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<concept id="GUID-C15F56E3-753C-55CA-B3EF-63B2D139BCE4" xml:lang="en"><title>Dynamic

Buffers Overview</title><shortdesc>This document provides an overview of dynamic buffers.</shortdesc><prolog><metadata><keywords/></metadata></prolog><conbody>

<section id="GUID-48A3C000-BAAB-4F20-801C-1F6E7C24C93D"><title>Purpose</title> <p>Manipulates data buffers of variable length.</p> <p>For

fixed length data buffers, or buffers whose length does not vary much from

a known maximum size, use descriptors rather than this API.</p> </section>

<section id="GUID-092B2DE6-4E3D-424A-879A-B7BEC34796B0"><title>Description</title> <p>The API has three key concepts: dynamic

buffer base, flat dynamic buffer, and segmented dynamic buffer. </p> <p><b>Dynamic

buffer base</b> </p> <p>The dynamic buffer base specifies a common interface

to dynamic buffers. It provides operations to manage the buffer position,

a byte offset into the buffer’s data. Clients use a buffer position to reference

the buffer, rather than explicit pointers, which can become outdated when

reallocations occur.</p> <p>The dynamic buffer base interface is provided

by the abstract class <xref href="GUID-33BEE1B4-20A1-392B-89B3-DA5D4F46418E.dita"><apiname>CBufBase</apiname></xref>.</p> <p><b>Flat dynamic buffer</b> </p> <p>The flat dynamic buffer stores all data

in a single contiguous memory area. A flat buffer is the most efficient choice

when resizing the buffer beyond a certain maximum length is not expected often.</p> <p>The

flat dynamic buffer interface is provided by <xref href="GUID-F915EF7D-7C06-3902-AB84-C8E89ABE7F18.dita"><apiname>CBufFlat</apiname></xref>.</p> <p><b>Segmented dynamic buffer</b> </p> <p>The segmented dynamic buffer can

store data in multiple memory areas. They are to be preferred for very large

amounts of data, and where resizing of the buffer is commonly expected. </p> <p>The

segmented dynamic buffer interface is provided by <xref href="GUID-74CD841C-49EE-3512-9C05-2A05924A63A7.dita"><apiname>CBufSeg</apiname></xref>.</p> </section>

<section id="GUID-1DA4B527-F43B-4762-A747-C0F639A14291"><title>See also</title> <p><xref href="GUID-0817AD1D-58CF-5108-ACBF-26DFD4BA395E.dita">Descriptors

Overview</xref> </p> </section>

</conbody></concept>