push almost all of colors back to compile time using macros

benches/benchmark.rs

@@ -1,8 +1,8 @@
 use criterion::{Criterion, criterion_group, criterion_main};
 use microfetch_lib::{
   UtsName,
-  colors::print_dots,
   desktop::get_desktop_info,
+  dots::print_dots,
   release::{get_os_pretty_name, get_system_info},
   system::{
     get_memory_usage,

src/colors.rs

@@ -1,5 +1,22 @@
 use std::sync::LazyLock;
 
+// All this because concat!() doesn't accept const parameters
+// See https://github.com/rust-lang/rust/issues/31383
+#[macro_export]
+macro_rules! RESET    {() => {"\x1b[0m"}}
+#[macro_export]
+macro_rules! BLUE     {() => {"\x1b[34m"}}
+#[macro_export]
+macro_rules! CYAN     {() => {"\x1b[34m"}}
+#[macro_export]
+macro_rules! GREEN    {() => {"\x1b[32m"}}
+#[macro_export]
+macro_rules! YELLOW   {() => {"\x1b[33m"}}
+#[macro_export]
+macro_rules! RED      {() => {"\x1b[31m"}}
+#[macro_export]
+macro_rules! MAGENTA  {() => {"\x1b[35m"}}
+
 pub struct Colors {
   pub reset:   &'static str,
   pub blue:    &'static str,
@@ -7,7 +24,6 @@ pub struct Colors {
   pub green:   &'static str,
   pub yellow:  &'static str,
   pub red:     &'static str,
-  pub magenta: &'static str,
 }
 
 impl Colors {
@@ -20,62 +36,26 @@ impl Colors {
         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",
+        reset:   RESET!(),
+        blue:    BLUE!(),
+        cyan:    CYAN!(),
+        green:   GREEN!(),
+        yellow:  YELLOW!(),
+        red:     RED!(),
       }
     }
   }
 }
 
-pub static COLORS: LazyLock<Colors> = LazyLock::new(|| {
+pub static IS_NO_COLOR: LazyLock<bool> = LazyLock::new(|| {
+  // Check for NO_COLOR once at startup
   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)
+  unsafe { !libc::getenv(NO_COLOR).is_null() }
 });
 
-#[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
-}
+pub static COLORS: LazyLock<Colors> = LazyLock::new(|| {
+  Colors::new(*IS_NO_COLOR)
+});

src/dots.rs

@@ -0,0 +1,33 @@
+use crate::{colors::IS_NO_COLOR, BLUE, CYAN, GREEN, MAGENTA, RED, RESET, YELLOW};
+
+macro_rules! GLYPH  {() => {""}}
+
+macro_rules! GAP    {() => {"  "}}
+
+const NO_COLORS_STR: &str = concat!(
+    GLYPH!(), GAP!(),
+    GLYPH!(), GAP!(),
+    GLYPH!(), GAP!(),
+    GLYPH!(), GAP!(),
+    GLYPH!(), GAP!(),
+    GLYPH!(),
+);
+
+const COLORS_STR: &str = concat!(
+    BLUE!(),    GLYPH!(), GAP!(),
+    CYAN!(),    GLYPH!(), GAP!(),
+    GREEN!(),   GLYPH!(), GAP!(),
+    YELLOW!(),  GLYPH!(), GAP!(),
+    RED!(),     GLYPH!(), GAP!(),
+    MAGENTA!(), GLYPH!(), RESET!(),
+);
+
+#[must_use]
+#[cfg_attr(feature = "hotpath", hotpath::measure)]
+pub fn print_dots() -> &'static str {
+  if *IS_NO_COLOR {
+    NO_COLORS_STR
+  } else {
+    COLORS_STR
+  }
+}

src/lib.rs

@@ -1,5 +1,6 @@
 pub mod colors;
 pub mod desktop;
+pub mod dots;
 pub mod release;
 pub mod syscall;
 pub mod system;

src/main.rs

@@ -1,5 +1,6 @@
 mod colors;
 mod desktop;
+mod dots;
 mod release;
 mod syscall;
 mod system;
@@ -10,8 +11,8 @@ use std::io::{self, Cursor, Write};
 pub use microfetch_lib::UtsName;
 
 use crate::{
-  colors::print_dots,
   desktop::get_desktop_info,
+  dots::print_dots,
   release::{get_os_pretty_name, get_system_info},
   system::{
     get_memory_usage,
@@ -37,7 +38,7 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
       uptime:         get_current()?,
       memory_usage:   get_memory_usage()?,
       storage:        get_root_disk_usage()?,
-      colors:         print_dots(),
+      dots:         print_dots(),
     };
     print_system_info(&fields)?;
   }
@@ -57,7 +58,7 @@ struct Fields {
   desktop:        String,
   memory_usage:   String,
   storage:        String,
-  colors:         String,
+  dots:           &'static str,
 }
 
 #[cfg_attr(feature = "hotpath", hotpath::measure)]
@@ -75,7 +76,7 @@ fn print_system_info(
     desktop,
     memory_usage,
     storage,
-    colors,
+    dots,
   } = fields;
 
   let cyan = COLORS.cyan;
@@ -96,7 +97,7 @@ fn print_system_info(
     {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"
+    {cyan}     ▟█▘ ▜█▖    {blue}▝█▛         {cyan}  {blue}Colors{reset}        {dots}\n\n"
   )?;
 
   let len = cursor.position() as usize;