Merge pull request #541 from KodrAus/feat/macros-scaffold

Scaffold out a uuid-macros crate that shares the parser

Cargo.toml

@@ -55,6 +55,7 @@ repository = "uuid-rs/uuid"
 default = ["std"]
 guid = ["winapi"]
 std = []
+macros = ["uuid-macros"]
 v1 = ["atomic"]
 v3 = ["md-5"]
 v4 = ["getrandom"]
@@ -87,6 +88,11 @@ default-features = false
 optional = true
 version = "0.9"
 
+# Public: Re-expored
+[dependencies.uuid-macros]
+path = "macros"
+optional = true
+
 # Public: Used in trait impls on `Uuid`
 [dependencies.serde]
 default-features = false
@@ -130,3 +136,8 @@ version = "0.3"
 [target.'cfg(windows)'.dev-dependencies.winapi]
 version = "0.3"
 features = ["combaseapi"]
+
+[workspace]
+members = [
+    "macros"
+]

macros/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "uuid-macros"
+version = "0.0.0"
+edition = "2018"
+
+[lib]
+proc-macro = true
+
+[dependencies]

macros/src/lib.rs

@@ -0,0 +1,17 @@
+use std;
+
+#[path = "../../shared/error.rs"]
+#[allow(dead_code)]
+mod error;
+
+#[path = "../../shared/parser.rs"]
+#[allow(dead_code)]
+mod parser;
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn it_works() {
+        assert_eq!(2 + 2, 4);
+    }
+}

shared/README.md

@@ -0,0 +1,3 @@
+# Shared source
+
+This source is shared between `uuid` and `uuid-macros` to avoid circular dependencies or creating additional dependencies for `uuid`.

shared/error.rs

@@ -0,0 +1,148 @@
+use crate::std::fmt;
+
+/// A general error that can occur when working with UUIDs.
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+pub struct Error(pub(crate) ErrorKind);
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+pub(crate) enum ErrorKind {
+    /// Invalid character in the [`Uuid`] string.
+    ///
+    /// [`Uuid`]: ../struct.Uuid.html
+    InvalidCharacter {
+        /// The expected characters.
+        expected: &'static str,
+        /// The invalid character found.
+        found: char,
+        /// The invalid character position.
+        index: usize,
+        /// Indicates the [`Uuid`] starts with `urn:uuid:`.
+        ///
+        /// This is a special case for [`Urn`] adapter parsing.
+        ///
+        /// [`Uuid`]: ../Uuid.html
+        urn: UrnPrefix,
+    },
+    /// Invalid number of segments in the [`Uuid`] string.
+    ///
+    /// [`Uuid`]: ../struct.Uuid.html
+    InvalidGroupCount {
+        /// The expected number of segments.
+        expected: ExpectedLength,
+        /// The number of segments found.
+        found: usize,
+    },
+    /// Invalid length of a segment in a [`Uuid`] string.
+    ///
+    /// [`Uuid`]: ../struct.Uuid.html
+    InvalidGroupLength {
+        /// The expected length of the segment.
+        expected: ExpectedLength,
+        /// The length of segment found.
+        found: usize,
+        /// The segment with invalid length.
+        group: usize,
+    },
+    /// Invalid length of the [`Uuid`] string.
+    ///
+    /// [`Uuid`]: ../struct.Uuid.html
+    InvalidLength {
+        /// The expected length(s).
+        expected: ExpectedLength,
+        /// The invalid length found.
+        found: usize,
+    },
+}
+
+/// The expected length.
+#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+pub(crate) enum ExpectedLength {
+    /// Expected any one of the given values.
+    Any(&'static [usize]),
+    /// Expected the given value.
+    Exact(usize),
+}
+
+/// Urn prefix value.
+#[derive(Clone, Copy, Debug, Eq, Hash, Ord, PartialEq, PartialOrd)]
+pub(crate) enum UrnPrefix {
+    /// The `urn:uuid:` prefix should optionally provided.
+    Optional,
+}
+
+impl fmt::Display for ExpectedLength {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match *self {
+            ExpectedLength::Any(crits) => write!(f, "one of {:?}", crits),
+            ExpectedLength::Exact(crit) => write!(f, "{}", crit),
+        }
+    }
+}
+
+impl From<ErrorKind> for Error {
+    fn from(kind: ErrorKind) -> Self {
+        Error(kind)
+    }
+}
+
+impl fmt::Display for Error {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "{}: ",
+            match self.0 {
+                ErrorKind::InvalidCharacter { .. } => "invalid character",
+                ErrorKind::InvalidGroupCount { .. } =>
+                    "invalid number of groups",
+                ErrorKind::InvalidGroupLength { .. } => "invalid group length",
+                ErrorKind::InvalidLength { .. } => "invalid length",
+            }
+        )?;
+
+        match self.0 {
+            ErrorKind::InvalidCharacter {
+                expected,
+                found,
+                index,
+                urn,
+            } => {
+                let urn_str = match urn {
+                    UrnPrefix::Optional => {
+                        " an optional prefix of `urn:uuid:` followed by"
+                    }
+                };
+
+                write!(
+                    f,
+                    "expected{} {}, found {} at {}",
+                    urn_str, expected, found, index
+                )
+            }
+            ErrorKind::InvalidGroupCount {
+                ref expected,
+                found,
+            } => write!(f, "expected {}, found {}", expected, found),
+            ErrorKind::InvalidGroupLength {
+                ref expected,
+                found,
+                group,
+            } => write!(
+                f,
+                "expected {}, found {} in group {}",
+                expected, found, group,
+            ),
+            ErrorKind::InvalidLength {
+                ref expected,
+                found,
+            } => write!(f, "expected {}, found {}", expected, found),
+        }
+    }
+}
+
+#[cfg(feature = "std")]
+mod std_support {
+    use super::*;
+    use crate::std::error;
+
+    impl error::Error for Error {}
+}

shared/parser.rs

@@ -0,0 +1,167 @@
+// Copyright 2013-2014 The Rust Project Developers.
+// Copyright 2018 The Uuid Project Developers.
+//
+// See the COPYRIGHT file at the top-level directory of this distribution.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+use crate::{error::*, std::str};
+
+/// Check if the length matches any of the given criteria lengths.
+fn len_matches_any(len: usize, crits: &[usize]) -> bool {
+    for crit in crits {
+        if len == *crit {
+            return true;
+        }
+    }
+
+    false
+}
+
+// Accumulated length of each hyphenated group in hex digits.
+const ACC_GROUP_LENS: [usize; 5] = [8, 12, 16, 20, 32];
+
+// Length of each hyphenated group in hex digits.
+const GROUP_LENS: [usize; 5] = [8, 4, 4, 4, 12];
+
+pub fn parse_str(mut input: &str) -> Result<[u8; 16], Error> {
+    // Ensure length is valid for any of the supported formats
+    let len = input.len();
+
+    if len == 45 && input.starts_with("urn:uuid:") {
+        input = &input[9..];
+    } else if !len_matches_any(
+        len,
+        &[36, 32],
+    ) {
+        return Err(ErrorKind::InvalidLength {
+            expected: ExpectedLength::Any(&[
+                36,
+                32,
+            ]),
+            found: len,
+        }
+        .into());
+    }
+
+    // `digit` counts only hexadecimal digits, `i_char` counts all chars.
+    let mut digit = 0;
+    let mut group = 0;
+    let mut acc = 0;
+    let mut buffer = [0u8; 16];
+
+    for (i_char, chr) in input.bytes().enumerate() {
+        if digit as usize >= 32 && group != 4 {
+            if group == 0 {
+                return Err(ErrorKind::InvalidLength {
+                    expected: ExpectedLength::Any(&[
+                        36,
+                        32,
+                    ]),
+                    found: len,
+                }
+                .into());
+            }
+
+            return Err(ErrorKind::InvalidGroupCount {
+                expected: ExpectedLength::Any(&[1, 5]),
+                found: group + 1,
+            }
+            .into());
+        }
+
+        if digit % 2 == 0 {
+            // First digit of the byte.
+            match chr {
+                // Calculate upper half.
+                b'0'..=b'9' => acc = chr - b'0',
+                b'a'..=b'f' => acc = chr - b'a' + 10,
+                b'A'..=b'F' => acc = chr - b'A' + 10,
+                // Found a group delimiter
+                b'-' => {
+                    if ACC_GROUP_LENS[group] as u8 != digit {
+                        // Calculate how many digits this group consists of
+                        // in the input.
+                        let found = if group > 0 {
+                            digit - ACC_GROUP_LENS[group - 1] as u8
+                        } else {
+                            digit
+                        };
+
+                        return Err(ErrorKind::InvalidGroupLength {
+                            expected: ExpectedLength::Exact(
+                                GROUP_LENS[group],
+                            ),
+                            found: found as usize,
+                            group,
+                        }
+                        .into());
+                    }
+                    // Next group, decrement digit, it is incremented again
+                    // at the bottom.
+                    group += 1;
+                    digit -= 1;
+                }
+                _ => {
+                    return Err(ErrorKind::InvalidCharacter {
+                        expected: "0123456789abcdefABCDEF-",
+                        found: input[i_char..].chars().next().unwrap(),
+                        index: i_char,
+                        urn: UrnPrefix::Optional,
+                    }
+                    .into());
+                }
+            }
+        } else {
+            // Second digit of the byte, shift the upper half.
+            acc *= 16;
+            match chr {
+                b'0'..=b'9' => acc += chr - b'0',
+                b'a'..=b'f' => acc += chr - b'a' + 10,
+                b'A'..=b'F' => acc += chr - b'A' + 10,
+                b'-' => {
+                    // The byte isn't complete yet.
+                    let found = if group > 0 {
+                        digit - ACC_GROUP_LENS[group - 1] as u8
+                    } else {
+                        digit
+                    };
+
+                    return Err(ErrorKind::InvalidGroupLength {
+                        expected: ExpectedLength::Exact(GROUP_LENS[group]),
+                        found: found as usize,
+                        group,
+                    }
+                    .into());
+                }
+                _ => {
+                    return Err(ErrorKind::InvalidCharacter {
+                        expected: "0123456789abcdefABCDEF-",
+                        found: input[i_char..].chars().next().unwrap(),
+                        index: i_char,
+                        urn: UrnPrefix::Optional,
+                    }
+                    .into());
+                }
+            }
+            buffer[(digit / 2) as usize] = acc;
+        }
+        digit += 1;
+    }
+
+    // Now check the last group.
+    if ACC_GROUP_LENS[4] as u8 != digit {
+        return Err(ErrorKind::InvalidGroupLength {
+            expected: ExpectedLength::Exact(GROUP_LENS[4]),
+            found: (digit as usize - ACC_GROUP_LENS[3]),
+            group,
+        }
+        .into());
+    }
+
+    Ok(buffer)
+}