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src/share/vm/classfile/classFileStream.hpp@a61af66fc99e (annotated)

src/share/vm/classfile/classFileStream.hpp

Sat, 01 Dec 2007 00:00:00 +0000

author

duke

date

Sat, 01 Dec 2007 00:00:00 +0000

changeset 435

a61af66fc99e

child 1907

c18cbe5936b8

permissions

-rw-r--r--

Initial load

duke@435	1	/*
duke@435	2	* Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved.
duke@435	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
duke@435	4	*
duke@435	5	* This code is free software; you can redistribute it and/or modify it
duke@435	6	* under the terms of the GNU General Public License version 2 only, as
duke@435	7	* published by the Free Software Foundation.
duke@435	8	*
duke@435	9	* This code is distributed in the hope that it will be useful, but WITHOUT
duke@435	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
duke@435	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
duke@435	12	* version 2 for more details (a copy is included in the LICENSE file that
duke@435	13	* accompanied this code).
duke@435	14	*
duke@435	15	* You should have received a copy of the GNU General Public License version
duke@435	16	* 2 along with this work; if not, write to the Free Software Foundation,
duke@435	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
duke@435	18	*
duke@435	19	* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
duke@435	20	* CA 95054 USA or visit www.sun.com if you need additional information or
duke@435	21	* have any questions.
duke@435	22	*
duke@435	23	*/
duke@435	24
duke@435	25	// Input stream for reading .class file
duke@435	26	//
duke@435	27	// The entire input stream is present in a buffer allocated by the caller.
duke@435	28	// The caller is responsible for deallocating the buffer and for using
duke@435	29	// ResourceMarks appropriately when constructing streams.
duke@435	30
duke@435	31	class ClassFileStream: public ResourceObj {
duke@435	32	private:
duke@435	33	u1* _buffer_start; // Buffer bottom
duke@435	34	u1* _buffer_end; // Buffer top (one past last element)
duke@435	35	u1* _current; // Current buffer position
duke@435	36	char* _source; // Source of stream (directory name, ZIP/JAR archive name)
duke@435	37	bool _need_verify; // True if verification is on for the class file
duke@435	38
duke@435	39	void truncated_file_error(TRAPS);
duke@435	40	public:
duke@435	41	// Constructor
duke@435	42	ClassFileStream(u1* buffer, int length, char* source);
duke@435	43
duke@435	44	// Buffer access
duke@435	45	u1* buffer() const { return _buffer_start; }
duke@435	46	int length() const { return _buffer_end - _buffer_start; }
duke@435	47	u1* current() const { return _current; }
duke@435	48	void set_current(u1* pos) { _current = pos; }
duke@435	49	char* source() const { return _source; }
duke@435	50	void set_verify(bool flag) { _need_verify = flag; }
duke@435	51
duke@435	52	void check_truncated_file(bool b, TRAPS) {
duke@435	53	if (b) {
duke@435	54	truncated_file_error(THREAD);
duke@435	55	}
duke@435	56	}
duke@435	57
duke@435	58	void guarantee_more(int size, TRAPS) {
duke@435	59	size_t remaining = (size_t)(_buffer_end - _current);
duke@435	60	unsigned int usize = (unsigned int)size;
duke@435	61	check_truncated_file(usize > remaining, CHECK);
duke@435	62	}
duke@435	63
duke@435	64	// Read u1 from stream
duke@435	65	u1 get_u1(TRAPS);
duke@435	66	u1 get_u1_fast() {
duke@435	67	return *_current++;
duke@435	68	}
duke@435	69
duke@435	70	// Read u2 from stream
duke@435	71	u2 get_u2(TRAPS);
duke@435	72	u2 get_u2_fast() {
duke@435	73	u2 res = Bytes::get_Java_u2(_current);
duke@435	74	_current += 2;
duke@435	75	return res;
duke@435	76	}
duke@435	77
duke@435	78	// Read u4 from stream
duke@435	79	u4 get_u4(TRAPS);
duke@435	80	u4 get_u4_fast() {
duke@435	81	u4 res = Bytes::get_Java_u4(_current);
duke@435	82	_current += 4;
duke@435	83	return res;
duke@435	84	}
duke@435	85
duke@435	86	// Read u8 from stream
duke@435	87	u8 get_u8(TRAPS);
duke@435	88	u8 get_u8_fast() {
duke@435	89	u8 res = Bytes::get_Java_u8(_current);
duke@435	90	_current += 8;
duke@435	91	return res;
duke@435	92	}
duke@435	93
duke@435	94	// Get direct pointer into stream at current position.
duke@435	95	// Returns NULL if length elements are not remaining. The caller is
duke@435	96	// responsible for calling skip below if buffer contents is used.
duke@435	97	u1* get_u1_buffer() {
duke@435	98	return _current;
duke@435	99	}
duke@435	100
duke@435	101	u2* get_u2_buffer() {
duke@435	102	return (u2*) _current;
duke@435	103	}
duke@435	104
duke@435	105	// Skip length u1 or u2 elements from stream
duke@435	106	void skip_u1(int length, TRAPS);
duke@435	107	void skip_u1_fast(int length) {
duke@435	108	_current += length;
duke@435	109	}
duke@435	110
duke@435	111	void skip_u2(int length, TRAPS);
duke@435	112	void skip_u2_fast(int length) {
duke@435	113	_current += 2 * length;
duke@435	114	}
duke@435	115
duke@435	116	// Tells whether eos is reached
duke@435	117	bool at_eos() const { return _current == _buffer_end; }
duke@435	118	};