DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289
// Copyright 2013 The Servo 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.

//! Heterogeneous immutable arrays.

pub use core_foundation_sys::array::*;
pub use core_foundation_sys::base::CFIndex;
use core_foundation_sys::base::{CFTypeRef, CFRelease, kCFAllocatorDefault};
use libc::c_void;
use std::mem;
use std::mem::ManuallyDrop;
use std::marker::PhantomData;
use std;
use std::ops::Deref;
use std::fmt::{Debug, Formatter};

use base::{CFIndexConvertible, TCFType, TCFTypeRef, CFRange};

/// A heterogeneous immutable array.
pub struct CFArray<T = *const c_void>(CFArrayRef, PhantomData<T>);

/// A reference to an element inside the array
pub struct ItemRef<'a, T: 'a>(ManuallyDrop<T>, PhantomData<&'a T>);

impl<'a, T> Deref for ItemRef<'a, T> {
    type Target = T;

    fn deref(&self) -> &T {
        &self.0
    }
}

impl<'a, T: Debug> Debug for ItemRef<'a, T> {
    fn fmt(&self, f: &mut Formatter) -> Result<(), std::fmt::Error> {
        self.0.fmt(f)
    }
}

/// A trait describing how to convert from the stored *const c_void to the desired T
pub unsafe trait FromVoid {
    unsafe fn from_void<'a>(x: *const c_void) -> ItemRef<'a, Self> where Self: std::marker::Sized;
}

unsafe impl FromVoid for u32 {
    unsafe fn from_void<'a>(x: *const c_void) -> ItemRef<'a, Self> {
        // Functions like CGFontCopyTableTags treat the void*'s as u32's
        // so we convert by casting directly
        ItemRef(ManuallyDrop::new(x as u32), PhantomData)
    }
}

unsafe impl<T: TCFType> FromVoid for T {
    unsafe fn from_void<'a>(x: *const c_void) -> ItemRef<'a, Self> {
        ItemRef(ManuallyDrop::new(TCFType::wrap_under_create_rule(T::Ref::from_void_ptr(x))), PhantomData)
    }
}

impl<T> Drop for CFArray<T> {
    fn drop(&mut self) {
        unsafe { CFRelease(self.as_CFTypeRef()) }
    }
}

pub struct CFArrayIterator<'a, T: 'a> {
    array: &'a CFArray<T>,
    index: CFIndex,
    len: CFIndex,
}

impl<'a, T: FromVoid> Iterator for CFArrayIterator<'a, T> {
    type Item = ItemRef<'a, T>;

    fn next(&mut self) -> Option<ItemRef<'a, T>> {
        if self.index >= self.len {
            None
        } else {
            let value = unsafe { self.array.get_unchecked(self.index) };
            self.index += 1;
            Some(value)
        }
    }
}

impl<'a, T: FromVoid> ExactSizeIterator for CFArrayIterator<'a, T> {
    fn len(&self) -> usize {
        (self.array.len() - self.index) as usize
    }
}

impl_TCFTypeGeneric!(CFArray, CFArrayRef, CFArrayGetTypeID);
impl_CFTypeDescriptionGeneric!(CFArray);

impl<T> CFArray<T> {
    /// Creates a new `CFArray` with the given elements, which must be `CFType` objects.
    pub fn from_CFTypes(elems: &[T]) -> CFArray<T> where T: TCFType {
        unsafe {
            let elems: Vec<CFTypeRef> = elems.iter().map(|elem| elem.as_CFTypeRef()).collect();
            let array_ref = CFArrayCreate(kCFAllocatorDefault,
                                          mem::transmute(elems.as_ptr()),
                                          elems.len().to_CFIndex(),
                                          &kCFTypeArrayCallBacks);
            TCFType::wrap_under_create_rule(array_ref)
        }
    }

    #[inline]
    pub fn to_untyped(&self) -> CFArray {
        unsafe { CFArray::wrap_under_get_rule(self.0) }
    }

    /// Returns the same array, but with the type reset to void pointers.
    /// Equal to `to_untyped`, but is faster since it does not increment the retain count.
    #[inline]
    pub fn into_untyped(self) -> CFArray {
        let reference = self.0;
        mem::forget(self);
        unsafe { CFArray::wrap_under_create_rule(reference) }
    }

    /// Iterates over the elements of this `CFArray`.
    ///
    /// Careful; the loop body must wrap the reference properly. Generally, when array elements are
    /// Core Foundation objects (not always true), they need to be wrapped with
    /// `TCFType::wrap_under_get_rule()`.
    #[inline]
    pub fn iter<'a>(&'a self) -> CFArrayIterator<'a, T> {
        CFArrayIterator {
            array: self,
            index: 0,
            len: self.len(),
        }
    }

    #[inline]
    pub fn len(&self) -> CFIndex {
        unsafe {
            CFArrayGetCount(self.0)
        }
    }

    #[inline]
    pub unsafe fn get_unchecked<'a>(&'a self, index: CFIndex) -> ItemRef<'a, T> where T: FromVoid {
        T::from_void(CFArrayGetValueAtIndex(self.0, index))
    }

    #[inline]
    pub fn get<'a>(&'a self, index: CFIndex) -> Option<ItemRef<'a, T>> where T: FromVoid {
        if index < self.len() {
            Some(unsafe { T::from_void(CFArrayGetValueAtIndex(self.0, index)) } )
        } else {
            None
        }
    }

    pub fn get_values(&self, range: CFRange) -> Vec<*const c_void> {
        let mut vec = Vec::with_capacity(range.length as usize);
        unsafe {
            CFArrayGetValues(self.0, range, vec.as_mut_ptr());
            vec.set_len(range.length as usize);
            vec
        }
    }

    pub fn get_all_values(&self) -> Vec<*const c_void> {
        self.get_values(CFRange {
            location: 0,
            length: self.len()
        })
    }
}

impl<'a, T: FromVoid> IntoIterator for &'a CFArray<T> {
    type Item = ItemRef<'a, T>;
    type IntoIter = CFArrayIterator<'a, T>;

    fn into_iter(self) -> CFArrayIterator<'a, T> {
        self.iter()
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use std::mem;
    use base::CFType;

    #[test]
    fn to_untyped_correct_retain_count() {
        let array = CFArray::<CFType>::from_CFTypes(&[]);
        assert_eq!(array.retain_count(), 1);

        let untyped_array = array.to_untyped();
        assert_eq!(array.retain_count(), 2);
        assert_eq!(untyped_array.retain_count(), 2);

        mem::drop(array);
        assert_eq!(untyped_array.retain_count(), 1);
    }

    #[test]
    fn into_untyped() {
        let array = CFArray::<CFType>::from_CFTypes(&[]);
        let array2 = array.to_untyped();
        assert_eq!(array.retain_count(), 2);

        let untyped_array = array.into_untyped();
        assert_eq!(untyped_array.retain_count(), 2);

        mem::drop(array2);
        assert_eq!(untyped_array.retain_count(), 1);
    }

    #[test]
    fn borrow() {
        use string::CFString;

        let string = CFString::from_static_string("bar");
        assert_eq!(string.retain_count(), 1);
        let x;
        {
            let arr: CFArray<CFString> = CFArray::from_CFTypes(&[string]);
            {
                let p = arr.get(0).unwrap();
                assert_eq!(p.retain_count(), 1);
            }
            {
                x = arr.get(0).unwrap().clone();
                assert_eq!(x.retain_count(), 2);
                assert_eq!(x.to_string(), "bar");
            }
        }
        assert_eq!(x.retain_count(), 1);
    }

    #[test]
    fn should_box_and_unbox() {
        use number::CFNumber;

        let n0 = CFNumber::from(0);
        let n1 = CFNumber::from(1);
        let n2 = CFNumber::from(2);
        let n3 = CFNumber::from(3);
        let n4 = CFNumber::from(4);
        let n5 = CFNumber::from(5);

        let arr = CFArray::from_CFTypes(&[
            n0.as_CFType(),
            n1.as_CFType(),
            n2.as_CFType(),
            n3.as_CFType(),
            n4.as_CFType(),
            n5.as_CFType(),
        ]);

        assert!(arr.get_all_values() == &[n0.as_CFTypeRef(),
                                        n1.as_CFTypeRef(),
                                        n2.as_CFTypeRef(),
                                        n3.as_CFTypeRef(),
                                        n4.as_CFTypeRef(),
                                        n5.as_CFTypeRef()]);

        let mut sum = 0;

        let mut iter = arr.iter();
        assert_eq!(iter.len(), 6);
        assert!(iter.next().is_some());
        assert_eq!(iter.len(), 5);

        for elem in iter {
            let number: CFNumber = elem.downcast::<CFNumber>().unwrap();
            sum += number.to_i64().unwrap()
        }

        assert!(sum == 15);

        for elem in arr.iter() {
            let number: CFNumber = elem.downcast::<CFNumber>().unwrap();
            sum += number.to_i64().unwrap()
        }

        assert!(sum == 30);
    }
}