duke@435: /*
stefank@2314:  * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
duke@435:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435:  *
duke@435:  * This code is free software; you can redistribute it and/or modify it
duke@435:  * under the terms of the GNU General Public License version 2 only, as
duke@435:  * published by the Free Software Foundation.
duke@435:  *
duke@435:  * This code is distributed in the hope that it will be useful, but WITHOUT
duke@435:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
duke@435:  * version 2 for more details (a copy is included in the LICENSE file that
duke@435:  * accompanied this code).
duke@435:  *
duke@435:  * You should have received a copy of the GNU General Public License version
duke@435:  * 2 along with this work; if not, write to the Free Software Foundation,
duke@435:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
duke@435:  *
duke@435:  */
duke@435: 
stefank@2314: #ifndef SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP
stefank@2314: #define SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP
stefank@2314: 
stefank@2314: #include "utilities/top.hpp"
stefank@2314: #ifdef TARGET_ARCH_x86
stefank@2314: # include "bytes_x86.hpp"
stefank@2314: #endif
stefank@2314: #ifdef TARGET_ARCH_sparc
stefank@2314: # include "bytes_sparc.hpp"
stefank@2314: #endif
stefank@2314: #ifdef TARGET_ARCH_zero
stefank@2314: # include "bytes_zero.hpp"
stefank@2314: #endif
stefank@2314: 
duke@435: // Input stream for reading .class file
duke@435: //
duke@435: // The entire input stream is present in a buffer allocated by the caller.
duke@435: // The caller is responsible for deallocating the buffer and for using
duke@435: // ResourceMarks appropriately when constructing streams.
duke@435: 
duke@435: class ClassFileStream: public ResourceObj {
duke@435:  private:
duke@435:   u1*   _buffer_start; // Buffer bottom
duke@435:   u1*   _buffer_end;   // Buffer top (one past last element)
duke@435:   u1*   _current;      // Current buffer position
duke@435:   char* _source;       // Source of stream (directory name, ZIP/JAR archive name)
duke@435:   bool  _need_verify;  // True if verification is on for the class file
duke@435: 
duke@435:   void truncated_file_error(TRAPS);
duke@435:  public:
duke@435:   // Constructor
duke@435:   ClassFileStream(u1* buffer, int length, char* source);
duke@435: 
duke@435:   // Buffer access
duke@435:   u1* buffer() const           { return _buffer_start; }
duke@435:   int length() const           { return _buffer_end - _buffer_start; }
duke@435:   u1* current() const          { return _current; }
duke@435:   void set_current(u1* pos)    { _current = pos; }
duke@435:   char* source() const         { return _source; }
duke@435:   void set_verify(bool flag)   { _need_verify = flag; }
duke@435: 
duke@435:   void check_truncated_file(bool b, TRAPS) {
duke@435:     if (b) {
duke@435:       truncated_file_error(THREAD);
duke@435:     }
duke@435:   }
duke@435: 
duke@435:   void guarantee_more(int size, TRAPS) {
duke@435:     size_t remaining = (size_t)(_buffer_end - _current);
duke@435:     unsigned int usize = (unsigned int)size;
duke@435:     check_truncated_file(usize > remaining, CHECK);
duke@435:   }
duke@435: 
duke@435:   // Read u1 from stream
duke@435:   u1 get_u1(TRAPS);
duke@435:   u1 get_u1_fast() {
duke@435:     return *_current++;
duke@435:   }
duke@435: 
duke@435:   // Read u2 from stream
duke@435:   u2 get_u2(TRAPS);
duke@435:   u2 get_u2_fast() {
duke@435:     u2 res = Bytes::get_Java_u2(_current);
duke@435:     _current += 2;
duke@435:     return res;
duke@435:   }
duke@435: 
duke@435:   // Read u4 from stream
duke@435:   u4 get_u4(TRAPS);
duke@435:   u4 get_u4_fast() {
duke@435:     u4 res = Bytes::get_Java_u4(_current);
duke@435:     _current += 4;
duke@435:     return res;
duke@435:   }
duke@435: 
duke@435:   // Read u8 from stream
duke@435:   u8 get_u8(TRAPS);
duke@435:   u8 get_u8_fast() {
duke@435:     u8 res = Bytes::get_Java_u8(_current);
duke@435:     _current += 8;
duke@435:     return res;
duke@435:   }
duke@435: 
duke@435:   // Get direct pointer into stream at current position.
duke@435:   // Returns NULL if length elements are not remaining. The caller is
duke@435:   // responsible for calling skip below if buffer contents is used.
duke@435:   u1* get_u1_buffer() {
duke@435:     return _current;
duke@435:   }
duke@435: 
duke@435:   u2* get_u2_buffer() {
duke@435:     return (u2*) _current;
duke@435:   }
duke@435: 
duke@435:   // Skip length u1 or u2 elements from stream
duke@435:   void skip_u1(int length, TRAPS);
duke@435:   void skip_u1_fast(int length) {
duke@435:     _current += length;
duke@435:   }
duke@435: 
duke@435:   void skip_u2(int length, TRAPS);
duke@435:   void skip_u2_fast(int length) {
duke@435:     _current += 2 * length;
duke@435:   }
duke@435: 
duke@435:   // Tells whether eos is reached
duke@435:   bool at_eos() const          { return _current == _buffer_end; }
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_CLASSFILE_CLASSFILESTREAM_HPP