[
https://issues.apache.org/jira/browse/THRIFT-2933?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14299205#comment-14299205
]
Andrew de Andrade commented on THRIFT-2933:
-------------------------------------------
I actually want this reorganization into separate files for browserify reasons
(i.e. there no reason to include all protocols in the browser if you only need
one).
Randy, if you go ahead and accept this patch as is, I'll split apart the
transport and protocol files and upload a patch to this issue I just created.
https://issues.apache.org/jira/browse/THRIFT-2964
I've taken care to note in that issue that readDouble is different for both
implementations, and I've referenced this issue.
> v0.9.2: doubles encoded in node with compact protocol cannot be decoded by
> python
> ---------------------------------------------------------------------------------
>
> Key: THRIFT-2933
> URL: https://issues.apache.org/jira/browse/THRIFT-2933
> Project: Thrift
> Issue Type: Bug
> Components: Node.js - Library
> Affects Versions: 0.9.2
> Reporter: Dan Heller
> Attachments: double-endianness-2.patch, little-endian.patch,
> thrift-double.tgz
>
>
> I've noticed that with Thrift v0.9.2, using the Compact protocol, I can't
> encode doubles in node and decode them in python. It looks like in python,
> we're decoding little-endian for compact and big-endian for binary, and in
> node, writing big-endian in all cases (therefore, Binary works fine). I've
> attached a test program to show this behavior. I have not found the thrift
> binary spec, so I'm not sure which side is wrong.
> {code}
> [~/thrift-double]$ thrift --version
> Thrift version 0.9.2
> [~/thrift-double]$ grep -i thrift package.json
> "thrift": "0.9.2"
> "compile": "thrift --gen js:node --gen py test.thrift"
> [~/thrift-double]$ pip show thrift
> ---
> Name: thrift
> Version: 0.9.2
> Location: /Library/Python/2.7/site-packages
> Requires:
> [~/thrift-double]$ npm run compile
> > [email protected] compile /Users/dh/thrift-double
> > thrift --gen js:node --gen py test.thrift
> [~/thrift-double]$ node test.js binary | python test.py binary
> Trying to send { intField: 100, doubleField: 99.88 }
> Reading with binary protocol.
> Got test object: TestType(intField=100, doubleField=99.88)
> [~/thrift-double]$ node test.js compact | python test.py compact
> Trying to send { intField: 100, doubleField: 99.88 }
> Reading with compact protocol.
> Got test object: TestType(intField=100, doubleField=-2.24248483894553e-38)
> [~/thrift-double]$
> {code}
> I notice the following snippets.
> * TBinaryProtocol.py: network format (big-endian)
> {code}
> def readDouble(self):
> buff = self.trans.readAll(8)
> val, = unpack('!d', buff)
> return val
> {code}
> * TCompactProtocol.py: little-endian
> {code}
> def readDouble(self):
> buff = self.trans.readAll(8)
> val, = unpack('<d', buff)
> return val
> {code}
> * binary.js: my best IEEE floating point days are behind me but this looks
> big-endian. In any case it's used for both compact and binary.
> {code}
> exports.writeDouble = function(buff, v) {
> var m, e, c;
> buff[0] = (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[1] = (e << 4) & 0xf0;
> buff[0] |= (e >> 4) & 0x7f;
> buff[7] = m & 0xff;
> m = Math.floor(m / POW_8);
> buff[6] = m & 0xff;
> m = Math.floor(m / POW_8);
> buff[5] = m & 0xff;
> m = Math.floor(m / POW_8);
> buff[4] = m & 0xff;
> m >>= 8;
> buff[3] = m & 0xff;
> m >>= 8;
> buff[2] = m & 0xff;
> m >>= 8;
> buff[1] |= m & 0x0f;
> return buff;
> };
> {code}
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
