Hi, I am using below code to read load Json file in boost::property_tree::ptree object. Function read_json(.) read all file content at a time. I want to know is there any way to read file content segment by segment. Thanks and regards, Vijay int _tmai3n(int argc, _TCHAR* argv[]) { try { std::stringstream ss; std::ifstream file("D:\\EdisphereComp\\kit\\1003_Kit\\1003\\Inputfiles\\AI98_Test_3.json", std::ios::binary); // Make sure we have something to read. if (!file.is_open()) { throw (std::exception("Could not open file.")); } // Copy contents "as efficiently as possible". ss << file.rdbuf(); boost::property_tree::ptree pt; boost::property_tree::read_json(ss, pt); boost::property_tree::write_json("D:\\EdisphereComp\\kit\\1003_Kit\\1003\\In putfiles\\AI98_Test_3_sprite.json", pt); } catch (boost::property_tree::json_parser_error e) { ; } //} return 0; }
On 06.07.2015 08:45, vijay.singh@edisphere.com wrote:
The PropertyTree parser is not a streaming parser, it builds a tree out of the entire contents of a file. This cannot be changed. I also don't know of any DOM parser for any semi-structured language that supports this; I wouldn't know how to do this in a useful way. Can you explain your use case in more detail perhaps? Sebastian
On 07/06/2015 09:55 AM, Sebastian Redl wrote:
I am working on a streaming JSON parser [1] (documentation is still missing though.) One of the examples [2] is a reimplementation of property_tree::read_json(). It currently parses the entire content, but only because it mimics the original behavior. It could be rewritten to build the property_tree incrementally. [1] https://github.com/breese/protocol [2] https://github.com/breese/protocol/tree/master/example/json/property_tree
On 06.07.2015 16:47, Boris Rasin wrote:
When do you plan to release it? The test matrix is going green, so it should be in 1.59. But I hope that
https://svn.boost.org/trac/boost/ticket/5520 the new Boost.Test will be merged to master first, since a workaround in my test cases is affected by an internals change between the old and new version. Sebastian
On 7/6/2015 6:20 PM, Sebastian Redl wrote:
Yes, that's what I was asking. Currently, to use PropertyTree JSON reader/writer in multi-threaded environment (even if each ptree object is only accessed by single thread) one has to define BOOST_SPIRIT_THREADSAFE which brings boost/thread in. That pretty much makes use of PropertyTree JSON reader/writer in multi-threaded environment dependent on boost/thread. Anyway, I'm looking forward to new version, and thanks for the great work.
On 07/06/2015 11:06 AM, Sebastian Redl wrote:
Yes, mine is a pull parser. Pull parsers are more versatile than push parsers, and therefore better suited as building-blocks. For instance, it is trivial to create a push parser with a pull parser. It is just a loop and switch as can be seen in this example: https://github.com/breese/protocol/blob/master/example/json/push_parser/push... Try creating a push parser with a pull parser ;-) It is also fairly easy to create Boost.Serialization archives with pull parsers.
Agreed.
participants (4)
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Bjorn Reese -
Boris Rasin -
Sebastian Redl -
vijay.singh＠edisphere.com