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authorLuke Shumaker <LukeShu@sbcglobal.net>2014-01-28 09:50:25 -0500
committerLuke Shumaker <LukeShu@sbcglobal.net>2014-01-28 09:50:25 -0500
commit5744df39e15f85c6cc8a9faf8924d77e76d2b216 (patch)
treea8c8dd40a94d1fa0d5377566aa5548ae55a163da /includes/HashRing.php
parent4bb2aeca1d198391ca856aa16c40b8559c68daec (diff)
parent224b22a051051f6c2e494c3a2fb4adb42898e2d1 (diff)
Merge branch 'archwiki'
Conflicts: extensions/FluxBBAuthPlugin.php extensions/SyntaxHighlight_GeSHi/README extensions/SyntaxHighlight_GeSHi/SyntaxHighlight_GeSHi.class.php extensions/SyntaxHighlight_GeSHi/SyntaxHighlight_GeSHi.i18n.php extensions/SyntaxHighlight_GeSHi/SyntaxHighlight_GeSHi.php extensions/SyntaxHighlight_GeSHi/geshi/docs/CHANGES extensions/SyntaxHighlight_GeSHi/geshi/docs/THANKS extensions/SyntaxHighlight_GeSHi/geshi/docs/TODO extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractClass.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractClass_logo.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractMethod.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractPrivateClass.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractPrivateClass_logo.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/AbstractPrivateMethod.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/Class.png 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extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/blank.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/class_folder.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/file.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/folder.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/function_folder.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/next_button.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/next_button_disabled.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/package.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/package_folder.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/previous_button.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/previous_button_disabled.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/private_class_logo.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/tutorial.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/tutorial_folder.png extensions/SyntaxHighlight_GeSHi/geshi/docs/api/media/images/up_button.png extensions/SyntaxHighlight_GeSHi/geshi/docs/geshi-doc.html extensions/SyntaxHighlight_GeSHi/geshi/docs/geshi-doc.txt extensions/SyntaxHighlight_GeSHi/geshi/geshi.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/4cs.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/6502acme.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/6502kickass.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/6502tasm.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/68000devpac.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/abap.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/actionscript.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/actionscript3.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/ada.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/algol68.php 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extensions/SyntaxHighlight_GeSHi/geshi/geshi/cuesheet.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/d.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/dcs.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/delphi.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/diff.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/div.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/dos.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/dot.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/e.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/ecmascript.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/eiffel.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/email.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/epc.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/erlang.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/euphoria.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/f1.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/falcon.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/fo.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/fortran.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/freebasic.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/fsharp.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/gambas.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/gdb.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/genero.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/genie.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/gettext.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/glsl.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/gml.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/gnuplot.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/go.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/groovy.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/gwbasic.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/haskell.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/hicest.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/hq9plus.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/html4strict.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/html5.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/icon.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/idl.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/ini.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/inno.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/intercal.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/io.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/j.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/java.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/java5.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/javascript.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/jquery.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/kixtart.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/klonec.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/klonecpp.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/latex.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/lb.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/lisp.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/llvm.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/locobasic.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/logtalk.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/lolcode.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/lotusformulas.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/lotusscript.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/lscript.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/lsl2.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/lua.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/m68k.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/magiksf.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/make.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/mapbasic.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/matlab.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/mirc.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/mmix.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/modula2.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/modula3.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/mpasm.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/mxml.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/mysql.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/newlisp.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/nsis.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/oberon2.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/objc.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/objeck.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/ocaml-brief.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/ocaml.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/oobas.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/oracle11.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/oracle8.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/oxygene.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/oz.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/pascal.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/pcre.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/per.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/perl.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/perl6.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/pf.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/php-brief.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/php.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/pic16.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/pike.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/pixelbender.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/pli.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/plsql.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/postgresql.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/povray.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/powerbuilder.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/powershell.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/proftpd.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/progress.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/prolog.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/properties.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/providex.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/purebasic.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/pycon.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/python.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/q.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/qbasic.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/rails.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/rebol.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/reg.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/robots.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/rpmspec.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/rsplus.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/ruby.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/sas.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/scala.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/scheme.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/scilab.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/sdlbasic.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/smalltalk.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/smarty.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/sql.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/systemverilog.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/tcl.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/teraterm.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/text.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/thinbasic.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/tsql.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/typoscript.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/unicon.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/uscript.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/vala.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/vb.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/vbnet.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/verilog.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/vhdl.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/vim.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/visualfoxpro.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/visualprolog.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/whitespace.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/whois.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/winbatch.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/xbasic.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/xml.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/xorg_conf.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/xpp.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/yaml.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/z80.php extensions/SyntaxHighlight_GeSHi/geshi/geshi/zxbasic.php
Diffstat (limited to 'includes/HashRing.php')
-rw-r--r--includes/HashRing.php142
1 files changed, 142 insertions, 0 deletions
diff --git a/includes/HashRing.php b/includes/HashRing.php
new file mode 100644
index 00000000..930f8c0a
--- /dev/null
+++ b/includes/HashRing.php
@@ -0,0 +1,142 @@
+<?php
+/**
+ * Convenience class for weighted consistent hash rings.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ * @author Aaron Schulz
+ */
+
+/**
+ * Convenience class for weighted consistent hash rings
+ *
+ * @since 1.22
+ */
+class HashRing {
+ /** @var Array (location => weight) */
+ protected $sourceMap = array();
+ /** @var Array (location => (start, end)) */
+ protected $ring = array();
+
+ const RING_SIZE = 268435456; // 2^28
+
+ /**
+ * @param array $map (location => weight)
+ */
+ public function __construct( array $map ) {
+ $map = array_filter( $map, function( $w ) { return $w > 0; } );
+ if ( !count( $map ) ) {
+ throw new MWException( "Ring is empty or all weights are zero." );
+ }
+ $this->sourceMap = $map;
+ // Sort the locations based on the hash of their names
+ $hashes = array();
+ foreach ( $map as $location => $weight ) {
+ $hashes[$location] = sha1( $location );
+ }
+ uksort( $map, function ( $a, $b ) use ( $hashes ) {
+ return strcmp( $hashes[$a], $hashes[$b] );
+ } );
+ // Fit the map to weight-proportionate one with a space of size RING_SIZE
+ $sum = array_sum( $map );
+ $standardMap = array();
+ foreach ( $map as $location => $weight ) {
+ $standardMap[$location] = (int)floor( $weight / $sum * self::RING_SIZE );
+ }
+ // Build a ring of RING_SIZE spots, with each location at a spot in location hash order
+ $index = 0;
+ foreach ( $standardMap as $location => $weight ) {
+ // Location covers half-closed interval [$index,$index + $weight)
+ $this->ring[$location] = array( $index, $index + $weight );
+ $index += $weight;
+ }
+ // Make sure the last location covers what is left
+ end( $this->ring );
+ $this->ring[key( $this->ring )][1] = self::RING_SIZE;
+ }
+
+ /**
+ * Get the location of an item on the ring
+ *
+ * @param string $item
+ * @return string Location
+ */
+ public function getLocation( $item ) {
+ $locations = $this->getLocations( $item, 1 );
+ return $locations[0];
+ }
+
+ /**
+ * Get the location of an item on the ring, as well as the next clockwise locations
+ *
+ * @param string $item
+ * @param integer $limit Maximum number of locations to return
+ * @return array List of locations
+ */
+ public function getLocations( $item, $limit ) {
+ $locations = array();
+ $primaryLocation = null;
+ $spot = hexdec( substr( sha1( $item ), 0, 7 ) ); // first 28 bits
+ foreach ( $this->ring as $location => $range ) {
+ if ( count( $locations ) >= $limit ) {
+ break;
+ }
+ // The $primaryLocation is the location the item spot is in.
+ // After that is reached, keep appending the next locations.
+ if ( ( $range[0] <= $spot && $spot < $range[1] ) || $primaryLocation !== null ) {
+ if ( $primaryLocation === null ) {
+ $primaryLocation = $location;
+ }
+ $locations[] = $location;
+ }
+ }
+ // If more locations are requested, wrap-around and keep adding them
+ reset( $this->ring );
+ while ( count( $locations ) < $limit ) {
+ list( $location, ) = each( $this->ring );
+ if ( $location === $primaryLocation ) {
+ break; // don't go in circles
+ }
+ $locations[] = $location;
+ }
+ return $locations;
+ }
+
+ /**
+ * Get the map of locations to weight (ignores 0-weight items)
+ *
+ * @return array
+ */
+ public function getLocationWeights() {
+ return $this->sourceMap;
+ }
+
+ /**
+ * Get a new hash ring with a location removed from the ring
+ *
+ * @param string $location
+ * @return HashRing|bool Returns false if no non-zero weighted spots are left
+ */
+ public function newWithoutLocation( $location ) {
+ $map = $this->sourceMap;
+ unset( $map[$location] );
+ if ( count( $map ) ) {
+ return new self( $map );
+ }
+ return false;
+ }
+}