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- <?xml version="1.0" encoding="UTF-8" standalone="no"?>
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- <!-- $Id$ -->
- <!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V1.3//EN" "http://forrest.apache.org/dtd/document-v13.dtd">
-
- <document>
- <header>
- <title>Apache™ FOP Design: Optimisations</title>
- <version>$Revision$</version>
- <authors>
- <person name="Keiron Liddle" email="keiron@aftexsw.com"/>
- </authors>
- </header>
-
- <body>
- <section id="intro">
- <title>Introduction</title>
- <p>
- Apache™ FOP should be able to handle very large documents. A document can be
- supplied using SAX and the information should be passed entirely through
- the system, from fo elements to rendered output as soon as possible.
- </p>
- <p>
- A top level block area, immediately below the flow, can be added to the
- page layout as soon as the element is complete.
- </p>
- <p>
- The fo elements used to construct a page can be discarded as soon as the
- layout for the page is complete. Some information may be stored in the
- area tree of the page in order to handle unresolved page references
- and links.
- </p>
- <p>
- Once the layout of a page has been completed, all elements are fully
- resolved, then the page can be rendered. Some renderers may support
- out of order rendering of pages.
- </p>
- <p>
- The main problem that will remain is that any page with forward
- references will need to be stored until the refence is resolved.
- This means that the information contained in the page should be
- as minimal as possible.
- </p>
- <p>
- Line areas can be optimised once the layout for the line has
- been finalised. Consecutive characters with the same properties
- can be combined into a "word" to hold the information with
- limited overhead.
- </p>
- <p>
- If there are a large number of pages where forward references
- cannot be resolved the a method of writing a page onto disk
- could be used to save memory. The easiest way to achieve this
- is to make the page and all children serializable.
- </p>
- </section>
-
- </body>
- </document>
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