Add Criterion to measure performance

Author: zbraniecki

Cargo.toml

@@ -24,6 +24,11 @@ serde_yaml = "^0.8"
 serde = { version = "^1.0", features = ["derive"] }
 difference = "^2.0"
 ansi_term = "^0.12"
+criterion = "0.3"
+
+[[bench]]
+name = "simple"
+harness = false
 
 [features]
 default = []

benches/simple.rs

@@ -0,0 +1,71 @@
+#[macro_use]
+extern crate criterion;
+
+use criterion::black_box;
+use criterion::Criterion;
+
+use annotate_snippets::display_list::DisplayList;
+use annotate_snippets::formatter::DisplayListFormatter;
+use annotate_snippets::snippet::{Annotation, AnnotationType, Slice, Snippet, SourceAnnotation};
+
+fn create_snippet() {
+    let snippet = Snippet {
+        slices: vec![Slice {
+            source: r#") -> Option<String> {
+    for ann in annotations {
+        match (ann.range.0, ann.range.1) {
+            (None, None) => continue,
+            (Some(start), Some(end)) if start > end_index => continue,
+            (Some(start), Some(end)) if start >= start_index => {
+                let label = if let Some(ref label) = ann.label {
+                    format!(" {}", label)
+                } else {
+                    String::from("")
+                };
+
+                return Some(format!(
+                    "{}{}{}",
+                    " ".repeat(start - start_index),
+                    "^".repeat(end - start),
+                    label
+                ));
+            }
+            _ => continue,
+        }
+    }"#
+            .to_string(),
+            line_start: 51,
+            origin: Some("src/format.rs".to_string()),
+            fold: false,
+            annotations: vec![
+                SourceAnnotation {
+                    label: "expected `Option<String>` because of return type".to_string(),
+                    annotation_type: AnnotationType::Warning,
+                    range: (5, 19),
+                },
+                SourceAnnotation {
+                    label: "expected enum `std::option::Option`".to_string(),
+                    annotation_type: AnnotationType::Error,
+                    range: (23, 745),
+                },
+            ],
+        }],
+        title: Some(Annotation {
+            label: Some("mismatched types".to_string()),
+            id: Some("E0308".to_string()),
+            annotation_type: AnnotationType::Error,
+        }),
+        footer: vec![],
+    };
+
+    let dl = DisplayList::from(snippet);
+    let dlf = DisplayListFormatter::new(true, false);
+    let _result = dlf.format(&dl);
+}
+
+pub fn criterion_benchmark(c: &mut Criterion) {
+    c.bench_function("format", |b| b.iter(|| black_box(create_snippet())));
+}
+
+criterion_group!(benches, criterion_benchmark);
+criterion_main!(benches);

src/formatter/mod.rs

@@ -10,9 +10,9 @@ use self::style::{Style, StyleClass, Stylesheet};
 use crate::display_list::*;
 use std::cmp;
 
-use crate::stylesheets::no_color::NoColorStylesheet;
 #[cfg(feature = "ansi_term")]
 use crate::stylesheets::color::AnsiTermStylesheet;
+use crate::stylesheets::no_color::NoColorStylesheet;
 
 fn repeat_char(c: char, n: usize) -> String {
     let mut s = String::with_capacity(c.len_utf8());
@@ -93,7 +93,7 @@ impl DisplayListFormatter {
                 } else {
                     cmp::max(lineno.to_string().len(), max)
                 }
-            },
+            }
             _ => max,
         });
         let inline_marks_width = dl.body.iter().fold(0, |max, line| match line {
@@ -303,7 +303,7 @@ impl DisplayListFormatter {
                 inline_marks,
                 line,
             } => {
-                let lineno = if self.anonymized_line_numbers  && lineno.is_some() {
+                let lineno = if self.anonymized_line_numbers && lineno.is_some() {
                     Self::ANONYMIZED_LINE_NUM.to_string()
                 } else {
                     self.format_lineno(*lineno, lineno_width)

tests/fixtures.rs renamed to tests/fixtures_test.rs

@@ -6,12 +6,12 @@ use annotate_snippets::display_list::DisplayList;
 use annotate_snippets::formatter::DisplayListFormatter;
 use annotate_snippets::snippet::Snippet;
 use glob::glob;
+use serde::Deserialize;
 use std::error::Error;
 use std::fs::File;
 use std::io;
 use std::io::prelude::*;
 use std::path::Path;
-use serde::Deserialize;
 
 fn read_file(path: &str) -> Result<String, io::Error> {
     let mut f = File::open(path)?;

tests/snippet/mod.rs

@@ -1,8 +1,6 @@
-use serde::{Serialize, Deserialize, Deserializer};
+use serde::{Deserialize, Deserializer, Serialize};
 
-use annotate_snippets::snippet::{
-    Annotation, AnnotationType, Slice, Snippet, SourceAnnotation,
-};
+use annotate_snippets::snippet::{Annotation, AnnotationType, Slice, Snippet, SourceAnnotation};
 
 #[derive(Deserialize)]
 #[serde(remote = "Snippet")]