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_CODE_COMPRESSEDSTREAM_HPP
stefank@2314: #define SHARE_VM_CODE_COMPRESSEDSTREAM_HPP
stefank@2314: 
stefank@2314: #include "memory/allocation.hpp"
stefank@2314: 
duke@435: // Simple interface for filing out and filing in basic types
duke@435: // Used for writing out and reading in debugging information.
duke@435: 
duke@435: class CompressedStream : public ResourceObj {
duke@435:   friend class VMStructs;
duke@435:  protected:
duke@435:   u_char* _buffer;
duke@435:   int     _position;
duke@435: 
duke@435:   enum {
duke@435:     // Constants for UNSIGNED5 coding of Pack200
duke@435:     lg_H = 6, H = 1<<lg_H,    // number of high codes (64)
duke@435:     L = (1<<BitsPerByte)-H,   // number of low codes (192)
duke@435:     MAX_i = 4                 // bytes are numbered in (0..4), max 5 bytes
duke@435:   };
duke@435: 
duke@435:   // these inlines are defined only in compressedStream.cpp
duke@435:   static inline juint encode_sign(jint  value);  // for Pack200 SIGNED5
duke@435:   static inline jint  decode_sign(juint value);  // for Pack200 SIGNED5
duke@435:   static inline juint reverse_int(juint bits);   // to trim trailing float 0's
duke@435: 
duke@435:  public:
duke@435:   CompressedStream(u_char* buffer, int position = 0) {
duke@435:     _buffer   = buffer;
duke@435:     _position = position;
duke@435:   }
duke@435: 
duke@435:   u_char* buffer() const               { return _buffer; }
duke@435: 
duke@435:   // Positioning
duke@435:   int position() const                 { return _position; }
duke@435:   void set_position(int position)      { _position = position; }
duke@435: };
duke@435: 
duke@435: 
duke@435: class CompressedReadStream : public CompressedStream {
duke@435:  private:
duke@435:   inline u_char read()                 { return _buffer[_position++]; }
duke@435: 
duke@435:   jint     read_int_mb(jint b0);  // UNSIGNED5 coding, 2-5 byte cases
duke@435: 
duke@435:  public:
duke@435:   CompressedReadStream(u_char* buffer, int position = 0)
duke@435:   : CompressedStream(buffer, position) {}
duke@435: 
duke@435:   jboolean read_bool()                 { return (jboolean) read();      }
duke@435:   jbyte    read_byte()                 { return (jbyte   ) read();      }
duke@435:   jchar    read_char()                 { return (jchar   ) read_int();  }
duke@435:   jshort   read_short()                { return (jshort  ) read_signed_int(); }
duke@435:   jint     read_int()                  { jint   b0 = read();
duke@435:                                          if (b0 < L)  return b0;
duke@435:                                          else         return read_int_mb(b0);
duke@435:                                        }
duke@435:   jint     read_signed_int();
duke@435:   jfloat   read_float();               // jfloat_cast(reverse_int(read_int()))
duke@435:   jdouble  read_double();              // jdouble_cast(2*reverse_int(read_int))
duke@435:   jlong    read_long();                // jlong_from(2*read_signed_int())
duke@435: };
duke@435: 
duke@435: 
duke@435: class CompressedWriteStream : public CompressedStream {
duke@435:  private:
duke@435:   bool full() {
duke@435:     return _position >= _size;
duke@435:   }
duke@435:   void store(u_char b) {
duke@435:     _buffer[_position++] = b;
duke@435:   }
duke@435:   void write(u_char b) {
duke@435:     if (full()) grow();
duke@435:     store(b);
duke@435:   }
duke@435:   void grow();
duke@435: 
duke@435:   void write_int_mb(jint value);  // UNSIGNED5 coding, 1-5 byte cases
duke@435: 
duke@435:  protected:
duke@435:   int _size;
duke@435: 
duke@435:  public:
duke@435:   CompressedWriteStream(int initial_size);
duke@435:   CompressedWriteStream(u_char* buffer, int initial_size, int position = 0)
duke@435:   : CompressedStream(buffer, position) { _size = initial_size; }
duke@435: 
duke@435:   void write_bool(jboolean value)      { write(value);      }
duke@435:   void write_byte(jbyte value)         { write(value);      }
duke@435:   void write_char(jchar value)         { write_int(value); }
duke@435:   void write_short(jshort value)       { write_signed_int(value);  }
duke@435:   void write_int(jint value)           { if ((juint)value < L && !full())
duke@435:                                                store((u_char)value);
duke@435:                                          else  write_int_mb(value);  }
duke@435:   void write_signed_int(jint value);   // write_int(encode_sign(value))
duke@435:   void write_float(jfloat value);      // write_int(reverse_int(jint_cast(v)))
duke@435:   void write_double(jdouble value);    // write_int(reverse_int(<low,high>))
duke@435:   void write_long(jlong value);        // write_signed_int(<low,high>)
duke@435: };
stefank@2314: 
stefank@2314: #endif // SHARE_VM_CODE_COMPRESSEDSTREAM_HPP