| /* |
| * Copyright 1997-2005 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| * |
| */ |
| |
| // 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 ClassFileStream: public ResourceObj { |
| private: |
| u1* _buffer_start; // Buffer bottom |
| u1* _buffer_end; // Buffer top (one past last element) |
| u1* _current; // Current buffer position |
| char* _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); |
| public: |
| // Constructor |
| ClassFileStream(u1* buffer, int length, char* source); |
| |
| // Buffer access |
| u1* buffer() const { return _buffer_start; } |
| int length() const { return _buffer_end - _buffer_start; } |
| u1* current() const { return _current; } |
| void set_current(u1* pos) { _current = pos; } |
| char* source() const { return _source; } |
| void set_verify(bool flag) { _need_verify = flag; } |
| |
| void check_truncated_file(bool b, TRAPS) { |
| if (b) { |
| truncated_file_error(THREAD); |
| } |
| } |
| |
| void guarantee_more(int size, TRAPS) { |
| 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); |
| u1 get_u1_fast() { |
| return *_current++; |
| } |
| |
| // Read u2 from stream |
| u2 get_u2(TRAPS); |
| u2 get_u2_fast() { |
| u2 res = Bytes::get_Java_u2(_current); |
| _current += 2; |
| return res; |
| } |
| |
| // Read u4 from stream |
| u4 get_u4(TRAPS); |
| u4 get_u4_fast() { |
| u4 res = Bytes::get_Java_u4(_current); |
| _current += 4; |
| return res; |
| } |
| |
| // Read u8 from stream |
| u8 get_u8(TRAPS); |
| u8 get_u8_fast() { |
| u8 res = Bytes::get_Java_u8(_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. |
| u1* get_u1_buffer() { |
| return _current; |
| } |
| |
| u2* get_u2_buffer() { |
| return (u2*) _current; |
| } |
| |
| // Skip length u1 or u2 elements from stream |
| void skip_u1(int length, TRAPS); |
| void skip_u1_fast(int length) { |
| _current += length; |
| } |
| |
| void skip_u2(int length, TRAPS); |
| void skip_u2_fast(int length) { |
| _current += 2 * length; |
| } |
| |
| // Tells whether eos is reached |
| bool at_eos() const { return _current == _buffer_end; } |
| }; |