Help:Extension:Translate/Translation memories/da

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The Translate extension translation memory supports ElasticSearch. This page aims to guide you in installing ElasticSearch, and exploring its specifications in deeper detail.

Unlike other translation aids, for instance external machine translation services, the translation memory is constantly updated by new translations in your wiki. Advanced search across translations is also available at Special:SearchTranslations if you choose to use ElasticSearch.

The database backend is used by default: it has no dependencies and doesn't need configuration. The database backend can't be shared among multiple wikis and it does not scale to large amounts of translated content. Hence we also support ElasticSearch as a backend. It is also possible to use another wiki's translation memory if their web API is open. Unlike ElasticSearch, remote backends are not updated with translations from the current wiki.

Database Fjernbetjent API ElasticSearch
Aktiveret som standard <translate> Yes</translate> <translate> No</translate> <translate> No</translate>
Kan have flere kilder <translate> No</translate> <translate> Yes</translate> <translate> Yes</translate>
Opdateret med lokale oversættelser <translate> Yes</translate> <translate> No</translate> <translate> Yes</translate>
Åbner database direkte <translate> Yes</translate> <translate> No</translate> <translate> No</translate>
Adgang til kilde Skribent Link Lokal skribent eller link
Kan deles som en API-tjeneste <translate> Yes</translate> <translate> Yes</translate> <translate> Yes</translate>
Optræden Does not scale well Ukendt Reasonable

Krav

ElasticSearch backend

ElasticSearch is relatively easy to set up. If it is not available in your distribution packages, you can get it from their website. You will also need to get the Elastica extension. Finally, please see puppet/modules/elasticsearch/files/elasticsearch.yml for specific configuration needed by Translate.

The bootstrap script will create necessary schemas. If you are using ElasticSearch backend with multiple wikis, they will share the translation memory by default, unless you set the index parameter in the configuration.

When upgrading to the next major version of ElasticSearch (e.g. upgrading from 2.x to 5.x), it is highly recommended to read the release notes and the documentation regarding the upgrade process.

Installation

After putting the requirements in place, installation requires you to tweak the configuration and then execute the bootstrap.

Konfiguration

Al oversættelses-hjælp, herunder oversættelses-hukommelse er konfigureret med $wgTranslateTranslationServices-konfigurationsindstillingen. Eksempel på konfiguration af TTMServers:

The primary translation memory backend must use the key TTMServer. The primary backend receives translation updates and is used by Special:SearchTranslations.

Example configuration of TTMServers:

Standard konfiguration
$wgTranslateTranslationServices['TTMServer'] = array(
        'database' => false, // Passed to wfGetDB
        'cutoff' => 0.75,
        'type' => 'ttmserver',
        'public' => false,
);
Fjernbetjent API-konfiguration
$wgTranslateTranslationServices['example'] = array(
        'url' => 'http://example.com/w/api.php',
        'displayname' => 'example.com',
        'cutoff' => 0.75,
        'timeout' => 3,
        'type' => 'ttmserver',
        'class' => 'RemoteTTMServer',
);
ElasticSearch backend configuration
In this case the single back-end service will be used both for reads & writes.
$wgTranslateTranslationServices['TTMServer'] = array(
        'type' => 'ttmserver',
        'class' => 'ElasticSearchTTMServer',
        'cutoff' => 0.75,
        /*
         * See http://elastica.io/getting-started/installation.html
         * See https://github.com/ruflin/Elastica/blob/8.x/src/Client.php
        'config' => This will be passed to \Elastica\Client
         */
);
ElasticSearch multiple backends configuration (supported by MLEB 2017.04, dropped in MLEB 2023.10)
// Defines the default service used for read operations
// Allows to quickly switch to another backend
// 'mirrors' configuration option is no longer supported since MLEB 2023.10
$wgTranslateTranslationDefaultService = 'cluster1';
$wgTranslateTranslationServices['cluster1'] = array(
        'type' => 'ttmserver',
        'class' => 'ElasticSearchTTMServer',
        'cutoff' => 0.75,
        /*
         * Defines the list of services to replicate writes to.
         * Only "writable" services are allowed here.
         */
        'mirrors' => [ 'cluster2' ],
        'config' => [ 'servers' => [ 'host' => 'elastic1001.cluster1.mynet' ] ]
);
$wgTranslateTranslationServices['cluster2'] = array(
        'type' => 'ttmserver',
        'class' => 'ElasticSearchTTMServer',
        'cutoff' => 0.75,
        /*
         * if "cluster2" is defined as the default service it will start to replicate writes to "cluster1".
         */
        'mirrors' => [ 'cluster1' ],
        'config' => [ 'servers' => [ 'host' => 'elastic2001.cluster2.mynet' ] ]
);
ElasticSearch multiple services with single readable service using writable configuration (supported by MLEB 2023.04)
With writable configuration the following rules are enforced:
  • If writable is specified, services marked as writable are considered write only and others are considered read only.
  • If no service is specified as writable then services are considered both readable and writable.
  • The default service must always be readable.

If a service is marked as writable, the mirrors configuration will not be allowed.

// Three services configured with one being readable and the others being writable.
$wgTranslateTranslationServices['dc0'] = [
	'type' => 'ttmserver',
	'class' => 'ElasticSearchTTMServer',
	'cutoff' => 0.75,
	// Default service cannot be marked as write-only
];

$wgTranslateTranslationServices['dc1'] = [
	'type' => 'ttmserver',
	'class' => 'ElasticSearchTTMServer',
	'cutoff' => 0.75,
	// Marks this service as write-only 
	'writable' => true,
];

$wgTranslateTranslationServices['dc2'] = [
	'type' => 'ttmserver',
	'class' => 'ElasticSearchTTMServer',
	'cutoff' => 0.75,
	'writable' => true
];

$wgTranslateTranslationDefaultService = 'dc0';

Mulige nøgler og værdier er:

Nøgle Gælder til Beskrivelse
config ElasticSearch Solr eksempel-konfiguration for Solarium, se nedenfor.
cutoff Alle Minimumsgrænse for matchende forslag. Kun få de bedste forslag er vist, selv hvis der var flere over grænsen.
database Lokal Hvis du ønsker at gemme oversættelses-hukommelsen et andet sted, kan du angive databasenavnet her. Du skal også konfigurere MediaWiki's load balancer, så den ved hvordan der oprettes forbindelse til databasen.
displayname Fjernbejent Teksten vises i værktøjs-tippet når der peges på forslagets kildelink (punkterne).
index ElasticSearch The index to use in ElasticSearch. Default: ttmserver.
public Alle Hvorvidt denne TTMServer kan forespørges via denne wikis api.php
replicas ElasticSearch If you are running a cluster, you can increase the number of replicas. Default: 0.
shards ElasticSearch How many shards to use. Default: 5.
timeout Fjernbetjent Ventetid på et svar fra fjernbetjent service i sekunder.
type Alle TTMServer-type i form af resultat-format.
url Fjernbetjent URL til api.php af den fjernbetjente TTMServer.
use_wikimedia_extra ElasticSearch Boolean, when the extra plugin is deployed you can disable dynamic scripting on Elastic v1.x. This plugin is now mandatory for Elastic 2.x clusters.
mirrors (DEPRECATED Since MLEB 2023.04) Writable services Array of strings, defines the list of services to replicate writes to, it allows to keep multiple TTM services up to date. Useful for fast switch-overs or to reduce downtime during planned maintenance operations (Added in MLEB 2017.04). Cannot be used along with the newly added writable configuration.
writable (Added in MLEB 2023.04) Write-only services Boolean value, defined for a service if that service is write-only. The default service (wgTranslateTranslationDefaultService) cannot be marked as write-only. If out of all the translation memory services configured, none are marked as writable then all services are considered to be readable and writable. Se <translate> task <tvar name=1>T322284</tvar></translate>
Du skal bruge nøglen TTMServer som matrixindekset til $wgTranslateTranslationServices, hvis du ønsker at oversættelseshukommelsen skal opdateres med nye oversættelser. Fjernbetjente TTMServer'ere kan ikke anvendes til det, fordi de ikke kan opdateres. As of MLEB 2017.04 the key TTMServer can be configured with the configuration variable $wgTranslateTranslationDefaultService. Support for Solr backend was dropped in MLEB-2019.10, in October, 2019.

I øjeblikket understøttes kun MySQL for databaserne.

Bootstrap

Once you have chosen ElasticSearch and set up the requirements and configuration, run ttmserver-export.php to bootstrap the translation memory. Bootstrapping is also required when changing translation memory backend. If you are using a shared translation memory backend for multiple wikis, you'll need to bootstrap each of them separately.

Sites with lots of translations should consider using multiple threads with the --thread parameter to speed up the process. The time depends heavily on how complete the message group completion stats are (incomplete ones will be calculated during the bootstrap). New translations are automatically added by a hook. New sources (message definitions) are added when the first translation is created.

Bootstrap does the following things, which don't happen otherwise:

  • adding and updating the translation memory schema;
  • populating the translation memory with existing translations;
  • cleaning up unused translation entries by emptying and re-populating the translation memory.

When the translation of a message is updated, the previous translation is removed from the translation memory. However, when translations are updated against a new definition, a new entry is added but the old definition and its old translations remain in the database until purged. When a message changes definition or is removed from all message groups, nothing happens immediately. Saving a translation as fuzzy does not add a new translation nor delete an old one in the translation memory.

TTMServer API

Hvis du ønsker at anvende din egen TTMServer-tjeneste er specifikationerne her.

Forespørgselsparametre:

Din tjeneste skal acceptere de følgende parametre:

Nøgle Værdi
format json
action ttmserver
service Valgfri tjeneste-id, hvis der er flere fælles oversættelseshukommelser. Hvis intet er angivet antages standard-tjenesten.
sourcelanguage Sprogkode som anvendt i MediaWiki, se IETF sprog-mærker og ISO693?
targetlanguage Sprogkode som anvendt i MediaWiki, se IETF sprog-mærker og ISO693?
test Kildetekst på originalsproget

Din tjeneste skal give et JSON-objekt, der skal have nøglen ttmserver med objekt-matrix. Disse objekter skal indeholde følgende data:

Nøgle Værdi
source Oprindelig kildetekst.
target Oversættelses-forslag.
context Lokal id for kilden, valgfrit.
location URL til siden hvor forslaget kan ses i brug.
quality Decimaltal i intervallet [0..1], som beskriver forslagets kvalitet. 1 betyder perfekt.

Eksempel:

{
        "ttmserver": [
                {
                        "source": "January",
                        "target": "tammikuu",
                        "context": "Wikimedia:Messages\\x5b'January'\\x5d\/en",
                        "location": "https:\/\/translatewiki.net\/wiki\/Wikimedia:Messages%5Cx5b%27January%27%5Cx5d\/fi",
                        "quality": 0.85714285714286
                },
                {
                        "source": "January",
                        "target": "tammikuu",
                        "context": "Mantis:S month january\/en",
                        "location": "https:\/\/translatewiki.net\/wiki\/Mantis:S_month_january\/fi",
                        "quality": 0.85714285714286
                },
                {
                        "source": "January",
                        "target": "Tammikuu",
                        "context": "FUDforum:Month 1\/en",
                        "location": "https:\/\/translatewiki.net\/wiki\/FUDforum:Month_1\/fi",
                        "quality": 0.85714285714286
                },
                {
                        "source": "January",
                        "target": "tammikuun",
                        "context": "MediaWiki:January-gen\/en",
                        "location": "https:\/\/translatewiki.net\/wiki\/MediaWiki:January-gen\/fi",
                        "quality": 0.85714285714286
                },
                {
                        "source": "January",
                        "target": "tammikuu",
                        "context": "MediaWiki:January\/en",
                        "location": "https:\/\/translatewiki.net\/wiki\/MediaWiki:January\/fi",
                        "quality": 0.85714285714286
                }
        ]
}

Database backend

Bagdelen indeholder tre tabeller: translate_tms, translate_tmt og translate_tmf. De svarer til kilder, mål og fuldtekst. Du kan finde tabeldefinitionerne i sql/translate_tm.sql. Kilderne indeholder alle meddelelses-definitionerne. Selvom de som regel altid er på det samme sprog, dvs. engelsk, opbevares tekstens sprog også i de sjældne tilfælde, at dette ikke er sandt.

Hver post har et unikt id og 2 ekstra felter, længde og kontekst. Længden bruges som første passerings-filter, så ved forespørgsel behøver vi ikke sammenligne teksten vi søger med hver post i databasen. Konteksten gemmer titlen på den side, hvor teksten kommer fra, for eksempel "MediaWiki:Jan/en". Ud fra denne information kan vi linke forslagene tilbage til "MediaWiki:Jan/da", som gør det muligt for oversættere hurtigt at rette ting eller bare at afgøre, hvor den slags oversættelse er brugt.

Den anden filtrerings-passage kommer fra fuldtekst-søgningen. Definitionerne er blandet med en ad hoc-algoritme. Først er teksten opdelt i inddelinger (ord) med MediaWikis Language::segmentByWord. Hvis der er nok inddelinger, fratager vi dybest set alt hvad der ikke er bogstaver og normaliserer bøjningen. Så kan vi tage de første 10 unikke ord, som er mindst 5 bytes lange (5 bogstaver på engelsk, men kortere ord for sprog med multibyte kodepunkter). Disse ord bliver så lagret i fuldtekst-indekset for yderligere filtrering i længere strenge.

Når vi har filtreret listen over kandidater, henter vi de matchende mål fra mål-tabellen. Så anvender vi Levenshteins afstands-algoritme til at lave den endelige filtrering og rangordning. Lad os definere:

E
redigerings-afstand
S
teksten vi søger forslag til
Tc
den foreslåede tekst
To
den oprindelige tekst som Tc er oversættelse af

Kvaliteten af forslaget Tc beregnes som E/min(længde(Tc),længde(To)). Afhængigt af længden af strengene bruger vi enten PHP's oprindelige Levenshtein-funktion eller hvis en af strengene er længere end 255 byte, PHP-anvendelse af Levenshtein-algoritmen. [1] Det er ikke blevet testet om den oprindelige anvendelse af Levenshtein håndterer multibyte tegn korrekt. Dette kan være et svagt punkt når kildesproget ikke er engelsk (de andre er fuldtekst-søgningen og inddeling).[2] It has not been tested whether the native implementation of levenshtein handles multibyte characters correctly. This might be another weak point when source language is not English (the others being the fulltext search and segmentation).