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<div class="tab-pane fade active in" id="c-info">
<p class="comment">
<h3>File</h3>
</p>
<p class="comment">
<code>src/core/interceptors/page.interceptor.ts</code>
</p>
<p class="comment">
<h3>Description</h3>
</p>
<p class="comment">
<p>Previous search data storage</p>
</p>
<section>
<h3 id="index">Index</h3>
<table class="table table-sm table-bordered index-table">
<tbody>
<tr>
<td class="col-md-4">
<h6><b>Properties</b></h6>
</td>
</tr>
<tr>
<td class="col-md-4">
<ul class="index-list">
<li>
<span class="modifier">Private</span>
<a href="#pit" >pit</a>
</li>
<li>
<span class="modifier">Private</span>
<a href="#prevPage" >prevPage</a>
</li>
<li>
<span class="modifier">Private</span>
<a href="#tiebreaker" >tiebreaker</a>
</li>
</ul>
</td>
</tr>
<tr>
<td class="col-md-4">
<h6><b>Methods</b></h6>
</td>
</tr>
<tr>
<td class="col-md-4">
<ul class="index-list">
<li>
<span class="modifier">Public</span>
<a href="#isSet" >isSet</a>
</li>
</ul>
</td>
</tr>
<tr>
<td class="col-md-4">
<h6><b>Accessors</b></h6>
</td>
</tr>
<tr>
<td class="col-md-4">
<ul class="index-list">
<li>
<a href="#_pit" >_pit</a>
</li>
<li>
<a href="#_tiebreaker" >_tiebreaker</a>
</li>
<li>
<a href="#_prevPage" >_prevPage</a>
</li>
</ul>
</td>
</tr>
</tbody>
</table>
</section>
<section>
<h3 id="constructor">Constructor</h3>
<table class="table table-sm table-bordered">
<tbody>
<tr>
<td class="col-md-4">
<code>constructor()</code>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="16" class="link-to-prism">src/core/interceptors/page.interceptor.ts:16</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-description"><p>Constructs an uninitialized object</p>
</div>
</td>
</tr>
</tbody>
</table>
</section>
<section>
<h3 id="inputs">
Properties
</h3>
<table class="table table-sm table-bordered">
<tbody>
<tr>
<td class="col-md-4">
<a name="pit"></a>
<span class="name">
<span class="modifier">Private</span>
<span ><b>pit</b></span>
<a href="#pit"><span class="icon ion-ios-link"></span></a>
</span>
</td>
</tr>
<tr>
<td class="col-md-4">
<i>Type : </i> <code><a href="../interfaces/EsPit.html" target="_self" >EsPit</a></code>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="29" class="link-to-prism">src/core/interceptors/page.interceptor.ts:29</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-description"><p>PIT object of the previous search</p>
</div>
</td>
</tr>
</tbody>
</table>
<table class="table table-sm table-bordered">
<tbody>
<tr>
<td class="col-md-4">
<a name="prevPage"></a>
<span class="name">
<span class="modifier">Private</span>
<span ><b>prevPage</b></span>
<a href="#prevPage"><span class="icon ion-ios-link"></span></a>
</span>
</td>
</tr>
<tr>
<td class="col-md-4">
<i>Type : </i> <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/number" target="_blank" >number</a></code>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="51" class="link-to-prism">src/core/interceptors/page.interceptor.ts:51</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-description"><p>Number of the previous page</p>
</div>
</td>
</tr>
</tbody>
</table>
<table class="table table-sm table-bordered">
<tbody>
<tr>
<td class="col-md-4">
<a name="tiebreaker"></a>
<span class="name">
<span class="modifier">Private</span>
<span ><b>tiebreaker</b></span>
<a href="#tiebreaker"><span class="icon ion-ios-link"></span></a>
</span>
</td>
</tr>
<tr>
<td class="col-md-4">
<i>Type : </i> <code>[]</code>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="40" class="link-to-prism">src/core/interceptors/page.interceptor.ts:40</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-description"><p>Tiebreaker and sort parameters</p>
</div>
</td>
</tr>
</tbody>
</table>
</section>
<section>
<h3 id="methods">
Methods
</h3>
<table class="table table-sm table-bordered">
<tbody>
<tr>
<td class="col-md-4">
<a name="isSet"></a>
<span class="name">
<span class="modifier">Public</span>
<span ><b>isSet</b></span>
<a href="#isSet"><span class="icon ion-ios-link"></span></a>
</span>
</td>
</tr>
<tr>
<td class="col-md-4">
<span class="modifier-icon icon ion-ios-reset"></span>
<code>isSet()</code>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="63"
class="link-to-prism">src/core/interceptors/page.interceptor.ts:63</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-description"><p>Checks if there was the search before current one</p>
</div>
<div>
</div>
<div class="io-description">
<b>Returns : </b> <code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/boolean" target="_blank" >boolean</a></code>
</div>
<div class="io-description">
<p>true/false, showing whether or not there was another search before</p>
</div>
</td>
</tr>
</tbody>
</table>
</section>
<section>
<h3 id="accessors">
Accessors
</h3>
<table class="table table-sm table-bordered">
<tbody>
<tr>
<td class="col-md-4">
<a name="_pit"></a>
<span class="name"><b>_pit</b><a href="#_pit"><span class="icon ion-ios-link"></span></a></span>
</td>
</tr>
<tr>
<td class="col-md-4">
<span class="accessor"><b>get</b><code>_pit()</code></span>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="33" class="link-to-prism">src/core/interceptors/page.interceptor.ts:33</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<span class="accessor"><b>set</b><code>_pit(pit: <a href="../interfaces/EsPit.html" target="_self">EsPit</a>)</code></span>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="30" class="link-to-prism">src/core/interceptors/page.interceptor.ts:30</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-description">
<b>Parameters :</b>
<table class="params">
<thead>
<tr>
<td>Name</td>
<td>Type</td>
<td>Optional</td>
</tr>
</thead>
<tbody>
<tr>
<td>pit</td>
<td>
<code><a href="../interfaces/EsPit.html" target="_self" >EsPit</a></code>
</td>
<td>
No
</td>
</tr>
</tbody>
</table>
</div>
<div>
</div>
<div class="io-description">
<b>Returns : </b> <code><a href="https://www.typescriptlang.org/docs/handbook/basic-types.html" target="_blank" >void</a></code>
</div>
</td>
</tr>
</tbody>
</table>
<table class="table table-sm table-bordered">
<tbody>
<tr>
<td class="col-md-4">
<a name="_tiebreaker"></a>
<span class="name"><b>_tiebreaker</b><a href="#_tiebreaker"><span class="icon ion-ios-link"></span></a></span>
</td>
</tr>
<tr>
<td class="col-md-4">
<span class="accessor"><b>get</b><code>_tiebreaker()</code></span>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="44" class="link-to-prism">src/core/interceptors/page.interceptor.ts:44</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<span class="accessor"><b>set</b><code>_tiebreaker(tiebreaker: [])</code></span>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="41" class="link-to-prism">src/core/interceptors/page.interceptor.ts:41</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-description">
<b>Parameters :</b>
<table class="params">
<thead>
<tr>
<td>Name</td>
<td>Type</td>
<td>Optional</td>
</tr>
</thead>
<tbody>
<tr>
<td>tiebreaker</td>
<td>
<code>[]</code>
</td>
<td>
No
</td>
</tr>
</tbody>
</table>
</div>
<div>
</div>
<div class="io-description">
<b>Returns : </b> <code><a href="https://www.typescriptlang.org/docs/handbook/basic-types.html" target="_blank" >void</a></code>
</div>
</td>
</tr>
</tbody>
</table>
<table class="table table-sm table-bordered">
<tbody>
<tr>
<td class="col-md-4">
<a name="_prevPage"></a>
<span class="name"><b>_prevPage</b><a href="#_prevPage"><span class="icon ion-ios-link"></span></a></span>
</td>
</tr>
<tr>
<td class="col-md-4">
<span class="accessor"><b>get</b><code>_prevPage()</code></span>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="55" class="link-to-prism">src/core/interceptors/page.interceptor.ts:55</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<span class="accessor"><b>set</b><code>_prevPage(page: <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/number" target="_blank">number</a>)</code></span>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-line">Defined in <a href="" data-line="52" class="link-to-prism">src/core/interceptors/page.interceptor.ts:52</a></div>
</td>
</tr>
<tr>
<td class="col-md-4">
<div class="io-description">
<b>Parameters :</b>
<table class="params">
<thead>
<tr>
<td>Name</td>
<td>Type</td>
<td>Optional</td>
</tr>
</thead>
<tbody>
<tr>
<td>page</td>
<td>
<code><a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/number" target="_blank" >number</a></code>
</td>
<td>
No
</td>
</tr>
</tbody>
</table>
</div>
<div>
</div>
<div class="io-description">
<b>Returns : </b> <code><a href="https://www.typescriptlang.org/docs/handbook/basic-types.html" target="_blank" >void</a></code>
</div>
</td>
</tr>
</tbody>
</table>
</section>
</div>
<div class="tab-pane fade tab-source-code" id="c-source">
<pre class="line-numbers compodoc-sourcecode"><code class="language-typescript">import { HttpService } from "@nestjs/axios";
import { CallHandler, ExecutionContext, Injectable, NestInterceptor } from "@nestjs/common";
import { Observable, map, take } from "rxjs";
import { PageDto } from "../domain/dtos";
import { EsQueryDto } from "../domain/dtos/elastic/es-query.dto";
import { RequestDto } from "../domain/dtos/request.dto";
import { SearchQueryDto } from "../domain/dtos/search-q.dto";
import { EsTime } from "../domain/enums/es-time.enum";
import { Order } from "../domain/enums/page-order.enum";
import { PageMeta } from "../domain/interfaces";
import { EsPit } from "../domain/interfaces/elastic/es-pit.interface";
/**
* Previous search data storage
*/
class PrevSearch {
/**
* Constructs an uninitialized object
*/
constructor() {
this.pit = undefined;
this.tiebreaker = undefined;
this.prevPage = -1;
}
/**
* PIT object of the previous search
*/
private pit: EsPit;
set _pit(pit: EsPit) {
this.pit = pit;
}
get _pit(): EsPit {
return this.pit;
}
/**
* Tiebreaker and sort parameters
*/
private tiebreaker: unknown[];
set _tiebreaker(tiebreaker: unknown[]) {
this.tiebreaker = tiebreaker;
}
get _tiebreaker(): unknown[] {
return this.tiebreaker;
}
/**
* Number of the previous page
*/
private prevPage: number;
set _prevPage(page: number) {
this.prevPage = page;
}
get _prevPage(): number {
return this.prevPage;
}
/**
* Checks if there was the search before current one
* @returns true/false, showing whether or not there was another search before
*/
public isSet(): boolean {
if (this.pit && this.tiebreaker && this.prevPage !== -1) return true;
return false;
}
}
/**
* Pagination-implementing interceptor
*/
@Injectable()
export class PageInterceptor implements NestInterceptor {
/**
* Injects needed dependencies and instantiates the storage object
* @param httpService
* @param searchService
*/
constructor(private readonly httpService: HttpService) {
this.prevSearch = new PrevSearch;
}
/**
* Override of intercept() method, specified in NestInterceptor interface
* @param context
* @param next
* @returns Page with content and metadata
*/
async intercept(context: ExecutionContext, next: CallHandler<any>): Promise<Observable<PageDto>> {
let request: RequestDto = context.switchToHttp().getRequest<RequestDto>();
const query: SearchQueryDto = request.query;
let reverse: boolean = false;
request.es_query = new EsQueryDto();
request.es_query.query = {
query_string: {
query: query.query,
default_field: 'content',
}
};
request.es_query.sort = [
{ _score: { order: !query?.order ? Order.DESC : query.order } },
{ _shard_doc: 'desc' }
];
if (this.prevSearch.isSet()) {
request.es_query.pit = this.prevSearch._pit;
request.es_query.search_after = this.prevSearch._tiebreaker;
let limit = !query?.limit ? 10 : query.limit;
request.es_query.size = limit * Math.abs(query.page - this.prevSearch._prevPage);
if (query.page < this.prevSearch._prevPage) {
request.es_query.sort = [{ _score: { order: 'asc' } }];
request.es_query.size += limit - 1;
reverse = true;
} else if (query.page == this.prevSearch._prevPage) {
// Caching should be HERE
request.es_query.sort = [{ _score: { order: 'asc' } }];
reverse = true;
}
} else {
this.prevSearch._pit = request.es_query.pit = await this.getPIT(1);
let limit = !query?.limit ? 10 : query.limit;
request.es_query.size = limit * query.page;
}
return next.handle().pipe(
map((res) => {
// Setting the page meta-data
let meta: PageMeta = {
total: res.hits.total.value,
pagenum: !query?.page ? 1 : +query.page,
order: query?.order?.toUpperCase() === Order.ASC ? Order.ASC : Order.DESC,
pagesize: !query?.limit ? 10 : query.limit,
hasNext: undefined,
hasPrev: undefined,
};
meta.hasNext = meta.pagenum * meta.pagesize < meta.total ? true : false;
meta.hasPrev = meta.pagenum != 1 ? true : false;
// Saving the search info
this.prevSearch._pit.id = res.pit_id;
this.prevSearch._tiebreaker = res.hits.hits[res.hits.hits.length - 1]?.sort;
this.prevSearch._prevPage = query.page;
// Check if the performed search is a backwards search
let data = res.hits.hits.slice(-meta.pagesize);
if (reverse) {
this.prevSearch._tiebreaker = data[0]?.sort;
data.reverse();
reverse = false;
}
// Omitting the redundant info and leaving only the document
data = data.map((el) => el._source);
// Return the page
return new PageDto(data, meta);
})
);
}
/**
* Elastichsearch server port-number
*/
private readonly ES_PORT = process.env.ES_PORT;
/**
* Elastichsearch IP address
*/
private readonly ES_IP = process.env.ES_CONTAINER_NAME;
/**
* Info about previously completed search
*/
private prevSearch: PrevSearch;
/**
* Acquires a PIT ID from Elasticsearch, needed for a request
* @param alive, amount of time in minutes (defaults to 1). If time unit is not specified - defaults to minutes.
* @returns PIT object <EsPit> containing PIT ID and keep_alive value
*/
public async getPIT(alive: number, unit: EsTime = EsTime.min): Promise<EsPit> {
return new Promise((resolve, reject) => {
try {
this.httpService.post<EsPit>(`http://${this.ES_IP}:${this.ES_PORT}/papers/_pit?keep_alive=${alive+unit}`)
.pipe(take(1), map(axiosRes => axiosRes.data))
.subscribe((res: EsPit) => {
res.keep_alive = alive + unit;
resolve(res);
});
} catch (error) {
reject(error);
}
});
}
/**
* Deletes the PIT specified by provided ID
* @param pitID, ID of the PIT, that would be deleted
* @returns true/false, depending on the result of deletion of the PIT
*/
async deletePIT(pitID: string): Promise<boolean> {
return new Promise((resolve, reject) => {
try {
this.httpService.delete(`http://${this.ES_IP}:${this.ES_PORT}/_pit`, {
data: { id: pitID },
headers: { 'Content-Type': 'application/json' },
})
.pipe(take(1), map(axiosRes => axiosRes.data))
.subscribe((res) => {
resolve(res.succeeded);
});
} catch (error) {
reject(error);
}
})
}
}</code></pre>
</div>
</div>
</div><div class="search-results">
<div class="has-results">
<h1 class="search-results-title"><span class='search-results-count'></span> results matching "<span class='search-query'></span>"</h1>
<ul class="search-results-list"></ul>
</div>
<div class="no-results">
<h1 class="search-results-title">No results matching "<span class='search-query'></span>"</h1>
</div>
</div>
</div>
<!-- END CONTENT -->
</div>
</div>
<label class="dark-mode-switch">
<input type="checkbox">
<span class="slider">
<svg class="slider-icon" viewBox="0 0 24 24" fill="none" height="20" stroke="#000" stroke-linecap="round" stroke-linejoin="round" stroke-width="2" width="20" xmlns="http://www.w3.org/2000/svg">
<path d="M21 12.79A9 9 0 1111.21 3 7 7 0 0021 12.79z"></path>
</svg>
</span>
</label>
<script>
var COMPODOC_CURRENT_PAGE_DEPTH = 1;
var COMPODOC_CURRENT_PAGE_CONTEXT = 'class';
var COMPODOC_CURRENT_PAGE_URL = 'PrevSearch.html';
var MAX_SEARCH_RESULTS = 15;
</script>
<script src="../js/libs/custom-elements.min.js"></script>
<script src="../js/libs/lit-html.js"></script>
<script src="../js/menu-wc.js" defer></script>
<script nomodule src="../js/menu-wc_es5.js" defer></script>
<script src="../js/libs/bootstrap-native.js"></script>
<script src="../js/libs/es6-shim.min.js"></script>
<script src="../js/libs/EventDispatcher.js"></script>
<script src="../js/libs/promise.min.js"></script>
<script src="../js/libs/zepto.min.js"></script>
<script src="../js/compodoc.js"></script>
<script src="../js/tabs.js"></script>
<script src="../js/menu.js"></script>
<script src="../js/libs/clipboard.min.js"></script>
<script src="../js/libs/prism.js"></script>
<script src="../js/sourceCode.js"></script>
<script src="../js/search/search.js"></script>
<script src="../js/search/lunr.min.js"></script>
<script src="../js/search/search-lunr.js"></script>
<script src="../js/search/search_index.js"></script>
<script src="../js/lazy-load-graphs.js"></script>
</body>
</html>