Mercurial > hg > truffle
diff src/share/vm/code/compressedStream.hpp @ 0:a61af66fc99e jdk7-b24
Initial load
author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
parents | |
children | c18cbe5936b8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/code/compressedStream.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,120 @@ +/* + * 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. + * + */ + +// Simple interface for filing out and filing in basic types +// Used for writing out and reading in debugging information. + +class CompressedStream : public ResourceObj { + friend class VMStructs; + protected: + u_char* _buffer; + int _position; + + enum { + // Constants for UNSIGNED5 coding of Pack200 + lg_H = 6, H = 1<<lg_H, // number of high codes (64) + L = (1<<BitsPerByte)-H, // number of low codes (192) + MAX_i = 4 // bytes are numbered in (0..4), max 5 bytes + }; + + // these inlines are defined only in compressedStream.cpp + static inline juint encode_sign(jint value); // for Pack200 SIGNED5 + static inline jint decode_sign(juint value); // for Pack200 SIGNED5 + static inline juint reverse_int(juint bits); // to trim trailing float 0's + + public: + CompressedStream(u_char* buffer, int position = 0) { + _buffer = buffer; + _position = position; + } + + u_char* buffer() const { return _buffer; } + + // Positioning + int position() const { return _position; } + void set_position(int position) { _position = position; } +}; + + +class CompressedReadStream : public CompressedStream { + private: + inline u_char read() { return _buffer[_position++]; } + + jint read_int_mb(jint b0); // UNSIGNED5 coding, 2-5 byte cases + + public: + CompressedReadStream(u_char* buffer, int position = 0) + : CompressedStream(buffer, position) {} + + jboolean read_bool() { return (jboolean) read(); } + jbyte read_byte() { return (jbyte ) read(); } + jchar read_char() { return (jchar ) read_int(); } + jshort read_short() { return (jshort ) read_signed_int(); } + jint read_int() { jint b0 = read(); + if (b0 < L) return b0; + else return read_int_mb(b0); + } + jint read_signed_int(); + jfloat read_float(); // jfloat_cast(reverse_int(read_int())) + jdouble read_double(); // jdouble_cast(2*reverse_int(read_int)) + jlong read_long(); // jlong_from(2*read_signed_int()) +}; + + +class CompressedWriteStream : public CompressedStream { + private: + bool full() { + return _position >= _size; + } + void store(u_char b) { + _buffer[_position++] = b; + } + void write(u_char b) { + if (full()) grow(); + store(b); + } + void grow(); + + void write_int_mb(jint value); // UNSIGNED5 coding, 1-5 byte cases + + protected: + int _size; + + public: + CompressedWriteStream(int initial_size); + CompressedWriteStream(u_char* buffer, int initial_size, int position = 0) + : CompressedStream(buffer, position) { _size = initial_size; } + + void write_bool(jboolean value) { write(value); } + void write_byte(jbyte value) { write(value); } + void write_char(jchar value) { write_int(value); } + void write_short(jshort value) { write_signed_int(value); } + void write_int(jint value) { if ((juint)value < L && !full()) + store((u_char)value); + else write_int_mb(value); } + void write_signed_int(jint value); // write_int(encode_sign(value)) + void write_float(jfloat value); // write_int(reverse_int(jint_cast(v))) + void write_double(jdouble value); // write_int(reverse_int(<low,high>)) + void write_long(jlong value); // write_signed_int(<low,high>) +};