Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 379 insertions, 0 deletions

diff --git a/storage/variant/Cargo.toml b/storage/variant/Cargo.toml
new file mode 100644
index 0000000000..26e30ea1ce
--- /dev/null
+++ b/storage/variant/Cargo.toml
@@ -0,0 +1,14 @@
+[package]
+name = "storage_variant"
+version = "0.1.0"
+authors = [
+    "Lina Cambridge <lina@yakshaving.ninja>",
+    "Myk Melez <myk@mykzilla.org>"
+]
+license = "MPL-2.0"
+
+[dependencies]
+libc = "0.2"
+nserror = { path = "../../xpcom/rust/nserror" }
+nsstring = { path = "../../xpcom/rust/nsstring" }
+xpcom = { path = "../../xpcom/rust/xpcom" }
diff --git a/storage/variant/src/bag.rs b/storage/variant/src/bag.rs
new file mode 100644
index 0000000000..91653ba226
--- /dev/null
+++ b/storage/variant/src/bag.rs
@@ -0,0 +1,135 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+use nserror::{nsresult, NS_ERROR_CANNOT_CONVERT_DATA, NS_OK};
+use nsstring::nsString;
+use xpcom::{
+    getter_addrefs,
+    interfaces::{nsIProperty, nsIPropertyBag, nsIWritablePropertyBag},
+    RefPtr, XpCom,
+};
+
+use crate::{NsIVariantExt, VariantType};
+
+extern "C" {
+    fn NS_NewHashPropertyBag(bag: *mut *const nsIWritablePropertyBag);
+}
+
+/// A hash property bag backed by storage variant values.
+pub struct HashPropertyBag(RefPtr<nsIWritablePropertyBag>);
+
+// This is safe as long as our `nsIWritablePropertyBag` is an instance of
+// `mozilla::nsHashPropertyBag`, which is atomically reference counted, and
+// all properties are backed by `Storage*Variant`s, all of which are
+// thread-safe.
+unsafe impl Send for HashPropertyBag {}
+unsafe impl Sync for HashPropertyBag {}
+
+impl Default for HashPropertyBag {
+    fn default() -> HashPropertyBag {
+        // This is safe to unwrap because `NS_NewHashPropertyBag` is infallible.
+        let bag = getter_addrefs(|p| {
+            unsafe { NS_NewHashPropertyBag(p) };
+            NS_OK
+        })
+        .unwrap();
+        HashPropertyBag(bag)
+    }
+}
+
+impl HashPropertyBag {
+    /// Creates an empty property bag.
+    #[inline]
+    pub fn new() -> Self {
+        Self::default()
+    }
+
+    /// Creates a property bag from an instance of `nsIPropertyBag`, cloning its
+    /// contents. The `source` bag can only contain primitive values for which
+    /// the `VariantType` trait is implemented. Attempting to clone a bag with
+    /// unsupported types, such as arrays, interface pointers, and `jsval`s,
+    /// fails with `NS_ERROR_CANNOT_CONVERT_DATA`.
+    ///
+    /// `clone_from_bag` can be used to clone a thread-unsafe `nsIPropertyBag`,
+    /// like one passed from JavaScript via XPConnect, into one that can be
+    /// shared across threads.
+    pub fn clone_from_bag(source: &nsIPropertyBag) -> Result<Self, nsresult> {
+        let enumerator = getter_addrefs(|p| unsafe { source.GetEnumerator(p) })?;
+        let b = HashPropertyBag::new();
+        while {
+            let mut has_more = false;
+            unsafe { enumerator.HasMoreElements(&mut has_more) }.to_result()?;
+            has_more
+        } {
+            let element = getter_addrefs(|p| unsafe { enumerator.GetNext(p) })?;
+            let property = element
+                .query_interface::<nsIProperty>()
+                .ok_or(NS_ERROR_CANNOT_CONVERT_DATA)?;
+            let mut name = nsString::new();
+            unsafe { property.GetName(&mut *name) }.to_result()?;
+            let value = getter_addrefs(|p| unsafe { property.GetValue(p) })?;
+            unsafe { b.0.SetProperty(&*name, value.try_clone()?.coerce()) }.to_result()?;
+        }
+        Ok(b)
+    }
+
+    /// Returns the value for a property name. Fails with `NS_ERROR_FAILURE`
+    /// if the property doesn't exist, or `NS_ERROR_CANNOT_CONVERT_DATA` if the
+    /// property exists, but is not of the value type `V`.
+    pub fn get<K, V>(&self, name: K) -> Result<V, nsresult>
+    where
+        K: AsRef<str>,
+        V: VariantType,
+    {
+        getter_addrefs(|p| unsafe { self.0.GetProperty(&*nsString::from(name.as_ref()), p) })
+            .and_then(|v| V::from_variant(v.coerce()))
+    }
+
+    /// Returns the value for a property name, or the default if not set or
+    /// not of the value type `V`.
+    #[inline]
+    pub fn get_or_default<K, V>(&self, name: K) -> V
+    where
+        K: AsRef<str>,
+        V: VariantType + Default,
+    {
+        self.get(name).unwrap_or_default()
+    }
+
+    /// Sets a property with the name to the value, overwriting any previous
+    /// value.
+    pub fn set<K, V>(&mut self, name: K, value: V)
+    where
+        K: AsRef<str>,
+        V: VariantType,
+    {
+        let v = value.into_variant();
+        unsafe {
+            // This is safe to unwrap because
+            // `nsHashPropertyBagBase::SetProperty` only returns an error if `v`
+            // is a null pointer.
+            self.0
+                .SetProperty(&*nsString::from(name.as_ref()), v.coerce())
+                .to_result()
+                .unwrap()
+        }
+    }
+
+    /// Deletes a property with the name. Returns `true` if the property
+    /// was previously in the bag, `false` if not.
+    pub fn delete(&mut self, name: impl AsRef<str>) -> bool {
+        unsafe {
+            self.0
+                .DeleteProperty(&*nsString::from(name.as_ref()))
+                .to_result()
+                .is_ok()
+        }
+    }
+
+    /// Returns a reference to the backing `nsIWritablePropertyBag`.
+    #[inline]
+    pub fn bag(&self) -> &nsIWritablePropertyBag {
+        &self.0
+    }
+}
diff --git a/storage/variant/src/lib.rs b/storage/variant/src/lib.rs
new file mode 100644
index 0000000000..4734705299
--- /dev/null
+++ b/storage/variant/src/lib.rs
@@ -0,0 +1,230 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+extern crate libc;
+extern crate nserror;
+extern crate nsstring;
+extern crate xpcom;
+
+mod bag;
+
+use std::{
+    borrow::Cow,
+    convert::{TryFrom, TryInto},
+};
+
+use libc::c_double;
+use nserror::{nsresult, NS_ERROR_CANNOT_CONVERT_DATA, NS_OK};
+use nsstring::{nsACString, nsAString, nsCString, nsString};
+use xpcom::{getter_addrefs, interfaces::nsIVariant, RefPtr};
+
+pub use crate::bag::HashPropertyBag;
+
+extern "C" {
+    fn NS_GetDataType(variant: *const nsIVariant) -> u16;
+    fn NS_NewStorageNullVariant(result: *mut *const nsIVariant);
+    fn NS_NewStorageBooleanVariant(value: bool, result: *mut *const nsIVariant);
+    fn NS_NewStorageIntegerVariant(value: i64, result: *mut *const nsIVariant);
+    fn NS_NewStorageFloatVariant(value: c_double, result: *mut *const nsIVariant);
+    fn NS_NewStorageTextVariant(value: *const nsAString, result: *mut *const nsIVariant);
+    fn NS_NewStorageUTF8TextVariant(value: *const nsACString, result: *mut *const nsIVariant);
+}
+
+// These are the relevant parts of the nsXPTTypeTag enum in xptinfo.h,
+// which nsIVariant.idl reflects into the nsIDataType struct class and uses
+// to constrain the values of nsIVariant::dataType.
+#[repr(u16)]
+#[derive(Debug, Copy, Clone, Eq, Hash, PartialEq)]
+pub enum DataType {
+    Int32 = 2,
+    Int64 = 3,
+    Double = 9,
+    Bool = 10,
+    Void = 13,
+    CharStr = 15,
+    WCharStr = 16,
+    StringSizeIs = 20,
+    WStringSizeIs = 21,
+    Utf8String = 24,
+    CString = 25,
+    AString = 26,
+    EmptyArray = 254,
+    Empty = 255,
+}
+
+impl TryFrom<u16> for DataType {
+    type Error = nsresult;
+
+    /// Converts a raw type tag for an `nsIVariant` into a `DataType` variant.
+    /// Returns `NS_ERROR_CANNOT_CONVERT_DATA` if the type isn't one that we
+    /// support.
+    fn try_from(raw: u16) -> Result<Self, Self::Error> {
+        Ok(match raw {
+            2 => DataType::Int32,
+            3 => DataType::Int64,
+            9 => DataType::Double,
+            10 => DataType::Bool,
+            13 => DataType::Void,
+            15 => DataType::CharStr,
+            16 => DataType::WCharStr,
+            20 => DataType::StringSizeIs,
+            21 => DataType::WStringSizeIs,
+            24 => DataType::Utf8String,
+            25 => DataType::CString,
+            26 => DataType::AString,
+            254 => DataType::EmptyArray,
+            255 => DataType::Empty,
+            _ => Err(NS_ERROR_CANNOT_CONVERT_DATA)?,
+        })
+    }
+}
+
+/// Extension methods implemented on `nsIVariant` types, to make them easier
+/// to work with.
+pub trait NsIVariantExt {
+    /// Returns the raw type tag for this variant. Call
+    /// `DataType::try_from()` on this tag to turn it into a `DataType`.
+    fn get_data_type(&self) -> u16;
+
+    /// Tries to clone this variant, failing with `NS_ERROR_CANNOT_CONVERT_DATA`
+    /// if its type is unsupported.
+    fn try_clone(&self) -> Result<RefPtr<nsIVariant>, nsresult>;
+}
+
+impl NsIVariantExt for nsIVariant {
+    fn get_data_type(&self) -> u16 {
+        unsafe { NS_GetDataType(self) }
+    }
+
+    fn try_clone(&self) -> Result<RefPtr<nsIVariant>, nsresult> {
+        Ok(match self.get_data_type().try_into()? {
+            DataType::Bool => bool::from_variant(self)?.into_variant(),
+            DataType::Int32 => i32::from_variant(self)?.into_variant(),
+            DataType::Int64 => i64::from_variant(self)?.into_variant(),
+            DataType::Double => f64::from_variant(self)?.into_variant(),
+            DataType::AString | DataType::WCharStr | DataType::WStringSizeIs => {
+                nsString::from_variant(self)?.into_variant()
+            }
+            DataType::CString
+            | DataType::CharStr
+            | DataType::StringSizeIs
+            | DataType::Utf8String => nsCString::from_variant(self)?.into_variant(),
+            DataType::Void | DataType::EmptyArray | DataType::Empty => ().into_variant(),
+        })
+    }
+}
+
+pub trait VariantType {
+    fn type_name() -> Cow<'static, str>;
+    fn into_variant(self) -> RefPtr<nsIVariant>;
+    fn from_variant(variant: &nsIVariant) -> Result<Self, nsresult>
+    where
+        Self: Sized;
+}
+
+/// Implements traits to convert between variants and their types.
+macro_rules! variant {
+    ($typ:ident, $constructor:ident, $getter:ident) => {
+        impl VariantType for $typ {
+            fn type_name() -> Cow<'static, str> {
+                stringify!($typ).into()
+            }
+            fn into_variant(self) -> RefPtr<nsIVariant> {
+                // getter_addrefs returns a Result<RefPtr<T>, nsresult>,
+                // but we know that our $constructor is infallible, so we can
+                // safely unwrap and return the RefPtr.
+                getter_addrefs(|p| {
+                    unsafe { $constructor(self.into(), p) };
+                    NS_OK
+                })
+                .unwrap()
+            }
+            fn from_variant(variant: &nsIVariant) -> Result<$typ, nsresult> {
+                let mut result = $typ::default();
+                let rv = unsafe { variant.$getter(&mut result) };
+                if rv.succeeded() {
+                    Ok(result)
+                } else {
+                    Err(rv)
+                }
+            }
+        }
+    };
+    (* $typ:ident, $constructor:ident, $getter:ident) => {
+        impl VariantType for $typ {
+            fn type_name() -> Cow<'static, str> {
+                stringify!($typ).into()
+            }
+            fn into_variant(self) -> RefPtr<nsIVariant> {
+                // getter_addrefs returns a Result<RefPtr<T>, nsresult>,
+                // but we know that our $constructor is infallible, so we can
+                // safely unwrap and return the RefPtr.
+                getter_addrefs(|p| {
+                    unsafe { $constructor(&*self, p) };
+                    NS_OK
+                })
+                .unwrap()
+            }
+            fn from_variant(variant: &nsIVariant) -> Result<$typ, nsresult> {
+                let mut result = $typ::new();
+                let rv = unsafe { variant.$getter(&mut *result) };
+                if rv.succeeded() {
+                    Ok(result)
+                } else {
+                    Err(rv)
+                }
+            }
+        }
+    };
+}
+
+// The unit type (()) is a reasonable equivalation of the null variant.
+// The macro can't produce its implementations of VariantType, however,
+// so we implement them concretely.
+impl VariantType for () {
+    fn type_name() -> Cow<'static, str> {
+        "()".into()
+    }
+    fn into_variant(self) -> RefPtr<nsIVariant> {
+        // getter_addrefs returns a Result<RefPtr<T>, nsresult>,
+        // but we know that NS_NewStorageNullVariant is infallible, so we can
+        // safely unwrap and return the RefPtr.
+        getter_addrefs(|p| {
+            unsafe { NS_NewStorageNullVariant(p) };
+            NS_OK
+        })
+        .unwrap()
+    }
+    fn from_variant(_variant: &nsIVariant) -> Result<Self, nsresult> {
+        Ok(())
+    }
+}
+
+impl<T> VariantType for Option<T>
+where
+    T: VariantType,
+{
+    fn type_name() -> Cow<'static, str> {
+        format!("Option<{}>", T::type_name()).into()
+    }
+    fn into_variant(self) -> RefPtr<nsIVariant> {
+        match self {
+            Some(v) => v.into_variant(),
+            None => ().into_variant(),
+        }
+    }
+    fn from_variant(variant: &nsIVariant) -> Result<Self, nsresult> {
+        Ok(match variant.get_data_type().try_into() {
+            Ok(DataType::Void) | Ok(DataType::EmptyArray) | Ok(DataType::Empty) => None,
+            _ => Some(VariantType::from_variant(variant)?),
+        })
+    }
+}
+
+variant!(bool, NS_NewStorageBooleanVariant, GetAsBool);
+variant!(i32, NS_NewStorageIntegerVariant, GetAsInt32);
+variant!(i64, NS_NewStorageIntegerVariant, GetAsInt64);
+variant!(f64, NS_NewStorageFloatVariant, GetAsDouble);
+variant!(*nsString, NS_NewStorageTextVariant, GetAsAString);
+variant!(*nsCString, NS_NewStorageUTF8TextVariant, GetAsAUTF8String);