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.aligncenter { clear: both; display: block; margin-left: auto; margin-right: auto } .crayon-line span::after { content: " " } p { font-size: 15px; text-indent: 2em } #colorbox.crayon-colorbox,#cboxOverlay.crayon-colorbox,.crayon-colorbox #cboxWrapper { position: absolute; top: 0; left: 0; z-index: 9999; overflow: hidden } #cboxOverlay.crayon-colorbox { position: fixed; width: 100%; height: 100% } .crayon-colorbox #cboxMiddleLeft,.crayon-colorbox #cboxBottomLeft { clear: left } .crayon-colorbox #cboxContent { position: relative } .crayon-colorbox #cboxLoadedContent { overflow: auto } .crayon-colorbox #cboxTitle { display: none !important } .crayon-colorbox #cboxLoadingOverlay,.crayon-colorbox #cboxLoadingGraphic { position: absolute; top: 0; left: 0; width: 100%; height: 100% } .crayon-colorbox #cboxPrevious,.crayon-colorbox #cboxNext,.crayon-colorbox #cboxClose,.crayon-colorbox #cboxSlideshow { cursor: pointer } .crayon-colorbox .cboxPhoto { float: left; margin: auto; border: 0; display: block; max-width: none } .crayon-colorbox .cboxIframe { width: 100%; height: 100%; display: block; border: 0 } #colorbox.crayon-colorbox,.crayon-colorbox #cboxContent,.crayon-colorbox #cboxLoadedContent { } #cboxOverlay.crayon-colorbox { background: #000 } #colorbox.crayon-colorbox { outline: 0 } .crayon-colorbox #cboxContent { margin-top: 20px; background: #000 } .crayon-colorbox .cboxIframe { background: #fff } .crayon-colorbox #cboxError { padding: 50px; border: 1px solid #ccc } .crayon-colorbox #cboxLoadedContent { border: 5px solid #000; background: #fff } .crayon-colorbox #cboxTitle { position: absolute; top: -20px; left: 0; color: #ccc } .crayon-colorbox #cboxCurrent { position: absolute; top: -20px; right: 0; color: #ccc } .crayon-colorbox #cboxPrevious,.crayon-colorbox #cboxNext,.crayon-colorbox #cboxSlideshow,.crayon-colorbox #cboxClose { border: 0; padding: 0; margin: 0; overflow: visible; width: auto; background: 0 } .crayon-colorbox #cboxPrevious:active,.crayon-colorbox #cboxNext:active,.crayon-colorbox #cboxSlideshow:active,.crayon-colorbox #cboxClose:active { outline: 0 } .crayon-colorbox #cboxSlideshow { position: absolute; top: -20px; right: 90px; color: #fff } .crayon-colorbox #cboxContent { margin-top: 0 } .crayon-colorbox #cboxLoadedContent { border: 0 } #crayon-main-wrap .form-table th { width: 100px } #crayon-log { display: none; max-height: 200px; border-color: #dfdfdf; background-color: white; border-width: 1px; border-style: solid; margin: 1px; padding: 3px; overflow: auto; white-space: pre; margin-bottom: 5px } .crayon-span,.crayon-span-5,.crayon-span-10,.crayon-span-50,.crayon-span-100,.crayon-span-110 { line-height: 24px; display: inline-block } .crayon-span-5 { min-width: 5px } .crayon-span-10 { min-width: 10px } .crayon-span-50 { min-width: 50px } .crayon-span-100 { min-width: 100px } .crayon-span-110 { min-width: 117px } .crayon-span-margin { margin-left: 5px } #height_mode,#width_mode { min-width: 65px } .crayon-error { color: #F00 } .crayon-success { color: #00F } .crayon-warning { color: #ff8000 } .crayon-help { min-height: 30px; padding: 5px 10px } .crayon-help .crayon-help-close,.crayon-help .crayon-help-close:active,.crayon-help .crayon-help-close:hover { text-decoration: none; float: right; color: #000 } .crayon-help span,.crayon-help a { margin: 0; padding: 0; font-size: 12px } #crayon-log-text { font: 11px/13px Monaco, "MonacoRegular", "Courier New", monospace } #crayon-log-controls { float: left; margin-right: 5px } .crayon-table { font-size: 12px; border: 1px solid #999; padding: 0; margin: 0; margin-top: 12px } .crayon-table td { vertical-align: top; border-bottom: 1px solid #AAA; padding: 0 6px; margin: 0; background: #EEE } .crayon-table-light td { background: #f8f8f8 } .crayon-table-header td { font-weight: bold; background: #CCC } .crayon-table-last td,.crayon-table tr:last-child td { border: 0 } #lang-info div { padding: 5px 0 } .crayon-table .not-parsed { color: #F00 } .crayon-table .parsed-with-errors { color: #f90 } .crayon-table .successfully-parsed { color: #77a000 } #crayon-live-preview,#crayon-log-wrapper { padding: 0; width: 100%; float: left; clear: both } #crayon-live-preview { float: none; padding: 0 } #crayon-logo { text-align: center } #crayon-info,#crayon-info td { border: 0; padding: 0 5px; margin: 0 } .crayon-admin-button { display: inline-block; text-align: center } #crayon-subsection-langs-info { margin-top: 5px } #crayon-theme-editor-admin-buttons { display: inline } #crayon-theme-editor-admin-buttons .crayon-admin-button { margin-left: 5px } #crayon-theme-info { display: table; padding: 0; margin: 0; margin-top: 5px } #crayon-theme-info>div { display: table-cell; vertical-align: middle } #crayon-theme-info .content * { float: left } #crayon-theme-info .field { font-weight: bold } #crayon-theme-info .field,#crayon-theme-info .value { margin-left: 5px } #crayon-theme-info .description.value { font-style: italic; color: #999 } #crayon-theme-info .type { text-align: center; min-width: 120px; font-weight: bold; border-right: 1px solid #ccc; padding-right: 5px } #crayon-theme-info .type.stock { color: #666 } #crayon-theme-info .type.user { color: #5b9a00 } #crayon-editor-table td { vertical-align: top } .small-icon { width: 24px; height: 24px; display: inline-block; margin: 5px 5px 0 0 } #twitter-icon { background: url("../images/twitter.png") } #gmail-icon { background: url("../images/google.png") } #docs-icon { background: url("../images/docs.png") } #git-icon { background: url("../images/github.png") } #wp-icon { background: url("../images/wordpress-blue.png") } #donate-icon { background: url("../images/donate.png"); width: 75px } #crayon-donate,#crayon-donate input { margin: 0; display: inline; padding: 0 } #crayon-theme-editor-info a { text-decoration: none !important; font-style: italic !important; color: #666 !important } #crayon-main-wrap .form-table .note { font-style: italic; color: #999 } #crayon-change-code-text { width: 400px; height: 300px } .crayon-syntax { overflow: hidden !important; position: relative !important; text-align: left; direction: ltr !important } .crayon-syntax div { background: 0; border: 0; padding: 0; margin: 0; text-align: left } .crayon-syntax.crayon-loading { visibility: hidden } .crayon-syntax,.crayon-syntax .crayon-main,.crayon-syntax .crayon-toolbar,.crayon-syntax .crayon-info,.crayon-syntax .crayon-plain,.crayon-syntax .crayon-code { width: 100% } .crayon-syntax .crayon-main,.crayon-syntax .crayon-plain { overflow: auto } .crayon-syntax,.crayon-syntax .crayon-main,.crayon-syntax .crayon-plain,.crayon-syntax .crayon-table { padding: 0; margin: 0 } .crayon-syntax-inline { margin: 0 2px; padding: 0 2px } .crayon-syntax .crayon-table { border: none !important; background: none !important; padding: 0 !important; margin-top: 0 !important; margin-right: 0 !important; margin-bottom: 0 !important; width: auto !important; border-spacing: 0 !important; border-collapse: collapse !important; table-layout: auto !important } .crayon-syntax .crayon-table td,.crayon-syntax .crayon-table tr { padding: 0 !important; border: none !important; background: 0; vertical-align: top !important; margin: 0 !important } .crayon-syntax .crayon-invisible { display: none !important } .crayon-plain-tag { margin-bottom: 12px } .crayon-popup .crayon-plain { display: block !important; width: 100% !important; height: 100% !important; opacity: 100 !important; position: relative !important } .crayon-popup-window { background: #fff } .crayon-syntax .crayon-num { text-align: center; padding: 0 5px; margin: 0 } .crayon-syntax .crayon-toolbar { position: relative; overflow: hidden; z-index: 4 } .crayon-syntax .crayon-info { position: absolute; overflow: hidden; display: none; z-index: 3; padding: 0; min-height: 18px; line-height: 18px } .crayon-syntax .crayon-info div { padding: 2px !important; text-align: center } .crayon-syntax .crayon-toolbar span { padding: 0 4px !important } .crayon-syntax .crayon-toolbar .crayon-button { display: inline; float: left !important; position: relative; width: 24px; background-repeat: no-repeat; line-height: 15px; border: 0; text-decoration: none } .crayon-toolbar .crayon-button,.crayon-toolbar .crayon-button:hover,.crayon-toolbar .crayon-button.crayon-pressed:hover { background-position: 0 center } .crayon-toolbar .crayon-button.crayon-pressed,.crayon-toolbar .crayon-button:active,.crayon-toolbar .crayon-button.crayon-pressed:active { background-position: -24px 0 } .crayon-toolbar .crayon-button.crayon-popup-button .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-popup-button:hover .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-popup-button.crayon-pressed:hover .crayon-button-icon { background-position: 0 0 } .crayon-toolbar .crayon-button.crayon-copy-button .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-copy-button:hover .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-copy-button.crayon-pressed:hover .crayon-button-icon { background-position: 0 -16px } .crayon-toolbar .crayon-button.crayon-nums-button .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-nums-button:hover .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-nums-button.crayon-pressed:hover .crayon-button-icon { background-position: 0 -32px } .crayon-toolbar .crayon-button.crayon-plain-button .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-plain-button:hover .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-plain-button.crayon-pressed:hover .crayon-button-icon { background-position: 0 -48px } .crayon-toolbar .crayon-button.crayon-mixed-button .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-mixed-button:hover .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-mixed-button.crayon-pressed:hover .crayon-button-icon { background-position: 0 -64px } .crayon-toolbar .crayon-button.crayon-minimize .crayon-button-icon { background-position: 0 -80px; background-color: transparent !important } .crayon-toolbar .crayon-button.crayon-expand-button .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-expand-button:hover .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-expand-button.crayon-pressed:hover .crayon-button-icon { background-position: 0 -96px } .crayon-toolbar .crayon-button.crayon-wrap-button .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-wrap-button:hover .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-wrap-button.crayon-pressed:hover .crayon-button-icon { background-position: 0 -112px } .crayon-toolbar .crayon-button.crayon-popup-button.crayon-pressed .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-popup-button:active .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-popup-button.crayon-pressed:active .crayon-button-icon { background-position: -24px 0 } .crayon-toolbar .crayon-button.crayon-copy-button.crayon-pressed .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-copy-button:active .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-copy-button.crayon-pressed:active .crayon-button-icon { background-position: -24px -16px } .crayon-toolbar .crayon-button.crayon-nums-button.crayon-pressed .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-nums-button:active .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-nums-button.crayon-pressed:active .crayon-button-icon { background-position: -24px -32px } .crayon-toolbar .crayon-button.crayon-plain-button.crayon-pressed .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-plain-button:active .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-plain-button.crayon-pressed:active .crayon-button-icon { background-position: -24px -48px } .crayon-toolbar .crayon-button.crayon-mixed-button.crayon-pressed .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-mixed-button:active .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-mixed-button.crayon-pressed:active .crayon-button-icon { background-position: -24px -64px } .crayon-toolbar .crayon-button.crayon-minimize .crayon-button-icon { background-position: -24px -80px; background-color: transparent !important } .crayon-toolbar .crayon-button.crayon-expand-button.crayon-pressed .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-expand-button:active .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-expand-button.crayon-pressed:active .crayon-button-icon { background-position: -24px -96px } .crayon-toolbar .crayon-button.crayon-wrap-button.crayon-pressed .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-wrap-button:active .crayon-button-icon,.crayon-toolbar .crayon-button.crayon-wrap-button.crayon-pressed:active .crayon-button-icon { background-position: -24px -112px } .crayon-syntax .crayon-toolbar .crayon-language { padding-right: 8px !important } .crayon-syntax .crayon-title,.crayon-syntax .crayon-language { float: left } .crayon-main::-webkit-scrollbar,.crayon-plain::-webkit-scrollbar { height: 6px; overflow: visible; width: 6px; background: #EEE } .crayon-main::-webkit-scrollbar-thumb,.crayon-plain::-webkit-scrollbar-thumb { background-color: #CCC; border: 1px solid #AAA; min-height: 8px; padding: 0; border-width: 1px } .crayon-main::-webkit-scrollbar-button,.crayon-plain::-webkit-scrollbar-button { height: 0; width: 0; padding: 0 } .crayon-main::-webkit-scrollbar-track,.crayon-plain::-webkit-scrollbar-track { border-width: 0 0 0 4px; border: 1px solid #BBB; border-right: 0; border-bottom: 0 } .crayon-main::-webkit-scrollbar-corner,.crayon-plain::-webkit-scrollbar-corner { background: #EEE } .crayon-main::-webkit-scrollbar-thumb:hover,.crayon-plain::-webkit-scrollbar-thumb:hover { background: #AAA; border: 1px solid #777 } .crayon-syntax .crayon-pre,.crayon-syntax pre { color: #000; white-space: pre; margin: 0; padding: 0; overflow: visible; background: none !important; border: none !important } .crayon-syntax .crayon-line { padding: 0 5px } .crayon-syntax.crayon-wrapped .crayon-line { white-space: pre-wrap !important; height: auto } .crayon-syntax-inline .crayon-pre,.crayon-syntax-inline pre { white-space: normal } .crayon-syntax-inline-nowrap .crayon-pre,.crayon-syntax-inline-nowrap pre { white-space: pre } .crayon-syntax { font-family: Monaco, "MonacoRegular", "Courier New", monospace; font-weight: 500 } .crayon-syntax .crayon-toolbar *::selection,.crayon-syntax .crayon-nums *::selection { background: transparent } .crayon-table .crayon-nums-content { white-space: nowrap } .crayon-syntax .crayon-num,.crayon-syntax .crayon-pre .crayon-line,.crayon-syntax .crayon-toolbar *,.crayon-syntax .crayon-pre * { font-family: inherit; font-size: inherit !important; line-height: inherit !important; font-weight: inherit !important; height: inherit } .crayon-syntax .crayon-toolbar .crayon-button .crayon-button-icon { background-image: url("../images/toolbar/buttons.png"); height: 16px !important; width: 100%; position: absolute; left: 0; top: 50%; margin-top: -8px } .crayon-syntax .crayon-toolbar .crayon-tools { position: absolute; right: 0 } .crayon-syntax.crayon-expanded { position: absolute !important; margin: 0 !important } .crayon-syntax.crayon-expanded .crayon-main { overflow: hidden !important } .crayon-placeholder { width: 100% !important } .crayon-toolbar-visible .crayon-toolbar { position: relative !important; margin-top: 0 !important; display: block !important } .crayon-syntax.crayon-expanded .crayon-toolbar .crayon-tools { position: relative; right: auto; float: left !important } .crayon-syntax .crayon-plain-wrap { height: auto !important; padding: 0 !important; margin: 0 !important } .crayon-syntax .crayon-plain { width: 100%; height: 100%; position: absolute; opacity: 0; padding: 0 5px; margin: 0; border: 0; white-space: pre; overflow: auto; color: #000; background: #FFF } .crayon-wrapped .crayon-plain { white-space: pre-wrap } .bbp-body .crayon-syntax { clear: none !important } .crayon-minimized .crayon-toolbar { cursor: pointer } .crayon-minimized .crayon-plain-wrap,.crayon-minimized .crayon-main,.crayon-minimized .crayon-toolbar .crayon-tools * { display: none !important } .crayon-minimized .crayon-toolbar .crayon-tools .crayon-minimize { display: block !important } .crayon-minimized .crayon-toolbar { position: relative !important } .crayon-syntax.crayon-minimized .crayon-toolbar { border-bottom: none !important } .crayon-te *,#crayon-te-bar-content { font-family: "Lucida Grande", Arial, sans-serif !important; font-size: 12px } .crayon-te input[type="text"],.crayon-te textarea { background: #f9f9f9; border: 1px solid #CCC; padding: 2px 4px; border-width: 1px; border-style: solid } .crayon-te #crayon-code { font-family: monospace !important } #crayon-te-content,#crayon-te-table { width: 100%; height: auto !important } #crayon-range,#crayon-mark { width: 100px } #crayon-te-table th,#crayon-te-table td { vertical-align: top; text-align: left } .rtl #crayon-te-table th,.rtl #crayon-te-table td { text-align: right } #crayon-te-table .crayon-tr-center td,#crayon-te-table .crayon-tr-center th { vertical-align: middle } #crayon-te-table .crayon-nowrap { white-space: nowrap } #crayon-te-bar { position: absolute; top: 0; left: 0; width: 100% } #crayon-te-bar-content { border: 1px solid #666; border-bottom: 0; height: 26px; line-height: 25px; padding: 0 8px; padding-right: 0; background-color: #222; color: #cfcfcf } #crayon-te-bar-content a { line-height: 25px; padding: 5px 10px; color: #DDD; font-weight: bold; text-decoration: none !important } #crayon-te-bar-content a:hover { color: #FFF } .crayon-te-seperator { color: #666; margin: 0; padding: 0 } #crayon-te-bar-block { height: 34px; width: 100% } #crayon-te-title { float: left } #crayon-te-controls { float: right } #crayon-url-th { vertical-align: top !important; padding-top: 5px } .crayon-te-heading { font-size: 14px; font-weight: bold } #crayon-te-settings-info { text-align: center } .crayon-te-section { font-weight: bold; padding: 0 10px } #crayon-te-sub-section { margin-left: 10px } #crayon-te-sub-section .crayon-te-section { font-weight: normal; padding: 0 } #crayon-code { height: 200px; white-space: pre } #crayon-code,#crayon-url { width: 555px !important } .crayon-disabled { background: #EEE !important } .qt_crayon_highlight { background-image: linear-gradient(bottom,#daf2ff,white) !important } .qt_crayon_highlight:hover { background: #ddebf2 !important } .crayon-tag-editor-button-wrapper { display: inline-block } .mce_crayon_tinymce { padding: 0 !important; margin: 2px 3px !important } .mce-i-crayon_tinymce,.mce_crayon_tinymce { background: url("../images/crayon_tinymce.png") 0 0 !important } a.mce_crayon_tinymce { background-position: 2px 0 !important } .wp_themeSkin .mceButtonEnabled:hover span.mce_crayon_tinymce,.wp_themeSkin .mceButtonActive span.mce_crayon_tinymce { background-position: -20px 0 } .wp_themeSkin span.mce_crayon_tinymce { background: none !important } #crayon-te-table { margin-top: 26px; padding: 10px; border-collapse: separate !important; border-spacing: 2px !important } #crayon-te-table th { width: 100px } #crayon-te-clear { color: #666; background-color: #f4f4f4; border: 1px solid #CCC; margin-left: 8px } #crayon-title { width: 360px } #TB_window.crayon-te-ajax { overflow: auto !important } #TB_window.crayon-te-ajax,#TB_window.crayon-te-ajax #TB_ajaxContent,#TB_window.crayon-te-ajax #TB_title { width: 680px !important } #TB_window.crayon-te-ajax #TB_ajaxContent { padding: 0 !important; margin: 0 !important; width: 100% !important; height: auto !important; margin-top: 28px !important } #TB_window.crayon-te-ajax #TB_title { position: fixed !important } #TB_window.crayon-te-ajax #TB_title .crayon-te-submit { margin-top: 3px !important; float: right !important } #TB_window.crayon-te-ajax a { color: #2587e2; text-decoration: none } #TB_window.crayon-te-ajax a:hover { color: #499ce9 } .crayon-te-quote { background: #DDD; padding: 0 2px } #crayon-te-submit-wrapper { display: none } #crayon-te-clear { display: none; margin: 0; margin-top: 10px } .crayon-syntax-pre { background: red; white-space: pre; overflow: auto; display: block } .crayon-question { padding: 1px 4px !important; text-decoration: none !important; color: #83b3cb !important; height: 15px !important; width: 15px !important } .crayon-question:hover { background: #83b3cb !important; color: white !important; height: 15px !important; width: 15px !important } .crayon-setting-changed,.crayon-setting-selected { background: #fffaad !important } .crayon-question:hover { color: white; background: #a6d6ef } #crayon-te-warning { display: none } .crayon-te-info { padding: 5px !important; margin: 2px 0 !important } #crayon-te-submit { margin-bottom: 5px } .crayon-theme-github { margin-bottom: 25px !important; border: 1px solid #dedede !important; background-color: #f8f8ff !important; font-size: 100% !important; line-height: 130% !important } .crayon-theme-github .crayon-toolbar { border-bottom: 1px solid #dedede !important; background-color: #eee !important } .crayon-theme-github .crayon-toolbar .crayon-language,.crayon-theme-github .crayon-toolbar .crayon-title { font-size: 80% !important; color: #666 !important } .crayon-theme-github .crayon-table .crayon-nums { background-color: #eee !important } .crayon-theme-github .crayon-table .crayon-nums-content { padding-top: 5px !important; padding-bottom: 3px !important } .crayon-theme-github .crayon-table .crayon-num { min-width: 1.2em !important; border-right: 1px solid #dedede !important; text-align: right !important; color: #aaa !important } .crayon-theme-github .crayon-pre { padding-top: 5px !important; padding-bottom: 3px !important } .crayon-theme-github .crayon-marked-line { background: #fffee2 !important } .crayon-theme-github .crayon-marked-num { color: #1561ac !important; background: #b3d3f4 !important; border-width: 1px !important; border-color: #5999d9 !important } .crayon-theme-github .crayon-pre .crayon-c { color: #999 !important; font-style: italic !important } .crayon-theme-github .crayon-pre .crayon-s { color: #d14 !important } .crayon-theme-github .crayon-pre .crayon-p { color: #b85c00 !important } .crayon-theme-github .crayon-pre .crayon-ta { color: #FF0000 !important } .crayon-theme-github .crayon-pre .crayon-k { color: teal !important } .crayon-theme-github .crayon-pre .crayon-st { color: #000 !important; font-weight: bold !important } .crayon-theme-github .crayon-pre .crayon-r { color: #000 !important; font-weight: bold !important } .crayon-theme-github .crayon-pre .crayon-t { color: #800080 !important; font-weight: bold !important } .crayon-theme-github .crayon-pre .crayon-m { color: #800080 !important } .crayon-theme-github .crayon-pre .crayon-i { color: #000 !important } .crayon-theme-github .crayon-pre .crayon-e { color: teal !important } .crayon-theme-github .crayon-pre .crayon-v { color: #002D7A !important } .crayon-theme-github .crayon-pre .crayon-cn { color: #099 !important } .crayon-theme-github .crayon-pre .crayon-o { color: #006fe0 !important } .crayon-theme-github .crayon-pre .crayon-sy { color: #333 !important } .crayon-theme-github .crayon-pre .crayon-n { color: #666 !important; font-style: italic } .crayon-theme-github .crayon-pre .crayon-f { color: #999 !important } .crayon-theme-github .crayon-pre .crayon-h { color: #006fe0 !important } .crayon-syntax .crayon-pre,.crayon-syntax pre { white-space: initial } img { margin-top: 10px; margin-bottom: 10px } img { margin-top: 10px; margin-bottom: 10px }

我们在上一篇介绍了JS Object的实现,这一篇将进一步介绍JS Array的实现。

在此之前,笔者将Chromium升级到了最新版本60,上一次是在元旦的时候下的57,而当前最新发布的稳定版本是57。57是三月上旬发布的,所以Chrome发布一个大版本至少用了两、三个月的时间。Chrome 60的devTool增加了很多有趣的功能,这里顺便提一下:

例如把没有用到的CSS/JS按比例标红,增加了全页的截屏功能,和一个本地代码的编辑器:

回到正文。

JS的Array是一个万能的数据结构,为什么这么说呢?因为首先它可以当作一个普通的数组来使用,即通过下标找到数组的元素:

普通数组             JavaScript   var array = [19, 50, 99]; console.log(array[0]);
1 2 vararray=[19,50,99]; console.log(array[0]);

然后它可以当作一个栈来使用,我们知道栈的特点是先进后出,栈的基本操作是出栈和入栈:

栈             JavaScript   var stack = [1, 2, 3]; stack.push(4); //入栈 var top = stack.pop(); //出栈
1 2 3 varstack=[1,2,3]; stack.push(4);          //入栈 vartop=stack.pop();  //出栈

同时它还可以当作一个队列,队列的特点是先进先出,基本操作是出队和入队:

队列             JavaScript   var queue = [1, 2, 3]; queue.push(4); //入队 var head = queue.shift(); //出队
1 2 3 varqueue=[1,2,3]; queue.push(4);             //入队 varhead=queue.shift();  //出队

甚至它还可以当作一个哈表表来使用:

哈希             JavaScript   var map = []; map["id"] = 1234; map["name"] = yin; console.log(map["name"]);
1 2 3 4 varmap=[]; map["id"]=1234; map["name"]=yin; console.log(map["name"]);

另外,它还可以随时随地增删数组中任意位置的元素:

随时插入和删除元素             JavaScript   var array = [1, 2, 3, 4]; //从第3个元素开始,删掉1个元素,并插入-1,-2这两个元素 array.splice(2, 1, -1, -2); //再来个2000的索引 array[2000] = 10;
1 2 3 4 5 vararray=[1,2,3,4]; //从第3个元素开始,删掉1个元素,并插入-1,-2这两个元素 array.splice(2,1,-1,-2); //再来个2000的索引 array[2000]=10;

JS Array一方面提供了很大的便利,只要用一个数据结构就可以做很多事情,使用者不需要关心各者的区别,使得JS很容易入门。另一方面它屏蔽了数据结构的概念,不少写前端的都不知道什么是栈、队列、哈希、树,特别是那些不是学计算机,中途转过来的。然而这往往是不可取的。

另外一点是,即使是一些前端的老司机,他们也很难说清楚,这些数组函数操作的效率怎么样,例如说随意地往数组中间增加一个元素不会有性能问题么。所以就很有必要从源码的角度看一下数组是怎么实现的。

1. JS Array的实现

先看源码注释:

            C++   // The JSArray describes JavaScript Arrays // Such an array can be in one of two modes: // - fast, backing storage is a FixedArray and length <= elements.length(); // Please note: push and pop can be used to grow and shrink the array. // - slow, backing storage is a HashTable with numbers as keys. class JSArray: public JSObject { public: // [length]: The length property. DECL_ACCESSORS(length, Object) // Number of element slots to pre-allocate for an empty array. static const int kPreallocatedArrayElements = 4; };
1 2 3 4 5 6 7 8 9 10 11 12 13 // The JSArray describes JavaScript Arrays //  Such an array can be in one of two modes: //    - fast, backing storage is a FixedArray and length <= elements.length(); //       Please note: push and pop can be used to grow and shrink the array. //    - slow, backing storage is a HashTable with numbers as keys. classJSArray:publicJSObject{ public:   // [length]: The length property.   DECL_ACCESSORS(length,Object)     // Number of element slots to pre-allocate for an empty array.   staticconstintkPreallocatedArrayElements=4; };

这里说明一下,如果不熟悉C/C++的,那把它成伪码就好了。

源码里面说了,JSArray有两种模式,一种是快速的,一种是慢速的,快速的用的是索引直接定位,慢速的使用用哈希查找,这个在上一篇《从Chrome源码看JS Object的实现》就已经提及,由于JSArray是继承于JSObject,所以它也是同样的处理方式,如下面的:

            JavaScript   var array = [1, 2, 3] array[2000] = 10;
1 2 vararray=[1,2,3] array[2000]=10;

增加一个2000的索引时,array就会被转成慢元素。

如下的数组:

            JavaScript   var a = [8, 1, 2];
1 vara=[8,1,2];

把a打印出来:

– map = 0x939ebe04359 [FastProperties]

– prototype = 0x27e86e126289

– elements = 0xe70c791d4e9 [FAST_SMI_ELEMENTS (COW)]

– length = 3

– properties = 0x2b609d202241 {

#length: 0x2019c3e58da9 (const accessor descriptor)

}

elements= 0xe70c791d4e9 {

      0: 8

      1: 1

      2: 2

}

它有一个length的属性,它的elements有3个元素,按索引排列。当给它加一个2000的索引时:

            JavaScript   var a = [8, 1, 2]; a[2000] = 10;
1 2 vara=[8,1,2]; a[2000]=10;

打印出来的array变成:

– map = 0x333c83f9dbb9 [FastProperties]

– prototype = 0xdcc53ba6289

– elements = 0x21a208a1d541 [DICTIONARY_ELEMENTS]

– length = 2001

– properties = 0x885d1402241 {

#length: 0x1f564a958da9 (const accessor descriptor)

}

– elements= 0x21a208a1d541 {

2: 2 (data, dict_index: 0, attrs: [WEC])

0: 8 (data, dict_index: 0, attrs: [WEC])

2000: 10 (data, dict_index: 0, attrs: [WEC])

1: 1 (data, dict_index: 0, attrs: [WEC])

}

elements变成了一个慢元素哈希表,哈希表的容量为29。

由于快元素和慢元素上一节已经有详细讨论,这一节将不再重复。我们重点讨论数组的操作函数的实现。

2. Push和扩容

数组初始化大小为4:

            C++   // Number of element slots to pre-allocate for an empty array. static const int kPreallocatedArrayElements = 4;
1 2   // Number of element slots to pre-allocate for an empty array.   staticconstintkPreallocatedArrayElements=4;

执行push的时候会在数组的末尾添加新的元素,而一旦空间不足时,将进行扩容。

在源码里面push是用汇编实现的,在C++里面嵌入的汇编。这个应该是考虑到push是一个最为常用的操作,所以用汇编实现提高执行速度。在汇编的上面封装了一层,用C++调的封装的汇编的函数,在编译组装的时候,将把这些C++代码转成汇编代码。

计算新容量的函数:

            C++   Node* CodeStubAssembler::CalculateNewElementsCapacity(Node* old_capacity, ParameterMode mode) { Node* half_old_capacity = WordOrSmiShr(old_capacity, 1, mode); Node* new_capacity = IntPtrOrSmiAdd(half_old_capacity, old_capacity, mode); Node* padding = IntPtrOrSmiConstant(16, mode); return IntPtrOrSmiAdd(new_capacity, padding, mode); }
1 2 3 4 5 6 7 Node*CodeStubAssembler::CalculateNewElementsCapacity(Node*old_capacity,                                                       ParameterMode mode){   Node*half_old_capacity=WordOrSmiShr(old_capacity,1,mode);   Node*new_capacity=IntPtrOrSmiAdd(half_old_capacity,old_capacity,mode);   Node*padding=IntPtrOrSmiConstant(16,mode);   returnIntPtrOrSmiAdd(new_capacity,padding,mode); }

如上代码新容量等于 :

new_capacity = old_capacity /2 + old_capacity + 16

即老的容量的1.5倍加上16。初始化为4个,当push第5个的时候,容量将会变成:

new_capacity = 4 / 2 + 4 + 16 = 22

接着申请一块这么大的内存,把老的数据拷过去:

            C++   Node* CodeStubAssembler::GrowElementsCapacity( Node* object, Node* elements, Node* capacity, Node* new_capacity) { // Allocate the new backing store. Node* new_elements = AllocateFixedArray(new_capacity, mode); // Copy the elements from the old elements store to the new. CopyFixedArrayElements(elements, new_elements, capacity, new_capacity); return new_elements; }
1 2 3 4 5 6 7 8 9 Node*CodeStubAssembler::GrowElementsCapacity(     Node*object,Node*elements,Node*capacity,Node*new_capacity){   // Allocate the new backing store.   Node*new_elements=AllocateFixedArray(new_capacity,mode);     // Copy the elements from the old elements store to the new.   CopyFixedArrayElements(elements,new_elements,capacity,new_capacity);   returnnew_elements; }

由于复制是用的memcopy,把整一段内存空间拷贝过去,所以这个操作还是比较快的。

再把新元素放到当前length的位置,再把length增加1:

            C++   StoreFixedArrayElement(elements, var_length.value()); Increment(var_length, 1, mode);
1 2 StoreFixedArrayElement(elements,var_length.value()); Increment(var_length,1,mode);

可以来改点代码玩玩,我们知道push执行后的返回结果是新数组的长度,尝试把它改成返回老数组的长度:

            C++   Node *old_length = LoadJSArrayLength(receiver); Node *new_length = BuildAppendJSArray(/.../); //args.PopAndReturn(new_length); args.PopAndReturn(old_length);
1 2 3 4 Node*old_length=LoadJSArrayLength(receiver); Node*new_length=BuildAppendJSArray(/.../); //args.PopAndReturn(new_length); args.PopAndReturn(old_length);

重新编译Chrome,在控制台上执行比较如下:

右边的新Chrome返回了4,左边正常的Chrome返回5.

3. Pop和减容

push是用汇编实现,而pop的逻辑是用C++写的。在执行pop的时候,第一步,获取到当前的length,用这个length – 1得到要删除的元素,然后调用setLength调整容量,最后返回删除的元素:

            C++   int new_length = length - 1; int remove_index = remove_position == AT_START ? 0 : new_length; Handle result = Subclass::GetImpl(isolate, *backing_store, remove_index); Subclass::SetLengthImpl(isolate, receiver, new_length, backing_store); return result;
1 2 3 4 5 6 intnew_length=length-1; intremove_index=remove_position==AT_START?0:new_length; Handleresult=     Subclass::GetImpl(isolate,*backing_store,remove_index); Subclass::SetLengthImpl(isolate,receiver,new_length,backing_store); returnresult;

我们重点看下这个减容的过程:

            C++   if (2 * length <= capacity) { // If more than half the elements won't be used, trim the array. isolate->heap()->RightTrimFixedArray(*backing_store, capacity - length); } else { // Otherwise, fill the unused tail with holes. BackingStore::cast(*backing_store)->FillWithHoles(length, old_length); }
1 2 3 4 5 6 7 if(2*length<=capacity){   // If more than half the elements won't be used, trim the array.   isolate->heap()->RightTrimFixedArray(*backing_store,capacity-length); }else{   // Otherwise, fill the unused tail with holes.   BackingStore::cast(*backing_store)->FillWithHoles(length,old_length); }

如果容量大于等于length的2倍,则进行容量调整,否则用holes对象填充。第三行的rightTrim函数,会算出需要释放的空间大小,并做标记,并等待GC回收:

            C++   int bytes_to_trim = elements_to_trim * element_size; // Calculate location of new array end. Address old_end = object->address() + object->Size(); Address new_end = old_end - bytes_to_trim; CreateFillerObjectAt(new_end, bytes_to_trim, ClearRecordedSlots::kYes);
1 2 3 4 5 intbytes_to_trim=elements_to_trim*element_size; // Calculate location of new array end. Address old_end=object->address()+object->Size(); Address new_end=old_end-bytes_to_trim; CreateFillerObjectAt(new_end,bytes_to_trim,ClearRecordedSlots::kYes);

也就是说,当数组的元素个数小于容量的一半时,就会进行减少的操作,将容量调整为实际的大小。

4. shift和splice数组中间的操作

push和pop都是在数组末尾操作,相对比较简单,而shfit、unshfit、splice是在数组的开始或者中间进行操纵。我们来看一下,如果是这种情况的又是如何调整数组元素的。

(1)shift是出队,即删除并返回数组的第一个元素。shift和pop调的都是同样的删除函数,只不过shift传的删除的postion是AT_STRT,源码里面会判断如果是AT_START的话,会把元素进行移动:

            C++   if (remove_position == AT_START) { Subclass::MoveElements(isolate, receiver, backing_store, 0, 1, new_length, 0, 0); }
1 2 3 4 if(remove_position==AT_START){     Subclass::MoveElements(isolate,receiver,backing_store,0,1,new_length,                          0,0); }

从1的位置移到0的位置,如上面第2行的第4、5个参数,这个move将会调leftTrim,和上面的rightTrim相反:

            C++   *dst_elms.location() = BackingStore::cast(heap->LeftTrimFixedArray(*dst_elms, src_index)); receiver->set_elements(*dst_elms);
1 2 3 *dst_elms.location()=     BackingStore::cast(heap->LeftTrimFixedArray(*dst_elms,src_index)); receiver->set_elements(*dst_elms);

(2)unshfit在数组的开始位置插入元素,首先要判断容量是否足够存放,如果不够,将容量扩展为老容量的1.5倍加16,然后把老元素移到新的内存空间偏移为unshift元素个数的位置,也就是说要腾出起始的空间放unshfit传进来的元素,如果空间足够了,则直接执行memmove移动内存空间,最后再把unshif传进来的参数copy到开始的位置:

            C++   int insertion_index = add_position == AT_START ? 0 : length; // Copy the arguments to the start. Subclass::CopyArguments(args, backing_store, add_size, 1, insertion_index); // Set the length. receiver->set_length(Smi::FromInt(new_length));
1 2 3 4 5 intinsertion_index=add_position==AT_START?0:length; // Copy the arguments to the start. Subclass::CopyArguments(args,backing_store,add_size,1,insertion_index); // Set the length. receiver->set_length(Smi::FromInt(new_length));

并更新array的length。

(3)splice的操作已经几乎不用去看源码了,通过shift和unshift的操作是怎么样的,就可以想象到它的执行过程是怎样的,只是shift/unshfit操作的index是0,而splice可以指定index。具体代码如下:

            C++   // Delete and move elements to make space for add_count new elements. if (add_count < delete_count) { Subclass::SpliceShrinkStep(isolate, receiver, backing_store, start, delete_count, add_count, length, new_length); } else if (add_count > delete_count) { backing_store = Subclass::SpliceGrowStep(isolate, receiver, backing_store, start, delete_count, add_count, length, new_length); } // Copy over the arguments. Subclass::CopyArguments(args, backing_store, add_count, 3, start);
1 2 3 4 5 6 7 8 9 10 11 12 // Delete and move elements to make space for add_count new elements. if(add_countdelete_count){   backing_store=       Subclass::SpliceGrowStep(isolate,receiver,backing_store,start,                                delete_count,add_count,length,new_length); }   // Copy over the arguments. Subclass::CopyArguments(args,backing_store,add_count,3,start);

它需要先shrink或者grow中间元素的空间,以适应增加元素比删除元素少或者多的情况,然后进行容量调整和移动元素。

接着再来看下两个“小清新”的函数

5. Join和Sort

说它们是小清新,是因为它们是用JS实现的,然后再用wasm打包成native code。不过,join的实现逻辑并不简单,因为array的元素本身具有多样化,可能为慢元素或者快元素,还可能带有循环引用,对于慢元素,需要先排下序:

            C++   var keys = GetSortedArrayKeys(array, %GetArrayKeys(array, length));
1 varkeys=GetSortedArrayKeys(array,%GetArrayKeys(array,length));

预处理完之后,最后创建一个字符串数组,用连接符连起来:

            JavaScript   // Construct an array for the elements. var elements = new InternalArray(length); for (var i = 0; i < length; i++) { elements[i] = ConvertToString(use_locale, array[i]); } if (separator === '') { return %StringBuilderConcat(elements, length, ''); } else { return %StringBuilderJoin(elements, length, separator); }
1 2 3 4 5 6 7 8 9 10 11 // Construct an array for the elements. varelements=newInternalArray(length); for(vari=0;i

而sort函数是用的快速排序:

            JavaScript   function ArraySort(comparefn) { CHECK_OBJECT_COERCIBLE(this, "Array.prototype.sort"); %Log("js/array.js execute ArraySort"); //手动添加的log打印,确保执行的是这里 var array = TO_OBJECT(this); var length = TO_LENGTH(array.length); return InnerArraySort(array, length, comparefn); }
1 2 3 4 5 6 7 8 functionArraySort(comparefn){   CHECK_OBJECT_COERCIBLE(this,"Array.prototype.sort");   %Log("js/array.js execute ArraySort");  //手动添加的log打印,确保执行的是这里     vararray=TO_OBJECT(this);   varlength=TO_LENGTH(array.length);   returnInnerArraySort(array,length,comparefn); }

当数组元素的个数不超过10个时,是用的插入排序:

            JavaScript   function InnerArraySort(array, length, comparefn) { // In-place QuickSort algorithm. // For short (length <= 10) arrays, insertion sort is used for efficiency. function QuickSort(a, from, to) { var third_index = 0; while (true) { // Insertion sort is faster for short arrays. if (to - from <= 10) { InsertionSort(a, from, to); return; } //other code ... } } }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 functionInnerArraySort(array,length,comparefn){   // In-place QuickSort algorithm.   // For short (length <= 10) arrays, insertion sort is used for efficiency.   functionQuickSort(a,from,to){     varthird_index=0;     while(true){       // Insertion sort is faster for short arrays.       if(to-from<=10){         InsertionSort(a,from,to);         return;       }       //other code ...     }   } }

快速排序算法里面有一个比较重要的地方是选择枢纽元素,最简单的是每次都是选取第一个元素,或者中间的元素,在源码里面是这样选择的:

            JavaScript   if (to - from > 1000) { third_index = GetThirdIndex(a, from, to); } else { third_index = from + ((to - from) >> 1); }
1 2 3 4 5 if(to-from>1000){   third_index=GetThirdIndex(a,from,to); }else{   third_index=from+((to-from)>>1); }

如果元素个数在1000以内,则使用它们的中间元素,否则要算一下, 这个算法比较有趣:

            JavaScript   function GetThirdIndex(a, from, to) { var t_array = new InternalArray(); // Use both 'from' and 'to' to determine the pivot candidates. var increment = 200 + ((to - from) & 15); var j = 0; from += 1; to -= 1; for (var i = from; i < to; i += increment) { t_array[j] = [i, a[i]]; j++; } t_array.sort(function(a, b) { return comparefn(a[1], b[1]); }); var third_index = t_array[t_array.length >> 1][0]; return third_index; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 functionGetThirdIndex(a,from,to){   vart_array=newInternalArray();   // Use both 'from' and 'to' to determine the pivot candidates.   varincrement=200+((to-from)&15);   varj=0;   from+=1;   to-=1;   for(vari=from;i>1][0];   returnthird_index; }

先取一个递增间距200~215之间,再循环取出原元素里面落到这个间距的元素,放到一个新的数组里面(这个数组是C++里面的数组),然后排下序,取中间的元素。因为枢纽元素的刚好是所有元素的中位数时,排序的效果最好,而这里是取出少数元素的中位数,类似于抽样模拟,缺点是它得再借助另外的排序算法。

最后再比较一下Array和线性链接的速度。

6. Array和线性链接的速度

线性链接是一种非连续存储的数据结构,每个元素都有一个指针指向它的下一个元素,所以它删除元素的时候不需要移动其它元素,也不需要考虑扩容的事情,但是它的查找比较慢。我们实现一个简单的List和Array进行比较。

List的每个节点用一个Node表示:

            JavaScript   class Node{ constructor(value, next){ this.value = value; this.next = next; } }
1 2 3 4 5 6 classNode{     constructor(value,next){         this.value=value;         this.next=next;     } }

每个List都有一个头指针指向第一个元素,和一个length记录它的长度:

            JavaScript   class List{ constructor(){ this.head = null; this.tail = null; this.length = 0; } }
1 2 3 4 5 6 7 classList{     constructor(){         this.head=null;         this.tail=null;         this.length=0;     } }

然后实现它的push和unshift函数:

            C++   class List{ unshift(value){ return this.insert(0, value); } push(value){ if(this.head === null){ this.head = new Node(value, this.tail); this.length++; } else { this.insert(this.length, value); } return this.length; } }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 classList{     unshift(value){         returnthis.insert(0,value);     }     push(value){         if(this.head===null){             this.head=newNode(value,this.tail);             this.length++;         }else{             this.insert(this.length,value);         }         returnthis.length;     } }

两个函数都会调一个通用的insert函数:

            JavaScript   insert(index, value){ var insertPos = this.head; //找到需要插入的位置的节点 for(var i = 0; i < index - 1; i++){ insertPos = insertPos.next; } var node = null; if(index === 0){ node = new Node(value, this.head); this.head = node; } else { node = new Node(value, insertPos.next); insertPos.next = node; } this.length++; return value; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 insert(index,value){     varinsertPos=this.head;     //找到需要插入的位置的节点     for(vari=0;i-->