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-rw-r--r--js/src/vm/SharedImmutableStringsCache.cpp123
1 files changed, 123 insertions, 0 deletions
diff --git a/js/src/vm/SharedImmutableStringsCache.cpp b/js/src/vm/SharedImmutableStringsCache.cpp
new file mode 100644
index 000000000..84422810f
--- /dev/null
+++ b/js/src/vm/SharedImmutableStringsCache.cpp
@@ -0,0 +1,123 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/. */
+
+#include "vm/SharedImmutableStringsCache-inl.h"
+
+#include "jsstr.h"
+
+namespace js {
+
+SharedImmutableString::SharedImmutableString(
+ ExclusiveData<SharedImmutableStringsCache::Inner>::Guard& locked,
+ SharedImmutableStringsCache::StringBox* box)
+ : cache_(locked)
+ , box_(box)
+{
+ MOZ_ASSERT(box);
+ box->refcount++;
+}
+
+SharedImmutableString::SharedImmutableString(SharedImmutableString&& rhs)
+ : cache_(mozilla::Move(rhs.cache_))
+ , box_(rhs.box_)
+{
+ MOZ_ASSERT(this != &rhs, "self move not allowed");
+ MOZ_ASSERT(rhs.box_);
+ MOZ_ASSERT(rhs.box_->refcount > 0);
+
+ rhs.box_ = nullptr;
+}
+
+SharedImmutableString&
+SharedImmutableString::operator=(SharedImmutableString&& rhs) {
+ this->~SharedImmutableString();
+ new (this) SharedImmutableString(mozilla::Move(rhs));
+ return *this;
+}
+
+SharedImmutableTwoByteString::SharedImmutableTwoByteString(SharedImmutableString&& string)
+ : string_(mozilla::Move(string))
+{ }
+
+SharedImmutableTwoByteString::SharedImmutableTwoByteString(
+ ExclusiveData<SharedImmutableStringsCache::Inner>::Guard& locked,
+ SharedImmutableStringsCache::StringBox* box)
+ : string_(locked, box)
+{
+ MOZ_ASSERT(box->length() % sizeof(char16_t) == 0);
+}
+
+SharedImmutableTwoByteString::SharedImmutableTwoByteString(SharedImmutableTwoByteString&& rhs)
+ : string_(mozilla::Move(rhs.string_))
+{
+ MOZ_ASSERT(this != &rhs, "self move not allowed");
+}
+
+SharedImmutableTwoByteString&
+SharedImmutableTwoByteString::operator=(SharedImmutableTwoByteString&& rhs)
+{
+ this->~SharedImmutableTwoByteString();
+ new (this) SharedImmutableTwoByteString(mozilla::Move(rhs));
+ return *this;
+}
+
+SharedImmutableString::~SharedImmutableString() {
+ if (!box_)
+ return;
+
+ auto locked = cache_.inner_->lock();
+
+ MOZ_ASSERT(box_->refcount > 0);
+
+ box_->refcount--;
+ if (box_->refcount == 0)
+ box_->chars_.reset(nullptr);
+}
+
+SharedImmutableString
+SharedImmutableString::clone() const
+{
+ auto locked = cache_.inner_->lock();
+ MOZ_ASSERT(box_);
+ MOZ_ASSERT(box_->refcount > 0);
+ return SharedImmutableString(locked, box_);
+}
+
+SharedImmutableTwoByteString
+SharedImmutableTwoByteString::clone() const
+{
+ return SharedImmutableTwoByteString(string_.clone());
+}
+
+MOZ_MUST_USE mozilla::Maybe<SharedImmutableString>
+SharedImmutableStringsCache::getOrCreate(OwnedChars&& chars, size_t length)
+{
+ OwnedChars owned(mozilla::Move(chars));
+ MOZ_ASSERT(owned);
+ return getOrCreate(owned.get(), length, [&]() { return mozilla::Move(owned); });
+}
+
+MOZ_MUST_USE mozilla::Maybe<SharedImmutableString>
+SharedImmutableStringsCache::getOrCreate(const char* chars, size_t length)
+{
+ return getOrCreate(chars, length, [&]() { return DuplicateString(chars, length); });
+}
+
+MOZ_MUST_USE mozilla::Maybe<SharedImmutableTwoByteString>
+SharedImmutableStringsCache::getOrCreate(OwnedTwoByteChars&& chars, size_t length)
+{
+ OwnedTwoByteChars owned(mozilla::Move(chars));
+ MOZ_ASSERT(owned);
+ return getOrCreate(owned.get(), length, [&]() { return mozilla::Move(owned); });
+}
+
+MOZ_MUST_USE mozilla::Maybe<SharedImmutableTwoByteString>
+SharedImmutableStringsCache::getOrCreate(const char16_t* chars, size_t length)
+{
+ return getOrCreate(chars, length, [&]() { return DuplicateString(chars, length); });
+}
+
+} // namespace js