From 2cc6b47fcf9c2768bb08e8b45208e2ecc132c18d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luka=20Zakraj=C5=A1ek?= <luka@bancek.net>
Date: Tue, 16 Feb 2021 19:48:16 +0100
Subject: [PATCH] Use http-range library for HttpRange (#2003)

---
 actix-files/Cargo.toml   |  1 +
 actix-files/src/range.rs | 87 +++++-----------------------------------
 2 files changed, 10 insertions(+), 78 deletions(-)

diff --git a/actix-files/Cargo.toml b/actix-files/Cargo.toml
index 45fa18a69..08b7b36fc 100644
--- a/actix-files/Cargo.toml
+++ b/actix-files/Cargo.toml
@@ -25,6 +25,7 @@ bitflags = "1"
 bytes = "1"
 futures-core = { version = "0.3.7", default-features = false }
 futures-util = { version = "0.3.7", default-features = false }
+http-range = "0.1.4"
 derive_more = "0.99.5"
 log = "0.4"
 mime = "0.3"
diff --git a/actix-files/src/range.rs b/actix-files/src/range.rs
index 6718980cb..8d9fe9445 100644
--- a/actix-files/src/range.rs
+++ b/actix-files/src/range.rs
@@ -10,9 +10,6 @@ pub struct HttpRange {
     pub length: u64,
 }
 
-const PREFIX: &str = "bytes=";
-const PREFIX_LEN: usize = 6;
-
 #[derive(Debug, Clone, Display, Error)]
 #[display(fmt = "Parse HTTP Range failed")]
 pub struct ParseRangeErr(#[error(not(source))] ());
@@ -23,82 +20,16 @@ impl HttpRange {
     /// `header` is HTTP Range header (e.g. `bytes=bytes=0-9`).
     /// `size` is full size of response (file).
     pub fn parse(header: &str, size: u64) -> Result<Vec<HttpRange>, ParseRangeErr> {
-        if header.is_empty() {
-            return Ok(Vec::new());
+        match http_range::HttpRange::parse(header, size) {
+            Ok(ranges) => Ok(ranges
+                .iter()
+                .map(|range| HttpRange {
+                    start: range.start,
+                    length: range.length,
+                })
+                .collect()),
+            Err(_) => Err(ParseRangeErr(())),
         }
-        if !header.starts_with(PREFIX) {
-            return Err(ParseRangeErr(()));
-        }
-
-        let size_sig = size as i64;
-        let mut no_overlap = false;
-
-        let all_ranges: Vec<Option<HttpRange>> = header[PREFIX_LEN..]
-            .split(',')
-            .map(|x| x.trim())
-            .filter(|x| !x.is_empty())
-            .map(|ra| {
-                let mut start_end_iter = ra.split('-');
-
-                let start_str = start_end_iter.next().ok_or(ParseRangeErr(()))?.trim();
-                let end_str = start_end_iter.next().ok_or(ParseRangeErr(()))?.trim();
-
-                if start_str.is_empty() {
-                    // If no start is specified, end specifies the
-                    // range start relative to the end of the file.
-                    let mut length: i64 = end_str.parse().map_err(|_| ParseRangeErr(()))?;
-
-                    if length > size_sig {
-                        length = size_sig;
-                    }
-
-                    Ok(Some(HttpRange {
-                        start: (size_sig - length) as u64,
-                        length: length as u64,
-                    }))
-                } else {
-                    let start: i64 = start_str.parse().map_err(|_| ParseRangeErr(()))?;
-
-                    if start < 0 {
-                        return Err(ParseRangeErr(()));
-                    }
-                    if start >= size_sig {
-                        no_overlap = true;
-                        return Ok(None);
-                    }
-
-                    let length = if end_str.is_empty() {
-                        // If no end is specified, range extends to end of the file.
-                        size_sig - start
-                    } else {
-                        let mut end: i64 = end_str.parse().map_err(|_| ParseRangeErr(()))?;
-
-                        if start > end {
-                            return Err(ParseRangeErr(()));
-                        }
-
-                        if end >= size_sig {
-                            end = size_sig - 1;
-                        }
-
-                        end - start + 1
-                    };
-
-                    Ok(Some(HttpRange {
-                        start: start as u64,
-                        length: length as u64,
-                    }))
-                }
-            })
-            .collect::<Result<_, _>>()?;
-
-        let ranges: Vec<HttpRange> = all_ranges.into_iter().filter_map(|x| x).collect();
-
-        if no_overlap && ranges.is_empty() {
-            return Err(ParseRangeErr(()));
-        }
-
-        Ok(ranges)
     }
 }