| /* |
| * Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| * |
| */ |
| |
| #ifndef SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP |
| #define SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP |
| |
| #include "utilities/bytes.hpp" |
| #include "utilities/top.hpp" |
| |
| // Input stream for reading .class file |
| // |
| // The entire input stream is present in a buffer allocated by the caller. |
| // The caller is responsible for deallocating the buffer and for using |
| // ResourceMarks appropriately when constructing streams. |
| |
| class ClassPathEntry; |
| |
| class ClassFileStream: public ResourceObj { |
| private: |
| const u1* const _buffer_start; // Buffer bottom |
| const u1* const _buffer_end; // Buffer top (one past last element) |
| mutable const u1* _current; // Current buffer position |
| const char* const _source; // Source of stream (directory name, ZIP/JAR archive name) |
| bool _need_verify; // True if verification is on for the class file |
| |
| void truncated_file_error(TRAPS) const ; |
| |
| protected: |
| const u1* clone_buffer() const; |
| const char* const clone_source() const; |
| |
| public: |
| static const bool no_verification; |
| static const bool verify; |
| |
| ClassFileStream(const u1* buffer, |
| int length, |
| const char* source, |
| bool verify_stream = verify); // to be verified by default |
| |
| virtual const ClassFileStream* clone() const; |
| |
| // Buffer access |
| const u1* buffer() const { return _buffer_start; } |
| int length() const { return _buffer_end - _buffer_start; } |
| const u1* current() const { return _current; } |
| void set_current(const u1* pos) const { |
| assert(pos >= _buffer_start && pos <= _buffer_end, "invariant"); |
| _current = pos; |
| } |
| |
| // for relative positioning |
| juint current_offset() const { |
| return (juint)(_current - _buffer_start); |
| } |
| const char* source() const { return _source; } |
| bool need_verify() const { return _need_verify; } |
| void set_verify(bool flag) { _need_verify = flag; } |
| |
| void check_truncated_file(bool b, TRAPS) const { |
| if (b) { |
| truncated_file_error(THREAD); |
| } |
| } |
| |
| void guarantee_more(int size, TRAPS) const { |
| size_t remaining = (size_t)(_buffer_end - _current); |
| unsigned int usize = (unsigned int)size; |
| check_truncated_file(usize > remaining, CHECK); |
| } |
| |
| // Read u1 from stream |
| u1 get_u1(TRAPS) const; |
| u1 get_u1_fast() const { |
| return *_current++; |
| } |
| |
| // Read u2 from stream |
| u2 get_u2(TRAPS) const; |
| u2 get_u2_fast() const { |
| u2 res = Bytes::get_Java_u2((address)_current); |
| _current += 2; |
| return res; |
| } |
| |
| // Read u4 from stream |
| u4 get_u4(TRAPS) const; |
| u4 get_u4_fast() const { |
| u4 res = Bytes::get_Java_u4((address)_current); |
| _current += 4; |
| return res; |
| } |
| |
| // Read u8 from stream |
| u8 get_u8(TRAPS) const; |
| u8 get_u8_fast() const { |
| u8 res = Bytes::get_Java_u8((address)_current); |
| _current += 8; |
| return res; |
| } |
| |
| // Get direct pointer into stream at current position. |
| // Returns NULL if length elements are not remaining. The caller is |
| // responsible for calling skip below if buffer contents is used. |
| const u1* get_u1_buffer() const { |
| return _current; |
| } |
| |
| const u2* get_u2_buffer() const { |
| return (const u2*) _current; |
| } |
| |
| // Skip length u1 or u2 elements from stream |
| void skip_u1(int length, TRAPS) const; |
| void skip_u1_fast(int length) const { |
| _current += length; |
| } |
| |
| void skip_u2(int length, TRAPS) const; |
| void skip_u2_fast(int length) const { |
| _current += 2 * length; |
| } |
| |
| void skip_u4(int length, TRAPS) const; |
| void skip_u4_fast(int length) const { |
| _current += 4 * length; |
| } |
| |
| // Tells whether eos is reached |
| bool at_eos() const { return _current == _buffer_end; } |
| }; |
| |
| #endif // SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP |