Import protobuf-2.14.0

* Add OWNERS and Android.bp
* add generated version.rs into out

Bug: 143953733
Test: make
Change-Id: Ib53a973b74679c4dd78e2de2fa54141e55048c17
diff --git a/src/singular.rs b/src/singular.rs
new file mode 100644
index 0000000..71d4f0a
--- /dev/null
+++ b/src/singular.rs
@@ -0,0 +1,580 @@
+#[cfg(feature = "with-serde")]
+use serde;
+
+use std::default::Default;
+use std::fmt;
+use std::hash::Hash;
+use std::hash::Hasher;
+use std::mem;
+use std::option;
+
+use clear::Clear;
+
+/// Like `Option<T>`, but keeps the actual element on `clear`.
+pub struct SingularField<T> {
+    value: T,
+    set: bool,
+}
+
+/// Like `Option<Box<T>>`, but keeps the actual element on `clear`.
+pub struct SingularPtrField<T> {
+    value: Option<Box<T>>,
+    set: bool,
+}
+
+impl<T> SingularField<T> {
+    /// Construct this object from given value.
+    #[inline]
+    pub fn some(value: T) -> SingularField<T> {
+        SingularField {
+            value: value,
+            set: true,
+        }
+    }
+
+    /// True iff this object contains data.
+    #[inline]
+    pub fn is_some(&self) -> bool {
+        self.set
+    }
+
+    /// True iff this object contains no data.
+    #[inline]
+    pub fn is_none(&self) -> bool {
+        !self.is_some()
+    }
+
+    /// Convert this object into `Option`.
+    #[inline]
+    pub fn into_option(self) -> Option<T> {
+        if self.set {
+            Some(self.value)
+        } else {
+            None
+        }
+    }
+
+    /// View data as `Option`.
+    #[inline]
+    pub fn as_ref<'a>(&'a self) -> Option<&'a T> {
+        if self.set {
+            Some(&self.value)
+        } else {
+            None
+        }
+    }
+
+    /// View data as mutable `Option`.
+    #[inline]
+    pub fn as_mut<'a>(&'a mut self) -> Option<&'a mut T> {
+        if self.set {
+            Some(&mut self.value)
+        } else {
+            None
+        }
+    }
+
+    /// Unwrap data as reference.
+    #[inline]
+    pub fn unwrap_ref<'a>(&'a self) -> &'a T {
+        self.as_ref().unwrap()
+    }
+
+    /// Unwrap data as mutable reference.
+    #[inline]
+    pub fn unwrap_mut_ref<'a>(&'a mut self) -> &'a mut T {
+        self.as_mut().unwrap()
+    }
+
+    /// Unwrap data, panic if not set.
+    #[inline]
+    pub fn unwrap(self) -> T {
+        if self.set {
+            self.value
+        } else {
+            panic!();
+        }
+    }
+
+    /// Unwrap data or return given default value.
+    #[inline]
+    pub fn unwrap_or(self, def: T) -> T {
+        if self.set {
+            self.value
+        } else {
+            def
+        }
+    }
+
+    /// Unwrap data or return given default value.
+    #[inline]
+    pub fn unwrap_or_else<F>(self, f: F) -> T
+    where
+        F: FnOnce() -> T,
+    {
+        if self.set {
+            self.value
+        } else {
+            f()
+        }
+    }
+
+    /// Apply a function to contained element and store result in new `SingularPtrField`.
+    #[inline]
+    pub fn map<U, F>(self, f: F) -> SingularPtrField<U>
+    where
+        F: FnOnce(T) -> U,
+    {
+        SingularPtrField::from_option(self.into_option().map(f))
+    }
+
+    /// View as iterator over references.
+    #[inline]
+    pub fn iter<'a>(&'a self) -> option::IntoIter<&'a T> {
+        self.as_ref().into_iter()
+    }
+
+    /// View as iterator over mutable references.
+    #[inline]
+    pub fn mut_iter<'a>(&'a mut self) -> option::IntoIter<&'a mut T> {
+        self.as_mut().into_iter()
+    }
+
+    /// Clear this object.
+    /// Note, contained object destructor is not called, so allocated memory could be reused.
+    #[inline]
+    pub fn clear(&mut self) {
+        self.set = false;
+    }
+}
+
+impl<T: Default> SingularField<T> {
+    /// Construct a `SingularField` with no data.
+    #[inline]
+    pub fn none() -> SingularField<T> {
+        SingularField {
+            value: Default::default(),
+            set: false,
+        }
+    }
+
+    /// Construct `SingularField` from `Option`.
+    #[inline]
+    pub fn from_option(option: Option<T>) -> SingularField<T> {
+        match option {
+            Some(x) => SingularField::some(x),
+            None => SingularField::none(),
+        }
+    }
+
+    /// Return data as option, clear this object.
+    #[inline]
+    pub fn take(&mut self) -> Option<T> {
+        if self.set {
+            self.set = false;
+            Some(mem::replace(&mut self.value, Default::default()))
+        } else {
+            None
+        }
+    }
+}
+
+impl<T> SingularPtrField<T> {
+    /// Construct `SingularPtrField` from given object.
+    #[inline]
+    pub fn some(value: T) -> SingularPtrField<T> {
+        SingularPtrField {
+            value: Some(Box::new(value)),
+            set: true,
+        }
+    }
+
+    /// Construct an empty `SingularPtrField`.
+    #[inline]
+    pub fn none() -> SingularPtrField<T> {
+        SingularPtrField {
+            value: None,
+            set: false,
+        }
+    }
+
+    /// Construct `SingularPtrField` from optional.
+    #[inline]
+    pub fn from_option(option: Option<T>) -> SingularPtrField<T> {
+        match option {
+            Some(x) => SingularPtrField::some(x),
+            None => SingularPtrField::none(),
+        }
+    }
+
+    /// True iff this object contains data.
+    #[inline]
+    pub fn is_some(&self) -> bool {
+        self.set
+    }
+
+    /// True iff this object contains no data.
+    #[inline]
+    pub fn is_none(&self) -> bool {
+        !self.is_some()
+    }
+
+    /// Convert into `Option<T>`.
+    #[inline]
+    pub fn into_option(self) -> Option<T> {
+        if self.set {
+            Some(*self.value.unwrap())
+        } else {
+            None
+        }
+    }
+
+    /// View data as reference option.
+    #[inline]
+    pub fn as_ref<'a>(&'a self) -> Option<&'a T> {
+        if self.set {
+            Some(&**self.value.as_ref().unwrap())
+        } else {
+            None
+        }
+    }
+
+    /// View data as mutable reference option.
+    #[inline]
+    pub fn as_mut<'a>(&'a mut self) -> Option<&'a mut T> {
+        if self.set {
+            Some(&mut **self.value.as_mut().unwrap())
+        } else {
+            None
+        }
+    }
+
+    /// Get data as reference.
+    /// Panics if empty.
+    #[inline]
+    pub fn get_ref<'a>(&'a self) -> &'a T {
+        self.as_ref().unwrap()
+    }
+
+    /// Get data as mutable reference.
+    /// Panics if empty.
+    #[inline]
+    pub fn get_mut_ref<'a>(&'a mut self) -> &'a mut T {
+        self.as_mut().unwrap()
+    }
+
+    /// Take the data.
+    /// Panics if empty
+    #[inline]
+    pub fn unwrap(self) -> T {
+        if self.set {
+            *self.value.unwrap()
+        } else {
+            panic!();
+        }
+    }
+
+    /// Take the data or return supplied default element if empty.
+    #[inline]
+    pub fn unwrap_or(self, def: T) -> T {
+        if self.set {
+            *self.value.unwrap()
+        } else {
+            def
+        }
+    }
+
+    /// Take the data or return supplied default element if empty.
+    #[inline]
+    pub fn unwrap_or_else<F>(self, f: F) -> T
+    where
+        F: FnOnce() -> T,
+    {
+        if self.set {
+            *self.value.unwrap()
+        } else {
+            f()
+        }
+    }
+
+    /// Apply given function to contained data to construct another `SingularPtrField`.
+    /// Returns empty `SingularPtrField` if this object is empty.
+    #[inline]
+    pub fn map<U, F>(self, f: F) -> SingularPtrField<U>
+    where
+        F: FnOnce(T) -> U,
+    {
+        SingularPtrField::from_option(self.into_option().map(f))
+    }
+
+    /// View data as iterator.
+    #[inline]
+    pub fn iter<'a>(&'a self) -> option::IntoIter<&'a T> {
+        self.as_ref().into_iter()
+    }
+
+    /// View data as mutable iterator.
+    #[inline]
+    pub fn mut_iter<'a>(&'a mut self) -> option::IntoIter<&'a mut T> {
+        self.as_mut().into_iter()
+    }
+
+    /// Take data as option, leaving this object empty.
+    #[inline]
+    pub fn take(&mut self) -> Option<T> {
+        if self.set {
+            self.set = false;
+            Some(*self.value.take().unwrap())
+        } else {
+            None
+        }
+    }
+
+    /// Clear this object, but do not call destructor of underlying data.
+    #[inline]
+    pub fn clear(&mut self) {
+        self.set = false;
+    }
+}
+
+impl<T: Default + Clear> SingularField<T> {
+    /// Get contained data, consume self. Return default value for type if this is empty.
+    #[inline]
+    pub fn unwrap_or_default(mut self) -> T {
+        self.value.clear();
+        self.value
+    }
+
+    /// Initialize this object with default value.
+    /// This operation can be more efficient then construction of clear element,
+    /// because it may reuse previously contained object.
+    #[inline]
+    pub fn set_default<'a>(&'a mut self) -> &'a mut T {
+        self.set = true;
+        self.value.clear();
+        &mut self.value
+    }
+}
+
+impl<T: Default + Clear> SingularPtrField<T> {
+    /// Get contained data, consume self. Return default value for type if this is empty.
+    #[inline]
+    pub fn unwrap_or_default(mut self) -> T {
+        if self.set {
+            self.unwrap()
+        } else if self.value.is_some() {
+            self.value.clear();
+            *self.value.unwrap()
+        } else {
+            Default::default()
+        }
+    }
+
+    /// Initialize this object with default value.
+    /// This operation can be more efficient then construction of clear element,
+    /// because it may reuse previously contained object.
+    #[inline]
+    pub fn set_default<'a>(&'a mut self) -> &'a mut T {
+        self.set = true;
+        if self.value.is_some() {
+            self.value.as_mut().unwrap().clear();
+        } else {
+            self.value = Some(Default::default());
+        }
+        self.as_mut().unwrap()
+    }
+}
+
+impl<T: Default> Default for SingularField<T> {
+    #[inline]
+    fn default() -> SingularField<T> {
+        SingularField::none()
+    }
+}
+
+impl<T> Default for SingularPtrField<T> {
+    #[inline]
+    fn default() -> SingularPtrField<T> {
+        SingularPtrField::none()
+    }
+}
+
+impl<T: Default> From<Option<T>> for SingularField<T> {
+    fn from(o: Option<T>) -> Self {
+        SingularField::from_option(o)
+    }
+}
+
+impl<T> From<Option<T>> for SingularPtrField<T> {
+    fn from(o: Option<T>) -> Self {
+        SingularPtrField::from_option(o)
+    }
+}
+
+impl<T: Clone + Default> Clone for SingularField<T> {
+    #[inline]
+    fn clone(&self) -> SingularField<T> {
+        if self.set {
+            SingularField::some(self.value.clone())
+        } else {
+            SingularField::none()
+        }
+    }
+}
+
+impl<T: Clone> Clone for SingularPtrField<T> {
+    #[inline]
+    fn clone(&self) -> SingularPtrField<T> {
+        if self.set {
+            SingularPtrField::some(self.as_ref().unwrap().clone())
+        } else {
+            SingularPtrField::none()
+        }
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for SingularField<T> {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        if self.is_some() {
+            write!(f, "Some({:?})", *self.as_ref().unwrap())
+        } else {
+            write!(f, "None")
+        }
+    }
+}
+
+impl<T: fmt::Debug> fmt::Debug for SingularPtrField<T> {
+    #[inline]
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        if self.is_some() {
+            write!(f, "Some({:?})", *self.as_ref().unwrap())
+        } else {
+            write!(f, "None")
+        }
+    }
+}
+
+impl<T: PartialEq> PartialEq for SingularField<T> {
+    #[inline]
+    fn eq(&self, other: &SingularField<T>) -> bool {
+        self.as_ref() == other.as_ref()
+    }
+}
+
+impl<T: Eq> Eq for SingularField<T> {}
+
+impl<T: PartialEq> PartialEq for SingularPtrField<T> {
+    #[inline]
+    fn eq(&self, other: &SingularPtrField<T>) -> bool {
+        self.as_ref() == other.as_ref()
+    }
+}
+
+impl<T: Eq> Eq for SingularPtrField<T> {}
+
+impl<T: Hash> Hash for SingularField<T> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.as_ref().hash(state);
+    }
+}
+
+impl<T: Hash> Hash for SingularPtrField<T> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.as_ref().hash(state);
+    }
+}
+
+impl<'a, T> IntoIterator for &'a SingularField<T> {
+    type Item = &'a T;
+    type IntoIter = option::IntoIter<&'a T>;
+
+    fn into_iter(self) -> option::IntoIter<&'a T> {
+        self.iter()
+    }
+}
+
+impl<'a, T> IntoIterator for &'a SingularPtrField<T> {
+    type Item = &'a T;
+    type IntoIter = option::IntoIter<&'a T>;
+
+    fn into_iter(self) -> option::IntoIter<&'a T> {
+        self.iter()
+    }
+}
+
+#[cfg(feature = "with-serde")]
+impl<T: serde::Serialize> serde::Serialize for SingularPtrField<T> {
+    fn serialize<S>(
+        &self,
+        serializer: S,
+    ) -> Result<<S as serde::Serializer>::Ok, <S as serde::Serializer>::Error>
+    where
+        S: serde::Serializer,
+    {
+        self.as_ref().serialize(serializer)
+    }
+}
+
+#[cfg(feature = "with-serde")]
+impl<T: serde::Serialize> serde::Serialize for SingularField<T> {
+    fn serialize<S>(
+        &self,
+        serializer: S,
+    ) -> Result<<S as serde::Serializer>::Ok, <S as serde::Serializer>::Error>
+    where
+        S: serde::Serializer,
+    {
+        self.as_ref().serialize(serializer)
+    }
+}
+
+#[cfg(feature = "with-serde")]
+impl<'de, T: serde::Deserialize<'de>> serde::Deserialize<'de> for SingularPtrField<T> {
+    fn deserialize<D>(deserializer: D) -> Result<Self, <D as serde::Deserializer<'de>>::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        Option::deserialize(deserializer).map(SingularPtrField::from_option)
+    }
+}
+
+#[cfg(feature = "with-serde")]
+impl<'de, T: serde::Deserialize<'de> + Default> serde::Deserialize<'de> for SingularField<T> {
+    fn deserialize<D>(deserializer: D) -> Result<Self, <D as serde::Deserializer<'de>>::Error>
+    where
+        D: serde::Deserializer<'de>,
+    {
+        Option::deserialize(deserializer).map(SingularField::from_option)
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::SingularField;
+    use clear::Clear;
+
+    #[test]
+    fn test_set_default_clears() {
+        #[derive(Default)]
+        struct Foo {
+            b: isize,
+        }
+
+        impl Clear for Foo {
+            fn clear(&mut self) {
+                self.b = 0;
+            }
+        }
+
+        let mut x = SingularField::some(Foo { b: 10 });
+        x.clear();
+        x.set_default();
+        assert_eq!(0, x.as_ref().unwrap().b);
+
+        x.as_mut().unwrap().b = 11;
+        // without clear
+        x.set_default();
+        assert_eq!(0, x.as_ref().unwrap().b);
+    }
+}