1 /* 2 * Copyright (C) 2010 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #include <sys/types.h> 18 19 #include "AAtomizer.h" 20 21 namespace android { 22 23 // static 24 AAtomizer AAtomizer::gAtomizer; 25 26 // static 27 const char *AAtomizer::Atomize(const char *name) { 28 return gAtomizer.atomize(name); 29 } 30 31 AAtomizer::AAtomizer() { 32 for (size_t i = 0; i < 128; ++i) { 33 mAtoms.push(List<AString>()); 34 } 35 } 36 37 const char *AAtomizer::atomize(const char *name) { 38 Mutex::Autolock autoLock(mLock); 39 40 const size_t n = mAtoms.size(); 41 size_t index = AAtomizer::Hash(name) % n; 42 List<AString> &entry = mAtoms.editItemAt(index); 43 List<AString>::iterator it = entry.begin(); 44 while (it != entry.end()) { 45 if ((*it) == name) { 46 return (*it).c_str(); 47 } 48 ++it; 49 } 50 51 entry.push_back(AString(name)); 52 53 return (*--entry.end()).c_str(); 54 } 55 56 // static 57 uint32_t AAtomizer::Hash(const char *s) { 58 uint32_t sum = 0; 59 while (*s != '\0') { 60 sum = (sum * 31) + *s; 61 ++s; 62 } 63 64 return sum; 65 } 66 67 } // namespace android 68
