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Diffstat (limited to 'compiler/utils/string_reference.h')
-rw-r--r-- | compiler/utils/string_reference.h | 65 |
1 files changed, 65 insertions, 0 deletions
diff --git a/compiler/utils/string_reference.h b/compiler/utils/string_reference.h new file mode 100644 index 0000000000..e4c34ca605 --- /dev/null +++ b/compiler/utils/string_reference.h @@ -0,0 +1,65 @@ +/* + * Copyright (C) 2016 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#ifndef ART_COMPILER_UTILS_STRING_REFERENCE_H_ +#define ART_COMPILER_UTILS_STRING_REFERENCE_H_ + +#include <stdint.h> + +#include "base/logging.h" +#include "dex_file-inl.h" +#include "utf-inl.h" + +namespace art { + +// A string is located by its DexFile and the string_ids_ table index into that DexFile. +struct StringReference { + StringReference(const DexFile* file, uint32_t index) : dex_file(file), string_index(index) { } + + const char* GetStringData() const { + return dex_file->GetStringData(dex_file->GetStringId(string_index)); + } + + const DexFile* dex_file; + uint32_t string_index; +}; + +// Compare the actual referenced string values. Used for string reference deduplication. +struct StringReferenceValueComparator { + bool operator()(StringReference sr1, StringReference sr2) const { + // Note that we want to deduplicate identical strings even if they are referenced + // by different dex files, so we need some (any) total ordering of strings, rather + // than references. However, the references should usually be from the same dex file, + // so we choose the dex file string ordering so that we can simply compare indexes + // and avoid the costly string comparison in the most common case. + if (sr1.dex_file == sr2.dex_file) { + // Use the string order enforced by the dex file verifier. + DCHECK_EQ( + sr1.string_index < sr2.string_index, + CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(sr1.GetStringData(), + sr2.GetStringData()) < 0); + return sr1.string_index < sr2.string_index; + } else { + // Cannot compare indexes, so do the string comparison. + return CompareModifiedUtf8ToModifiedUtf8AsUtf16CodePointValues(sr1.GetStringData(), + sr2.GetStringData()) < 0; + } + } +}; + +} // namespace art + +#endif // ART_COMPILER_UTILS_STRING_REFERENCE_H_ |