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    10 <!DOCTYPE concept

    11   PUBLIC "-//OASIS//DTD DITA Concept//EN" "concept.dtd">

    12 <concept id="GUID-763A2636-D448-5353-9E31-F61FE7EB39DA" xml:lang="en"><title>Flat

    13 or segmented buffer?</title><shortdesc>Describes the occasions you should choose a flat buffer and when

    14 to choose a segmented buffers.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

    15 <p>The choice between using an array implemented with a flat buffer against

    16 using an array implemented with a segmented buffer depends on the characteristics

    17 of the application.</p>

    18 <p>Choose a flat buffer:</p>

    19 <ul>

    20 <li id="GUID-0FC7D827-EA67-598C-8DE6-91860661DA7C"><p>if efficiency in transforming

    21 between buffer position and memory address is very important.</p> </li>

    22 <li id="GUID-73802049-15D7-550A-8093-87BF3CA2E387"><p>if the re-allocations

    23 needed to extend the buffer are sufficiently rare that they do not cause intolerable

    24 amounts of data copying or heap fragmentation.</p> </li>

    25 <li id="GUID-2129EE71-7859-5B77-91FD-F036348C92D6"><p>if there is an upper

    26 bound on the size limit and can reserve sufficient room before inserting elements.</p> </li>

    27 </ul>

    28 <p>Choose a segmented buffer:</p>

    29 <ul>

    30 <li id="GUID-912802E0-C66D-56F1-9977-6B04BFD833AC"><p>to minimise the heap

    31 thrashing and copying that can be associated with reallocating

    32 a single flat buffer.</p> </li>

    33 <li id="GUID-CE5DB4C3-BC72-5D09-B55A-552D08CB8EF6"><p>if the performance of

    34 frequent insertions and deletions is a concern. This can be better with segmented

    35 buffers, because not all data after the insertion/deletion point needs to

    36 be shuffled to complete the operation.</p> </li>

    37 </ul>

    38 </conbody></concept>