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src/share/vm/code/compressedStream.hpp@ac27a9c85bea (annotated)

src/share/vm/code/compressedStream.hpp

Thu, 24 May 2018 18:41:44 +0800

author

aoqi

date

Thu, 24 May 2018 18:41:44 +0800

changeset 8856

ac27a9c85bea

parent 6876

710a3c8b516e

permissions

-rw-r--r--

Merge

aoqi@0	1	/*
aoqi@0	2	* Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
aoqi@0	3	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0	4	*
aoqi@0	5	* This code is free software; you can redistribute it and/or modify it
aoqi@0	6	* under the terms of the GNU General Public License version 2 only, as
aoqi@0	7	* published by the Free Software Foundation.
aoqi@0	8	*
aoqi@0	9	* This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
aoqi@0	12	* version 2 for more details (a copy is included in the LICENSE file that
aoqi@0	13	* accompanied this code).
aoqi@0	14	*
aoqi@0	15	* You should have received a copy of the GNU General Public License version
aoqi@0	16	* 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0	17	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0	18	*
aoqi@0	19	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0	20	* or visit www.oracle.com if you need additional information or have any
aoqi@0	21	* questions.
aoqi@0	22	*
aoqi@0	23	*/
aoqi@0	24
aoqi@0	25	#ifndef SHARE_VM_CODE_COMPRESSEDSTREAM_HPP
aoqi@0	26	#define SHARE_VM_CODE_COMPRESSEDSTREAM_HPP
aoqi@0	27
aoqi@0	28	#include "memory/allocation.hpp"
aoqi@0	29
aoqi@0	30	// Simple interface for filing out and filing in basic types
aoqi@0	31	// Used for writing out and reading in debugging information.
aoqi@0	32
aoqi@0	33	class CompressedStream : public ResourceObj {
aoqi@0	34	friend class VMStructs;
aoqi@0	35	protected:
aoqi@0	36	u_char* _buffer;
aoqi@0	37	int _position;
aoqi@0	38
aoqi@0	39	enum {
aoqi@0	40	// Constants for UNSIGNED5 coding of Pack200
aoqi@0	41	lg_H = 6, H = 1<<lg_H, // number of high codes (64)
aoqi@0	42	L = (1<<BitsPerByte)-H, // number of low codes (192)
aoqi@0	43	MAX_i = 4 // bytes are numbered in (0..4), max 5 bytes
aoqi@0	44	};
aoqi@0	45
aoqi@0	46	// these inlines are defined only in compressedStream.cpp
aoqi@0	47	static inline juint encode_sign(jint value); // for Pack200 SIGNED5
aoqi@0	48	static inline jint decode_sign(juint value); // for Pack200 SIGNED5
aoqi@0	49	static inline juint reverse_int(juint bits); // to trim trailing float 0's
aoqi@0	50
aoqi@0	51	public:
aoqi@0	52	CompressedStream(u_char* buffer, int position = 0) {
aoqi@0	53	_buffer = buffer;
aoqi@0	54	_position = position;
aoqi@0	55	}
aoqi@0	56
aoqi@0	57	u_char* buffer() const { return _buffer; }
aoqi@0	58
aoqi@0	59	// Positioning
aoqi@0	60	int position() const { return _position; }
aoqi@0	61	void set_position(int position) { _position = position; }
aoqi@0	62	};
aoqi@0	63
aoqi@0	64
aoqi@0	65	class CompressedReadStream : public CompressedStream {
aoqi@0	66	private:
aoqi@0	67	inline u_char read() { return _buffer[_position++]; }
aoqi@0	68
aoqi@0	69	jint read_int_mb(jint b0); // UNSIGNED5 coding, 2-5 byte cases
aoqi@0	70
aoqi@0	71	public:
aoqi@0	72	CompressedReadStream(u_char* buffer, int position = 0)
aoqi@0	73	: CompressedStream(buffer, position) {}
aoqi@0	74
aoqi@0	75	jboolean read_bool() { return (jboolean) read(); }
aoqi@0	76	jbyte read_byte() { return (jbyte ) read(); }
aoqi@0	77	jchar read_char() { return (jchar ) read_int(); }
aoqi@0	78	jshort read_short() { return (jshort ) read_signed_int(); }
aoqi@0	79	jint read_int() { jint b0 = read();
aoqi@0	80	if (b0 < L) return b0;
aoqi@0	81	else return read_int_mb(b0);
aoqi@0	82	}
aoqi@0	83	jint read_signed_int();
aoqi@0	84	jfloat read_float(); // jfloat_cast(reverse_int(read_int()))
aoqi@0	85	jdouble read_double(); // jdouble_cast(2*reverse_int(read_int))
aoqi@0	86	jlong read_long(); // jlong_from(2*read_signed_int())
aoqi@0	87	};
aoqi@0	88
aoqi@0	89
aoqi@0	90	class CompressedWriteStream : public CompressedStream {
aoqi@0	91	private:
aoqi@0	92	bool full() {
aoqi@0	93	return _position >= _size;
aoqi@0	94	}
aoqi@0	95	void store(u_char b) {
aoqi@0	96	_buffer[_position++] = b;
aoqi@0	97	}
aoqi@0	98	void write(u_char b) {
aoqi@0	99	if (full()) grow();
aoqi@0	100	store(b);
aoqi@0	101	}
aoqi@0	102	void grow();
aoqi@0	103
aoqi@0	104	void write_int_mb(jint value); // UNSIGNED5 coding, 1-5 byte cases
aoqi@0	105
aoqi@0	106	protected:
aoqi@0	107	int _size;
aoqi@0	108
aoqi@0	109	public:
aoqi@0	110	CompressedWriteStream(int initial_size);
aoqi@0	111	CompressedWriteStream(u_char* buffer, int initial_size, int position = 0)
aoqi@0	112	: CompressedStream(buffer, position) { _size = initial_size; }
aoqi@0	113
aoqi@0	114	void write_bool(jboolean value) { write(value); }
aoqi@0	115	void write_byte(jbyte value) { write(value); }
aoqi@0	116	void write_char(jchar value) { write_int(value); }
aoqi@0	117	void write_short(jshort value) { write_signed_int(value); }
aoqi@0	118	void write_int(jint value) { if ((juint)value < L && !full())
aoqi@0	119	store((u_char)value);
aoqi@0	120	else write_int_mb(value); }
aoqi@0	121	void write_signed_int(jint value); // write_int(encode_sign(value))
aoqi@0	122	void write_float(jfloat value); // write_int(reverse_int(jint_cast(v)))
aoqi@0	123	void write_double(jdouble value); // write_int(reverse_int(<low,high>))
aoqi@0	124	void write_long(jlong value); // write_signed_int(<low,high>)
aoqi@0	125	};
aoqi@0	126
aoqi@0	127	#endif // SHARE_VM_CODE_COMPRESSEDSTREAM_HPP