jdk8-mips64-public/hotspot: src/share/vm/classfile/classFileStream.hpp@8adf45218add

     1 /*

     2  * Copyright (c) 1997, 2015, 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  */

    25 #ifndef SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP

    26 #define SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP

    28 #include "utilities/top.hpp"

    29 #ifdef TARGET_ARCH_x86

    30 # include "bytes_x86.hpp"

    31 #endif

    32 #ifdef TARGET_ARCH_sparc

    33 # include "bytes_sparc.hpp"

    34 #endif

    35 #ifdef TARGET_ARCH_zero

    36 # include "bytes_zero.hpp"

    37 #endif

    38 #ifdef TARGET_ARCH_arm

    39 # include "bytes_arm.hpp"

    40 #endif

    41 #ifdef TARGET_ARCH_ppc

    42 # include "bytes_ppc.hpp"

    43 #endif

    45 // Input stream for reading .class file

    46 //

    47 // The entire input stream is present in a buffer allocated by the caller.

    48 // The caller is responsible for deallocating the buffer and for using

    49 // ResourceMarks appropriately when constructing streams.

    51 class ClassFileStream: public ResourceObj {

    52  private:

    53   u1*   _buffer_start; // Buffer bottom

    54   u1*   _buffer_end;   // Buffer top (one past last element)

    55   u1*   _current;      // Current buffer position

    56   const char* _source; // Source of stream (directory name, ZIP/JAR archive name)

    57   bool  _need_verify;  // True if verification is on for the class file

    59   void truncated_file_error(TRAPS);

    61 #if INCLUDE_JFR

    62   u1* clone_buffer() const;

    63   const char* const clone_source() const;

    64 #endif

    66  public:

    67   // Constructor

    68   ClassFileStream(u1* buffer, int length, const char* source, bool need_verify = false);

    70   // Buffer access

    71   u1* buffer() const           { return _buffer_start; }

    72   int length() const           { return _buffer_end - _buffer_start; }

    73   u1* current() const          { return _current; }

    74   void set_current(u1* pos)    { _current = pos; }

    75   // for relative positioning

    76   juint current_offset() const {

    77     return (juint)(_current - _buffer_start);

    78   }

    79   const char* source() const   { return _source; }

    80   void set_verify(bool flag)   { _need_verify = flag; }

    82   void check_truncated_file(bool b, TRAPS) {

    83     if (b) {

    84       truncated_file_error(THREAD);

    85     }

    86   }

    88   void guarantee_more(int size, TRAPS) {

    89     size_t remaining = (size_t)(_buffer_end - _current);

    90     unsigned int usize = (unsigned int)size;

    91     check_truncated_file(usize > remaining, CHECK);

    92   }

    94   // Read u1 from stream

    95   u1 get_u1(TRAPS);

    96   u1 get_u1_fast() {

    97     return *_current++;

    98   }

   100   // Read u2 from stream

   101   u2 get_u2(TRAPS);

   102   u2 get_u2_fast() {

   103     u2 res = Bytes::get_Java_u2(_current);

   104     _current += 2;

   105     return res;

   106   }

   108   // Read u4 from stream

   109   u4 get_u4(TRAPS);

   110   u4 get_u4_fast() {

   111     u4 res = Bytes::get_Java_u4(_current);

   112     _current += 4;

   113     return res;

   114   }

   116   // Read u8 from stream

   117   u8 get_u8(TRAPS);

   118   u8 get_u8_fast() {

   119     u8 res = Bytes::get_Java_u8(_current);

   120     _current += 8;

   121     return res;

   122   }

   124   // Get direct pointer into stream at current position.

   125   // Returns NULL if length elements are not remaining. The caller is

   126   // responsible for calling skip below if buffer contents is used.

   127   u1* get_u1_buffer() {

   128     return _current;

   129   }

   131   u2* get_u2_buffer() {

   132     return (u2*) _current;

   133   }

   135   // Skip length u1 or u2 elements from stream

   136   void skip_u1(int length, TRAPS);

   137   void skip_u1_fast(int length) {

   138     _current += length;

   139   }

   141   void skip_u2(int length, TRAPS);

   142   void skip_u2_fast(int length) {

   143     _current += 2 * length;

   144   }

   146   void skip_u4(int length, TRAPS);

   147   void skip_u4_fast(int length) {

   148     _current += 4 * length;

   149   }

   151   // Tells whether eos is reached

   152   bool at_eos() const          { return _current == _buffer_end; }

   154 #if INCLUDE_JFR

   155   ClassFileStream* clone() const;

   157   bool need_verify() const { return _need_verify; }

   158 #endif

   159 };

   161 #endif // SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP

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