parsav  Diff

* mongoose
* json-c
* mbedtls
* **postgresql backend:**
  * postgresql-libs 













## building

first, either install any missing dependencies as shared libraries, or build them as static libraries with the command `make dep.$LIBRARY`. as a shortcut, `make dep` will build all dependencies as static libraries. note that if the build system finds a static version of a librari in the `lib/` folder, it will use that instead of any system library.

postgresql-libs must be installed systemwide, as `parsav` does not currently provide for statically compiling and linking it

## configuring

the `parsav` configuration is comprised of two components: the backends list and the config store. the backends list is a simple text file that tells `parsav` which data sources to draw from. the config store is a key-value store which contains the rest of the server's configuration, and is loaded from the backends. the configuration store can be spread across the backends; backends will be checked for configuration keys according to the order in which they are listed. changes to the configuration store affect parsav in real time; you only need to restart the server if you make a change to the backend list.

* mongoose
* json-c
* mbedtls
* **postgresql backend:**
  * postgresql-libs 

additional build-time dependencies are necessary if you are building directly from trunk, rather than from a release tarball that includes certain build artifacts which need to be embedded in the binary:

* inkscape, for rendering out UI graphics
* cwebp (libwebp package), for transforming inkscape PNGs to webp
* sassc, for compiling the SCSS stylesheet into its final CSS

all builds require terra, which, unfortunately, requires installing an older version of llvm, v9 at the latest (which i develop parsav under). with any luck, your distro will be clever enough to package terra and its dependencies properly (it's trivial on nix, tho you'll need to tweak the terra expression to select a more recent llvm package); Arch Linux is one of those distros which is not so clever, and whose (AUR) terra package is totally broken. due to these unfortunate circumstances, terra is distributed not just in source form, but also in the the form of LLVM IR. distributions will also be made in the form of tarballed object code and assembly listings for various common platforms, currently including x86-32/64, arm7hf, aarch64, riscv, mips32/64, and ppc64/64le.

i've noticed that terra (at least with llvm9) seems to get a bit cantankerous and trigger llvm to fail with bizarre errors when you try to cross-compile parsav from x86-64 to any other platform, even x86-32. i don't know if this problem exists on other architectures or in what form, but as a workaround, the current cross-compile process consists of generating LLVM IR (ostensible for x86-64, though this is in reality an architecture-independent language), and then compiling that down to an object file with llc. this is an enormous hassle; hopefully the terra people will fix this eventually.

also note that, while parsav has a flag to build with ASAN, ASAN has proven unusable for most purposes as it routinely reports false positive buffer-heap-overflows. if you figure out how to defuckulate this, i will be overjoyed.

## building

first, either install any missing dependencies as shared libraries, or build them as static libraries with the command `make dep.$LIBRARY`. as a shortcut, `make dep` will build all dependencies as static libraries. note that if the build system finds a static version of a library in the `lib/` folder, it will use that instead of any system library. note that these commands require GNU make (it may be installed as `gmake` on your system), although this is a fairly soft dependency -- if you really need to build it on BSD make, you can probably translate it with a minute or so of work; you'll just have to do some of the various gmake functions' work manually. this may be worthwhile if you're packaging for a BSD.

postgresql-libs must be installed systemwide, as `parsav` does not currently provide for statically compiling and linking it

## configuring

the `parsav` configuration is comprised of two components: the backends list and the config store. the backends list is a simple text file that tells `parsav` which data sources to draw from. the config store is a key-value store which contains the rest of the server's configuration, and is loaded from the backends. the configuration store can be spread across the backends; backends will be checked for configuration keys according to the order in which they are listed. changes to the configuration store affect parsav in real time; you only need to restart the server if you make a change to the backend list.