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stylo: Add uses of fallible Vec, SmallVec and HashMap facilities.
Bug: 1395064 Reviewed-by: emilio
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815fb6b058
commit
c85633f48e
10 changed files with 125 additions and 57 deletions
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@ -2,8 +2,10 @@
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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extern crate hashglobe;
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extern crate smallvec;
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use hashglobe::FailedAllocationError;
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use smallvec::Array;
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use smallvec::SmallVec;
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use std::mem;
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@ -17,8 +19,8 @@ extern "C" {
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pub trait FallibleVec<T> {
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/// Append |val| to the end of |vec|. Returns Ok(()) on success,
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/// Err(()) if it fails, which can only be due to lack of memory.
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fn try_push(&mut self, value: T) -> Result<(), ()>;
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/// Err(reason) if it fails, with |reason| describing the failure.
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fn try_push(&mut self, value: T) -> Result<(), FailedAllocationError>;
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}
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@ -27,7 +29,7 @@ pub trait FallibleVec<T> {
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impl<T> FallibleVec<T> for Vec<T> {
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#[inline]
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fn try_push(&mut self, val: T) -> Result<(), ()> {
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fn try_push(&mut self, val: T) -> Result<(), FailedAllocationError> {
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if self.capacity() == self.len() {
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try_double_vec(self)?;
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debug_assert!(self.capacity() > self.len());
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@ -38,19 +40,25 @@ impl<T> FallibleVec<T> for Vec<T> {
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}
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// Double the capacity of |vec|, or fail to do so due to lack of memory.
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// Returns Ok(()) on success, Err(()) on failure.
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// Returns Ok(()) on success, Err(..) on failure.
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#[inline(never)]
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#[cold]
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fn try_double_vec<T>(vec: &mut Vec<T>) -> Result<(), ()> {
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fn try_double_vec<T>(vec: &mut Vec<T>) -> Result<(), FailedAllocationError> {
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let old_ptr = vec.as_mut_ptr();
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let old_len = vec.len();
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let old_cap: usize = vec.capacity();
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let new_cap: usize =
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if old_cap == 0 { 4 } else { old_cap.checked_mul(2).ok_or(()) ? };
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let new_cap: usize = if old_cap == 0 {
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4
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} else {
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old_cap.checked_mul(2).ok_or(FailedAllocationError::new(
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"capacity overflow for Vec",
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))?
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};
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let new_size_bytes =
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new_cap.checked_mul(mem::size_of::<T>()).ok_or(()) ? ;
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let new_size_bytes = new_cap.checked_mul(mem::size_of::<T>()).ok_or(
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FailedAllocationError::new("capacity overflow for Vec"),
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)?;
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let new_ptr = unsafe {
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if old_cap == 0 {
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@ -61,7 +69,9 @@ fn try_double_vec<T>(vec: &mut Vec<T>) -> Result<(), ()> {
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};
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if new_ptr.is_null() {
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return Err(());
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return Err(FailedAllocationError::new(
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"out of memory when allocating Vec",
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));
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}
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let new_vec = unsafe {
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@ -78,7 +88,7 @@ fn try_double_vec<T>(vec: &mut Vec<T>) -> Result<(), ()> {
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impl<T: Array> FallibleVec<T::Item> for SmallVec<T> {
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#[inline]
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fn try_push(&mut self, val: T::Item) -> Result<(), ()> {
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fn try_push(&mut self, val: T::Item) -> Result<(), FailedAllocationError> {
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if self.capacity() == self.len() {
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try_double_small_vec(self)?;
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debug_assert!(self.capacity() > self.len());
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@ -88,11 +98,12 @@ impl<T: Array> FallibleVec<T::Item> for SmallVec<T> {
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}
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}
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// Double the capacity of |vec|, or fail to do so due to lack of memory.
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// Returns Ok(()) on success, Err(()) on failure.
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// Double the capacity of |svec|, or fail to do so due to lack of memory.
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// Returns Ok(()) on success, Err(..) on failure.
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#[inline(never)]
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#[cold]
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fn try_double_small_vec<T>(svec: &mut SmallVec<T>) -> Result<(), ()>
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fn try_double_small_vec<T>(svec: &mut SmallVec<T>)
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-> Result<(), FailedAllocationError>
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where
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T: Array,
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{
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@ -100,16 +111,23 @@ where
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let old_len = svec.len();
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let old_cap: usize = svec.capacity();
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let new_cap: usize =
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if old_cap == 0 { 4 } else { old_cap.checked_mul(2).ok_or(()) ? };
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let new_cap: usize = if old_cap == 0 {
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4
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} else {
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old_cap.checked_mul(2).ok_or(FailedAllocationError::new(
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"capacity overflow for SmallVec",
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))?
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};
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// This surely shouldn't fail, if |old_cap| was previously accepted as a
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// valid value. But err on the side of caution.
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let old_size_bytes =
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old_cap.checked_mul(mem::size_of::<T>()).ok_or(()) ? ;
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let old_size_bytes = old_cap.checked_mul(mem::size_of::<T>()).ok_or(
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FailedAllocationError::new("capacity overflow for SmallVec"),
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)?;
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let new_size_bytes =
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new_cap.checked_mul(mem::size_of::<T>()).ok_or(()) ? ;
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let new_size_bytes = new_cap.checked_mul(mem::size_of::<T>()).ok_or(
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FailedAllocationError::new("capacity overflow for SmallVec"),
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)?;
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let new_ptr;
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if svec.spilled() {
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@ -130,7 +148,9 @@ where
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}
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if new_ptr.is_null() {
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return Err(());
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return Err(FailedAllocationError::new(
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"out of memory when allocating SmallVec",
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));
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}
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let new_vec = unsafe {
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