1 /*

     2  * Copyright (c) 2015, 2018, 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 "classfile/javaClasses.hpp"

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

    31 #include "memory/filemap.hpp"

    32 #include "memory/heapShared.inline.hpp"

    33 #include "oops/oop.hpp"

    34 

    35 template <class T, class N>

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

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

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

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

    40     assert(sym->refcount() == PERM_REFCOUNT, "must be shared");

    41     return sym;

    42   }

    43 

    44   return NULL;

    45 }

    46 

    47 template <class T, class N>

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

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

    50   narrowOop v = (narrowOop)offset;

    51   oop string = HeapShared::decode_from_archive(v);

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

    53     return string;

    54   }

    55 

    56   return NULL;

    57 }

    58 

    59 template <class T, class N>

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

    61   if (_entry_count > 0) {

    62     int index = hash % _bucket_count;

    63     u4 bucket_info = _buckets[index];

    64     u4 bucket_offset = BUCKET_OFFSET(bucket_info);

    65     int bucket_type = BUCKET_TYPE(bucket_info);

    66     u4* entry = _entries + bucket_offset;

    67 

    68     if (bucket_type == VALUE_ONLY_BUCKET_TYPE) {

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

    70       if (res != NULL) {

    71         return res;

    72       }

    73     } else {

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

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

    76       // Seek until the end of the bucket.

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

    78       while (entry < entry_max) {

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

    80         if (h == hash) {

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

    82           if (res != NULL) {

    83             return res;

    84           }

    85         }

    86         entry += 2;

    87       }

    88     }

    89   }

    90   return NULL;

    91 }

    92 

    93 #endif // SHARE_VM_CLASSFILE_COMPACTHASHTABLE_INLINE_HPP