIN ? BSON.BSON_DATA_LONG : BSON.BSON_DATA_INT;
var int64 = value >= BSON.BSON_INT32_MAX || value < BSON.BSON_INT32_MIN;
buffer[index++] = int64 ? BSON.BSON_DATA_LONG : BSON.BSON_DATA_INT;
// Write the name
if(name != null) {
index = index + buffer.write(name, index, 'utf8') + 1;
buffer[index - 1] = 0;
}

if(value >= BSON.BSON_INT32_MAX || value < BSON.BSON_INT32_MIN) {
if(int64) {
// Write the number
var long = Long.fromNumber(value);
binaryutils.encodeIntInPlace(long.getLowBits(), buffer, index);
binaryutils.encodeIntInPlace(long.getHighBits(), buffer, index + 4);
index += 8;
} else {
// Write the int value to the buffer
buffer[index + 3] = (value >> 24) & 0xff;
buffer[index + 2] = (value >> 16) & 0xff;
buffer[index + 1] = (value >> 8) & 0xff;
buffer[index] = value & 0xff;
// Ajust the index
binaryutils.encodeIntInPlace(value, buffer, index);
index = index + 4;
}
} else if(typeof value == 'number' || toString.call(value) === '[object Number]') {
Expand Down Expand Up @@ -636,7 +639,9 @@ BSON.serialize = function serialize(object, checkKeys, asBuffer) {
stack.push({keys:keys, object:currentObject});
currentObject = value;
keys = Object.keys(value)
} else if(typeof value == 'number' && value === parseInt(value, 10)) {
} else if((typeof value == 'number' || toString.call(value) === '[object Number]') &&
value === parseInt(value, 10) &&
value >= BSON.JS_INT_MIN && value <= BSON.JS_INT_MAX) {
if(value >= BSON.BSON_INT32_MAX || value < BSON.BSON_INT32_MIN) {
totalLength += (name != null ? (Buffer.byteLength(name) + 1) : 0) + (8 + 1);
} else {
Expand Down Expand Up @@ -796,28 +801,27 @@ BSON.serialize = function serialize(object, checkKeys, asBuffer) {
index = index + size - 1;
// Write zero
buffer[index++] = 0;
} else if(typeof value == 'number' && value === parseInt(value, 10)) {
} else if((typeof value == 'number' || toString.call(value) === '[object Number]') &&
value === parseInt(value, 10) &&
value >= BSON.JS_INT_MIN && value <= BSON.JS_INT_MAX) {
// Write the type
buffer[index++] = value >= BSON.BSON_INT32_MAX || value < BSON.BSON_INT32_MIN ? BSON.BSON_DATA_LONG : BSON.BSON_DATA_INT;
var int64 = value >= BSON.BSON_INT32_MAX || value < BSON.BSON_INT32_MIN;
buffer[index++] = int64 ? BSON.BSON_DATA_LONG : BSON.BSON_DATA_INT;
// Write the name
if(name != null) {
index = index + buffer.write(name, index, 'utf8') + 1;
buffer[index - 1] = 0;
}

if(value >= BSON.BSON_INT32_MAX || value < BSON.BSON_INT32_MIN) {
if(int64) {
// Write the number
var long = Long.fromNumber(value);
binaryutils.encodeIntInPlace(long.getLowBits(), buffer, index);
binaryutils.encodeIntInPlace(long.getHighBits(), buffer, index + 4);
index += 8;
} else {
// Write the int value to the buffer
buffer[index + 3] = (value >> 24) & 0xff;
buffer[index + 2] = (value >> 16) & 0xff;
buffer[index + 1] = (value >> 8) & 0xff;
buffer[index] = value & 0xff;
// Ajust the index
binaryutils.encodeIntInPlace(value, buffer, index);
index = index + 4;
}
} else if(typeof value == 'number' || toString.call(value) === '[object Number]') {
Expand Down Expand Up @@ -1423,7 +1427,18 @@ BSON.deserialize = function(data) {
var high_bits = data[index] | data[index + 1] << 8 | data[index + 2] << 16 | data[index + 3] << 24;
// Adjust index
index = index + 4;
var value = type === BSON.BSON_DATA_LONG ? new Long(low_bits, high_bits) : new Timestamp(low_bits, high_bits);
var value;
if (type === BSON.BSON_DATA_LONG) {
value = new Long(low_bits, high_bits);
// Tricky: if this value is in [-2^53, 2^53], then it's perfectly
// representable as a Number.
if ((high_bits < 0x200000 || (high_bits === 0x200000 && low_bits === 0)) &&
high_bits >= -0x200000) {
value = value.toNumber();
}
} else {
value = new Timestamp(low_bits, high_bits);
}

// Set object property
currentObject[Array.isArray(currentObject) ? parseInt(string_name, 10) : string_name] = value;
Expand Down
38 changes: 36 additions & 2 deletions test/bson/bson_test.js
View file
Expand Up @@ -307,7 +307,7 @@ var tests = testCase({
var doc = {doc:2147483648};
var serialized_data = BSONSE.BSON.serialize(doc, false, true);
var doc2 = BSONDE.BSON.deserialize(serialized_data);
test.deepEqual(doc.doc, doc2.doc.toNumber())
test.deepEqual(doc.doc, doc2.doc)
test.done();
},

Expand All @@ -328,6 +328,40 @@ var tests = testCase({
test.deepEqual(doc.doc, deserialized_data.doc);
test.done();
},

'Should Deserialize Large Integers as Number not Long' : function(test) {
function roundTrip(val) {
var doc = {doc: val};
var serialized_data = BSONSE.BSON.serialize(doc, false, true);
var deserialized_data = BSONDE.BSON.deserialize(serialized_data);
test.deepEqual(doc.doc, deserialized_data.doc);
};

roundTrip(Math.pow(2,52));
roundTrip(Math.pow(2,53) - 1);
roundTrip(Math.pow(2,53));
roundTrip(-Math.pow(2,52));
roundTrip(-Math.pow(2,53) + 1);
roundTrip(-Math.pow(2,53));
roundTrip(Math.pow(2,65)); // Too big for Long.
roundTrip(-Math.pow(2,65));
roundTrip(1234567890123456800); // Bigger than 2^53, stays a double.
roundTrip(-1234567890123456800);
test.done();
},

'Should Deserialize Larger Integers as Long not Number' : function(test) {
function roundTrip(val) {
var doc = {doc: val};
var serialized_data = BSONSE.BSON.serialize(doc, false, true);
var deserialized_data = BSONDE.BSON.deserialize(serialized_data);
test.deepEqual(doc.doc, deserialized_data.doc);
};

roundTrip(Long.fromNumber(Math.pow(2,53)).add(Long.ONE));
roundTrip(Long.fromNumber(-Math.pow(2,53)).subtract(Long.ONE));
test.done();
},

'Should Correctly Serialize and Deserialize Long Integer and Timestamp as different types' : function(test) {
var long = Long.fromNumber(9223372036854775807);
Expand Down Expand Up @@ -594,4 +628,4 @@ var tests = testCase({
});

// Assign out tests
module.exports = tests;
module.exports = tests;

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