Allow StatusCode to support 600-999 range

dekellum · quininer · web-flow · commit be05ed241882 · 2020-12-08T12:26:09.000-08:00
Additionally, reduces the size of the static memory included, and reduces some of the complicated macro usage resulting in faster compiles!

Co-authored-by: quininer &lt;quininer@live.com&gt;
Co-authored-by: David Kellum &lt;dek-oss@gravitext.com&gt;
diff --git a/src/status.rs b/src/status.rs
@@ -15,19 +15,22 @@
 //! ```
 
 use std::convert::TryFrom;
+use std::num::NonZeroU16;
 use std::error::Error;
 use std::fmt;
 use std::str::FromStr;
 
 /// An HTTP status code (`status-code` in RFC 7230 et al.).
 ///
-/// This type contains constants for all common status codes.
-/// It allows status codes in the range [100, 599].
+/// Constants are provided for known status codes, including those in the IANA
+/// [HTTP Status Code Registry](
+/// https://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml).
 ///
-/// IANA maintain the [Hypertext Transfer Protocol (HTTP) Status Code
-/// Registry](http://www.iana.org/assignments/http-status-codes/http-status-codes.xhtml) which is
-/// the source for this enum (with one exception, 418 I'm a teapot, which is
-/// inexplicably not in the register).
+/// Status code values in the range 100-999 (inclusive) are supported by this
+/// type. Values in the range 100-599 are semantically classified by the most
+/// significant digit. See [`StatusCode::is_success`], etc. Values above 599
+/// are unclassified but allowed for legacy compatibility, though their use is
+/// discouraged. Applications may interpret such values as protocol errors.
 ///
 /// # Examples
 ///
@@ -39,12 +42,12 @@ use std::str::FromStr;
 /// assert!(StatusCode::OK.is_success());
 /// ```
 #[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
-pub struct StatusCode(u16);
+pub struct StatusCode(NonZeroU16);
 
 /// A possible error value when converting a `StatusCode` from a `u16` or `&str`
 ///
 /// This error indicates that the supplied input was not a valid number, was less
-/// than 100, or was greater than 599.
+/// than 100, or was greater than 999.
 pub struct InvalidStatusCode {
     _priv: (),
 }
@@ -53,7 +56,7 @@ impl StatusCode {
     /// Converts a u16 to a status code.
     ///
     /// The function validates the correctness of the supplied u16. It must be
-    /// greater or equal to 100 but less than 600.
+    /// greater or equal to 100 and less than 1000.
     ///
     /// # Example
     ///
@@ -68,11 +71,13 @@ impl StatusCode {
     /// ```
     #[inline]
     pub fn from_u16(src: u16) -> Result<StatusCode, InvalidStatusCode> {
-        if src < 100 || src >= 600 {
+        if src < 100 || src >= 1000 {
             return Err(InvalidStatusCode::new());
         }
 
-        Ok(StatusCode(src))
+        NonZeroU16::new(src)
+            .map(StatusCode)
+            .ok_or_else(InvalidStatusCode::new)
     }
 
     /// Converts a &[u8] to a status code
@@ -85,12 +90,14 @@ impl StatusCode {
         let b = src[1].wrapping_sub(b'0') as u16;
         let c = src[2].wrapping_sub(b'0') as u16;
 
-        if a == 0 || a > 5 || b > 9 || c > 9 {
+        if a == 0 || a > 9 || b > 9 || c > 9 {
             return Err(InvalidStatusCode::new());
         }
 
         let status = (a * 100) + (b * 10) + c;
-        Ok(StatusCode(status))
+        NonZeroU16::new(status)
+            .map(StatusCode)
+            .ok_or_else(InvalidStatusCode::new)
     }
 
     /// Returns the `u16` corresponding to this `StatusCode`.
@@ -126,7 +133,17 @@ impl StatusCode {
     /// ```
     #[inline]
     pub fn as_str(&self) -> &str {
-        CODES_AS_STR[(self.0 - 100) as usize]
+        let offset = (self.0.get() - 100) as usize;
+        let offset = offset * 3;
+
+        // Invariant: self has checked range [100, 999] and CODE_DIGITS is
+        // ASCII-only, of length 900 * 3 = 2700 bytes
+
+        #[cfg(debug_assertions)]
+        { &CODE_DIGITS[offset..offset+3] }
+
+        #[cfg(not(debug_assertions))]
+        unsafe { CODE_DIGITS.get_unchecked(offset..offset+3) }
     }
 
     /// Get the standardised `reason-phrase` for this status code.
@@ -148,37 +165,37 @@ impl StatusCode {
     /// assert_eq!(status.canonical_reason(), Some("OK"));
     /// ```
     pub fn canonical_reason(&self) -> Option<&'static str> {
-        canonical_reason(self.0)
+        canonical_reason(self.0.get())
     }
 
     /// Check if status is within 100-199.
     #[inline]
     pub fn is_informational(&self) -> bool {
-        200 > self.0 && self.0 >= 100
+        200 > self.0.get() && self.0.get() >= 100
     }
 
     /// Check if status is within 200-299.
     #[inline]
     pub fn is_success(&self) -> bool {
-        300 > self.0 && self.0 >= 200
+        300 > self.0.get() && self.0.get() >= 200
     }
 
     /// Check if status is within 300-399.
     #[inline]
     pub fn is_redirection(&self) -> bool {
-        400 > self.0 && self.0 >= 300
+        400 > self.0.get() && self.0.get() >= 300
     }
 
     /// Check if status is within 400-499.
     #[inline]
     pub fn is_client_error(&self) -> bool {
-        500 > self.0 && self.0 >= 400
+        500 > self.0.get() && self.0.get() >= 400
     }
 
     /// Check if status is within 500-599.
     #[inline]
     pub fn is_server_error(&self) -> bool {
-        600 > self.0 && self.0 >= 500
+        600 > self.0.get() && self.0.get() >= 500
     }
 }
 
@@ -231,7 +248,7 @@ impl PartialEq<StatusCode> for u16 {
 impl From<StatusCode> for u16 {
     #[inline]
     fn from(status: StatusCode) -> u16 {
-        status.0
+        status.0.get()
     }
 }
 
@@ -287,7 +304,7 @@ macro_rules! status_codes {
         impl StatusCode {
         $(
             $(#[$docs])*
-            pub const $konst: StatusCode = StatusCode($num);
+            pub const $konst: StatusCode = StatusCode(unsafe { NonZeroU16::new_unchecked($num) });
         )+
 
         }
@@ -521,40 +538,51 @@ impl fmt::Display for InvalidStatusCode {
 
 impl Error for InvalidStatusCode {}
 
-macro_rules! status_code_strs {
-    ($($num:expr,)+) => {
-        const CODES_AS_STR: [&'static str; 500] = [ $( stringify!($num), )+ ];
-    }
-}
-
-status_code_strs!(
-    100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,
-    120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139,
-    140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
-    160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179,
-    180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199,
-
-    200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,
-    220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
-    240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259,
-    260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279,
-    280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299,
-
-    300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319,
-    320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339,
-    340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359,
-    360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378, 379,
-    380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, 398, 399,
-
-    400, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419,
-    420, 421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434, 435, 436, 437, 438, 439,
-    440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459,
-    460, 461, 462, 463, 464, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476, 477, 478, 479,
-    480, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499,
-
-    500, 501, 502, 503, 504, 505, 506, 507, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519,
-    520, 521, 522, 523, 524, 525, 526, 527, 528, 529, 530, 531, 532, 533, 534, 535, 536, 537, 538, 539,
-    540, 541, 542, 543, 544, 545, 546, 547, 548, 549, 550, 551, 552, 553, 554, 555, 556, 557, 558, 559,
-    560, 561, 562, 563, 564, 565, 566, 567, 568, 569, 570, 571, 572, 573, 574, 575, 576, 577, 578, 579,
-    580, 581, 582, 583, 584, 585, 586, 587, 588, 589, 590, 591, 592, 593, 594, 595, 596, 597, 598, 599,
-    );
+// A string of packed 3-ASCII-digit status code values for the supported range
+// of [100, 999] (900 codes, 2700 bytes).
+const CODE_DIGITS: &'static str = "\
+100101102103104105106107108109110111112113114115116117118119\
+120121122123124125126127128129130131132133134135136137138139\
+140141142143144145146147148149150151152153154155156157158159\
+160161162163164165166167168169170171172173174175176177178179\
+180181182183184185186187188189190191192193194195196197198199\
+200201202203204205206207208209210211212213214215216217218219\
+220221222223224225226227228229230231232233234235236237238239\
+240241242243244245246247248249250251252253254255256257258259\
+260261262263264265266267268269270271272273274275276277278279\
+280281282283284285286287288289290291292293294295296297298299\
+300301302303304305306307308309310311312313314315316317318319\
+320321322323324325326327328329330331332333334335336337338339\
+340341342343344345346347348349350351352353354355356357358359\
+360361362363364365366367368369370371372373374375376377378379\
+380381382383384385386387388389390391392393394395396397398399\
+400401402403404405406407408409410411412413414415416417418419\
+420421422423424425426427428429430431432433434435436437438439\
+440441442443444445446447448449450451452453454455456457458459\
+460461462463464465466467468469470471472473474475476477478479\
+480481482483484485486487488489490491492493494495496497498499\
+500501502503504505506507508509510511512513514515516517518519\
+520521522523524525526527528529530531532533534535536537538539\
+540541542543544545546547548549550551552553554555556557558559\
+560561562563564565566567568569570571572573574575576577578579\
+580581582583584585586587588589590591592593594595596597598599\
+600601602603604605606607608609610611612613614615616617618619\
+620621622623624625626627628629630631632633634635636637638639\
+640641642643644645646647648649650651652653654655656657658659\
+660661662663664665666667668669670671672673674675676677678679\
+680681682683684685686687688689690691692693694695696697698699\
+700701702703704705706707708709710711712713714715716717718719\
+720721722723724725726727728729730731732733734735736737738739\
+740741742743744745746747748749750751752753754755756757758759\
+760761762763764765766767768769770771772773774775776777778779\
+780781782783784785786787788789790791792793794795796797798799\
+800801802803804805806807808809810811812813814815816817818819\
+820821822823824825826827828829830831832833834835836837838839\
+840841842843844845846847848849850851852853854855856857858859\
+860861862863864865866867868869870871872873874875876877878879\
+880881882883884885886887888889890891892893894895896897898899\
+900901902903904905906907908909910911912913914915916917918919\
+920921922923924925926927928929930931932933934935936937938939\
+940941942943944945946947948949950951952953954955956957958959\
+960961962963964965966967968969970971972973974975976977978979\
+980981982983984985986987988989990991992993994995996997998999";
diff --git a/tests/status_code.rs b/tests/status_code.rs
@@ -3,13 +3,13 @@ use http::*;
 #[test]
 fn from_bytes() {
     for ok in &[
-        "100", "101", "199", "200", "250", "299", "321", "399", "499", "599",
+        "100", "101", "199", "200", "250", "299", "321", "399", "499", "599", "600", "999"
     ] {
         assert!(StatusCode::from_bytes(ok.as_bytes()).is_ok());
     }
 
     for not_ok in &[
-        "0", "00", "10", "40", "99", "000", "010", "099", "600", "610", "999",
+        "0", "00", "10", "40", "99", "000", "010", "099", "1000", "1999",
     ] {
         assert!(StatusCode::from_bytes(not_ok.as_bytes()).is_err());
     }
@@ -22,48 +22,12 @@ fn equates_with_u16() {
     assert_eq!(status, 200u16);
 }
 
-macro_rules! test_round_trip {
-    ($($num:expr,)+) => {
-        #[test]
-        fn roundtrip() {
-            $(
-                let status = StatusCode::from_bytes(stringify!($num).as_bytes()).unwrap();
-                let expect = $num;
-
-                assert_eq!(u16::from(status), expect);
-            )+
-        }
+#[test]
+fn roundtrip() {
+    for s in 100..1000 {
+        let sstr = s.to_string();
+        let status = StatusCode::from_bytes(sstr.as_bytes()).unwrap();
+        assert_eq!(s, u16::from(status));
+        assert_eq!(sstr, status.as_str());
     }
 }
-
-test_round_trip!(
-    100, 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, 113, 114, 115, 116, 117, 118, 119,
-    120, 121, 122, 123, 124, 125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139,
-    140, 141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155, 156, 157, 158, 159,
-    160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174, 175, 176, 177, 178, 179,
-    180, 181, 182, 183, 184, 185, 186, 187, 188, 189, 190, 191, 192, 193, 194, 195, 196, 197, 198, 199,
-
-    200, 201, 202, 203, 204, 205, 206, 207, 208, 209, 210, 211, 212, 213, 214, 215, 216, 217, 218, 219,
-    220, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237, 238, 239,
-    240, 241, 242, 243, 244, 245, 246, 247, 248, 249, 250, 251, 252, 253, 254, 255, 256, 257, 258, 259,
-    260, 261, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271, 272, 273, 274, 275, 276, 277, 278, 279,
-    280, 281, 282, 283, 284, 285, 286, 287, 288, 289, 290, 291, 292, 293, 294, 295, 296, 297, 298, 299,
-
-    300, 301, 302, 303, 304, 305, 306, 307, 308, 309, 310, 311, 312, 313, 314, 315, 316, 317, 318, 319,
-    320, 321, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334, 335, 336, 337, 338, 339,
-    340, 341, 342, 343, 344, 345, 346, 347, 348, 349, 350, 351, 352, 353, 354, 355, 356, 357, 358, 359,
-    360, 361, 362, 363, 364, 365, 366, 367, 368, 369, 370, 371, 372, 373, 374, 375, 376, 377, 378, 379,
-    380, 381, 382, 383, 384, 385, 386, 387, 388, 389, 390, 391, 392, 393, 394, 395, 396, 397, 398, 399,
-
-    400, 401, 402, 403, 404, 405, 406, 407, 408, 409, 410, 411, 412, 413, 414, 415, 416, 417, 418, 419,
-    420, 421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432, 433, 434, 435, 436, 437, 438, 439,
-    440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 450, 451, 452, 453, 454, 455, 456, 457, 458, 459,
-    460, 461, 462, 463, 464, 465, 466, 467, 468, 469, 470, 471, 472, 473, 474, 475, 476, 477, 478, 479,
-    480, 481, 482, 483, 484, 485, 486, 487, 488, 489, 490, 491, 492, 493, 494, 495, 496, 497, 498, 499,
-
-    500, 501, 502, 503, 504, 505, 506, 507, 508, 509, 510, 511, 512, 513, 514, 515, 516, 517, 518, 519,
-    520, 521, 522, 523, 524, 525, 526, 527, 528, 529, 530, 531, 532, 533, 534, 535, 536, 537, 538, 539,
-    540, 541, 542, 543, 544, 545, 546, 547, 548, 549, 550, 551, 552, 553, 554, 555, 556, 557, 558, 559,
-    560, 561, 562, 563, 564, 565, 566, 567, 568, 569, 570, 571, 572, 573, 574, 575, 576, 577, 578, 579,
-    580, 581, 582, 583, 584, 585, 586, 587, 588, 589, 590, 591, 592, 593, 594, 595, 596, 597, 598, 599,
-    );
