Merge pull request #32 from NotAShelf/dependabot/cargo/criterion-0.8.1

chore(deps): bump criterion from 0.8.0 to 0.8.1

.cargo/config.toml

@@ -0,0 +1,4 @@
+# https://github.com/rui314/mold?tab=readme-ov-file#how-to-use
+[target.'cfg(target_os = "linux")']
+linker = "clang"
+rustflags = ["-C", "link-arg=-fuse-ld=mold"]

.github/dependabot.yml

@@ -0,0 +1,14 @@
+version: 2
+updates:
+  # Update Cargo deps
+  - package-ecosystem: cargo
+    directory: "/"
+    schedule:
+      interval: "weekly"
+
+  # Update used workflows
+  - package-ecosystem: github-actions
+    directory: "/"
+    schedule:
+      interval: daily
+

.github/workflows/hotpath-comment.yml

@@ -0,0 +1,62 @@
+name: hotpath-comment
+
+on:
+  workflow_run:
+    workflows: ["hotpath-profile"]
+    types:
+      - completed
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  comment:
+    runs-on: ubuntu-latest
+    if: ${{ github.event.workflow_run.conclusion == 'success' }}
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Download profiling results
+        uses: actions/download-artifact@v6
+        with:
+          name: hotpath-results
+          path: /tmp/
+          github-token: ${{ secrets.GITHUB_TOKEN }}
+          run-id: ${{ github.event.workflow_run.id }}
+
+      - name: Setup Rust
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+
+      - name: Install hotpath CLI
+        run: cargo install hotpath
+
+      - name: Post timing comparison comment
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -euo pipefail
+          HEAD_METRICS=$(cat /tmp/head_timing.json)
+          BASE_METRICS=$(cat /tmp/base_timing.json)
+          PR_NUMBER=$(cat /tmp/pr_number.txt)
+          hotpath profile-pr \
+            --head-metrics "$HEAD_METRICS" \
+            --base-metrics "$BASE_METRICS" \
+            --github-token "$GH_TOKEN" \
+            --pr-number "$PR_NUMBER"
+
+      - name: Post allocation comparison comment
+        env:
+          GH_TOKEN: ${{ github.token }}
+        run: |
+          set -euo pipefail
+          HEAD_METRICS=$(cat /tmp/head_alloc.json)
+          BASE_METRICS=$(cat /tmp/base_alloc.json)
+          PR_NUMBER=$(cat /tmp/pr_number.txt)
+          hotpath profile-pr \
+            --head-metrics "$HEAD_METRICS" \
+            --base-metrics "$BASE_METRICS" \
+            --github-token "$GH_TOKEN" \
+            --pr-number "$PR_NUMBER"

.github/workflows/hotpath-profile.yml

@@ -0,0 +1,65 @@
+name: hotpath-profile
+
+on:
+  pull_request:
+    branches: [ "main" ]
+
+env:
+  CARGO_TERM_COLOR: always
+
+jobs:
+  profile:
+    runs-on: ubuntu-latest
+    
+    steps:
+      - name: Checkout PR HEAD
+        uses: actions/checkout@v6
+        with:
+          fetch-depth: 0
+      
+      - name: Setup Rust
+        uses: actions-rust-lang/setup-rust-toolchain@v1
+      
+      - name: Run timing profiling on HEAD
+        env:
+          HOTPATH_JSON: "true"
+        run: |
+          cargo run --features='hotpath' 2>&1 | grep '^{"hotpath_profiling_mode"' > /tmp/head_timing.json
+      
+      - name: Run allocation profiling on HEAD
+        env:
+          HOTPATH_JSON: "true"
+        run: |
+          cargo run --features='hotpath,hotpath-alloc' 2>&1 | grep '^{"hotpath_profiling_mode"' > /tmp/head_alloc.json
+      
+      - name: Checkout base branch
+        run: |
+          git checkout ${{ github.event.pull_request.base.sha }}
+      
+      - name: Run timing profiling on base
+        env:
+          HOTPATH_JSON: "true"
+        run: |
+          cargo run --features='hotpath' 2>&1 | grep '^{"hotpath_profiling_mode"' > /tmp/base_timing.json || echo '{}' > /tmp/base_timing.json
+      
+      - name: Run allocation profiling on base
+        env:
+          HOTPATH_JSON: "true"
+        run: |
+          cargo run --features='hotpath,hotpath-alloc' 2>&1 | grep '^{"hotpath_profiling_mode"' > /tmp/base_alloc.json || echo '{}' > /tmp/base_alloc.json
+      
+      - name: Save PR number
+        run: |
+          echo '${{ github.event.pull_request.number }}' > /tmp/pr_number.txt
+      
+      - name: Upload profiling results
+        uses: actions/upload-artifact@v5
+        with:
+          name: hotpath-results
+          path: |
+            /tmp/head_timing.json
+            /tmp/head_alloc.json
+            /tmp/base_timing.json
+            /tmp/base_alloc.json
+            /tmp/pr_number.txt
+          retention-days: 1

.github/workflows/rust.yml

@@ -10,12 +10,45 @@ env:
   CARGO_TERM_COLOR: always
 
 jobs:
-  build:
-
-    runs-on: ubuntu-latest
+  test:
+    name: Test on ${{ matrix.target }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-latest
+            target: x86_64-unknown-linux-gnu
+          - os: ubuntu-latest
+            target: aarch64-unknown-linux-gnu
 
     steps:
     - name: "Checkout"
-      uses: actions/checkout@v4
-    - name: "Build with Cargo"
-      run: cargo build --verbose
+      uses: actions/checkout@v6
+
+    - name: "Setup Rust toolchain"
+      uses: actions-rust-lang/setup-rust-toolchain@v1
+      with:
+        target: ${{ matrix.target }}
+
+    - name: "Install cross-compilation tools"
+      if: matrix.target == 'aarch64-unknown-linux-gnu'
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y gcc-aarch64-linux-gnu
+
+    - name: "Configure linker for aarch64"
+      if: matrix.target == 'aarch64-unknown-linux-gnu'
+      run: |
+        mkdir -p .cargo
+        cat >> .cargo/config.toml << EOF
+        [target.aarch64-unknown-linux-gnu]
+        linker = "aarch64-linux-gnu-gcc"
+        EOF
+
+    - name: "Build"
+      run: cargo build --verbose --target ${{ matrix.target }}
+
+    - name: "Run tests"
+      if: matrix.target == 'x86_64-unknown-linux-gnu'
+      run: cargo test --verbose --target ${{ matrix.target }}

.gitignore

@@ -1,2 +1,3 @@
 /target
 result*
+/.direnv

.rustfmt.toml

@@ -0,0 +1,26 @@
+condense_wildcard_suffixes   = true
+doc_comment_code_block_width = 80
+edition                      = "2024"               # Keep in sync with Cargo.toml.
+enum_discrim_align_threshold = 60
+force_explicit_abi           = false
+force_multiline_blocks       = true
+format_code_in_doc_comments  = true
+format_macro_matchers        = true
+format_strings               = true
+group_imports                = "StdExternalCrate"
+hex_literal_case             = "Upper"
+imports_granularity          = "Crate"
+imports_layout               = "HorizontalVertical"
+inline_attribute_width       = 60
+match_block_trailing_comma   = true
+max_width                    = 80
+newline_style                = "Unix"
+normalize_comments           = true
+normalize_doc_attributes     = true
+overflow_delimited_expr      = true
+struct_field_align_threshold = 60
+tab_spaces                   = 2
+unstable_features            = true
+use_field_init_shorthand     = true
+use_try_shorthand            = true
+wrap_comments                = true

.taplo.toml

@@ -0,0 +1,13 @@
+[formatting]
+align_entries         = true
+column_width          = 100
+compact_arrays        = false
+reorder_inline_tables = true
+reorder_keys          = true
+
+[[rule]]
+include = [ "**/Cargo.toml" ]
+keys    = [ "package" ]
+
+[rule.formatting]
+reorder_keys = false

Cargo.toml

@@ -1,7 +1,7 @@
 [package]
-name = "microfetch"
-version = "0.4.0"
-edition = "2021"
+name    = "microfetch"
+version = "0.4.12"
+edition = "2024"
 
 [lib]
 name = "microfetch_lib"
@@ -12,28 +12,57 @@ name = "microfetch"
 path = "src/main.rs"
 
 [dependencies]
-nix = { version = "0.29", features = ["fs", "hostname", "feature"] }
-color-eyre = { version = "0.6", default-features = false }
+hotpath = { optional = true, version = "0.8.0" }
+libc    = "0.2.178"
 
 [dev-dependencies]
-criterion = "0.5"
+criterion = "0.8.1"
+
+[features]
+hotpath       = [ "dep:hotpath", "hotpath/hotpath" ]
+hotpath-alloc = [ "hotpath/hotpath-alloc" ]
+hotpath-off   = [ "hotpath/hotpath-off" ]
 
 [[bench]]
-name = "benchmark"
 harness = false
+name    = "benchmark"
 
 [profile.dev]
-opt-level = 3
+opt-level = 1
 
 [profile.release]
-strip = true
-opt-level = "z"
-lto = true
 codegen-units = 1
-panic = "abort"
+lto           = true
+opt-level     = "s"
+panic         = "abort"
+strip         = true
 
 [profile.profiler]
-inherits = "release"
-debug = true
+debug           = true
+inherits        = "release"
 split-debuginfo = "unpacked"
-strip = "none"
+strip           = "none"
+
+[lints.clippy]
+complexity = { level = "warn", priority = -1 }
+nursery    = { level = "warn", priority = -1 }
+pedantic   = { level = "warn", priority = -1 }
+perf       = { level = "warn", priority = -1 }
+style      = { level = "warn", priority = -1 }
+
+# The lint groups above enable some less-than-desirable rules, we should manually
+# enable those to keep our sanity.
+absolute_paths                 = "allow"
+arbitrary_source_item_ordering = "allow"
+implicit_return                = "allow"
+missing_docs_in_private_items  = "allow"
+non_ascii_literal              = "allow"
+pattern_type_mismatch          = "allow"
+print_stdout                   = "allow"
+question_mark_used             = "allow"
+similar_names                  = "allow"
+single_call_fn                 = "allow"
+std_instead_of_core            = "allow"
+too_long_first_doc_paragraph   = "allow"
+too_many_lines                 = "allow"
+unused_trait_names             = "allow"

README.md

@@ -1,17 +1,30 @@
+<!-- markdownlint-disable MD013 MD033 MD041 -->
+
 <div align="center">
     <img src="https://deps.rs/repo/github/notashelf/microfetch/status.svg" alt="https://deps.rs/repo/github/notashelf/microfetch">
-    <!-- <img src="https://img.shields.io/github/v/release/notashelf/microfetch?display_name=tag&color=DEA584"> -->
-    <img src="https://img.shields.io/github/stars/notashelf/microfetch?label=stars&color=DEA584">
+    <img src="https://img.shields.io/github/stars/notashelf/microfetch?label=stars&color=DEA584" alt="stars">
 </div>
 
-<h1 align="center">Microfetch</h1>
+<div id="doc-begin" align="center">
+  <h1 id="header">Microfetch</h1>
+  <p>Microscopic fetch tool in Rust, for NixOS systems, with special emphasis on speed</p>
+  <br/>
+  <a href="#synopsis">Synopsis</a><br/>
+  <a href="#features">Features</a> | <a href="#motivation">Motivation</a><br/> | <a href="#benchmarks">Benchmarks</a><br/>
+  <a href="#installation">Installation</a>
+  <br/>
+</div>
 
-Stupidly simple, laughably fast fetch tool. Written in Rust for speed and ease
-of maintainability. Runs in a _fraction of a millisecond_ and displays _most_ of
-the nonsense you'd see posted on r/unixporn or other internet communities. Aims
-to replace [fastfetch](https://github.com/fastfetch-cli/fastfetch) on my
-personal system, but [probably not yours](#customizing). Though, you are more
-than welcome to use it on your system: it's pretty [fast...](#benchmarks)
+## Synopsis
+
+[fastfetch]: https://github.com/fastfetch-cli/fastfetch
+
+Stupidly small and simple, laughably fast and pretty fetch tool. Written in Rust
+for speed and ease of maintainability. Runs in a _fraction of a millisecond_ and
+displays _most_ of the nonsense you'd see posted on r/unixporn or other internet
+communities. Aims to replace [fastfetch] on my personal system, but
+[probably not yours](#customizing). Though, you are more than welcome to use it
+on your system: it is pretty _[fast](#benchmarks)_...
 
 <p align="center">
   <img
@@ -26,6 +39,7 @@ than welcome to use it on your system: it's pretty [fast...](#benchmarks)
 - Fast
 - Really fast
 - Minimal dependencies
+- Tiny binary (~370kb [^1])
 - Actually really fast
 - Cool NixOS logo (other, inferior, distros are not supported)
 - Reliable detection of following info:
@@ -34,40 +48,90 @@ than welcome to use it on your system: it's pretty [fast...](#benchmarks)
     - Name
     - Version
     - Architecture
-  - Current shell (from $SHELL, trimmed if store path)
+  - Current shell (from `$SHELL`, trimmed if store path)
   - Current Desktop (DE/WM/Compositor and display backend)
   - Memory Usage/Total Memory
   - Storage Usage/Total Storage (for `/` only)
   - Shell Colors
 - Did I mention fast?
+- Respects [`NO_COLOR` spec](https://no-color.org/)
+
+[^1]: With the Mold linker, which is enabled by default in the Flake package,
+    the binary size is roughly 350kb. That's nearly 20kb reduction in size :)
 
 ## Motivation
 
-Fastfetch, as its name indicates, a very fast fetch tool written in C, however,
-I am not interested in any of its additional features and I very much dislike
-the defaults. Microfetch is a fetch tool that you would normally write in Bash
-and put in your `~/.bashrc` but actually _really_ fast because it opts-out of
-all customization options provided by Fastfetch. Why? Because I can.
+[Rube-Goldmark Machine]: https://en.wikipedia.org/wiki/Rube_Goldberg_machine
 
-I cannot re-iterate it enough, Microfetch is annoyingly fast.
+Fastfetch, as its name _probably_ already hinted, is a very fast fetch tool
+written in C. I used to use Fastfetch on my systems, but I eventually came to
+the realization that I am _not interested in any of its additional features_. I
+don't use Sixel, I don't change my configuration more than maybe once a year and
+I don't even display most of the fields that it does. Sure the configurability
+is nice and I can configure the defaults that I do not like but how often do I
+really do that?
+
+Since I already enjoy programming challenges, and don't use a fetch program that
+often, I eventually came to try and answer the question _how fast can I make my
+fetch script?_ It is an _even faster_ fetch tool that I would've written in Bash
+and put in my `~/.bashrc` but is _actually_ incredibly fast because it opts out
+of all the customization options provided by tools such as Fastfetch. Since
+Fetch scripts are kind of a coming-of-age ritual for most Linux users, I've
+decided to use it on my system. You also might be interested if you like the
+defaults and like speed.
+
+Ultimately, it's a small, opinionated binary with a nice size that doesn't
+bother me, and incredible speed. Customization? No thank you. I cannot
+re-iterate it enough, Microfetch is _annoyingly fast_. It does not, however,
+solve a technical problem. The "problem" Microfetch solves is entirely
+self-imposed. On the matter of _size_, the project is written in Rust, which
+comes at the cost of "bloated" dependency trees and the increased build times,
+but we make an extended effort to keep the dependencies minimal and build times
+managable. The latter is also very easily mitigated with Nix's binary cache
+systems. Since Microfetch is already in Nixpkgs, you are recommended to use it
+to utilize the binary cache properly. The usage of Rust _is_ nice, however,
+since it provides us with incredible tooling and a very powerful language that
+allows for Microfetch to be as fast as possible. ~~Sure C could've been used
+here as well, but do you think I hate myself?~~ Microfetch now features
+handwritten assembly to unsafely optimize some areas. In hindsight you all
+should have seen this coming. Is it faster? Yes.
+
+Also see: [Rube-Goldmark Machine]
 
 ## Benchmarks
 
-Microfetch's performance is mostly hardware-dependant, however, the overall
-trend seems to be < 2ms on any modern (2015 and after) CPU. Below are the
-benchmarks with Hyperfine on my desktop system.
+Below are the benchmarks that I've used to back up my claims of Microfetch's
+speed. It is fast, it is _very_ fast and that is the point of its existence. It
+_could_ be faster, and it will be. Eventually.
 
-| Command      |   Mean [ms] | Min [ms] | Max [ms] |       Relative | Written by raf? |
-| :----------- | ----------: | -------: | -------: | -------------: | --------------: |
-| `microfetch` |   1.3 ± 0.0 |      1.3 |      1.4 |           1.00 |             yes |
-| `fastfetch`  |  31.9 ± 0.8 |     30.8 |     33.8 |   24.08 ± 0.98 |              no |
-| `pfetch`     | 254.2 ± 4.8 |    246.7 |    264.9 |  191.97 ± 7.10 |              no |
-| `neofetch`   | 735.4 ± 9.5 |    721.1 |    752.8 | 555.48 ± 19.08 |              no |
+At this point in time, the performance may be sometimes influenced by
+hardware-specific race conditions or even your kernel configuration. Which means
+that Microfetch's speed may (at times) depend on your hardware setup. However,
+even with the worst possible hardware I could find in my house, I've achieved a
+nice less-than-1ms invocation time. Which is pretty good. While Microfetch
+_could_ be made faster, we're in the territory of environmental bottlenecks
+given how little Microfetch actually allocates.
 
-_As far as I'm concerned, Microfetch is faster than almost every fetch tool
-there is. The only downside of using Rust is introducing more "bloated"
-dependency trees and increasing build times. The latter is easily mitigated with
-Nix's binary cache, though._
+Below are the actual benchmarks with Hyperfine measured on my Desktop system.
+The benchmarks were performed under medium system load, and may not be the same
+on your system. Please _also_ note that those benchmarks will not be always kept
+up to date, but I will try to update the numbers as I make Microfetch faster.
+
+| Command      |         Mean [µs] | Min [µs] | Max [µs] |       Relative | Written by raf? |
+| :----------- | ----------------: | -------: | -------: | -------------: | --------------: |
+| `microfetch` |      604.4 ± 64.2 |    516.0 |   1184.6 |           1.00 |             Yes |
+| `fastfetch`  | 140836.6 ± 1258.6 | 139204.7 | 143299.4 | 233.00 ± 24.82 |              No |
+| `pfetch`     | 177036.6 ± 1614.3 | 174199.3 | 180830.2 | 292.89 ± 31.20 |              No |
+| `neofetch`   | 406309.9 ± 1810.0 | 402757.3 | 409526.3 | 672.20 ± 71.40 |              No |
+| `nitch`      | 127743.7 ± 1391.7 | 123933.5 | 130451.2 | 211.34 ± 22.55 |              No |
+| `macchina`   |   13603.7 ± 339.7 |  12642.9 |  14701.4 |   22.51 ± 2.45 |              No |
+
+The point stands that Microfetch is significantly faster than every other fetch
+tool I have tried. This is to be expected, of course, since Microfetch is
+designed _explicitly_ for speed and makes some tradeoffs to achieve it's
+signature speed.
+
+### Benchmarking Individual Functions
 
 [Criterion.rs]: https://github.com/bheisler/criterion.rs
 [Getting Started Guide]: https://bheisler.github.io/criterion.rs/book/getting_started.html
@@ -76,11 +140,52 @@ To benchmark individual functions, [Criterion.rs] is used. See Criterion's
 [Getting Started Guide] for details or just run `cargo bench` to benchmark all
 features of Microfetch.
 
+### Profiling Allocations and Timing
+
+[Hotpath]: https://github.com/pawurb/hotpath
+
+Microfetch uses [Hotpath] for profiling function execution timing and heap
+allocations. This helps identify performance bottlenecks and track optimization
+progress. It is so effective that thanks to Hotpath, Microfetch has seen a 60%
+reduction in the number of allocations.
+
+To profile timing:
+
+```bash
+HOTPATH_JSON=true cargo run --features=hotpath
+```
+
+To profile allocations:
+
+```bash
+HOTPATH_JSON=true cargo run --features=hotpath,hotpath-alloc
+```
+
+The JSON output can be analyzed with the `hotpath` CLI tool for detailed
+performance metrics. On pull requests, GitHub Actions automatically profiles
+both timing and allocations, posting comparison comments to help catch
+performance regressions.
+
 ## Installation
 
-Microfetch is packaged in [nixpkgs](https://github.com/nixos/nixpkgs). You can
-get it through the unstable channel for the time being. The Nix flake can also
-be used for bleeding-edge builds.
+> [!NOTE]
+> You will need a Nerdfonts patched font installed, and for your terminal
+> emulator to support said font. Microfetch uses nerdfonts glyphs by default,
+> but this can be changed by [patching the program](#customizing).
+
+Microfetch is packaged in [nixpkgs](https://github.com/nixos/nixpkgs). It can be
+installed by adding `pkgs.microfetch` to your `environment.systemPackages`.
+Additionally, you can try out Microfetch in a Nix shell.
+
+```bash
+nix shell nixpkgs#microfetch
+```
+
+Or run it directly with `nix run`
+
+```bash
+nix run nixpkgs#microfetch
+```
 
 Non-Nix users will have to build Microfetch with `cargo`. It is not published
 anywhere but I imagine you can use `cargo install --git` to install it from
@@ -99,17 +204,31 @@ You can't.
 
 ### Why?
 
-Customization, of any kind, is expensive: I could try reading environment
-variables, parse command-line arguments or read a configuration file but all of
-those increment execution time and resource consumption by a lot.
+Customization, of most kinds, are expensive: I could try reading environment
+variables, parse command-line arguments or read a configuration file to allow
+configuring various fields but those inflate execution time and the resource
+consumption by a lot. Since Microfetch is closer to a code golf challenge than a
+program that attempts to fill a gap, I have elected not to make this trade.
 
 ### Really?
 
-To be fair, you _can_ customize Microfetch by, well, patching it. It's not the
-best way per se, but it will be the only way that does not compromise on speed.
+[main module]: ./src/main.rs
+[discussions tab]: https://github.com/NotAShelf/microfetch/discussions
+
+To be fair, you _can_ customize Microfetch by, well, patching it. It is
+certainly not the easiest way of doing so but if you are planning to change
+something in Microfetch, patching is the best way to go. It will also the only
+way that does not compromise on speed, unless you patch in bad code. Various
+users have adapted Microfetch to their distribution by patching the
+[main module] and inserting the logo of their choice. This is also the best way
+to go if you plan to make small changes. If your changes are not small, you
+might want to look for a program that is designed to be customizable; Microfetch
+is built for maximum performance.
 
 The Nix package allows passing patches in a streamlined manner by passing
-`.overrideAttrs` to the derivation.
+`.overrideAttrs` to the derivation. You can apply your patches in `patches` and
+share your derivations with people. Feel free to use the [discussions tab] to
+share your own variants of Microfetch!
 
 ## Contributing
 
@@ -121,13 +240,22 @@ Contributions that help improve performance in specific areas of Microfetch are
 welcome. Though, prepare to be bombarded with questions if your changes are
 large.
 
-## Hacking
+### Hacking
 
-A Nix flake is provided. `nix develop` to get started. Direnv users may simply
-run `direnv allow` to get started.
+A Nix flake is provided. You may use `nix develop` to get started. Direnv users
+may instead run `direnv allow` to get a complete environment with shell
+integration.
 
-Non-nix users will need `cargo` and `gcc` installed on their system, see
-`Cargo.toml` for available release profiles.
+Non-Nix user will need `cargo`, `clang` and `mold` installed on their system to
+build Microfetch. As Mold seems to yield _slightly_ better results than the
+default linker, it has been set as the default in `.cargo/config.toml` for
+x86-64 Linux. You may override those defaults using the `RUSTFLAGS` environment
+variable. For example:
+
+```sh
+# Use ld instead of Mold
+$ RUSTFLAGS="-C linker=/path/to/ld.lld" cargo build
+```
 
 ## Thanks
 
@@ -144,6 +272,7 @@ person about current issues. To list a few, special thanks to:
 - [@sioodmy](https://github.com/sioodmy) - Being cute
 - [@mewoocat](https://github.com/mewoocat) - The awesome NixOS logo ASCII used
   in Microfetch
+- [@uzaaft](https://github.com/uzaaft) - Helping me going faster
 
 Additionally a big thank you to everyone who used, talked about or criticized
 Microfetch. I might have missed your name here, but you have my thanks.

benches/benchmark.rs

@@ -1,26 +1,32 @@
-use criterion::{criterion_group, criterion_main, Criterion};
-use microfetch_lib::colors::print_dots;
-use microfetch_lib::desktop::get_desktop_info;
-use microfetch_lib::release::{get_os_pretty_name, get_system_info};
-use microfetch_lib::system::{
-    get_memory_usage, get_root_disk_usage, get_shell, get_username_and_hostname,
+use criterion::{Criterion, criterion_group, criterion_main};
+use microfetch_lib::{
+  UtsName,
+  colors::print_dots,
+  desktop::get_desktop_info,
+  release::{get_os_pretty_name, get_system_info},
+  system::{
+    get_memory_usage,
+    get_root_disk_usage,
+    get_shell,
+    get_username_and_hostname,
+  },
+  uptime::get_current,
 };
-use microfetch_lib::uptime::get_current;
 
 fn main_benchmark(c: &mut Criterion) {
-    let utsname = nix::sys::utsname::uname().expect("lol");
-    c.bench_function("user_info", |b| {
-        b.iter(|| get_username_and_hostname(&utsname))
-    });
-    c.bench_function("os_name", |b| b.iter(get_os_pretty_name));
-    c.bench_function("kernel_version", |b| b.iter(|| get_system_info(&utsname)));
-    c.bench_function("shell", |b| b.iter(get_shell));
+  let utsname = UtsName::uname().expect("Failed to get uname");
+  c.bench_function("user_info", |b| {
+    b.iter(|| get_username_and_hostname(&utsname));
+  });
+  c.bench_function("os_name", |b| b.iter(get_os_pretty_name));
+  c.bench_function("kernel_version", |b| b.iter(|| get_system_info(&utsname)));
+  c.bench_function("shell", |b| b.iter(get_shell));
 
-    c.bench_function("desktop", |b| b.iter(get_desktop_info));
-    c.bench_function("uptime", |b| b.iter(get_current));
-    c.bench_function("memory_usage", |b| b.iter(get_memory_usage));
-    c.bench_function("storage", |b| b.iter(get_root_disk_usage));
-    c.bench_function("colors", |b| b.iter(print_dots));
+  c.bench_function("desktop", |b| b.iter(get_desktop_info));
+  c.bench_function("uptime", |b| b.iter(get_current));
+  c.bench_function("memory_usage", |b| b.iter(get_memory_usage));
+  c.bench_function("storage", |b| b.iter(get_root_disk_usage));
+  c.bench_function("colors", |b| b.iter(print_dots));
 }
 
 criterion_group!(benches, main_benchmark);

flake.lock

@@ -2,15 +2,19 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1722719969,
-        "narHash": "sha256-E47qbT/mRtBCSZra+9S9208sp/QnNeOAq7EhHX+eMNE=",
+        "lastModified": 1743359643,
+        "narHash": "sha256-RkyJ9a67s0zEIz4O66TyZOIGh4TFZ4dKHKMgnxZCh2I=",
+        "lastModified": 1763381801,
+        "narHash": "sha256-325fR0JmHW7B74/gHPv/S9w1Rfj/M2HniwQFUwdrZ9k=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "83a364ced9d5b8a6bdac897bbef6b91e70777b97",
+        "rev": "ca77b4bc80e558ce59f2712fdb276f90c0ee309a",
+        "rev": "46931757ea8bdbba25c076697f8e73b8dc39fef5",
         "type": "github"
       },
       "original": {
         "owner": "NixOS",
+        "ref": "nixos-unstable",
         "repo": "nixpkgs",
         "type": "github"
       }

flake.nix

@@ -1,6 +1,6 @@
 {
   description = "A microscopic fetch script in Rust, for NixOS systems";
-  inputs.nixpkgs.url = "github:NixOS/nixpkgs";
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs?ref=nixos-unstable";
 
   outputs = {
     self,
@@ -10,9 +10,12 @@
     forEachSystem = nixpkgs.lib.genAttrs systems;
     pkgsForEach = nixpkgs.legacyPackages;
   in {
-    packages = forEachSystem (system: {
+    packages = forEachSystem (system: let
+      pkgs = pkgsForEach.${system};
+    in {
       default = self.packages.${system}.microfetch;
-      microfetch = pkgsForEach.${system}.callPackage ./nix/package.nix {};
+      microfetch = pkgs.callPackage ./nix/package.nix {};
+      microfetch-mold = pkgs.callPackage ./nix/package.nix {useMold = true;};
     });
 
     devShells = forEachSystem (system: {

nix/package.nix

@@ -1,30 +1,53 @@
 {
   lib,
-  rustPlatform,
+  stdenv,
   stdenvAdapters,
+  rustPlatform,
   llvm,
+  useMold ? stdenv.isLinux && !stdenv.hostPlatform.isAarch,
 }: let
   toml = (lib.importTOML ../Cargo.toml).package;
   pname = toml.name;
   inherit (toml) version;
+
+  # Select stdenv based on useMold flag
+  stdenv =
+    if useMold
+    then stdenvAdapters.useMoldLinker llvm.stdenv
+    else llvm.stdenv;
 in
-  rustPlatform.buildRustPackage.override {stdenv = stdenvAdapters.useMoldLinker llvm.stdenv;} {
-    RUSTFLAGS = "-C link-arg=-fuse-ld=mold";
-
+  rustPlatform.buildRustPackage.override {inherit stdenv;} {
     inherit pname version;
-
-    src = builtins.path {
-      name = "${pname}-${version}";
-      path = lib.sources.cleanSource ../.;
-    };
+    src = let
+      fs = lib.fileset;
+      s = ../.;
+    in
+      fs.toSource {
+        root = s;
+        fileset = fs.unions [
+          (fs.fileFilter (file: builtins.any file.hasExt ["rs"]) (s + /src))
+          (s + /Cargo.lock)
+          (s + /Cargo.toml)
+          (s + /benches)
+        ];
+      };
 
     cargoLock.lockFile = ../Cargo.lock;
+    enableParallelBuilding = true;
+    buildNoDefaultFeatures = true;
+    doCheck = false;
+
+    # Only set RUSTFLAGS for mold if useMold is enabled
+    env = lib.optionalAttrs useMold {
+      CARGO_LINKER = "clang";
+      RUSTFLAGS = "-C link-arg=-fuse-ld=mold";
+    };
 
     meta = {
-      description = "A microscopic fetch script in Rust, for NixOS systems";
+      description = "Microscopic fetch script in Rust, for NixOS systems";
       homepage = "https://github.com/NotAShelf/microfetch";
       license = lib.licenses.gpl3Only;
-      maintainers = with lib.maintainers; [NotAShelf];
+      maintainers = [lib.maintainers.NotAShelf];
       mainProgram = "microfetch";
     };
   }

nix/shell.nix

@@ -1,27 +1,31 @@
 {
   mkShell,
+  cargo,
+  rustc,
+  mold,
+  clang,
   rust-analyzer-unwrapped,
   rustfmt,
   clippy,
-  cargo,
-  rustc,
-  gcc,
+  taplo,
   rustPlatform,
   gnuplot,
 }:
 mkShell {
+  name = "microfetch";
   strictDeps = true;
-
   nativeBuildInputs = [
     cargo
     rustc
-    gcc
+    mold
+    clang
 
     rust-analyzer-unwrapped
-    rustfmt
+    (rustfmt.override {asNightly = true;})
     clippy
+    taplo
 
-    gnuplot # For Criterion.rs plots
+    gnuplot # for Criterion.rs plots
   ];
 
   env.RUST_SRC_PATH = "${rustPlatform.rustLibSrc}";

src/colors.rs

@@ -1,11 +1,81 @@
-pub const RESET: &str = "\x1b[0m";
-pub const BLUE: &str = "\x1b[34m";
-pub const CYAN: &str = "\x1b[36m";
-pub const GREEN: &str = "\x1b[32m";
-pub const YELLOW: &str = "\x1b[33m";
-pub const RED: &str = "\x1b[31m";
-pub const MAGENTA: &str = "\x1b[35m";
+use std::sync::LazyLock;
 
-pub fn print_dots() -> String {
-    format!("{BLUE}  {CYAN}  {GREEN}  {YELLOW}  {RED}  {MAGENTA}  {RESET}")
+pub struct Colors {
+  pub reset:   &'static str,
+  pub blue:    &'static str,
+  pub cyan:    &'static str,
+  pub green:   &'static str,
+  pub yellow:  &'static str,
+  pub red:     &'static str,
+  pub magenta: &'static str,
+}
+
+impl Colors {
+  const fn new(is_no_color: bool) -> Self {
+    if is_no_color {
+      Self {
+        reset:   "",
+        blue:    "",
+        cyan:    "",
+        green:   "",
+        yellow:  "",
+        red:     "",
+        magenta: "",
+      }
+    } else {
+      Self {
+        reset:   "\x1b[0m",
+        blue:    "\x1b[34m",
+        cyan:    "\x1b[36m",
+        green:   "\x1b[32m",
+        yellow:  "\x1b[33m",
+        red:     "\x1b[31m",
+        magenta: "\x1b[35m",
+      }
+    }
+  }
+}
+
+pub static COLORS: LazyLock<Colors> = LazyLock::new(|| {
+  const NO_COLOR: *const libc::c_char = c"NO_COLOR".as_ptr();
+  let is_no_color = unsafe { !libc::getenv(NO_COLOR).is_null() };
+  Colors::new(is_no_color)
+});
+
+#[must_use]
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
+pub fn print_dots() -> String {
+  // Pre-calculate capacity: 6 color codes + "  " (glyph + 2 spaces) per color
+  const GLYPH: &str = "";
+  let capacity = COLORS.blue.len()
+    + COLORS.cyan.len()
+    + COLORS.green.len()
+    + COLORS.yellow.len()
+    + COLORS.red.len()
+    + COLORS.magenta.len()
+    + COLORS.reset.len()
+    + (GLYPH.len() + 2) * 6;
+
+  let mut result = String::with_capacity(capacity);
+  result.push_str(COLORS.blue);
+  result.push_str(GLYPH);
+  result.push_str("  ");
+  result.push_str(COLORS.cyan);
+  result.push_str(GLYPH);
+  result.push_str("  ");
+  result.push_str(COLORS.green);
+  result.push_str(GLYPH);
+  result.push_str("  ");
+  result.push_str(COLORS.yellow);
+  result.push_str(GLYPH);
+  result.push_str("  ");
+  result.push_str(COLORS.red);
+  result.push_str(GLYPH);
+  result.push_str("  ");
+  result.push_str(COLORS.magenta);
+  result.push_str(GLYPH);
+  result.push_str("  ");
+  result.push_str(COLORS.reset);
+
+  result
 }

src/desktop.rs

@@ -1,28 +1,42 @@
+use std::{ffi::CStr, fmt::Write};
+
+#[must_use]
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
 pub fn get_desktop_info() -> String {
-    // Retrieve the environment variables and handle Result types
-    let desktop_env = std::env::var("XDG_CURRENT_DESKTOP");
-    let display_backend_result = std::env::var("XDG_SESSION_TYPE");
-
-    // Capitalize the first letter of the display backend value
-    let mut display_backend = display_backend_result.unwrap_or_default();
-    if let Some(c) = display_backend.as_mut_str().get_mut(0..1) {
-        c.make_ascii_uppercase();
-    }
-
-    // Trim "none+" from the start of desktop_env if present
-    // Use "Unknown" if desktop_env is empty or has an error
-    let desktop_env = match desktop_env {
-        Err(_) => "Unknown".to_string(),
-        Ok(s) => s.trim_start_matches("none+").to_string(),
-    };
-
-    // Handle the case where display_backend might be empty after capitalization
-    let display_backend = if display_backend.is_empty() {
-        "Unknown"
+  // Retrieve the environment variables and handle Result types
+  let desktop_str = unsafe {
+    let ptr = libc::getenv(c"XDG_CURRENT_DESKTOP".as_ptr());
+    if ptr.is_null() {
+      "Unknown"
     } else {
-        &display_backend
+      let s = CStr::from_ptr(ptr).to_str().unwrap_or("Unknown");
+      s.strip_prefix("none+").unwrap_or(s)
     }
-    .to_string();
+  };
 
-    format!("{desktop_env} ({display_backend})")
+  let backend_str = unsafe {
+    let ptr = libc::getenv(c"XDG_SESSION_TYPE".as_ptr());
+    if ptr.is_null() {
+      "Unknown"
+    } else {
+      let s = CStr::from_ptr(ptr).to_str().unwrap_or("Unknown");
+      if s.is_empty() { "Unknown" } else { s }
+    }
+  };
+
+  // Pre-calculate capacity: desktop_len + " (" + backend_len + ")"
+  // Capitalize first char needs temporary allocation only if backend exists
+  let mut result =
+    String::with_capacity(desktop_str.len() + backend_str.len() + 3);
+  result.push_str(desktop_str);
+  result.push_str(" (");
+
+  // Capitalize first character of backend
+  if let Some(first_char) = backend_str.chars().next() {
+    let _ = write!(result, "{}", first_char.to_ascii_uppercase());
+    result.push_str(&backend_str[first_char.len_utf8()..]);
+  }
+
+  result.push(')');
+  result
 }

src/lib.rs

@@ -1,5 +1,46 @@
 pub mod colors;
 pub mod desktop;
 pub mod release;
+pub mod syscall;
 pub mod system;
 pub mod uptime;
+
+use std::mem::MaybeUninit;
+
+/// Wrapper for `libc::utsname` with safe accessor methods
+pub struct UtsName(libc::utsname);
+
+impl UtsName {
+  /// Calls `uname` syscall and returns a `UtsName` wrapper
+  ///
+  /// # Errors
+  ///
+  /// Returns an error if the `uname` syscall fails
+  pub fn uname() -> Result<Self, std::io::Error> {
+    let mut uts = MaybeUninit::uninit();
+    if unsafe { libc::uname(uts.as_mut_ptr()) } != 0 {
+      return Err(std::io::Error::last_os_error());
+    }
+    Ok(Self(unsafe { uts.assume_init() }))
+  }
+
+  #[must_use]
+  pub const fn nodename(&self) -> &std::ffi::CStr {
+    unsafe { std::ffi::CStr::from_ptr(self.0.nodename.as_ptr()) }
+  }
+
+  #[must_use]
+  pub const fn sysname(&self) -> &std::ffi::CStr {
+    unsafe { std::ffi::CStr::from_ptr(self.0.sysname.as_ptr()) }
+  }
+
+  #[must_use]
+  pub const fn release(&self) -> &std::ffi::CStr {
+    unsafe { std::ffi::CStr::from_ptr(self.0.release.as_ptr()) }
+  }
+
+  #[must_use]
+  pub const fn machine(&self) -> &std::ffi::CStr {
+    unsafe { std::ffi::CStr::from_ptr(self.0.machine.as_ptr()) }
+  }
+}

src/main.rs

@@ -1,79 +1,112 @@
 mod colors;
 mod desktop;
 mod release;
+mod syscall;
 mod system;
 mod uptime;
 
-use std::io::Write;
+use std::io::{self, Cursor, Write};
 
-use crate::colors::{print_dots, BLUE, CYAN, RESET};
-use crate::desktop::get_desktop_info;
-use crate::release::{get_os_pretty_name, get_system_info};
-use crate::system::{get_memory_usage, get_root_disk_usage, get_shell, get_username_and_hostname};
-use crate::uptime::get_current;
+pub use microfetch_lib::UtsName;
 
-use color_eyre::Report;
+use crate::{
+  colors::print_dots,
+  desktop::get_desktop_info,
+  release::{get_os_pretty_name, get_system_info},
+  system::{
+    get_memory_usage,
+    get_root_disk_usage,
+    get_shell,
+    get_username_and_hostname,
+  },
+  uptime::get_current,
+};
 
-fn main() -> Result<(), Report> {
-    color_eyre::install()?;
-
-    let utsname = nix::sys::utsname::uname()?;
+#[cfg_attr(feature = "hotpath", hotpath::main)]
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+  if Some("--version") == std::env::args().nth(1).as_deref() {
+    println!("Microfetch {}", env!("CARGO_PKG_VERSION"));
+  } else {
+    let utsname = UtsName::uname()?;
     let fields = Fields {
-        user_info: get_username_and_hostname(&utsname),
-        os_name: get_os_pretty_name()?,
-        kernel_version: get_system_info(&utsname)?,
-        shell: get_shell(),
-        desktop: get_desktop_info(),
-        uptime: get_current()?,
-        memory_usage: get_memory_usage()?,
-        storage: get_root_disk_usage()?,
-        colors: print_dots(),
+      user_info:      get_username_and_hostname(&utsname),
+      os_name:        get_os_pretty_name()?,
+      kernel_version: get_system_info(&utsname),
+      shell:          get_shell(),
+      desktop:        get_desktop_info(),
+      uptime:         get_current()?,
+      memory_usage:   get_memory_usage()?,
+      storage:        get_root_disk_usage()?,
+      colors:         print_dots(),
     };
+    print_system_info(&fields)?;
+  }
 
-    print_system_info(&fields);
-
-    Ok(())
+  Ok(())
 }
 
-// Struct to hold all the fields we need to print
-// helps avoid clippy warnings about argument count
-// and makes it easier to pass around, though its
-// not like we need to
+// Struct to hold all the fields we need in order to print the fetch. This
+// helps avoid Clippy warnings about argument count, and makes it slightly
+// easier to pass data around. Though, it is not like we really need to.
 struct Fields {
-    user_info: String,
-    os_name: String,
-    kernel_version: String,
-    shell: String,
-    uptime: String,
-    desktop: String,
-    memory_usage: String,
-    storage: String,
-    colors: String,
+  user_info:      String,
+  os_name:        String,
+  kernel_version: String,
+  shell:          String,
+  uptime:         String,
+  desktop:        String,
+  memory_usage:   String,
+  storage:        String,
+  colors:         String,
 }
 
-fn print_system_info(fields: &Fields) {
-    let Fields {
-        user_info,
-        os_name,
-        kernel_version,
-        shell,
-        uptime,
-        desktop,
-        memory_usage,
-        storage,
-        colors,
-    } = fields;
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
+fn print_system_info(
+  fields: &Fields,
+) -> Result<(), Box<dyn std::error::Error>> {
+  use crate::colors::COLORS;
 
-    let _ = std::io::stdout().write_all(format!(
-        "
- {CYAN}     ▟█▖    {BLUE}▝█▙ ▗█▛          {user_info} ~{RESET}
- {CYAN}  ▗▄▄▟██▄▄▄▄▄{BLUE}▝█▙█▛  {CYAN}▖        {CYAN}  {BLUE}System{RESET}        {os_name}
- {CYAN}  ▀▀▀▀▀▀▀▀▀▀▀▘{BLUE}▝██  {CYAN}▟█▖       {CYAN}  {BLUE}Kernel{RESET}        {kernel_version}
- {BLUE}     ▟█▛       {BLUE}▝█▘{CYAN}▟█▛        {CYAN}  {BLUE}Shell{RESET}         {shell}
- {BLUE}▟█████▛          {CYAN}▟█████▛     {CYAN}  {BLUE}Uptime{RESET}        {uptime}
- {BLUE}   ▟█▛{CYAN}▗█▖       {CYAN}▟█▛          {CYAN}  {BLUE}Desktop{RESET}       {desktop}
- {BLUE}  ▝█▛  {CYAN}██▖{BLUE}▗▄▄▄▄▄▄▄▄▄▄▄       {CYAN}󰍛  {BLUE}Memory{RESET}        {memory_usage}
- {BLUE}   ▝  {CYAN}▟█▜█▖{BLUE}▀▀▀▀▀██▛▀▀▘       {CYAN}󱥎  {BLUE}Storage (/){RESET}   {storage}
- {CYAN}     ▟█▘ ▜█▖    {BLUE}▝█▛          {CYAN}  {BLUE}Colors{RESET}        {colors}
-").as_bytes());
+  let Fields {
+    user_info,
+    os_name,
+    kernel_version,
+    shell,
+    uptime,
+    desktop,
+    memory_usage,
+    storage,
+    colors,
+  } = fields;
+
+  let cyan = COLORS.cyan;
+  let blue = COLORS.blue;
+  let reset = COLORS.reset;
+
+  let mut buf = [0u8; 2048];
+  let mut cursor = Cursor::new(&mut buf[..]);
+
+  write!(
+    cursor,
+    "
+    {cyan}     ▟█▖    {blue}▝█▙ ▗█▛         {user_info} ~{reset}
+    {cyan}  ▗▄▄▟██▄▄▄▄▄{blue}▝█▙█▛  {cyan}▖       {cyan}  {blue}System{reset}        {os_name}
+    {cyan}  ▀▀▀▀▀▀▀▀▀▀▀▘{blue}▝██  {cyan}▟█▖      {cyan}  {blue}Kernel{reset}        {kernel_version}
+    {blue}     ▟█▛       {blue}▝█▘{cyan}▟█▛       {cyan}  {blue}Shell{reset}         {shell}
+    {blue}▟█████▛          {cyan}▟█████▛    {cyan}  {blue}Uptime{reset}        {uptime}
+    {blue}   ▟█▛{cyan}▗█▖       {cyan}▟█▛         {cyan}  {blue}Desktop{reset}       {desktop}
+    {blue}  ▝█▛  {cyan}██▖{blue}▗▄▄▄▄▄▄▄▄▄▄▄      {cyan}󰍛  {blue}Memory{reset}        {memory_usage}
+    {blue}   ▝  {cyan}▟█▜█▖{blue}▀▀▀▀▀██▛▀▀▘      {cyan}󱥎  {blue}Storage (/){reset}   {storage}
+    {cyan}     ▟█▘ ▜█▖    {blue}▝█▛         {cyan}  {blue}Colors{reset}        {colors}\n\n"
+  )?;
+
+  let len = cursor.position() as usize;
+  // Direct syscall to avoid stdout buffering allocation
+  let written = unsafe { libc::write(libc::STDOUT_FILENO, buf.as_ptr().cast(), len) };
+  if written < 0 {
+    return Err(io::Error::last_os_error().into());
+  }
+  if written as usize != len {
+    return Err(io::Error::new(io::ErrorKind::WriteZero, "partial write to stdout").into());
+  }
+  Ok(())
 }

src/release.rs

@@ -1,27 +1,69 @@
-use color_eyre::Result;
-use nix::sys::utsname::UtsName;
-use std::{
-    fs::File,
-    io::{self, Read},
-};
+use std::{fmt::Write as _, io};
 
-pub fn get_system_info(utsname: &UtsName) -> nix::Result<String> {
-    Ok(format!(
-        "{} {} ({})",
-        utsname.sysname().to_str().unwrap_or("Unknown"),
-        utsname.release().to_str().unwrap_or("Unknown"),
-        utsname.machine().to_str().unwrap_or("Unknown")
-    ))
+use crate::{UtsName, syscall::read_file_fast};
+
+#[must_use]
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
+pub fn get_system_info(utsname: &UtsName) -> String {
+  let sysname = utsname.sysname().to_str().unwrap_or("Unknown");
+  let release = utsname.release().to_str().unwrap_or("Unknown");
+  let machine = utsname.machine().to_str().unwrap_or("Unknown");
+
+  // Pre-allocate capacity: sysname + " " + release + " (" + machine + ")"
+  let capacity = sysname.len() + 1 + release.len() + 2 + machine.len() + 1;
+  let mut result = String::with_capacity(capacity);
+
+  write!(result, "{sysname} {release} ({machine})").unwrap();
+  result
 }
 
+/// Gets the pretty name of the OS from `/etc/os-release`.
+///
+/// # Errors
+///
+/// Returns an error if `/etc/os-release` cannot be read.
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
 pub fn get_os_pretty_name() -> Result<String, io::Error> {
-    let mut os_release_content = String::with_capacity(1024);
-    File::open("/etc/os-release")?.read_to_string(&mut os_release_content)?;
+  // Fast byte-level scanning for PRETTY_NAME=
+  const PREFIX: &[u8] = b"PRETTY_NAME=";
 
-    let pretty_name = os_release_content
-        .lines()
-        .find(|line| line.starts_with("PRETTY_NAME="))
-        .map(|line| line.trim_start_matches("PRETTY_NAME=").trim_matches('"'));
+  let mut buffer = [0u8; 1024];
 
-    Ok(pretty_name.unwrap_or("Unknown").to_string())
+  // Use fast syscall-based file reading
+  let bytes_read = read_file_fast("/etc/os-release", &mut buffer)?;
+  let content = &buffer[..bytes_read];
+
+  let mut offset = 0;
+
+  while offset < content.len() {
+    let remaining = &content[offset..];
+
+    // Find newline or end
+    let line_end = remaining
+      .iter()
+      .position(|&b| b == b'\n')
+      .unwrap_or(remaining.len());
+    let line = &remaining[..line_end];
+
+    if line.starts_with(PREFIX) {
+      let value = &line[PREFIX.len()..];
+
+      // Strip quotes if present
+      let trimmed = if value.len() >= 2
+        && value[0] == b'"'
+        && value[value.len() - 1] == b'"'
+      {
+        &value[1..value.len() - 1]
+      } else {
+        value
+      };
+
+      // Convert to String - should be valid UTF-8
+      return Ok(String::from_utf8_lossy(trimmed).into_owned());
+    }
+
+    offset += line_end + 1;
+  }
+
+  Ok("Unknown".to_owned())
 }

src/syscall.rs

@@ -0,0 +1,210 @@
+//! Incredibly fast syscall wrappers for using inline assembly. Serves the
+//! purposes of completely bypassing Rust's standard library in favor of
+//! handwritten Assembly. Is this a good idea? No. Is it fast? Yeah, but only
+//! marginally. Either way it serves a purpose and I will NOT accept criticism.
+//! What do you mean I wasted two whole hours to make the program only 100µs
+//! faster?
+//!
+//! Supports `x86_64` and `aarch64` architectures. Riscv support will be
+//! implemented when and ONLY WHEN I can be bothered to work on it.
+
+use std::io;
+
+/// Direct syscall to open a file
+///
+/// # Returns
+///
+/// File descriptor or -1 on error
+///
+/// # Safety
+///
+/// The caller must ensure:
+///
+/// - `path` points to a valid null-terminated C string
+/// - The pointer remains valid for the duration of the syscall
+#[inline]
+#[must_use]
+pub unsafe fn sys_open(path: *const u8, flags: i32) -> i32 {
+  #[cfg(target_arch = "x86_64")]
+  unsafe {
+    let fd: i64;
+    std::arch::asm!(
+      "syscall",
+      in("rax") 2i64,  // SYS_open
+      in("rdi") path,
+      in("rsi") flags,
+      in("rdx") 0i32,  // mode (not used for reading)
+      lateout("rax") fd,
+      lateout("rcx") _,
+      lateout("r11") _,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      fd as i32
+    }
+  }
+  #[cfg(target_arch = "aarch64")]
+  unsafe {
+    let fd: i64;
+    std::arch::asm!(
+      "svc #0",
+      in("x8") 56i64,  // SYS_openat
+      in("x0") -100i32,  // AT_FDCWD
+      in("x1") path,
+      in("x2") flags,
+      in("x3") 0i32,  // mode
+      lateout("x0") fd,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      fd as i32
+    }
+  }
+  #[cfg(not(any(target_arch = "x86_64", target_arch = "aarch64")))]
+  {
+    compile_error!("Unsupported architecture for inline assembly syscalls");
+  }
+}
+
+/// Direct syscall to read from a file descriptor
+///
+/// # Returns n
+///
+/// Number of bytes read or -1 on error
+///
+/// # Safety
+///
+/// The caller must ensure:
+/// - `buf` points to a valid writable buffer of at least `count` bytes
+/// - `fd` is a valid open file descriptor
+#[inline]
+pub unsafe fn sys_read(fd: i32, buf: *mut u8, count: usize) -> isize {
+  #[cfg(target_arch = "x86_64")]
+  unsafe {
+    let ret: i64;
+    std::arch::asm!(
+      "syscall",
+      in("rax") 0i64,  // SYS_read
+      in("rdi") fd,
+      in("rsi") buf,
+      in("rdx") count,
+      lateout("rax") ret,
+      lateout("rcx") _,
+      lateout("r11") _,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      ret as isize
+    }
+  }
+  #[cfg(target_arch = "aarch64")]
+  unsafe {
+    let ret: i64;
+    std::arch::asm!(
+      "svc #0",
+      in("x8") 63i64,  // SYS_read
+      in("x0") fd,
+      in("x1") buf,
+      in("x2") count,
+      lateout("x0") ret,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      ret as isize
+    }
+  }
+  #[cfg(not(any(target_arch = "x86_64", target_arch = "aarch64")))]
+  {
+    compile_error!("Unsupported architecture for inline assembly syscalls");
+  }
+}
+
+/// Direct syscall to close a file descriptor
+///
+/// # Safety
+///
+/// The caller must ensure `fd` is a valid open file descriptor
+#[inline]
+#[must_use]
+pub unsafe fn sys_close(fd: i32) -> i32 {
+  #[cfg(target_arch = "x86_64")]
+  unsafe {
+    let ret: i64;
+    std::arch::asm!(
+      "syscall",
+      in("rax") 3i64,  // SYS_close
+      in("rdi") fd,
+      lateout("rax") ret,
+      lateout("rcx") _,
+      lateout("r11") _,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      ret as i32
+    }
+  }
+  #[cfg(target_arch = "aarch64")]
+  unsafe {
+    let ret: i64;
+    std::arch::asm!(
+      "svc #0",
+      in("x8") 57i64,  // SYS_close
+      in("x0") fd,
+      lateout("x0") ret,
+      options(nostack)
+    );
+    #[allow(clippy::cast_possible_truncation)]
+    {
+      ret as i32
+    }
+  }
+  #[cfg(not(any(target_arch = "x86_64", target_arch = "aarch64")))]
+  {
+    compile_error!("Unsupported architecture for inline assembly syscalls");
+  }
+}
+
+/// Read entire file using direct syscalls. This avoids libc overhead and can be
+/// significantly faster for small files.
+///
+/// # Errors
+///
+/// Returns an error if the file cannot be opened or read
+#[inline]
+pub fn read_file_fast(path: &str, buffer: &mut [u8]) -> io::Result<usize> {
+  const O_RDONLY: i32 = 0;
+
+  // Use stack-allocated buffer for null-terminated path (max 256 bytes)
+  let path_bytes = path.as_bytes();
+  if path_bytes.len() >= 256 {
+    return Err(io::Error::new(io::ErrorKind::InvalidInput, "Path too long"));
+  }
+
+  let mut path_buf = [0u8; 256];
+  path_buf[..path_bytes.len()].copy_from_slice(path_bytes);
+  // XXX: Already zero-terminated since array is initialized to zeros
+
+  unsafe {
+    let fd = sys_open(path_buf.as_ptr(), O_RDONLY);
+    if fd < 0 {
+      return Err(io::Error::last_os_error());
+    }
+
+    let bytes_read = sys_read(fd, buffer.as_mut_ptr(), buffer.len());
+    let _ = sys_close(fd);
+
+    if bytes_read < 0 {
+      return Err(io::Error::last_os_error());
+    }
+
+    #[allow(clippy::cast_sign_loss)]
+    {
+      Ok(bytes_read as usize)
+    }
+  }
+}

src/system.rs

@@ -1,84 +1,184 @@
-use color_eyre::Result;
-use nix::sys::{statvfs::statvfs, utsname::UtsName};
+use std::{ffi::CStr, fmt::Write as _, io, mem::MaybeUninit};
 
-use std::{
-    env,
-    fs::File,
-    io::{self, Read},
-};
-
-use crate::colors::{CYAN, GREEN, RED, RESET, YELLOW};
+use crate::{UtsName, colors::COLORS, syscall::read_file_fast};
 
+#[must_use]
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
 pub fn get_username_and_hostname(utsname: &UtsName) -> String {
-    let username = env::var("USER").unwrap_or("unknown_user".to_string());
-    let hostname = utsname
-        .nodename()
-        .to_str()
-        .unwrap_or("unknown_host")
-        .to_string();
+  let username = unsafe {
+    let ptr = libc::getenv(c"USER".as_ptr());
+    if ptr.is_null() {
+      "unknown_user"
+    } else {
+      CStr::from_ptr(ptr).to_str().unwrap_or("unknown_user")
+    }
+  };
+  let hostname = utsname.nodename().to_str().unwrap_or("unknown_host");
 
-    format!("{YELLOW}{username}{RED}@{GREEN}{hostname}")
+  let capacity = COLORS.yellow.len()
+    + username.len()
+    + COLORS.red.len()
+    + 1
+    + COLORS.green.len()
+    + hostname.len()
+    + COLORS.reset.len();
+  let mut result = String::with_capacity(capacity);
+
+  result.push_str(COLORS.yellow);
+  result.push_str(username);
+  result.push_str(COLORS.red);
+  result.push('@');
+  result.push_str(COLORS.green);
+  result.push_str(hostname);
+  result.push_str(COLORS.reset);
+
+  result
 }
 
+#[must_use]
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
 pub fn get_shell() -> String {
-    let shell_path = env::var("SHELL").unwrap_or("unknown_shell".to_string());
-    let shell_name = shell_path.rsplit('/').next().unwrap_or("unknown_shell");
-
-    shell_name.to_string()
-}
-
-pub fn get_root_disk_usage() -> Result<String, io::Error> {
-    let vfs = statvfs("/")?;
-    let block_size = vfs.block_size() as u64;
-    let total_blocks = vfs.blocks();
-    let available_blocks = vfs.blocks_available();
-
-    let total_size = block_size * total_blocks;
-    let used_size = total_size - (block_size * available_blocks);
-
-    let total_size = total_size as f64 / (1024.0 * 1024.0 * 1024.0);
-    let used_size = used_size as f64 / (1024.0 * 1024.0 * 1024.0);
-    let usage = (used_size as f64 / total_size as f64) * 100.0;
-
-    Ok(format!(
-        "{used_size:.2} GiB / {total_size:.2} GiB ({CYAN}{usage:.0}%{RESET})"
-    ))
-}
-
-pub fn get_memory_usage() -> Result<String, io::Error> {
-    #[inline(always)]
-    fn parse_memory_info() -> Result<(f64, f64), io::Error> {
-        let mut total_memory_kb = 0.0;
-        let mut available_memory_kb = 0.0;
-
-        let mut meminfo = String::with_capacity(2048);
-        File::open("/proc/meminfo")?.read_to_string(&mut meminfo)?;
-
-        for line in meminfo.lines() {
-            let mut split = line.split_whitespace();
-            match split.next().unwrap_or_default() {
-                "MemTotal:" => total_memory_kb = split.next().unwrap_or("0").parse().unwrap_or(0.0),
-                "MemAvailable:" => {
-                    available_memory_kb = split.next().unwrap_or("0").parse().unwrap_or(0.0);
-
-                    // MemTotal comes before MemAvailable, stop parsing
-                    break;
-                }
-                _ => (),
-            }
-        }
-
-        let total_memory_gb = total_memory_kb / 1024.0 / 1024.0;
-        let available_memory_gb = available_memory_kb / 1024.0 / 1024.0;
-        let used_memory_gb = total_memory_gb - available_memory_gb;
-
-        Ok((used_memory_gb, total_memory_gb))
+  unsafe {
+    let ptr = libc::getenv(c"SHELL".as_ptr());
+    if ptr.is_null() {
+      return "unknown_shell".into();
     }
 
-    let (used_memory, total_memory) = parse_memory_info()?;
-    let percentage_used = (used_memory / total_memory * 100.0).round() as u64;
-
-    Ok(format!(
-        "{used_memory:.2} GiB / {total_memory:.2} GiB ({CYAN}{percentage_used}%{RESET})"
-    ))
+    let bytes = CStr::from_ptr(ptr).to_bytes();
+    let start = bytes.iter().rposition(|&b| b == b'/').map_or(0, |i| i + 1);
+    let name = std::str::from_utf8_unchecked(&bytes[start..]);
+    name.into()
+  }
+}
+
+/// Gets the root disk usage information.
+///
+/// # Errors
+///
+/// Returns an error if the filesystem information cannot be retrieved.
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
+#[allow(clippy::cast_precision_loss)]
+pub fn get_root_disk_usage() -> Result<String, io::Error> {
+  let mut vfs = MaybeUninit::uninit();
+  let path = b"/\0";
+
+  if unsafe { libc::statvfs(path.as_ptr().cast(), vfs.as_mut_ptr()) } != 0 {
+    return Err(io::Error::last_os_error());
+  }
+
+  let vfs = unsafe { vfs.assume_init() };
+  let block_size = vfs.f_bsize;
+  let total_blocks = vfs.f_blocks;
+  let available_blocks = vfs.f_bavail;
+
+  let total_size = block_size * total_blocks;
+  let used_size = total_size - (block_size * available_blocks);
+
+  let total_size = total_size as f64 / (1024.0 * 1024.0 * 1024.0);
+  let used_size = used_size as f64 / (1024.0 * 1024.0 * 1024.0);
+  let usage = (used_size / total_size) * 100.0;
+
+  let mut result = String::with_capacity(64);
+  write!(
+    result,
+    "{used_size:.2} GiB / {total_size:.2} GiB ({cyan}{usage:.0}%{reset})",
+    cyan = COLORS.cyan,
+    reset = COLORS.reset,
+  )
+  .unwrap();
+
+  Ok(result)
+}
+
+/// Fast integer parsing without stdlib overhead
+#[inline]
+fn parse_u64_fast(s: &[u8]) -> u64 {
+  let mut result = 0u64;
+  for &byte in s {
+    if byte.is_ascii_digit() {
+      result = result * 10 + u64::from(byte - b'0');
+    } else {
+      break;
+    }
+  }
+  result
+}
+
+/// Gets the system memory usage information.
+///
+/// # Errors
+///
+/// Returns an error if `/proc/meminfo` cannot be read.
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
+pub fn get_memory_usage() -> Result<String, io::Error> {
+  #[cfg_attr(feature = "hotpath", hotpath::measure)]
+  fn parse_memory_info() -> Result<(f64, f64), io::Error> {
+    let mut total_memory_kb = 0u64;
+    let mut available_memory_kb = 0u64;
+    let mut buffer = [0u8; 1024];
+
+    // Use fast syscall-based file reading
+    let bytes_read = read_file_fast("/proc/meminfo", &mut buffer)?;
+    let meminfo = &buffer[..bytes_read];
+
+    // Fast scanning for MemTotal and MemAvailable
+    let mut offset = 0;
+    let mut found_total = false;
+    let mut found_available = false;
+
+    while offset < meminfo.len() && (!found_total || !found_available) {
+      let remaining = &meminfo[offset..];
+
+      // Find newline or end
+      let line_end = remaining
+        .iter()
+        .position(|&b| b == b'\n')
+        .unwrap_or(remaining.len());
+      let line = &remaining[..line_end];
+
+      if line.starts_with(b"MemTotal:") {
+        // Skip "MemTotal:" and whitespace
+        let mut pos = 9;
+        while pos < line.len() && line[pos].is_ascii_whitespace() {
+          pos += 1;
+        }
+        total_memory_kb = parse_u64_fast(&line[pos..]);
+        found_total = true;
+      } else if line.starts_with(b"MemAvailable:") {
+        // Skip "MemAvailable:" and whitespace
+        let mut pos = 13;
+        while pos < line.len() && line[pos].is_ascii_whitespace() {
+          pos += 1;
+        }
+        available_memory_kb = parse_u64_fast(&line[pos..]);
+        found_available = true;
+      }
+
+      offset += line_end + 1;
+    }
+
+    #[allow(clippy::cast_precision_loss)]
+    let total_memory_gb = total_memory_kb as f64 / 1024.0 / 1024.0;
+    #[allow(clippy::cast_precision_loss)]
+    let available_memory_gb = available_memory_kb as f64 / 1024.0 / 1024.0;
+    let used_memory_gb = total_memory_gb - available_memory_gb;
+
+    Ok((used_memory_gb, total_memory_gb))
+  }
+
+  let (used_memory, total_memory) = parse_memory_info()?;
+  #[allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)]
+  let percentage_used = (used_memory / total_memory * 100.0).round() as u64;
+
+  let mut result = String::with_capacity(64);
+  write!(
+    result,
+    "{used_memory:.2} GiB / {total_memory:.2} GiB \
+     ({cyan}{percentage_used}%{reset})",
+    cyan = COLORS.cyan,
+    reset = COLORS.reset,
+  )
+  .unwrap();
+
+  Ok(result)
 }

src/uptime.rs

@@ -1,26 +1,114 @@
-use color_eyre::Result;
-use nix::sys::sysinfo::sysinfo;
-use std::io;
+use std::{io, mem::MaybeUninit};
 
-pub fn get_current() -> Result<String, io::Error> {
-    let info = sysinfo().map_err(|e| io::Error::new(io::ErrorKind::Other, e))?;
-    let uptime_seconds = info.uptime().as_secs_f64();
+/// Faster integer to string conversion without the formatting overhead.
+#[inline]
+fn itoa(mut n: u64, buf: &mut [u8]) -> &str {
+  if n == 0 {
+    return "0";
+  }
 
-    let total_minutes = (uptime_seconds / 60.0).round() as u64;
-    let days = total_minutes / (60 * 24);
-    let hours = (total_minutes % (60 * 24)) / 60;
-    let minutes = total_minutes % 60;
+  let mut i = buf.len();
+  while n > 0 {
+    i -= 1;
+    buf[i] = b'0' + (n % 10) as u8;
+    n /= 10;
+  }
 
-    let mut parts = Vec::with_capacity(3);
-    if days > 0 {
-        parts.push(format!("{days} days"));
-    }
-    if hours > 0 || days > 0 {
-        parts.push(format!("{hours} hours"));
-    }
-    if minutes > 0 || hours > 0 || days > 0 {
-        parts.push(format!("{minutes} minutes"));
-    }
-
-    Ok(parts.join(", "))
+  unsafe { std::str::from_utf8_unchecked(&buf[i..]) }
+}
+
+/// Direct `sysinfo` syscall using inline assembly
+///
+/// # Safety
+///
+/// This function uses inline assembly to make a direct syscall.
+/// The caller must ensure the sysinfo pointer is valid.
+#[inline]
+unsafe fn sys_sysinfo(info: *mut libc::sysinfo) -> i64 {
+  #[cfg(target_arch = "x86_64")]
+  {
+    let ret: i64;
+    unsafe {
+      std::arch::asm!(
+        "syscall",
+        in("rax") 99_i64, // __NR_sysinfo
+        in("rdi") info,
+        out("rcx") _,
+        out("r11") _,
+        lateout("rax") ret,
+        options(nostack)
+      );
+    }
+    ret
+  }
+
+  #[cfg(target_arch = "aarch64")]
+  {
+    let ret: i64;
+    unsafe {
+      std::arch::asm!(
+        "svc #0",
+        in("x8") 179_i64, // __NR_sysinfo
+        in("x0") info,
+        lateout("x0") ret,
+        options(nostack)
+      );
+    }
+    ret
+  }
+
+  #[cfg(not(any(target_arch = "x86_64", target_arch = "aarch64")))]
+  {
+    unsafe { libc::sysinfo(info) as i64 }
+  }
+}
+
+/// Gets the current system uptime.
+///
+/// # Errors
+///
+/// Returns an error if the system uptime cannot be retrieved.
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
+pub fn get_current() -> Result<String, io::Error> {
+  let uptime_seconds = {
+    let mut info = MaybeUninit::uninit();
+    if unsafe { sys_sysinfo(info.as_mut_ptr()) } != 0 {
+      return Err(io::Error::last_os_error());
+    }
+    #[allow(clippy::cast_sign_loss)]
+    unsafe {
+      info.assume_init().uptime as u64
+    }
+  };
+
+  let days = uptime_seconds / 86400;
+  let hours = (uptime_seconds / 3600) % 24;
+  let minutes = (uptime_seconds / 60) % 60;
+
+  let mut result = String::with_capacity(32);
+  let mut buf = [0u8; 20]; // Enough for u64::MAX
+
+  if days > 0 {
+    result.push_str(itoa(days, &mut buf));
+    result.push_str(if days == 1 { " day" } else { " days" });
+  }
+  if hours > 0 {
+    if !result.is_empty() {
+      result.push_str(", ");
+    }
+    result.push_str(itoa(hours, &mut buf));
+    result.push_str(if hours == 1 { " hour" } else { " hours" });
+  }
+  if minutes > 0 {
+    if !result.is_empty() {
+      result.push_str(", ");
+    }
+    result.push_str(itoa(minutes, &mut buf));
+    result.push_str(if minutes == 1 { " minute" } else { " minutes" });
+  }
+  if result.is_empty() {
+    result.push_str("less than a minute");
+  }
+
+  Ok(result)
 }