1 /*
   2  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_UTILITIES_XMLSTREAM_HPP
  26 #define SHARE_VM_UTILITIES_XMLSTREAM_HPP
  27 
  28 #include "runtime/handles.hpp"
  29 #include "utilities/ostream.hpp"
  30 
  31 class xmlStream;
  32 class defaultStream;
  33 
  34 // Sub-stream for writing quoted text, as opposed to markup.
  35 // Characters written to this stream are subject to quoting,
  36 // as '<' => "&lt;", etc.
  37 class xmlTextStream : public outputStream {
  38   friend class xmlStream;
  39   friend class defaultStream; // tty
  40  private:
  41 
  42   xmlStream* _outer_xmlStream;
  43 
  44   xmlTextStream() { _outer_xmlStream = NULL; }
  45 
  46  public:
  47    virtual void flush(); // _outer.flush();
  48    virtual void write(const char* str, size_t len); // _outer->write_text()
  49 };
  50 
  51 
  52 // Output stream for writing XML-structured logs.
  53 // To write markup, use special calls elem, head/tail, etc.
  54 // Use the xmlStream::text() stream to write unmarked text.
  55 // Text written that way will be quoted as necessary using '&lt;', etc.
  56 // Characters written directly to an xmlStream via print_cr, etc.,
  57 // are directly written to the encapsulated stream, xmlStream::out().
  58 // This can be used to produce markup directly, character by character.
  59 // (Such writes are not checked for markup syntax errors.)
  60 
  61 class xmlStream : public outputStream {
  62   friend class defaultStream; // tty
  63  public:
  64   enum MarkupState { BODY,       // after end_head() call, in text
  65                      HEAD,       // after begin_head() call, in attrs
  66                      ELEM };     // after begin_elem() call, in attrs
  67 
  68  protected:
  69   outputStream* _out;            // file stream by which it goes
  70   julong        _last_flush;     // last position of flush
  71   MarkupState   _markup_state;   // where in the elem/head/tail dance
  72   outputStream* _text;           // text stream
  73   xmlTextStream _text_init;
  74 
  75   // for subclasses
  76   xmlStream() {}
  77   void initialize(outputStream* out);
  78 
  79   // protect this from public use:
  80   outputStream* out()                            { return _out; }
  81 
  82   // helpers for writing XML elements
  83   void          va_tag(bool push, const char* format, va_list ap);
  84   virtual void see_tag(const char* tag, bool push) NOT_DEBUG({});
  85   virtual void pop_tag(const char* tag) NOT_DEBUG({});
  86 
  87 #ifdef ASSERT
  88   // in debug mode, we verify matching of opening and closing tags
  89   int   _element_depth;              // number of unfinished elements
  90   char* _element_close_stack_high;   // upper limit of down-growing stack
  91   char* _element_close_stack_low;    // upper limit of down-growing stack
  92   char* _element_close_stack_ptr;    // pointer of down-growing stack
  93 #endif
  94 
  95  public:
  96   // creation
  97   xmlStream(outputStream* out) { initialize(out); }
  98   DEBUG_ONLY(virtual ~xmlStream();)
  99 
 100   bool is_open() { return _out != NULL; }
 101 
 102   // text output
 103   bool inside_attrs() { return _markup_state != BODY; }
 104 
 105   // flushing
 106   virtual void flush();  // flushes out, sets _last_flush = count()
 107   virtual void write(const char* s, size_t len);
 108   void    write_text(const char* s, size_t len);  // used by xmlTextStream
 109   int unflushed_count() { return (int)(out()->count() - _last_flush); }
 110 
 111   // writing complete XML elements
 112   void          elem(const char* format, ...);
 113   void    begin_elem(const char* format, ...);
 114   void      end_elem(const char* format, ...);
 115   void      end_elem();
 116   void          head(const char* format, ...);
 117   void    begin_head(const char* format, ...);
 118   void      end_head(const char* format, ...);
 119   void      end_head();
 120   void          done(const char* format, ...);  // xxx_done event, plus tail
 121   void          done_raw(const char * kind);
 122   void          tail(const char* kind);
 123 
 124   // va_list versions
 125   void       va_elem(const char* format, va_list ap);
 126   void va_begin_elem(const char* format, va_list ap);
 127   void       va_head(const char* format, va_list ap);
 128   void va_begin_head(const char* format, va_list ap);
 129   void       va_done(const char* format, va_list ap);
 130 
 131   // write text (with quoting of special XML characters <>&'" etc.)
 132   outputStream* text() { return _text; }
 133   void          text(const char* format, ...);
 134   void       va_text(const char* format, va_list ap) {
 135     text()->vprint(format, ap);
 136   }
 137 
 138   // commonly used XML attributes
 139   void          stamp();                 // stamp='1.234'
 140   void          method(methodHandle m);  // method='k n s' ...
 141   void          klass(KlassHandle k);    // klass='name'
 142   void          name(symbolHandle s);    // name='name'
 143   void          object(const char* attr, Handle val);
 144 
 145   // print the text alone (sans ''):
 146   void          method_text(methodHandle m);
 147   void          klass_text(KlassHandle k);    // klass='name'
 148   void          name_text(symbolHandle s);    // name='name'
 149   void          object_text(Handle x);
 150 
 151   /*  Example uses:
 152 
 153       // Empty element, simple case.
 154       elem("X Y='Z'");          <X Y='Z'/> \n
 155 
 156       // Empty element, general case.
 157       begin_elem("X Y='Z'");    <X Y='Z'
 158       ...attrs...               ...attrs...
 159       end_elem();               />
 160 
 161       // Compound element, simple case.
 162       head("X Y='Z'");          <X Y='Z'> \n
 163       ...body...                ...body...
 164       tail("X");                </X> \n
 165 
 166       // Compound element, general case.
 167       begin_head("X Y='Z'");    <X Y='Z'
 168       ...attrs...               ...attrs...
 169       end_head();               > \n
 170       ...body...                ...body...
 171       tail("X");                </X> \n
 172 
 173       // Printf-style formatting:
 174       elem("X Y='%s'", "Z");    <X Y='Z'/> \n
 175 
 176    */
 177 
 178 };
 179 
 180 // Standard log file, null if no logging is happening.
 181 extern xmlStream* xtty;
 182 
 183 // Note:  If ::xtty != NULL, ::tty == ::xtty->text().
 184 
 185 #endif // SHARE_VM_UTILITIES_XMLSTREAM_HPP