/[gzz]/manuscripts/Alph1/alph.rst
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revision 1.1 by tjl, Mon Sep 15 10:42:10 2003 UTC revision 1.2 by tjl, Wed Sep 17 07:44:39 2003 UTC
# Line 14  of the Xanalogical referential fluid med Line 14  of the Xanalogical referential fluid med
14  We present three techniques to make the model  We present three techniques to make the model
15  easily applicable to modern systems.  easily applicable to modern systems.
16    
17    The permanent addresses in the spans refer to *scrollblocks*,
18    clearly delimited, permanent blocks
19    of fluid media data. A span can only contain fluid media units
20    from one scrollblock.
21    
22  Random-id content-carrying spans are useful for text:  Random-id content-carrying spans are useful for text:
23  they allow most of the advantages  they allow most of the advantages
24  of Xanalogical fluid media with only an increase  of Xanalogical fluid media with only an increase
25  in space in non-Xanalogical uses, i.e., no  in space in non-Xanalogical uses, i.e., no
26  fetching the content of the span from afar.  fetching the content of the span from afar.
27    
 The permanent addresses in the spans refer to *scrollblocks*,  
 clearly delimited, permanent blocks  
 of fluid media data. A span can only contain fluid media units  
 from one scrollblock.  
   
28  PageImage scrollblocks are used for interoperability  PageImage scrollblocks are used for interoperability
29  with the modern real world, where  with the modern real world, where
30  receiving PDFs and Postscript files, i.e., images of pages, is a reality.  receiving PDFs and Postscript files, i.e., images of pages, is a reality.
# Line 44  The abstraction of the fundamental idea Line 44  The abstraction of the fundamental idea
44  systems described in [nelson99xanalogicalneeded]_  systems described in [nelson99xanalogicalneeded]_
45  is, formally,  is, formally,
46    
47  Making an implementation of referential fluid media practical  Making an implementation of referential fluid media practical: Two concrete models
48  =============================================================  ==================================================================================
49    
50  In this section, we present the three most important developments  In this section, we present two different
51    
52  As discussed by Nelson [nelson99xanalogicalneeded]_,  As discussed by Nelson [nelson99xanalogicalneeded]_,
53  the most fundamental and secret idea  the most fundamental and secret idea
# Line 57  pixel of image, sample of sound, pixel i Line 57  pixel of image, sample of sound, pixel i
57  with a permanent, universal  with a permanent, universal
58  identifier.  identifier.
59    
60  Scrollblocks  Content-addressed RFM (CARFM)
61  ------------  -------------------------------------------------
62    
63    Content addressing is a ... hash (NOTE)
64    
65    http://www.intranetjournal.com/articles/200306/ij_06_04_03a.html
66    
67    Instead of continuous permascrolls as the Udanax implementation uses,
68    the content-addressed referential fluid media (CARFM) model is based on
69    *scrollblocks* which are fixed blocks of fluid media referenced through
70    content-addressing.
71    
72    ... A *span* in Alph is a reference to a single, contiguous (rectangular)
73    block of fluid media units
74    inside a single scrollblock.
75    
76  We have presented the basic idea of scrollblocks in [lukka02guids]_,  Inserting text character by character is achieved through first creating
77    a *temporary*, modifiable scroll block and temporary span objects
78    using that, and converting the temporary scrollblock into a permanent,
79    content-addressed scroll block before saving the data.
80    
81    We have first presented the basic idea of using scrollblocks in [lukka02guids]_,
82    
83  Random-id content-carrying spans  Random-id content-carrying RFM (RICC RFM)
84  --------------------------------  -----------------------------------------
85    
86  Random-id content-carrying (RICC) spans are a novel twist  Random-id content-carrying (RICC) spans are a novel twist
87  on the basic referential fluid  on the basic referential fluid
# Line 80  Storing the actual content in the span i Line 97  Storing the actual content in the span i
97  there is no real  there is no real
98  reference in them, just the identifier.  reference in them, just the identifier.
99    
100  The spans with the same UUID form a virtual scrollblock...  - ... random numbers of 160 bits sufficient for ...
101    
102  Pros:  Pros:
103    
# Line 104  Cons: Line 121  Cons:
121      - not, e.g., the full keystroke record envisioned by Nelson      - not, e.g., the full keystroke record envisioned by Nelson
122        (private communication)        (private communication)
123    
124  PageImage Spans  - Spoofing ?
 ---------------  
125    
126        - cannot really do damage, as comparison is applied to *both* id *and* content
127    
128    
129  The Alph Fluid Media Model formally  Operability in a real-world context
130  ===================================  ===================================
131    
132  The Alph Fluid Media Model (AFMM) is a simple model  Page Image Spans (PS/PDF/DjVu/...)
133  based on the lowest-level referential fluid media concepts  ----------------------------------
 of the Xanalogical model.  
   
 Instead of continuous permascrolls as the Udanax implementation uses,  
 the Alph model is based on *scrollblocks* which are fixed blocks  
 of permanent media.  
   
 A *span* in Alph is a reference to a single, contiguous (rectangular)  
 block of fluid media units  
 inside a single scrollblock.  
134    
135    The support for *PageImages* is one of the aspects of Alph geared
136    towards reasonable operability in a modern context.
137    
138  Storm URIs  Fake Spans
139  ----------  ----------
140    
141  - Like Data URIs, but with content hashes instead of data  The Alph Content Format
142    =======================
 Text  
 ----  
   
 We have developed three different types of text spans  
   
 Storm text spans  
 """"""""""""""""  
   
 Storm text spans [lukka02guids]_ are the earliest  
 of the text spans developed  
 for Alph. A storm text span is simply a Storm URI  
 along with an offset and a length.  
143    
144  XXX Character sets?  - XML format used by ALPH
145    
146    - incl. URN-5, Storm URI
147    of the Xanalogical model.
148    
 Images  
 ------  
149    
150    Storm URIs
151    ----------
152    
153    - Like Data URIs, but with content hashes instead of data
154    
155  PageImages (PS/PDF/DjVu/...)  URN-5
156  ----------------------------  -----
157    
158  The support for *PageImages* is one of the aspects of Alph geared  The Alph DTD
159  towards reasonable operability in a modern context.  ------------
160    
161    
162  Implementation in Java + OpenGL  Implementation in Java + OpenGL
# Line 182  We call our model the Alph Fluid Media M Line 183  We call our model the Alph Fluid Media M
183  The name Alph has its origins in the same poem as Xanadu(tm),  The name Alph has its origins in the same poem as Xanadu(tm),
184  as the "sacred river".  as the "sacred river".
185    
186    160 bits of randomness, or of hash are sufficient. blah blah
187    
188    
189  The full model in a modern context  The full model in a modern context
190  ==================================  ==================================
191    
192    
193    
194  Aspects that have been implemented in other systems  Aspects that have been implemented in other systems
195  ---------------------------------------------------  ---------------------------------------------------
196    

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