1 /*

     2  * Copyright (c) 2015, 2016, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  *

    23  */

    24 

    25 #ifndef SHARE_VM_CLASSFILE_COMPACTHASHTABLE_INLINE_HPP

    26 #define SHARE_VM_CLASSFILE_COMPACTHASHTABLE_INLINE_HPP

    27 

    28 #include "classfile/compactHashtable.hpp"

    29 #include "memory/allocation.inline.hpp"

    30 #include "oops/oop.inline.hpp"

    31 

    32 template <class T, class N>

    33 inline Symbol* CompactHashtable<T, N>::decode_entry(CompactHashtable<Symbol*, char>* const t,

    34                                                     u4 offset, const char* name, int len) {

    35   Symbol* sym = (Symbol*)(_base_address + offset);

    36   if (sym->equals(name, len)) {

    37     assert(sym->refcount() == -1, "must be shared");

    38     return sym;

    39   }

    40 

    41   return NULL;

    42 }

    43 

    44 template <class T, class N>

    45 inline oop CompactHashtable<T, N>::decode_entry(CompactHashtable<oop, char>* const t,

    46                                                 u4 offset, const char* name, int len) {

    47   narrowOop obj = (narrowOop)offset;

    48   oop string = oopDesc::decode_heap_oop(obj);

    49   if (java_lang_String::equals(string, (jchar*)name, len)) {

    50     return string;

    51   }

    52 

    53   return NULL;

    54 }

    55 

    56 template <class T, class N>

    57 inline T CompactHashtable<T,N>::lookup(const N* name, unsigned int hash, int len) {

    58   if (_entry_count > 0) {

    59     int index = hash % _bucket_count;

    60     u4 bucket_info = _buckets[index];

    61     u4 bucket_offset = BUCKET_OFFSET(bucket_info);

    62     int bucket_type = BUCKET_TYPE(bucket_info);

    63     u4* entry = _entries + bucket_offset;

    64 

    65     if (bucket_type == VALUE_ONLY_BUCKET_TYPE) {

    66       T res = decode_entry(this, entry[0], name, len);

    67       if (res != NULL) {

    68         return res;

    69       }

    70     } else {

    71       // This is a regular bucket, which has more than one

    72       // entries. Each entry is a pair of entry (hash, offset).

    73       // Seek until the end of the bucket.

    74       u4* entry_max = _entries + BUCKET_OFFSET(_buckets[index + 1]);

    75       while (entry < entry_max) {

    76         unsigned int h = (unsigned int)(entry[0]);

    77         if (h == hash) {

    78           T res = decode_entry(this, entry[1], name, len);

    79           if (res != NULL) {

    80             return res;

    81           }

    82         }

    83         entry += 2;

    84       }

    85     }

    86   }

    87   return NULL;

    88 }

    89 

    90 #endif // SHARE_VM_CLASSFILE_COMPACTHASHTABLE_INLINE_HPP