Merge pull request askama-rs#216 from GuillaumeGomez/improve-filesizeformat

Relax `filesizeformat` filter requirements

Author: GuillaumeGomez

rinja/Cargo.toml

@@ -21,11 +21,10 @@ rustdoc-args = ["--generate-link-to-definition", "--cfg=docsrs"]
 maintenance = { status = "actively-developed" }
 
 [features]
-default = ["config", "humansize", "urlencode"]
+default = ["config", "urlencode"]
 full = ["default", "code-in-doc", "serde_json"]
 code-in-doc = ["rinja_derive/code-in-doc"]
 config = ["rinja_derive/config"]
-humansize = ["rinja_derive/humansize", "dep:humansize"]
 serde_json = ["rinja_derive/serde_json", "dep:serde", "dep:serde_json"]
 urlencode = ["rinja_derive/urlencode", "dep:percent-encoding"]
 
@@ -39,7 +38,6 @@ with-warp = ["rinja_derive/with-warp"]
 [dependencies]
 rinja_derive = { version = "=0.3.5", path = "../rinja_derive" }
 
-humansize = { version = "2", optional = true }
 num-traits = { version = "0.2.6", optional = true }
 percent-encoding = { version = "2.1.0", optional = true }
 serde = { version = "1.0", optional = true }

rinja/src/filters/humansize.rs

@@ -1,7 +1,9 @@
 use std::convert::Infallible;
 use std::fmt;
+use std::mem::MaybeUninit;
+use std::str::from_utf8_unchecked;
 
-use humansize::{DECIMAL, ISizeFormatter, ToF64};
+use super::FastWritable;
 
 /// Returns adequate string representation (in KB, ..) of number of bytes
 ///
@@ -21,24 +23,95 @@ use humansize::{DECIMAL, ISizeFormatter, ToF64};
 /// assert_eq!(tmpl.to_string(),  "Filesize: 1.23 MB.");
 /// ```
 #[inline]
-pub fn filesizeformat(b: &impl ToF64) -> Result<FilesizeFormatFilter, Infallible> {
-    Ok(FilesizeFormatFilter(b.to_f64()))
+pub fn filesizeformat(b: f32) -> Result<FilesizeFormatFilter, Infallible> {
+    Ok(FilesizeFormatFilter(b))
 }
 
 #[derive(Debug, Clone, Copy)]
-pub struct FilesizeFormatFilter(f64);
+pub struct FilesizeFormatFilter(f32);
 
 impl fmt::Display for FilesizeFormatFilter {
+    #[inline]
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.write_fmt(format_args!("{}", ISizeFormatter::new(self.0, &DECIMAL)))
+        self.write_into(f)
     }
 }
 
+impl FastWritable for FilesizeFormatFilter {
+    fn write_into<W: fmt::Write + ?Sized>(&self, dest: &mut W) -> fmt::Result {
+        if self.0 < 1e3 {
+            (self.0 as u32).write_into(dest)?;
+            dest.write_str(" B")
+        } else if let Some((prefix, factor)) = SI_PREFIXES
+            .iter()
+            .copied()
+            .find_map(|(prefix_factor, max)| (self.0 < max).then_some(prefix_factor))
+        {
+            // u32 is big enough to hold the number 999_999
+            let scaled = (self.0 * factor) as u32;
+            (scaled / 100).write_into(dest)?;
+            dest.write_str(format_frac(&mut MaybeUninit::uninit(), prefix, scaled))
+        } else {
+            too_big(self.0, dest)
+        }
+    }
+}
+
+/// Formats `buffer` to contain the decimal point, decimal places and unit
+fn format_frac(buffer: &mut MaybeUninit<[u8; 8]>, prefix: u8, scaled: u32) -> &str {
+    // LLVM generates better byte code for register sized buffers, so we add some NULs
+    let buffer = buffer.write(*b"..0 kB\0\0");
+    buffer[4] = prefix;
+
+    let frac = scaled % 100;
+    let buffer = if frac == 0 {
+        &buffer[3..6]
+    } else if frac % 10 == 0 {
+        // the decimal separator '.' is already contained in buffer[1]
+        buffer[2] = b'0' + (frac / 10) as u8;
+        &buffer[1..6]
+    } else {
+        // the decimal separator '.' is already contained in buffer[0]
+        buffer[1] = b'0' + (frac / 10) as u8;
+        buffer[2] = b'0' + (frac % 10) as u8;
+        &buffer[0..6]
+    };
+    // SAFETY: we know that the buffer contains only ASCII data
+    unsafe { from_utf8_unchecked(buffer) }
+}
+
+#[cold]
+fn too_big<W: fmt::Write + ?Sized>(value: f32, dest: &mut W) -> fmt::Result {
+    // the value exceeds 999 QB, so we omit the decimal places
+    write!(dest, "{:.0} QB", value / 1e30)
+}
+
+/// `((si_prefix, factor), limit)`, the factor is offset by 10**2 to account for 2 decimal places
+const SI_PREFIXES: &[((u8, f32), f32)] = &[
+    ((b'k', 1e-1), 1e6),
+    ((b'M', 1e-4), 1e9),
+    ((b'G', 1e-7), 1e12),
+    ((b'T', 1e-10), 1e15),
+    ((b'P', 1e-13), 1e18),
+    ((b'E', 1e-16), 1e21),
+    ((b'Z', 1e-19), 1e24),
+    ((b'Y', 1e-22), 1e27),
+    ((b'R', 1e-25), 1e30),
+    ((b'Q', 1e-28), 1e33),
+];
+
 #[test]
+#[allow(clippy::needless_borrows_for_generic_args)]
 fn test_filesizeformat() {
-    assert_eq!(filesizeformat(&0).unwrap().to_string(), "0 B");
-    assert_eq!(filesizeformat(&999u64).unwrap().to_string(), "999 B");
-    assert_eq!(filesizeformat(&1000i32).unwrap().to_string(), "1 kB");
-    assert_eq!(filesizeformat(&1023).unwrap().to_string(), "1.02 kB");
-    assert_eq!(filesizeformat(&1024usize).unwrap().to_string(), "1.02 kB");
+    assert_eq!(filesizeformat(0.).unwrap().to_string(), "0 B");
+    assert_eq!(filesizeformat(999.).unwrap().to_string(), "999 B");
+    assert_eq!(filesizeformat(1000.).unwrap().to_string(), "1 kB");
+    assert_eq!(filesizeformat(1023.).unwrap().to_string(), "1.02 kB");
+    assert_eq!(filesizeformat(1024.).unwrap().to_string(), "1.02 kB");
+    assert_eq!(filesizeformat(1100.).unwrap().to_string(), "1.1 kB");
+    assert_eq!(filesizeformat(9_499_014.).unwrap().to_string(), "9.49 MB");
+    assert_eq!(
+        filesizeformat(954_548_589.2).unwrap().to_string(),
+        "954.54 MB"
+    );
 }

rinja/src/filters/mod.rs

@@ -12,7 +12,6 @@
 
 mod builtin;
 mod escape;
-#[cfg(feature = "humansize")]
 mod humansize;
 #[cfg(feature = "serde_json")]
 mod json;
@@ -27,7 +26,6 @@ pub use self::escape::{
     AutoEscape, AutoEscaper, Escaper, FastWritable, Html, HtmlSafe, HtmlSafeOutput, MaybeSafe,
     Safe, Text, Unsafe, Writable, WriteWritable, e, escape, safe,
 };
-#[cfg(feature = "humansize")]
 pub use self::humansize::filesizeformat;
 #[cfg(feature = "serde_json")]
 pub use self::json::{AsIndent, json, json_pretty};

rinja/src/lib.rs

@@ -72,6 +72,7 @@ pub use rinja_derive::Template;
 #[doc(hidden)]
 pub use crate as shared;
 pub use crate::error::{Error, Result};
+pub use crate::helpers::PrimitiveType;
 
 /// Main `Template` trait; implementations are generally derived
 ///

rinja_actix/Cargo.toml

@@ -24,7 +24,6 @@ default = ["rinja/default"]
 full = ["rinja/full"]
 code-in-doc = ["rinja/code-in-doc"]
 config = ["rinja/config"]
-humansize = ["rinja/humansize"]
 serde_json = ["rinja/serde_json"]
 urlencode = ["rinja/urlencode"]
 

rinja_axum/Cargo.toml

@@ -24,7 +24,6 @@ default = ["rinja/default"]
 full = ["rinja/full"]
 code-in-doc = ["rinja/code-in-doc"]
 config = ["rinja/config"]
-humansize = ["rinja/humansize"]
 serde_json = ["rinja/serde_json"]
 urlencode = ["rinja/urlencode"]
 

rinja_derive/Cargo.toml

@@ -20,7 +20,6 @@ proc-macro = true
 [features]
 code-in-doc = ["dep:pulldown-cmark"]
 config = ["dep:serde", "dep:basic-toml", "parser/config"]
-humansize = []
 urlencode = []
 serde_json = []
 with-actix-web = []

rinja_derive/src/generator.rs

@@ -1657,21 +1657,15 @@ impl<'a> Generator<'a> {
         buf: &mut Buffer,
         name: &str,
         args: &[WithSpan<'_, Expr<'_>>],
-        node: &WithSpan<'_, T>,
+        _node: &WithSpan<'_, T>,
     ) -> Result<DisplayWrap, CompileError> {
-        if cfg!(not(feature = "humansize")) {
-            return Err(ctx.generate_error(
-                &format!("the `{name}` filter requires the `humansize` feature to be enabled"),
-                node,
-            ));
-        }
-
         // All filters return numbers, and any default formatted number is HTML safe.
         buf.write(format_args!(
-            "rinja::filters::HtmlSafeOutput(rinja::filters::{name}(",
+            "rinja::filters::HtmlSafeOutput(rinja::filters::{name}(\
+                 rinja::helpers::get_primitive_value(&("
         ));
         self._visit_args(ctx, buf, args)?;
-        buf.write(")?)");
+        buf.write(")) as rinja::helpers::core::primitive::f32)?)");
         Ok(DisplayWrap::Unwrapped)
     }
 

rinja_derive_standalone/Cargo.toml

@@ -23,7 +23,6 @@ __standalone = []
 
 code-in-doc = ["dep:pulldown-cmark"]
 config = ["dep:serde", "dep:basic-toml", "parser/config"]
-humansize = []
 urlencode = []
 serde_json = []
 with-actix-web = []

rinja_rocket/Cargo.toml

@@ -24,7 +24,6 @@ default = ["rinja/default"]
 full = ["rinja/full"]
 code-in-doc = ["rinja/code-in-doc"]
 config = ["rinja/config"]
-humansize = ["rinja/humansize"]
 serde_json = ["rinja/serde_json"]
 urlencode = ["rinja/urlencode"]