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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
commit | 2aa4a82499d4becd2284cdb482213d541b8804dd (patch) | |
tree | b80bf8bf13c3766139fbacc530efd0dd9d54394c /js/public/ValueArray.h | |
parent | Initial commit. (diff) | |
download | firefox-upstream.tar.xz firefox-upstream.zip |
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | js/public/ValueArray.h | 130 |
1 files changed, 130 insertions, 0 deletions
diff --git a/js/public/ValueArray.h b/js/public/ValueArray.h new file mode 100644 index 0000000000..0d520fb9b6 --- /dev/null +++ b/js/public/ValueArray.h @@ -0,0 +1,130 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * 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/. */ + +/** GC-safe representations of consecutive JS::Value in memory. */ + +#ifndef js_ValueArray_h +#define js_ValueArray_h + +#include "mozilla/Assertions.h" // MOZ_ASSERT +#include "mozilla/Attributes.h" // MOZ_IMPLICIT, MOZ_RAII + +#include <stdint.h> // size_t + +#include "js/CallArgs.h" // JS::CallArgs +#include "js/GCVector.h" // JS::RootedVector +#include "js/RootingAPI.h" // JS::AutoGCRooter, JS::{,Mutable}Handle +#include "js/Value.h" // JS::Value + +namespace js { +JS_PUBLIC_API void TraceValueArray(JSTracer* trc, size_t length, + JS::Value* elements); +} // namespace js + +namespace JS { + +/* A fixed-size array of values, for use inside Rooted<>. */ +template <size_t N> +struct ValueArray { + Value elements[N]; + void trace(JSTracer* trc) { js::TraceValueArray(trc, N, elements); } +}; + +/** RootedValueArray roots an internal fixed-size array of Values. */ +template <size_t N> +using RootedValueArray = Rooted<ValueArray<N>>; + +/** + * A generic handle to an array of rooted values. + * + * The rooted array refernced can take several forms, therfore this is not the + * same as Handle<js::ValueArray>. + */ +class HandleValueArray { + const size_t length_; + const Value* const elements_; + + HandleValueArray(size_t len, const Value* elements) + : length_(len), elements_(elements) {} + + public: + explicit HandleValueArray(Handle<Value> value) + : length_(1), elements_(value.address()) {} + + MOZ_IMPLICIT HandleValueArray(const RootedVector<Value>& values) + : length_(values.length()), elements_(values.begin()) {} + + template <size_t N> + MOZ_IMPLICIT HandleValueArray(const RootedValueArray<N>& values) + : length_(N), elements_(values.begin()) {} + + /** CallArgs must already be rooted somewhere up the stack. */ + MOZ_IMPLICIT HandleValueArray(const JS::CallArgs& args) + : length_(args.length()), elements_(args.array()) {} + + /** Use with care! Only call this if the data is guaranteed to be marked. */ + static HandleValueArray fromMarkedLocation(size_t len, + const Value* elements) { + return HandleValueArray(len, elements); + } + + static HandleValueArray subarray(const HandleValueArray& values, + size_t startIndex, size_t len) { + MOZ_ASSERT(startIndex + len <= values.length()); + return HandleValueArray(len, values.begin() + startIndex); + } + + static HandleValueArray empty() { return HandleValueArray(0, nullptr); } + + size_t length() const { return length_; } + const Value* begin() const { return elements_; } + + Handle<Value> operator[](size_t i) const { + MOZ_ASSERT(i < length_); + return Handle<Value>::fromMarkedLocation(&elements_[i]); + } +}; + +} // namespace JS + +namespace js { + +template <size_t N, typename Container> +class WrappedPtrOperations<JS::ValueArray<N>, Container> { + const JS::ValueArray<N>& array() const { + return static_cast<const Container*>(this)->get(); + } + + public: + size_t length() const { return N; } + const JS::Value* begin() const { return array().elements; } + + JS::HandleValue operator[](size_t i) const { + MOZ_ASSERT(i < N); + return JS::HandleValue::fromMarkedLocation(&array().elements[i]); + } +}; + +template <size_t N, typename Container> +class MutableWrappedPtrOperations<JS::ValueArray<N>, Container> + : public WrappedPtrOperations<JS::ValueArray<N>, Container> { + using Base = WrappedPtrOperations<JS::ValueArray<N>, Container>; + JS::ValueArray<N>& array() { return static_cast<Container*>(this)->get(); } + + public: + using Base::begin; + JS::Value* begin() { return array().elements; } + + using Base::operator[]; + JS::MutableHandleValue operator[](size_t i) { + MOZ_ASSERT(i < N); + return JS::MutableHandleValue::fromMarkedLocation(&array().elements[i]); + } +}; + +} // namespace js + +#endif // js_ValueArray_h |