GitHub user mygityf opened a pull request:
https://github.com/apache/thrift/pull/870
THRIFT-3636 The precision is 15 bits after dot of casting from double to
string in Thrift-cpp-library- json-protocol.
Cpp json protocol double precision should be 16 bits
You can merge this pull request into a Git repository by running:
$ git pull https://github.com/mygityf/thrift
cpp-json-protocol-double-precision-should-be-16bits
Alternatively you can review and apply these changes as the patch at:
https://github.com/apache/thrift/pull/870.patch
To close this pull request, make a commit to your master/trunk branch
with (at least) the following in the commit message:
This closes #870
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commit 93f0c9836dbcbb9564413c3f4a20e85799cafb7d
Author: Wang Yaofu <[email protected]>
Date: 2016-02-15T02:43:09Z
THRIFT-3636 The precision is 15 bits after dot of casting from double to
string in Thrift-cpp-library- json-protocol.
The precision is 15 bits after dot of format casting from double to string
in Thrift-cpp-library- json-protocol.
But the expected precision is 16 bits after dot in Thrift-json-protocol.
The solution:
To Change code 'str.precision(std::numeric_limits<double>::digits10 + 1);'
to 'str.precision(std::numeric_limits<double>::digits10 + 2);'
in function doubeToString file TJSONProtocol.cpp at line 524,
e.g:
before:
In C++ TJSONProtocol.cpp:
double a = 1.12345678906666663;
string astr = doubleToString(a);
double b = stringToDouble(astr);
the result as below:
a = 1.1234567890666667
astr = "1.123456789066667"
b = 1.1234567890666669
after changing:
the result as below:
a = 1.1234567890666667
astr = "1.1234567890666667"
b = 1.1234567890666667
This result is expected.
commit e0bebd14f9df02d31603506b72eb5dbcfea74ce6
Author: Wang Yaofu <[email protected]>
Date: 2016-02-15T02:46:48Z
THRIFT-3636 The precision is 15 bits after dot of casting from double to
string in Thrift-cpp-library- json-protocol.
The precision is 15 bits after dot of format casting from double to string
in Thrift-cpp-library- json-protocol.
But the expected precision is 16 bits after dot in Thrift-json-protocol.
The solution:
To Change code 'str.precision(std::numeric_limits<double>::digits10 + 1);'
to 'str.precision(std::numeric_limits<double>::digits10 + 2);'
in function doubeToString file TJSONProtocol.cpp at line 524,
e.g:
before:
In C++ TJsonProtocol.cpp:
double a = 1.12345678906666663;
string astr = doubleToString(a);
double b = stringToDouble(astr);
the result as below:
a = 1.1234567890666667
astr = "1.123456789066667"
b = 1.1234567890666669
after changing:
the result as below:
a = 1.1234567890666667
astr = "1.1234567890666667"
b = 1.1234567890666667
This result is expected.
----
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