FastWaveBackend/README.md
2022-09-09 02:59:33 -04:00

115 lines
4.4 KiB
Markdown

Copyright - Yehowshua Immanuel
# A High performance, VCD Parser written in Rust
# Current Features
- Robust Error Handling
FastWave currently offers highly robust error handling(at least on the sample
VCD files in this repository) which GTKWave doesn't have. For
example, selecting the ``UTILIZATON_ENABLED`` signal after opening
[test2x2_regex22_string1.vcd](./test-vcd-files/xilinx_isim/test2x2_regex22_string1.vcd)
(one of the sample xilinx vcd test files) in GtkWave, will crash GtkWave since
this signal is malformed. FastWave on the otherhand simply notes that the
signal is malformed.
# Performance
## Methods
I have been testing performance on a 3.04GB VCD file that can be found
[here](https://drive.google.com/file/d/1pfm2qo2l8fGTHHJ8TLrg1vSGaV_TUbp2/view?usp=sharing).
For getting the GtkWave results, I fired up GtkWave, clicked on
``File``->``Open New Window``, and selected the VCD file linked to above.
I started my stopwatch as soon as I pressed enter to beging loading the VCD
file, and stopped my stopwatch once the GtkWave titlebar reached 100%.
To get the memory consumption, I opened Activity Monitor on Mac, and recorded
the GtkWave memory usage before and after loading the large VCD file, and
took the difference.
I noticed that when running FastWave in the VsCode terminal as opposed
to the MacOS system terminal or the Lapce terminal, FastWave is notably
slower.
## Results
| Software | Time(s) | Memory(MB) |
|----------|---------|------------|
| FastWave | ~27.30 | 1100+ |
| GtkWave | ~30 | 89.8 |
# Current Limitations
Unable to handle VCD files that have signals with more than
2^32 - 1 = 4,294,967,295 deltas/changes.
# Running
This repository comes with several smaller VCD files emitted from
various EDA tools. If you want a larger VCD file, grab one from
[here](https://drive.google.com/file/d/1pfm2qo2l8fGTHHJ8TLrg1vSGaV_TUbp2/view?usp=sharing).
The first build of the program may take some time.
``cargo run --release --example parse_vcd tests/vcd-files/aldec/SPI_Write.vcd``
You can also run the vcd1 or vcd2 example with:
- cargo run --release --example vcd1
- cargo run --release --example vcd2
You can run all the tests with ``cargo test``
# Testing on Bad Files
You may wish to test the parser on a malformed VCD just to make
sure that the parser gives useful/sane errors.
Here's a command to test on a malformed VCD:
``cargo run --release --example parse_vcd tests/vcd-files/VCD_file_with_errors.vcd``
# TODO
## Features and Other
- [ ] add documenting comments
- [ ] perhaps we should be looking up signal values on the VCD class
- [ ] perhaps we should be returning signal trees from the VCD class
- [ ] add lz4 compression support and compare memory perf before and after
- [ ] may need to refactor with allow for get_mut for dynamic
compression-decompression for multiple signal structs
at once to allow for multi-threading
- [ ] test against large waveforms from the
[verilog-vcd-parser](https://github.com/ben-marshall/verilog-vcd-parser)
tool
- [ ] (a bit of work) consolidate error messages in validation phase
- [ ] once the access patterns of the GUI frontend are well understood,
create specific functions and restrict as many types to private
as possible
- [ ] be explicit with imports, remove exports as possible
once FastWave is known to be fairly stable.
- [ ] Print out git commit or release number.
- [ ] do a read through all the code - look for uneeded code
- [ ] Take a look at GTKWave parser to compare efficiency.
- [ ] Move part of the performance section to another markdown file.
## Repairs
- [ ] replace str bracket indices with get(slice)
- [ ] make a custom date parser for possibly up to 18 different versions(that is, for each possible tool).
- [ ] Consolidate error messages and add cursors throughout.
- [ ] Add file and line to the enum errors.
- [ ] Fix warnings especially usage and restriction warnings once I'm
able to successfully parse all sample VCDs.
## Code Consistency
- [ ] split impls in signal.rs into groups
- [ ] Change error messages to line and filenames. Go through all calls to unwrap.
- [ ] search for any unwraps or any direct vectors indexing
- [ ] Handle TODOs
- [ ] Remove debug code/comments.
## Documentation
- [ ] Document indexing structure with diagram and possibly include the rational
## Marketing
- [ ] Send survey to community