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efe780dcf13b2b95effabf897d694d8f23feac74trawick [<!ENTITY mdash "&#8212;">]>

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1122585e1e00bb81e9d0f054bf5c318cec23aa7dminfrin<refentry>

1122585e1e00bb81e9d0f054bf5c318cec23aa7dminfrin <refentryinfo>

1122585e1e00bb81e9d0f054bf5c318cec23aa7dminfrin <date>June 18, 2007</date>

b4e664baba9a4be0457c31f84b3dcc4c31f2cb07kbrand </refentryinfo>

b4e664baba9a4be0457c31f84b3dcc4c31f2cb07kbrand

b4e664baba9a4be0457c31f84b3dcc4c31f2cb07kbrand <refmeta>

b4e664baba9a4be0457c31f84b3dcc4c31f2cb07kbrand <refentrytitle>lwres_buffer</refentrytitle>

a52dab9b245d2bc88feacc380eb94bd6abcd5dd0kbrand <manvolnum>3</manvolnum>

b4e664baba9a4be0457c31f84b3dcc4c31f2cb07kbrand <refmiscinfo>BIND9</refmiscinfo>

ac0c8366f49659958162b4bfb3d625a77343eda3kbrand </refmeta>

ac0c8366f49659958162b4bfb3d625a77343eda3kbrand

001a44c352f89c9ec332ffd3e0a6927dcd19432chumbedooh <docinfo>

001a44c352f89c9ec332ffd3e0a6927dcd19432chumbedooh <copyright>

001a44c352f89c9ec332ffd3e0a6927dcd19432chumbedooh <year>2004</year>

efe780dcf13b2b95effabf897d694d8f23feac74trawick <year>2005</year>

793214f67dede32edfd9ee96c664ead04d175cbbjfclere <year>2007</year>

cc5a4a08dc9783fcbc52ce86f11e01c281a43810minfrin <year>2014</year>

33124689065ade0dfc8c54d8ebb734f9439cb89btrawick <holder>Internet Systems Consortium, Inc. ("ISC")</holder>

33124689065ade0dfc8c54d8ebb734f9439cb89btrawick </copyright>

33124689065ade0dfc8c54d8ebb734f9439cb89btrawick <copyright>

3ccfc257819b3bad063cd3ac9dd1670d5d2ae4d2kbrand <year>2000</year>

3ccfc257819b3bad063cd3ac9dd1670d5d2ae4d2kbrand <year>2001</year>

3ccfc257819b3bad063cd3ac9dd1670d5d2ae4d2kbrand <holder>Internet Software Consortium.</holder>

3ccfc257819b3bad063cd3ac9dd1670d5d2ae4d2kbrand </copyright>

9b0076ddd1103e5fa9c1f9bafde4b06ce244fbaecovener </docinfo>

9b0076ddd1103e5fa9c1f9bafde4b06ce244fbaecovener

9b0076ddd1103e5fa9c1f9bafde4b06ce244fbaecovener <refnamediv>

249d09d51808cb7981af99762c3b3736ca126cd5jkaluza <refname>lwres_buffer_init</refname>

249d09d51808cb7981af99762c3b3736ca126cd5jkaluza <refname>lwres_buffer_invalidate</refname>

249d09d51808cb7981af99762c3b3736ca126cd5jkaluza <refname>lwres_buffer_add</refname>

249d09d51808cb7981af99762c3b3736ca126cd5jkaluza <refname>lwres_buffer_subtract</refname>

56589be3d7a3e9343370df240010c6928cc78b39jkaluza <refname>lwres_buffer_clear</refname>

56589be3d7a3e9343370df240010c6928cc78b39jkaluza <refname>lwres_buffer_first</refname>

56589be3d7a3e9343370df240010c6928cc78b39jkaluza <refname>lwres_buffer_forward</refname>

8c4967445b49a1612b3f98c1dada65e597ecfe26trawick <refname>lwres_buffer_back</refname>

8c4967445b49a1612b3f98c1dada65e597ecfe26trawick <refname>lwres_buffer_getuint8</refname>

8c4967445b49a1612b3f98c1dada65e597ecfe26trawick <refname>lwres_buffer_putuint8</refname>

61fefed8ce5211c31b44f3a38a6e76ca055e5780trawick <refname>lwres_buffer_getuint16</refname>

61fefed8ce5211c31b44f3a38a6e76ca055e5780trawick <refname>lwres_buffer_putuint16</refname>

61fefed8ce5211c31b44f3a38a6e76ca055e5780trawick <refname>lwres_buffer_getuint32</refname>

61fefed8ce5211c31b44f3a38a6e76ca055e5780trawick <refname>lwres_buffer_putuint32</refname>

6001d914962deabb83a46251001612e969bdf67ajim <refname>lwres_buffer_putmem</refname>

6001d914962deabb83a46251001612e969bdf67ajim <refname>lwres_buffer_getmem</refname>

6001d914962deabb83a46251001612e969bdf67ajim <refpurpose>lightweight resolver buffer management</refpurpose>

c4e8006db0cf457c68876d7d4c30dcc451d8cba7jkaluza </refnamediv>

c4e8006db0cf457c68876d7d4c30dcc451d8cba7jkaluza

c4e8006db0cf457c68876d7d4c30dcc451d8cba7jkaluza <refsynopsisdiv>

652bacc79dd7f980249784cc8c4838e8f1de7e8acovener

652bacc79dd7f980249784cc8c4838e8f1de7e8acovener <funcsynopsis>

652bacc79dd7f980249784cc8c4838e8f1de7e8acovener<funcsynopsisinfo>

652bacc79dd7f980249784cc8c4838e8f1de7e8acovener#include &lt;lwres/lwbuffer.h&gt;

f4db898517ccc6ef1a403630de56918286d3a47eminfrin</funcsynopsisinfo>

f4db898517ccc6ef1a403630de56918286d3a47eminfrin

f4db898517ccc6ef1a403630de56918286d3a47eminfrin<funcprototype>

28a723b775c7666281298eab813c63ac42270f95humbedooh

28a723b775c7666281298eab813c63ac42270f95humbedooh <funcdef>

28a723b775c7666281298eab813c63ac42270f95humbedoohvoid

067698ad30941e38ef5d7f95f1c2736c2ebc5cb9humbedooh<function>lwres_buffer_init</function></funcdef>

067698ad30941e38ef5d7f95f1c2736c2ebc5cb9humbedooh <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

067698ad30941e38ef5d7f95f1c2736c2ebc5cb9humbedooh <paramdef>void *<parameter>base</parameter></paramdef>

d8a6de5eec06d4136839c8f7a56a6ab5acd2d3behumbedooh <paramdef>unsigned int <parameter>length</parameter></paramdef>

6e1e45624d6f32110383bb0bd06c254c1dba8123humbedooh </funcprototype>

77ca16c5676da23155311e13cee61e7eaba9fa3ejailletc

77ca16c5676da23155311e13cee61e7eaba9fa3ejailletc<funcprototype>

77ca16c5676da23155311e13cee61e7eaba9fa3ejailletc <funcdef>

77ca16c5676da23155311e13cee61e7eaba9fa3ejailletcvoid

921d32d80d8271da08f12fc374a69cb36d1d63b3covener<function>lwres_buffer_invalidate</function></funcdef>

921d32d80d8271da08f12fc374a69cb36d1d63b3covener <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

921d32d80d8271da08f12fc374a69cb36d1d63b3covener </funcprototype>

3e097af23e40c45aa32602545155f0964ab5c69dcovener<funcprototype>

3e097af23e40c45aa32602545155f0964ab5c69dcovener <funcdef>

3e097af23e40c45aa32602545155f0964ab5c69dcovenervoid

faea99bb676ec50ece38da6b1879aa37546483a2covener<function>lwres_buffer_add</function></funcdef>

faea99bb676ec50ece38da6b1879aa37546483a2covener <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

faea99bb676ec50ece38da6b1879aa37546483a2covener <paramdef>unsigned int <parameter>n</parameter></paramdef>

86a5604df726638a2b8085e993b4b79c4b3a5262covener </funcprototype>

faea99bb676ec50ece38da6b1879aa37546483a2covener

344f755169e100ea8ce51e847a0bf30a13b46917covener<funcprototype>

344f755169e100ea8ce51e847a0bf30a13b46917covener <funcdef>

344f755169e100ea8ce51e847a0bf30a13b46917covenervoid

fcd5c4e9e126e867eb270ed2d4138348cb1e46e5trawick<function>lwres_buffer_subtract</function></funcdef>

fcd5c4e9e126e867eb270ed2d4138348cb1e46e5trawick <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

fcd5c4e9e126e867eb270ed2d4138348cb1e46e5trawick <paramdef>unsigned int <parameter>n</parameter></paramdef>

50cfe8bbbaf4279375802531268e2bf0155215fetrawick </funcprototype>

50cfe8bbbaf4279375802531268e2bf0155215fetrawick

50cfe8bbbaf4279375802531268e2bf0155215fetrawick<funcprototype>

50cfe8bbbaf4279375802531268e2bf0155215fetrawick <funcdef>

ffaa9771884a8664f0e6267efbe9d26b40000461trawickvoid

ffaa9771884a8664f0e6267efbe9d26b40000461trawick<function>lwres_buffer_clear</function></funcdef>

ffaa9771884a8664f0e6267efbe9d26b40000461trawick <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

ffaa9771884a8664f0e6267efbe9d26b40000461trawick </funcprototype>

f87299dab99bc04b51a6b8cad51b6795db862c0atrawick

f87299dab99bc04b51a6b8cad51b6795db862c0atrawick<funcprototype>

f87299dab99bc04b51a6b8cad51b6795db862c0atrawick <funcdef>

4d12805e6c18253040223ea637acd6b3b3c18f60jortonvoid

4d12805e6c18253040223ea637acd6b3b3c18f60jorton<function>lwres_buffer_first</function></funcdef>

4d12805e6c18253040223ea637acd6b3b3c18f60jorton <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

4d12805e6c18253040223ea637acd6b3b3c18f60jorton </funcprototype>

4d12805e6c18253040223ea637acd6b3b3c18f60jorton

e5d909f2b06bd880fb3675cd49363df981caa631trawick<funcprototype>

a4df2cd1e1391575a327c2a90ba4315f805a0a78covener <funcdef>

a4df2cd1e1391575a327c2a90ba4315f805a0a78covenervoid

a4df2cd1e1391575a327c2a90ba4315f805a0a78covener<function>lwres_buffer_forward</function></funcdef>

cb666b29f81df1d11d65002250153353568021fccovener <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

cb666b29f81df1d11d65002250153353568021fccovener <paramdef>unsigned int <parameter>n</parameter></paramdef>

cb666b29f81df1d11d65002250153353568021fccovener </funcprototype>

6a80c3c6f4b8ea7ba5e89402b8b779b09ce020e0covener<funcprototype>

1c2cab00d988fc48cbe59032cf76cc0bab20d6f7covener

6a80c3c6f4b8ea7ba5e89402b8b779b09ce020e0covener <funcdef>

75a230a728338d84dcfe81edd375352f34de22d0covenervoid

75a230a728338d84dcfe81edd375352f34de22d0covener<function>lwres_buffer_back</function></funcdef>

75a230a728338d84dcfe81edd375352f34de22d0covener <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

1f50dc34ae069adeed20b2986e5ffdefa5c410e0covener <paramdef>unsigned int <parameter>n</parameter></paramdef>

1f50dc34ae069adeed20b2986e5ffdefa5c410e0covener </funcprototype>

1f50dc34ae069adeed20b2986e5ffdefa5c410e0covener

63a5ea80bddcc84a462e40f402b4f330e0e05411covener<funcprototype>

63a5ea80bddcc84a462e40f402b4f330e0e05411covener <funcdef>

63a5ea80bddcc84a462e40f402b4f330e0e05411covenerlwres_uint8_t

63a5ea80bddcc84a462e40f402b4f330e0e05411covener<function>lwres_buffer_getuint8</function></funcdef>

986f3ea2c314d4d4b3b937149853a0f23f6119aaminfrin <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

986f3ea2c314d4d4b3b937149853a0f23f6119aaminfrin </funcprototype>

986f3ea2c314d4d4b3b937149853a0f23f6119aaminfrin

65a4e663b82f8bce28ac22ab2edfd7502de36998sf<funcprototype>

65a4e663b82f8bce28ac22ab2edfd7502de36998sf <funcdef>

65a4e663b82f8bce28ac22ab2edfd7502de36998sfvoid

65a4e663b82f8bce28ac22ab2edfd7502de36998sf<function>lwres_buffer_putuint8</function></funcdef>

c7de1955eb0eaeabf7042902476397692672d549sf <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

74e7f6c55fd67b10cb400b3f6d1dc718a303d944minfrin <paramdef>lwres_uint8_t <parameter>val</parameter></paramdef>

74e7f6c55fd67b10cb400b3f6d1dc718a303d944minfrin </funcprototype>

74e7f6c55fd67b10cb400b3f6d1dc718a303d944minfrin

74e7f6c55fd67b10cb400b3f6d1dc718a303d944minfrin<funcprototype>

a511a29faf2ff7ead3b67680154a624effb31aafminfrin <funcdef>

a511a29faf2ff7ead3b67680154a624effb31aafminfrinlwres_uint16_t

a511a29faf2ff7ead3b67680154a624effb31aafminfrin<function>lwres_buffer_getuint16</function></funcdef>

a511a29faf2ff7ead3b67680154a624effb31aafminfrin <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

a511a29faf2ff7ead3b67680154a624effb31aafminfrin </funcprototype>

63921358ef93fcb41bc71d9894221ba3d7fbb87bminfrin

63921358ef93fcb41bc71d9894221ba3d7fbb87bminfrin<funcprototype>

63921358ef93fcb41bc71d9894221ba3d7fbb87bminfrin <funcdef>

deec48c67d4786bc77112ffbf3a4e70b931097edminfrinvoid

6d601599d3d65df0410eae6e573e75b2dbfb1fb4minfrin<function>lwres_buffer_putuint16</function></funcdef>

6d601599d3d65df0410eae6e573e75b2dbfb1fb4minfrin <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

6d601599d3d65df0410eae6e573e75b2dbfb1fb4minfrin <paramdef>lwres_uint16_t <parameter>val</parameter></paramdef>

6d601599d3d65df0410eae6e573e75b2dbfb1fb4minfrin </funcprototype>

4c02bab56a528a180bbe394d8b6e6fd9c1a3ac1esf

4c02bab56a528a180bbe394d8b6e6fd9c1a3ac1esf<funcprototype>

4c02bab56a528a180bbe394d8b6e6fd9c1a3ac1esf <funcdef>

4c02bab56a528a180bbe394d8b6e6fd9c1a3ac1esflwres_uint32_t

2c487ac43b583db869e743772a7a10b278aa2bcfminfrin<function>lwres_buffer_getuint32</function></funcdef>

684e0cfc200f66287a93bbd1708d1dd8a92a7eefcovener <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

684e0cfc200f66287a93bbd1708d1dd8a92a7eefcovener </funcprototype>

5c43d2fb853f84497b5ece2d414ef9484aa87e5fsf

05a5a9c3e16f21566e1b61f4bd68025ce1b741ccjoes<funcprototype>

05a5a9c3e16f21566e1b61f4bd68025ce1b741ccjoes <funcdef>

ef82e8fa164e0a1f8b813f7deb6b7ead96018c94niqvoid

26c5829347f6a355c00f1ba0301d575056b69536niq<function>lwres_buffer_putuint32</function></funcdef>

ef82e8fa164e0a1f8b813f7deb6b7ead96018c94niq <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

ef82e8fa164e0a1f8b813f7deb6b7ead96018c94niq <paramdef>lwres_uint32_t <parameter>val</parameter></paramdef>

ef82e8fa164e0a1f8b813f7deb6b7ead96018c94niq </funcprototype>

ef82e8fa164e0a1f8b813f7deb6b7ead96018c94niq

ef82e8fa164e0a1f8b813f7deb6b7ead96018c94niq<funcprototype>

ef82e8fa164e0a1f8b813f7deb6b7ead96018c94niq <funcdef>

413ee814748f37be168ff12407fa6dba0ceeabe6trawickvoid

c12917da693bae4028a1d5a5e8224bceed8c739dsf<function>lwres_buffer_putmem</function></funcdef>

c12917da693bae4028a1d5a5e8224bceed8c739dsf <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

eafcc0ebf263d0ba69855b6e10958c4c1a2361bdsf <paramdef>const unsigned char *<parameter>base</parameter></paramdef>

eafcc0ebf263d0ba69855b6e10958c4c1a2361bdsf <paramdef>unsigned int <parameter>length</parameter></paramdef>

eafcc0ebf263d0ba69855b6e10958c4c1a2361bdsf </funcprototype>

eafcc0ebf263d0ba69855b6e10958c4c1a2361bdsf

eafcc0ebf263d0ba69855b6e10958c4c1a2361bdsf<funcprototype>

d7ffd2da16d58b1a0de212e4d56f7aebb72bef26sf <funcdef>

d7ffd2da16d58b1a0de212e4d56f7aebb72bef26sfvoid

d7ffd2da16d58b1a0de212e4d56f7aebb72bef26sf<function>lwres_buffer_getmem</function></funcdef>

4576c1a9ef54cd1e5555ee07d016a7f559f80338sf <paramdef>lwres_buffer_t *<parameter>b</parameter></paramdef>

4576c1a9ef54cd1e5555ee07d016a7f559f80338sf <paramdef>unsigned char *<parameter>base</parameter></paramdef>

4576c1a9ef54cd1e5555ee07d016a7f559f80338sf <paramdef>unsigned int <parameter>length</parameter></paramdef>

9811aed12bbc71783d2e544ccb5fecd193843eadsf </funcprototype>

9811aed12bbc71783d2e544ccb5fecd193843eadsf

9811aed12bbc71783d2e544ccb5fecd193843eadsf</funcsynopsis>

1366443dc565c33e7b449ae428bbfc4c86f33935drh </refsynopsisdiv>

1366443dc565c33e7b449ae428bbfc4c86f33935drh

88fac54d9d64f85bbdab5d7010816f4377f95bd7rjung <refsect1>

88fac54d9d64f85bbdab5d7010816f4377f95bd7rjung

bd3f5647b96d378d9c75c954e3f13582af32c643sf <title>DESCRIPTION</title>

bd3f5647b96d378d9c75c954e3f13582af32c643sf <para>

bd3f5647b96d378d9c75c954e3f13582af32c643sf These functions provide bounds checked access to a region of memory

bd3f5647b96d378d9c75c954e3f13582af32c643sf where data is being read or written.

bd3f5647b96d378d9c75c954e3f13582af32c643sf They are based on, and similar to, the

2a7beea91d46beb41f043a84eaad060047ee04aafabien <literal>isc_buffer_</literal>

2a7beea91d46beb41f043a84eaad060047ee04aafabien functions in the ISC library.

2a7beea91d46beb41f043a84eaad060047ee04aafabien </para>

2a7beea91d46beb41f043a84eaad060047ee04aafabien <para>

584a85dd4047e38d3ed3a29b6662fcc9d100ae4csf A buffer is a region of memory, together with a set of related

584a85dd4047e38d3ed3a29b6662fcc9d100ae4csf subregions.

584a85dd4047e38d3ed3a29b6662fcc9d100ae4csf The <emphasis>used region</emphasis> and the

f21e9e3d0bfb7a507ecc5bc963f2159d693503d1sf <emphasis>available</emphasis> region are disjoint, and

f21e9e3d0bfb7a507ecc5bc963f2159d693503d1sf their union is the buffer's region.

f21e9e3d0bfb7a507ecc5bc963f2159d693503d1sf The used region extends from the beginning of the buffer region to the

f6b9c755a0b793e8a3a3aebd327ca20a86478117sf last used byte.

f6b9c755a0b793e8a3a3aebd327ca20a86478117sf The available region extends from one byte greater than the last used

f6b9c755a0b793e8a3a3aebd327ca20a86478117sf byte to the end of the buffer's region.

132ee6ac1c26d6e8953836316ba50734eefab47bsf The size of the used region can be changed using various

132ee6ac1c26d6e8953836316ba50734eefab47bsf buffer commands.

132ee6ac1c26d6e8953836316ba50734eefab47bsf Initially, the used region is empty.

85eacfc96a04547ef25aabbc06440039715084c2jorton </para>

85eacfc96a04547ef25aabbc06440039715084c2jorton <para>

85eacfc96a04547ef25aabbc06440039715084c2jorton The used region is further subdivided into two disjoint regions: the

536d2e7cd1fdec1255b8c3bdf41fdc714c506a54trawick <emphasis>consumed region</emphasis> and the <emphasis>remaining region</emphasis>.

536d2e7cd1fdec1255b8c3bdf41fdc714c506a54trawick The union of these two regions is the used region.

536d2e7cd1fdec1255b8c3bdf41fdc714c506a54trawick The consumed region extends from the beginning of the used region to

536d2e7cd1fdec1255b8c3bdf41fdc714c506a54trawick the byte before the <emphasis>current</emphasis> offset (if any).

79c5787b92ac5f0e1cc82393816c77a006399316trawick The <emphasis>remaining</emphasis> region the current pointer to the end

79c5787b92ac5f0e1cc82393816c77a006399316trawick of the used

79c5787b92ac5f0e1cc82393816c77a006399316trawick region.

79c5787b92ac5f0e1cc82393816c77a006399316trawick The size of the consumed region can be changed using various

c967bf3bc89e8aa60dbd30d9da388e448ddc1cc4trawick buffer commands.

79c5787b92ac5f0e1cc82393816c77a006399316trawick Initially, the consumed region is empty.

79c5787b92ac5f0e1cc82393816c77a006399316trawick </para>

79c5787b92ac5f0e1cc82393816c77a006399316trawick <para>

79c5787b92ac5f0e1cc82393816c77a006399316trawick The <emphasis>active region</emphasis> is an (optional) subregion of the

79c5787b92ac5f0e1cc82393816c77a006399316trawick remaining

7b395e4e878c28a4784919cfd2e704ddd14a3390jorton region.

7b395e4e878c28a4784919cfd2e704ddd14a3390jorton It extends from the current offset to an offset in the

7b395e4e878c28a4784919cfd2e704ddd14a3390jorton remaining region.

7b395e4e878c28a4784919cfd2e704ddd14a3390jorton Initially, the active region is empty.

536e48c08d674acac5d44929318f2ad928edc361jorton If the current offset advances beyond the chosen offset,

536e48c08d674acac5d44929318f2ad928edc361jorton the active region will also be empty.

e81785da447b469da66f218b3f0244aab507958djorton </para>

e81785da447b469da66f218b3f0244aab507958djorton <para><programlisting>

3e4e54d4e3fc0123c63d57aa84ac7ad7a8c73ff8jorton /------------entire length---------------\\

3e4e54d4e3fc0123c63d57aa84ac7ad7a8c73ff8jorton /----- used region -----\\/-- available --\\

3e4e54d4e3fc0123c63d57aa84ac7ad7a8c73ff8jorton +----------------------------------------+

53e9b27aba029b18be814df40bcf6f0428771d1efuankg | consumed | remaining | |

53e9b27aba029b18be814df40bcf6f0428771d1efuankg +----------------------------------------+

53e9b27aba029b18be814df40bcf6f0428771d1efuankg a b c d e

53e9b27aba029b18be814df40bcf6f0428771d1efuankg </programlisting>

53e9b27aba029b18be814df40bcf6f0428771d1efuankg </para>

6bb524f1895f30265a1431afc460977d391cb36bsf <para><programlisting>

6bb524f1895f30265a1431afc460977d391cb36bsf a == base of buffer.

ca61ccd0c306c2c72df153688ba1b49f3eceed80sf b == current pointer. Can be anywhere between a and d.

6bb524f1895f30265a1431afc460977d391cb36bsf c == active pointer. Meaningful between b and d.

e6dd71992459d05a676b98b7963423dc5dc1e24aminfrin d == used pointer.

e6dd71992459d05a676b98b7963423dc5dc1e24aminfrin e == length of buffer.

e6dd71992459d05a676b98b7963423dc5dc1e24aminfrin </programlisting>

e6dd71992459d05a676b98b7963423dc5dc1e24aminfrin </para>

23f1535d6a60817d2846bac0aea230ea475d7dccminfrin <para><programlisting>

23f1535d6a60817d2846bac0aea230ea475d7dccminfrin a-e == entire length of buffer.

23f1535d6a60817d2846bac0aea230ea475d7dccminfrin a-d == used region.

23f1535d6a60817d2846bac0aea230ea475d7dccminfrin a-b == consumed region.

ec7520b24cd80d34d82bbcaca153cbb23cc04bc0rjung b-d == remaining region.

ec7520b24cd80d34d82bbcaca153cbb23cc04bc0rjung b-c == optional active region.

ec7520b24cd80d34d82bbcaca153cbb23cc04bc0rjung</programlisting>

ec7520b24cd80d34d82bbcaca153cbb23cc04bc0rjung </para>

ec7520b24cd80d34d82bbcaca153cbb23cc04bc0rjung <para><function>lwres_buffer_init()</function>

ec7520b24cd80d34d82bbcaca153cbb23cc04bc0rjung initializes the

ec7520b24cd80d34d82bbcaca153cbb23cc04bc0rjung <type>lwres_buffer_t</type>

ec7520b24cd80d34d82bbcaca153cbb23cc04bc0rjung <parameter>*b</parameter>

6249dfa569d3b4f1f539665b979a80c6e335d93etrawick and assocates it with the memory region of size

6249dfa569d3b4f1f539665b979a80c6e335d93etrawick <parameter>length</parameter>

0827cb14e550f6f65018431c22c2c913631c8f25kbrand bytes starting at location

6249dfa569d3b4f1f539665b979a80c6e335d93etrawick <parameter>base.</parameter>

ae600ca541efc686b34f8b1f21bd3d0741d37674covener </para>

6249dfa569d3b4f1f539665b979a80c6e335d93etrawick <para><function>lwres_buffer_invalidate()</function>

cfa64348224b66dd1c9979b809406c4d15b1c137fielding marks the buffer <parameter>*b</parameter>

74499a117b3b2cd9666715a14f90c0e5d1a4ee8ajim as invalid. Invalidating a buffer after use is not required,

cfa64348224b66dd1c9979b809406c4d15b1c137fielding but makes it possible to catch its possible accidental use.

74499a117b3b2cd9666715a14f90c0e5d1a4ee8ajim </para>

cfa64348224b66dd1c9979b809406c4d15b1c137fielding <para>

74499a117b3b2cd9666715a14f90c0e5d1a4ee8ajim The functions

cfa64348224b66dd1c9979b809406c4d15b1c137fielding <function>lwres_buffer_add()</function>

74499a117b3b2cd9666715a14f90c0e5d1a4ee8ajim and

cfa64348224b66dd1c9979b809406c4d15b1c137fielding <function>lwres_buffer_subtract()</function>

respectively increase and decrease the used space in

buffer

<parameter>*b</parameter>

by

<parameter>n</parameter>

bytes.

<function>lwres_buffer_add()</function>

checks for buffer overflow and

<function>lwres_buffer_subtract()</function>

checks for underflow.

These functions do not allocate or deallocate memory.

They just change the value of

<structfield>used</structfield>.

</para>

<para>

A buffer is re-initialised by

<function>lwres_buffer_clear()</function>.

The function sets

<structfield>used</structfield>,

<structfield>current</structfield>

and

<structfield>active</structfield>

to zero.

</para>

<para><function>lwres_buffer_first</function>

makes the consumed region of buffer

<parameter>*p</parameter>

empty by setting

<structfield>current</structfield>

to zero (the start of the buffer).

</para>

<para><function>lwres_buffer_forward()</function>

increases the consumed region of buffer

<parameter>*b</parameter>

by

<parameter>n</parameter>

bytes, checking for overflow.

Similarly,

<function>lwres_buffer_back()</function>

decreases buffer

<parameter>b</parameter>'s

consumed region by

<parameter>n</parameter>

bytes and checks for underflow.

</para>

<para><function>lwres_buffer_getuint8()</function>

reads an unsigned 8-bit integer from

<parameter>*b</parameter>

and returns it.

<function>lwres_buffer_putuint8()</function>

writes the unsigned 8-bit integer

<parameter>val</parameter>

to buffer

<parameter>*b</parameter>.

</para>

<para><function>lwres_buffer_getuint16()</function>

and

<function>lwres_buffer_getuint32()</function>

are identical to

<function>lwres_buffer_putuint8()</function>

except that they respectively read an unsigned 16-bit or 32-bit integer

in network byte order from

<parameter>b</parameter>.

Similarly,

<function>lwres_buffer_putuint16()</function>

and

<function>lwres_buffer_putuint32()</function>

writes the unsigned 16-bit or 32-bit integer

<parameter>val</parameter>

to buffer

<parameter>b</parameter>,

in network byte order.

</para>

<para>

Arbitrary amounts of data are read or written from a lightweight

resolver buffer with

<function>lwres_buffer_getmem()</function>

and

<function>lwres_buffer_putmem()</function>

respectively.

<function>lwres_buffer_putmem()</function>

copies

<parameter>length</parameter>

bytes of memory at

<parameter>base</parameter>

to

<parameter>b</parameter>.

Conversely,

<function>lwres_buffer_getmem()</function>

copies

<parameter>length</parameter>

bytes of memory from

<parameter>b</parameter>

to

<parameter>base</parameter>.

</para>

</refsect1>

</refentry><!--