what data Brenthy, Walytis and walytis_api store, as well as how and where
When Brenthy is installed, it creates the following folders in its installation directory:
- Brenthy: contains the Brenthy and Walytis source code
- Python: the python virtual environment (python binary and libraries) used to run Brenthy
- Blockchains: Contains a subfolder for the storage requirements of each blockchains type. In the case of Walytis, its storage folder contains a subfolder for each Walytis blockchain.
The installation directory itself varies depending on the operating system, and might be customisable in the future, and is already hackable anyway!
Even though all blocks-files are stored on IPFS, Walytis keeps a copy of all block-files for redundancy in each blockchain's appdata directory.
Each blockchain also stores a list of all its blocks' IDs in a database in its appdata directory. The database management system is a custom one, coded in Walytis_Beta/block_records.py, where the block-file storage is also managed.
This database isn't an absolute necessity, technically. It would be simpler to just use the stored blocks-files to keep track of blockchains' blocks. However, this would be less efficient during runtime for some lookups of large numbers of blocks, because to get a block's ID, Walytis would have to read and decode the block-file, because the block-files themselves can't be named by their full IDs because filesystems have limits on filename lengths.
Applications each need to keep track of which blocks they have processed.
walytis_api has this functionality built into its Blockchain class, which is used if the programmer passes a value for the app_name or appdata_dir parameters when instantiating the class.
When using appdata_dir, the programmer provides the directory in which to store this data.
When using app_name, walytis_api creates an appdata folder with the path: {USER_APPDATA_DIR}/Brenthy/blockchains/{BLOCKCHAIN_TYPE}/{BLOCKCHAIN_ID}/Apps/{APP_NAME}