Maximum number of levels/depth?
ripe909 opened this issue · comments
Is there maximum number of levels that can be encoded in the JSON output?
I am creating a JSON tree structure of vectors and pointers that goes down 9 levels. On the ninth level I have a member std::array. As soon as I jsonExport at that level, the export hangs. If I move the std::array one level up, it works as expected.
class level8_cont
{
public:
std::array<int, 3> array9 = { 1, 2, 3 };
};
class level7
{
public:
level7()
{
levels8.emplace_back();
}
std::vector<level8_cont> levels8;
};
class level6_cont
{
public:
level6_cont()
{
nextLevel7 = new level7();
}
level7 *nextLevel7;
};
class level5
{
public:
level5()
{
levels6.emplace_back();
}
std::vector<level6_cont> levels6;
};
class level4_cont
{
public:
level4_cont()
{
nextLevel5 = new level5();
}
level5 *nextLevel5;
};
class level3
{
public:
level3()
{
levels4.emplace_back();
}
std::vector<level4_cont> levels4;
};
class level2_cont
{
public:
level2_cont()
{
nextLevel3 = new level3();
}
level3 *nextLevel3;
};
class level1
{
public:
level1()
{
levels2.emplace_back();
}
std::vector<level2_cont> levels2;
};
ThorsAnvil_MakeTrait(level1, levels2);
ThorsAnvil_MakeTrait(level2_cont, nextLevel3);
ThorsAnvil_MakeTrait(level3, levels4);
ThorsAnvil_MakeTrait(level4_cont, nextLevel5);
ThorsAnvil_MakeTrait(level5, levels6);
ThorsAnvil_MakeTrait(level6_cont, nextLevel7);
ThorsAnvil_MakeTrait(level7, levels8);
ThorsAnvil_MakeTrait(level8_cont, array9);
using ThorsAnvil::Serialize::jsonExport;
using ThorsAnvil::Serialize::jsonImport;
// Use the export function to serialize
level1 levelTest = level1();
std::cout << jsonExport(levelTest) << "\n";
this gives the (stalled) output:
{
"levels2": [
{
"nextLevel3":
{
"levels4": [
{
"nextLevel5":
{
"levels6": [
{
"nextLevel7":
{
"levels8": [
{
moving the array9 up a level gives correct output:
class level8_cont
{
public:
};
class level7
{
public:
level7()
{
levels8.emplace_back();
}
std::vector<level8_cont> levels8;
std::array<int, 3> array9 = { 1, 2, 3 };
};
class level6_cont
{
public:
level6_cont()
{
nextLevel7 = new level7();
}
level7 *nextLevel7;
};
class level5
{
public:
level5()
{
levels6.emplace_back();
}
std::vector<level6_cont> levels6;
};
class level4_cont
{
public:
level4_cont()
{
nextLevel5 = new level5();
}
level5 *nextLevel5;
};
class level3
{
public:
level3()
{
levels4.emplace_back();
}
std::vector<level4_cont> levels4;
};
class level2_cont
{
public:
level2_cont()
{
nextLevel3 = new level3();
}
level3 *nextLevel3;
};
class level1
{
public:
level1()
{
levels2.emplace_back();
}
std::vector<level2_cont> levels2;
};
ThorsAnvil_MakeTrait(level1, levels2);
ThorsAnvil_MakeTrait(level2_cont, nextLevel3);
ThorsAnvil_MakeTrait(level3, levels4);
ThorsAnvil_MakeTrait(level4_cont, nextLevel5);
ThorsAnvil_MakeTrait(level5, levels6);
ThorsAnvil_MakeTrait(level6_cont, nextLevel7);
ThorsAnvil_MakeTrait(level7, levels8, array9);
ThorsAnvil_MakeTrait(level8_cont);
using ThorsAnvil::Serialize::jsonExport;
using ThorsAnvil::Serialize::jsonImport;
level1 levelTest = level1();
std::cout << jsonExport(levelTest) << "\n";
which gives this (correct) output:
{
"levels2": [
{
"nextLevel3":
{
"levels4": [
{
"nextLevel5":
{
"levels6": [
{
"nextLevel7":
{
"levels8": [
{
}],
"array9": [ 1, 2, 3]
}
}]
}
}]
}
}]
}
There is no limit on the number of levels.
I built the following:
#include <ThorSerialize/SerUtil.h>
#include <ThorSerialize/JsonThor.h>
class level8_cont
{
public:
std::array<int, 3> array9 = { 1, 2, 3 };
};
class level7
{
public:
level7()
{
levels8.emplace_back();
}
std::vector<level8_cont> levels8;
};
class level6_cont
{
public:
level6_cont()
{
nextLevel7 = new level7();
}
level7 *nextLevel7;
};
class level5
{
public:
level5()
{
levels6.emplace_back();
}
std::vector<level6_cont> levels6;
};
class level4_cont
{
public:
level4_cont()
{
nextLevel5 = new level5();
}
level5 *nextLevel5;
};
class level3
{
public:
level3()
{
levels4.emplace_back();
}
std::vector<level4_cont> levels4;
};
class level2_cont
{
public:
level2_cont()
{
nextLevel3 = new level3();
}
level3 *nextLevel3;
};
class level1
{
public:
level1()
{
levels2.emplace_back();
}
std::vector<level2_cont> levels2;
};
ThorsAnvil_MakeTrait(level1, levels2);
ThorsAnvil_MakeTrait(level2_cont, nextLevel3);
ThorsAnvil_MakeTrait(level3, levels4);
ThorsAnvil_MakeTrait(level4_cont, nextLevel5);
ThorsAnvil_MakeTrait(level5, levels6);
ThorsAnvil_MakeTrait(level6_cont, nextLevel7);
ThorsAnvil_MakeTrait(level7, levels8);
ThorsAnvil_MakeTrait(level8_cont, array9);
using ThorsAnvil::Serialize::jsonExport;
using ThorsAnvil::Serialize::jsonImport;
// Use the export function to serialize
int main()
{
level1 levelTest = level1();
std::cout << jsonExport(levelTest) << "\n";
}
The I built and run like this:
> brew install thors-serializer
Updating Homebrew...
No stash entries found.
==> Auto-updated Homebrew!
Updated 1 tap (homebrew/core).
==> Updated Formulae
helmfile
==> Installing dependencies for thors-serializer: libyaml
==> Installing thors-serializer dependency: libyaml
==> Downloading https://homebrew.bintray.com/bottles/libyaml-0.2.4.catalina.bottle.tar.gz
######################################################################## 100.0%
==> Pouring libyaml-0.2.4.catalina.bottle.tar.gz
🍺 /usr/local/Cellar/libyaml/0.2.4: 10 files, 322.6KB
==> Installing thors-serializer
==> Downloading https://homebrew.bintray.com/bottles/thors-serializer-1.15.1.catalina.bottle.tar.gz
######################################################################## 100.0%
==> Pouring thors-serializer-1.15.1.catalina.bottle.tar.gz
🍺 /usr/local/Cellar/thors-serializer/1.15.1: 58 files, 919KB
> g++ -O3 -std=c++17 pl.cpp -lThorSerialize17
> ./a.out
{
"levels2": [
{
"nextLevel3":
{
"levels4": [
{
"nextLevel5":
{
"levels6": [
{
"nextLevel7":
{
"levels8": [
{
"array9": [ 1, 2, 3]
}]
}
}]
}
}]
}
}]
}
OK, I was able to get it working on my build. I am running from an embedded system, so I had to give it some more stack space.
Thanks!
No problem.
If I may ask are you running the version with pre-built libraries or the header only version? The header only version may result in the compiler being able to optimize out function calls (reduce stack space) at the cost of a slightly larger executable.
Please let me know how the project goes.
Loki
Currently I am using the header only version. I had to hack up a few things to get it working on ARM with arm-none-eabi. Specifically, removing the exception throwing, and setup of the config manually.
I am still in debug mode, so I haven't tried any compiler optimizations yet. I had enough RAM to increase my stack space for now.
Note: there is a header only version available for checkout.
git clone --single-branch --branch header-only https://github.com/Loki-Astari/ThorsSerializer.git
You should not need to modify the config.
Let me know if there might be something I can help fix.