js/src/vm/SharedImmutableStringsCache-inl.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: set ts=8 sts=2 et sw=2 tw=80:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef vm_SharedImmutableStringsCache_inl_h
   8 #define vm_SharedImmutableStringsCache_inl_h
   9
  10 #include "vm/SharedImmutableStringsCache.h"
  11
  12 namespace js {
  13
  14 template <typename IntoOwnedChars>
  15 [[nodiscard]] SharedImmutableString SharedImmutableStringsCache::getOrCreate(
  16     const char* chars, size_t length, IntoOwnedChars intoOwnedChars) {
  17   MOZ_ASSERT(inner_);
  18   MOZ_ASSERT(chars);
  19   Hasher::Lookup lookup(Hasher::hashLongString(chars, length), chars, length);
  20
  21   auto locked = inner_->lock();
  22   auto entry = locked->set.lookupForAdd(lookup);
  23   if (!entry) {
  24     OwnedChars ownedChars(intoOwnedChars());
  25     if (!ownedChars) {
  26       return SharedImmutableString();
  27     }
  28     MOZ_ASSERT(ownedChars.get() == chars ||
  29                memcmp(ownedChars.get(), chars, length) == 0);
  30     auto box = StringBox::Create(std::move(ownedChars), length, inner_);
  31     if (!box || !locked->set.add(entry, std::move(box))) {
  32       return SharedImmutableString();
  33     }
  34   }
  35
  36   MOZ_ASSERT(entry && *entry);
  37   return SharedImmutableString(entry->get());
  38 }
  39
  40 template <typename IntoOwnedTwoByteChars>
  41 [[nodiscard]] SharedImmutableTwoByteString
  42 SharedImmutableStringsCache::getOrCreate(
  43     const char16_t* chars, size_t length,
  44     IntoOwnedTwoByteChars intoOwnedTwoByteChars) {
  45   MOZ_ASSERT(inner_);
  46   MOZ_ASSERT(chars);
  47   auto hash = Hasher::hashLongString(reinterpret_cast<const char*>(chars),
  48                                      length * sizeof(char16_t));
  49   Hasher::Lookup lookup(hash, chars, length);
  50
  51   auto locked = inner_->lock();
  52   auto entry = locked->set.lookupForAdd(lookup);
  53   if (!entry) {
  54     OwnedTwoByteChars ownedTwoByteChars(intoOwnedTwoByteChars());
  55     if (!ownedTwoByteChars) {
  56       return SharedImmutableTwoByteString();
  57     }
  58     MOZ_ASSERT(
  59         ownedTwoByteChars.get() == chars ||
  60         memcmp(ownedTwoByteChars.get(), chars, length * sizeof(char16_t)) == 0);
  61     OwnedChars ownedChars(reinterpret_cast<char*>(ownedTwoByteChars.release()));
  62     auto box = StringBox::Create(std::move(ownedChars),
  63                                  length * sizeof(char16_t), inner_);
  64     if (!box || !locked->set.add(entry, std::move(box))) {
  65       return SharedImmutableTwoByteString();
  66     }
  67   }
  68
  69   MOZ_ASSERT(entry && *entry);
  70   return SharedImmutableTwoByteString(entry->get());
  71 }
  72
  73 }  // namespace js
  74
  75 #endif  // vm_SharedImmutableStringsCache_inl_h