Repository: trafficserver Updated Branches: refs/heads/master 963982e43 -> 062b4848d
doc: fix metalink plugin filenames Project: http://git-wip-us.apache.org/repos/asf/trafficserver/repo Commit: http://git-wip-us.apache.org/repos/asf/trafficserver/commit/062b4848 Tree: http://git-wip-us.apache.org/repos/asf/trafficserver/tree/062b4848 Diff: http://git-wip-us.apache.org/repos/asf/trafficserver/diff/062b4848 Branch: refs/heads/master Commit: 062b4848d3978003cef23681b7c71d70c0eff280 Parents: 963982e Author: James Peach <[email protected]> Authored: Mon Feb 24 15:27:15 2014 -0800 Committer: James Peach <[email protected]> Committed: Thu Feb 27 15:03:29 2014 -0800 ---------------------------------------------------------------------- .../reference/plugins/metafilter.en.po | 149 ------------------- .../reference/plugins/metalink.en.po | 148 ++++++++++++++++++ doc/reference/plugins/index.en.rst | 2 +- doc/reference/plugins/metafilter.en.rst | 113 -------------- doc/reference/plugins/metalink.en.rst | 113 ++++++++++++++ 5 files changed, 262 insertions(+), 263 deletions(-) ---------------------------------------------------------------------- http://git-wip-us.apache.org/repos/asf/trafficserver/blob/062b4848/doc/locale/ja/LC_MESSAGES/reference/plugins/metafilter.en.po ---------------------------------------------------------------------- diff --git a/doc/locale/ja/LC_MESSAGES/reference/plugins/metafilter.en.po b/doc/locale/ja/LC_MESSAGES/reference/plugins/metafilter.en.po deleted file mode 100644 index daf3597..0000000 --- a/doc/locale/ja/LC_MESSAGES/reference/plugins/metafilter.en.po +++ /dev/null @@ -1,149 +0,0 @@ -# -msgid "" -msgstr "" -"Project-Id-Version: Apache Traffic Server 4.1\n" -"Report-Msgid-Bugs-To: \n" -"POT-Creation-Date: 2013-11-08 17:57+0900\n" -"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" -"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" -"Language-Team: LANGUAGE <[email protected]>\n" -"MIME-Version: 1.0\n" -"Content-Type: text/plain; charset=UTF-8\n" -"Content-Transfer-Encoding: 8bit\n" - -#: ../../reference/plugins/metafilter.en.rst:21 -msgid "Metalink plugin" -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:23 -msgid "" -"The `metalink` plugin implements the `Metalink <http://en.wikipedia.org/"; -"wiki/Metalink>`_ protocol in order to try not to download the same file " -"twice. This improves cache efficiency and speeds up user downloads." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:28 -msgid "" -"Take standard headers and knowledge about objects in the cache and " -"potentially rewrite those headers so that a client will use a URL that is " -"already cached instead of one that isn't." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:32 -msgid "" -"The `metalink` headers are specified in :rfc:`6429` and :rfc:`3230` and are " -"sent by various download redirectors or content distribution networks." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:36 -msgid "" -"A lot of download sites distribute the same files from many different " -"mirrors and users don't know which mirrors are already cached. These sites " -"often present users with a simple download button, but the button doesn't " -"predictably access the same mirror, or a mirror that is already cached. To " -"users it seems like the download works sometimes (takes seconds) and not " -"others (takes hours), which is frustrating." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:43 -msgid "" -"An extreme example of this happens when users share a limited, possibly " -"unreliable internet connection, as is common in parts of Africa for example." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:48 -msgid "How it works" -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:50 -msgid "" -"When the `metalink` plugin sees a response with a ``Location: ...`` header " -"and a ``Digest: SHA-256=...`` header, it checks to see if the URL in the " -"Location header is already cached. If it isn't, then it tries to find a URL " -"that is cached to use instead. It looks in the cache for some object that " -"matches the digest in the Digest header and if it finds something, then it " -"rewites the ``Location`` header with the URL from that object." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:58 -msgid "" -"That way a client should get sent to a URL that's already cached and the " -"user won't end up downloading the file again." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:62 -msgid "Installation" -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:64 -msgid "" -"`metalink` is a global plugin. It is enabled by adding it to your :file:" -"`plugin.config` file. There are no options." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:68 -msgid "Implementation Status" -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:70 -msgid "" -"The `metalink` plugin implements the ``TS_HTTP_SEND_RESPONSE_HDR_HOOK`` " -"hook to check and potentially rewrite the ``Location: ...`` and ``Digest: " -"SHA-256=...`` headers after responses are cached. It doesn't do it before " -"they're cached because the contents of the cache can change after responses " -"are cached. It uses :c:func:`TSCacheRead` to check if the URL in the " -"``Location: ...`` header is already cached. In future, the plugin should " -"also check if the URL is fresh or not." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:79 -msgid "" -"The plugin implements ``TS_HTTP_READ_RESPONSE_HDR_HOOK`` and a null " -"transform to compute the SHA-256 digest for content as it's added to the " -"cache, then uses :c:func:`TSCacheWrite` to associate the digest with the " -"request URL. This adds a new cache object where the key is the digest and " -"the object is the request URL." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:85 -msgid "" -"To check if the cache already contains content that matches a digest, the " -"plugin must call :c:func:`TSCacheRead` with the digest as the key, read the " -"URL stored in the resultant object, and then call :c:func:`TSCacheRead` " -"again with this URL as the key. This is probably inefficient and should be " -"improved." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:91 -msgid "" -"An early version of the plugin scanned ``Link: <...>; rel=duplicate`` " -"headers. If the URL in the ``Location: ...`` header was not already cached, " -"it scanned ``Link: <...>; rel=duplicate`` headers for a URL that was. The " -"``Digest: SHA-256=...`` header is superior because it will find content " -"that already exists in the cache in every case that a ``Link: <...>; " -"rel=duplicate`` header would, plus in cases where the URL is not listed " -"among the ``Link: <...>; rel=duplicate`` headers, maybe because the content " -"was downloaded from a URL not participating in the content distribution " -"network, or maybe because there are too many mirrors to list in ``Link: <..." -">; rel=duplicate`` headers." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:103 -msgid "" -"The ``Digest: SHA-256=...`` header is also more efficient than ``Link: <..." -">; rel=duplicate`` headers because it involves a constant number of cache " -"lookups. :rfc:`6249` requires a ``Digest: SHA-256=...`` header or ``Link: " -"<...>; rel=duplicate`` headers MUST be ignored:" -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:108 -msgid "" -"If Instance Digests are not provided by the Metalink servers, the Link " -"header fields pertaining to this specification MUST be ignored." -msgstr "" - -#: ../../reference/plugins/metafilter.en.rst:111 -msgid "" -"Metalinks contain whole file hashes as described in Section 6, and MUST " -"include SHA-256, as specified in [FIPS-180-3]." -msgstr "" http://git-wip-us.apache.org/repos/asf/trafficserver/blob/062b4848/doc/locale/ja/LC_MESSAGES/reference/plugins/metalink.en.po ---------------------------------------------------------------------- diff --git a/doc/locale/ja/LC_MESSAGES/reference/plugins/metalink.en.po b/doc/locale/ja/LC_MESSAGES/reference/plugins/metalink.en.po new file mode 100644 index 0000000..1ebfd0d --- /dev/null +++ b/doc/locale/ja/LC_MESSAGES/reference/plugins/metalink.en.po @@ -0,0 +1,148 @@ +# +msgid "" +msgstr "" +"Project-Id-Version: Apache Traffic Server 4.1\n" +"Report-Msgid-Bugs-To: \n" +"POT-Creation-Date: 2013-11-08 17:57+0900\n" +"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n" +"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n" +"Language-Team: LANGUAGE <[email protected]>\n" +"MIME-Version: 1.0\n" +"Content-Type: text/plain; charset=UTF-8\n" +"Content-Transfer-Encoding: 8bit\n" + +#: ../../reference/plugins/metalink.en.rst:21 +msgid "Metalink plugin" +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:23 +msgid "" +"The `metalink` plugin implements the `Metalink <http://en.wikipedia.org/"; +"wiki/Metalink>`_ protocol in order to try not to download the same file " +"twice. This improves cache efficiency and speeds up user downloads." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:28 +msgid "" +"Take standard headers and knowledge about objects in the cache and " +"potentially rewrite those headers so that a client will use a URL that is " +"already cached instead of one that isn't." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:32 +msgid "" +"The `metalink` headers are specified in :rfc:`6429` and :rfc:`3230` and are " +"sent by various download redirectors or content distribution networks." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:36 +msgid "" +"A lot of download sites distribute the same files from many different " +"mirrors and users don't know which mirrors are already cached. These sites " +"often present users with a simple download button, but the button doesn't " +"predictably access the same mirror, or a mirror that is already cached. To " +"users it seems like the download works sometimes (takes seconds) and not " +"others (takes hours), which is frustrating." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:43 +msgid "" +"An extreme example of this happens when users share a limited, possibly " +"unreliable internet connection, as is common in parts of Africa for example." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:48 +msgid "How it works" +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:50 +msgid "" +"When the `metalink` plugin sees a response with a ``Location: ...`` header " +"and a ``Digest: SHA-256=...`` header, it checks to see if the URL in the " +"Location header is already cached. If it isn't, then it tries to find a URL " +"that is cached to use instead. It looks in the cache for some object that " +"matches the digest in the Digest header and if it finds something, then it " +"rewites the ``Location`` header with the URL from that object." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:58 +msgid "" +"That way a client should get sent to a URL that's already cached and the " +"user won't end up downloading the file again." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:62 +msgid "Installation" +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:64 +msgid "" +"`metalink` is a global plugin. It is enabled by adding it to your :file:" +"`plugin.config` file. There are no options." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:68 +msgid "Implementation Status" +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:70 +msgid "" +"The `metalink` plugin implements the ``TS_HTTP_SEND_RESPONSE_HDR_HOOK`` " +"hook to check and potentially rewrite the ``Location: ...`` and ``Digest: " +"SHA-256=...`` headers after responses are cached. It doesn't do it before " +"they're cached because the contents of the cache can change after responses " +"are cached. It uses :c:func:`TSCacheRead` to check if the URL in the " +"``Location: ...`` header is already cached. In future, the plugin should " +"also check if the URL is fresh or not." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:79 +msgid "" +"The plugin implements ``TS_HTTP_READ_RESPONSE_HDR_HOOK`` and a null " +"transform to compute the SHA-256 digest for content as it's added to the " +"cache, then uses :c:func:`TSCacheWrite` to associate the digest with the " +"request URL. This adds a new cache object where the key is the digest and " +"the object is the request URL." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:85 +msgid "" +"To check if the cache already contains content that matches a digest, the " +"plugin must call :c:func:`TSCacheRead` with the digest as the key, read the " +"URL stored in the resultant object, and then call :c:func:`TSCacheRead` " +"again with this URL as the key. This is probably inefficient and should be " +"improved." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:91 +msgid "" +"An early version of the plugin scanned ``Link: <...>; rel=duplicate`` " +"headers. If the URL in the ``Location: ...`` header was not already cached, " +"it scanned ``Link: <...>; rel=duplicate`` headers for a URL that was. The " +"``Digest: SHA-256=...`` header is superior because it will find content " +"that already exists in the cache in every case that a ``Link: <...>; " +"rel=duplicate`` header would, plus in cases where the URL is not listed " +"among the ``Link: <...>; rel=duplicate`` headers, maybe because the content " +"was downloaded from a URL not participating in the content distribution " +"network, or maybe because there are too many mirrors to list in ``Link: <..." +">; rel=duplicate`` headers." +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:103 +msgid "" +"The ``Digest: SHA-256=...`` header is also more efficient than ``Link: <..." +">; rel=duplicate`` headers because it involves a constant number of cache " +"lookups. :rfc:`6249` requires a ``Digest: SHA-256=...`` header or ``Link: " +"<...>; rel=duplicate`` headers MUST be ignored:" +msgstr "" + +#: ../../reference/plugins/metalink.en.rst:108 +msgid "" +"If Instance Digests are not provided by the Metalink servers, the Link " +"header fields pertaining to this specification MUST be ignored." +msgstr "" + +msgid "" +"Metalinks contain whole file hashes as described in Section 6, and MUST " +"include SHA-256, as specified in [FIPS-180-3]." +msgstr "" http://git-wip-us.apache.org/repos/asf/trafficserver/blob/062b4848/doc/reference/plugins/index.en.rst ---------------------------------------------------------------------- diff --git a/doc/reference/plugins/index.en.rst b/doc/reference/plugins/index.en.rst index db664b7..20feb63 100644 --- a/doc/reference/plugins/index.en.rst +++ b/doc/reference/plugins/index.en.rst @@ -69,7 +69,7 @@ directory of the Apache Traffic Server source tree. Exmperimental plugins can be esi.en geoip_acl.en hipes.en - metafilter.en + metalink.en mysql_remap.en stale_while_revalidate.en ts_lua.en http://git-wip-us.apache.org/repos/asf/trafficserver/blob/062b4848/doc/reference/plugins/metafilter.en.rst ---------------------------------------------------------------------- diff --git a/doc/reference/plugins/metafilter.en.rst b/doc/reference/plugins/metafilter.en.rst deleted file mode 100644 index f9785f8..0000000 --- a/doc/reference/plugins/metafilter.en.rst +++ /dev/null @@ -1,113 +0,0 @@ -.. Licensed to the Apache Software Foundation (ASF) under one - or more contributor license agreements. See the NOTICE file - distributed with this work for additional information - regarding copyright ownership. The ASF licenses this file - to you under the Apache License, Version 2.0 (the - "License"); you may not use this file except in compliance - with the License. You may obtain a copy of the License at - - http://www.apache.org/licenses/LICENSE-2.0 - - Unless required by applicable law or agreed to in writing, - software distributed under the License is distributed on an - "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY - KIND, either express or implied. See the License for the - specific language governing permissions and limitations - under the License. - -.. _metafilter-plugin: - -Metalink plugin -=============== - -The `metalink` plugin implements the -`Metalink <http://en.wikipedia.org/wiki/Metalink>`_ -protocol in order to try not to download the same file twice. This -improves cache efficiency and speeds up user downloads. - -Take standard headers and knowledge about objects in the cache and -potentially rewrite those headers so that a client will use a URL -that is already cached instead of one that isn't. - -The `metalink` headers are specified in :rfc:`6429` and :rfc:`3230` -and are sent by various download redirectors or content distribution -networks. - -A lot of download sites distribute the same files from many different -mirrors and users don't know which mirrors are already cached. These -sites often present users with a simple download button, but the -button doesn't predictably access the same mirror, or a mirror that -is already cached. To users it seems like the download works sometimes -(takes seconds) and not others (takes hours), which is frustrating. - -An extreme example of this happens when users share a limited, -possibly unreliable internet connection, as is common in parts of -Africa for example. - -How it works ------------- - -When the `metalink` plugin sees a response with a ``Location: ...`` header and a -``Digest: SHA-256=...`` header, it checks to see if the URL in the Location -header is already cached. If it isn't, then it tries to find a URL -that is cached to use instead. It looks in the cache for some object -that matches the digest in the Digest header and if it finds -something, then it rewites the ``Location`` header with the URL from -that object. - -That way a client should get sent to a URL that's already cached -and the user won't end up downloading the file again. - -Installation ------------- - -`metalink` is a global plugin. It is enabled by adding it to your -:file:`plugin.config` file. There are no options. - -Implementation Status ---------------------- - -The `metalink` plugin implements the ``TS_HTTP_SEND_RESPONSE_HDR_HOOK`` -hook to check and potentially rewrite the ``Location: ...`` and -``Digest: SHA-256=...`` headers after responses are cached. It -doesn't do it before they're cached because the contents of the -cache can change after responses are cached. It uses :c:func:`TSCacheRead` -to check if the URL in the ``Location: ...`` header is already -cached. In future, the plugin should also check if the URL is fresh -or not. - -The plugin implements ``TS_HTTP_READ_RESPONSE_HDR_HOOK`` and a null -transform to compute the SHA-256 digest for content as it's added -to the cache, then uses :c:func:`TSCacheWrite` to associate the -digest with the request URL. This adds a new cache object where the -key is the digest and the object is the request URL. - -To check if the cache already contains content that matches a digest, -the plugin must call :c:func:`TSCacheRead` with the digest as the -key, read the URL stored in the resultant object, and then call -:c:func:`TSCacheRead` again with this URL as the key. This is -probably inefficient and should be improved. - -An early version of the plugin scanned ``Link: <...>; rel=duplicate`` -headers. If the URL in the ``Location: ...`` header was not already -cached, it scanned ``Link: <...>; rel=duplicate`` headers for a URL -that was. The ``Digest: SHA-256=...`` header is superior because it -will find content that already exists in the cache in every case -that a ``Link: <...>; rel=duplicate`` header would, plus in cases -where the URL is not listed among the ``Link: <...>; rel=duplicate`` -headers, maybe because the content was downloaded from a URL not -participating in the content distribution network, or maybe because -there are too many mirrors to list in ``Link: <...>; rel=duplicate`` -headers. - -The ``Digest: SHA-256=...`` header is also more efficient than ``Link: -<...>; rel=duplicate`` headers because it involves a constant number -of cache lookups. :rfc:`6249` requires a ``Digest: SHA-256=...`` header -or ``Link: <...>; rel=duplicate`` headers MUST be ignored: - - If Instance Digests are not provided by the Metalink servers, the - Link header fields pertaining to this specification MUST be ignored. - - Metalinks contain whole file hashes as described in Section 6, - and MUST include SHA-256, as specified in [FIPS-180-3]. - http://git-wip-us.apache.org/repos/asf/trafficserver/blob/062b4848/doc/reference/plugins/metalink.en.rst ---------------------------------------------------------------------- diff --git a/doc/reference/plugins/metalink.en.rst b/doc/reference/plugins/metalink.en.rst new file mode 100644 index 0000000..7b804cc --- /dev/null +++ b/doc/reference/plugins/metalink.en.rst @@ -0,0 +1,113 @@ +.. Licensed to the Apache Software Foundation (ASF) under one + or more contributor license agreements. See the NOTICE file + distributed with this work for additional information + regarding copyright ownership. The ASF licenses this file + to you under the Apache License, Version 2.0 (the + "License"); you may not use this file except in compliance + with the License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, + software distributed under the License is distributed on an + "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + KIND, either express or implied. See the License for the + specific language governing permissions and limitations + under the License. + +.. _metalink-plugin: + +Metalink plugin +=============== + +The `metalink` plugin implements the +`Metalink <http://en.wikipedia.org/wiki/Metalink>`_ +protocol in order to try not to download the same file twice. This +improves cache efficiency and speeds up user downloads. + +Take standard headers and knowledge about objects in the cache and +potentially rewrite those headers so that a client will use a URL +that is already cached instead of one that isn't. + +The `metalink` headers are specified in :rfc:`6429` and :rfc:`3230` +and are sent by various download redirectors or content distribution +networks. + +A lot of download sites distribute the same files from many different +mirrors and users don't know which mirrors are already cached. These +sites often present users with a simple download button, but the +button doesn't predictably access the same mirror, or a mirror that +is already cached. To users it seems like the download works sometimes +(takes seconds) and not others (takes hours), which is frustrating. + +An extreme example of this happens when users share a limited, +possibly unreliable internet connection, as is common in parts of +Africa for example. + +How it works +------------ + +When the `metalink` plugin sees a response with a ``Location: ...`` header and a +``Digest: SHA-256=...`` header, it checks to see if the URL in the Location +header is already cached. If it isn't, then it tries to find a URL +that is cached to use instead. It looks in the cache for some object +that matches the digest in the Digest header and if it finds +something, then it rewites the ``Location`` header with the URL from +that object. + +That way a client should get sent to a URL that's already cached +and the user won't end up downloading the file again. + +Installation +------------ + +`metalink` is a global plugin. It is enabled by adding it to your +:file:`plugin.config` file. There are no options. + +Implementation Status +--------------------- + +The `metalink` plugin implements the ``TS_HTTP_SEND_RESPONSE_HDR_HOOK`` +hook to check and potentially rewrite the ``Location: ...`` and +``Digest: SHA-256=...`` headers after responses are cached. It +doesn't do it before they're cached because the contents of the +cache can change after responses are cached. It uses :c:func:`TSCacheRead` +to check if the URL in the ``Location: ...`` header is already +cached. In future, the plugin should also check if the URL is fresh +or not. + +The plugin implements ``TS_HTTP_READ_RESPONSE_HDR_HOOK`` and a null +transform to compute the SHA-256 digest for content as it's added +to the cache, then uses :c:func:`TSCacheWrite` to associate the +digest with the request URL. This adds a new cache object where the +key is the digest and the object is the request URL. + +To check if the cache already contains content that matches a digest, +the plugin must call :c:func:`TSCacheRead` with the digest as the +key, read the URL stored in the resultant object, and then call +:c:func:`TSCacheRead` again with this URL as the key. This is +probably inefficient and should be improved. + +An early version of the plugin scanned ``Link: <...>; rel=duplicate`` +headers. If the URL in the ``Location: ...`` header was not already +cached, it scanned ``Link: <...>; rel=duplicate`` headers for a URL +that was. The ``Digest: SHA-256=...`` header is superior because it +will find content that already exists in the cache in every case +that a ``Link: <...>; rel=duplicate`` header would, plus in cases +where the URL is not listed among the ``Link: <...>; rel=duplicate`` +headers, maybe because the content was downloaded from a URL not +participating in the content distribution network, or maybe because +there are too many mirrors to list in ``Link: <...>; rel=duplicate`` +headers. + +The ``Digest: SHA-256=...`` header is also more efficient than ``Link: +<...>; rel=duplicate`` headers because it involves a constant number +of cache lookups. :rfc:`6249` requires a ``Digest: SHA-256=...`` header +or ``Link: <...>; rel=duplicate`` headers MUST be ignored: + + If Instance Digests are not provided by the Metalink servers, the + Link header fields pertaining to this specification MUST be ignored. + + Metalinks contain whole file hashes as described in Section 6, + and MUST include SHA-256, as specified in [FIPS-180-3]. +
