Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream

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

1 files changed, 230 insertions, 0 deletions

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);