Add first and last pagination parameters (#502)

fili-core/src/main/java/com/yahoo/bard/webservice/data/dimension/impl/LuceneSearchProvider.java

@@ -563,7 +563,6 @@ private Pagination<DimensionRow> getResultsPage(Query query, PaginationParameter
             throws PageNotFoundException {
         int perPage = paginationParameters.getPerPage();
         validatePerPage(perPage);
-        int requestedPageNumber = paginationParameters.getPage();
 
         TreeSet<DimensionRow> filteredDimRows;
         int documentCount;
@@ -578,11 +577,11 @@ private Pagination<DimensionRow> getResultsPage(Query query, PaginationParameter
                         luceneIndexSearcher,
                         null,
                         query,
-                        perPage,
-                        requestedPageNumber
+                        perPage
                 );
                 hits = hitDocs.scoreDocs;
                 documentCount = hitDocs.totalHits;
+                int requestedPageNumber = paginationParameters.getPage(documentCount);
                 if (hits.length == 0) {
                     if (requestedPageNumber == 1) {
                         return new SinglePagePagination<>(Collections.emptyList(), paginationParameters, 0);
@@ -592,7 +591,7 @@ private Pagination<DimensionRow> getResultsPage(Query query, PaginationParameter
                 }
                 for (int currentPage = 1; currentPage < requestedPageNumber; currentPage++) {
                     ScoreDoc lastEntry = hits[hits.length - 1];
-                    hits = getPageOfData(luceneIndexSearcher, lastEntry, query, perPage, requestedPageNumber).scoreDocs;
+                    hits = getPageOfData(luceneIndexSearcher, lastEntry, query, perPage).scoreDocs;
                     if (hits.length == 0) {
                         throw new PageNotFoundException(requestedPageNumber, perPage, 0);
                     }
@@ -652,23 +651,21 @@ private void validatePerPage(int perPage) {
      * search after this entry (if lastEntry is null, the indexSearcher will begin its search from the beginning)
      * @param query  The Lucene query used to locate the desired dimension metadata
      * @param perPage  The number of entries per page
-     * @param currentPage  The desired page number
      *
      * @return The desired page of dimension metadata
      */
     private TopDocs getPageOfData(
             IndexSearcher indexSearcher,
             ScoreDoc lastEntry,
             Query query,
-            int perPage,
-            int currentPage
+            int perPage
     ) {
         TimeLimitingCollectorManager manager = new TimeLimitingCollectorManager(searchTimeout, lastEntry, perPage);
         lock.readLock().lock();
         try {
             return indexSearcher.search(query, manager);
         } catch (IOException e) {
-            String errorMessage = "Unable to find dimension rows for page " + currentPage;
+            String errorMessage = "Unable to find dimension rows for specified page.";
             LOG.error(errorMessage);
             throw new RuntimeException(errorMessage);
         } catch (TimeLimitingCollector.TimeExceededException e) {

fili-core/src/main/java/com/yahoo/bard/webservice/data/dimension/impl/ScanSearchProvider.java

@@ -332,7 +332,11 @@ public Pagination<DimensionRow> findFilteredDimensionRowsPaged(
     ) {
         TreeSet<DimensionRow> filteredDimensionRows = applyFilters(getAllOrderedDimensionRows(), filters);
         return new SinglePagePagination<>(
-                doPagination(filteredDimensionRows, paginationParameters.getPage(), paginationParameters.getPerPage())
+                doPagination(
+                        filteredDimensionRows,
+                        paginationParameters.getPage(filteredDimensionRows.size()),
+                        paginationParameters.getPerPage()
+                )
                         .stream()
                         .collect(Collectors.toList()),
                 paginationParameters,
@@ -349,9 +353,10 @@ public Pagination<DimensionRow> findFilteredDimensionRowsPaged(
      * @return  All dimension rows that belongs to a requested page
      */
     private TreeSet<DimensionRow> getAllDimensionRowsPaged(PaginationParameters paginationParameters) {
+        TreeSet<DimensionRow> allRows = getAllOrderedDimensionRows();
         return doPagination(
-                getAllOrderedDimensionRows(),
-                paginationParameters.getPage(),
+                allRows,
+                paginationParameters.getPage(allRows.size()),
                 paginationParameters.getPerPage()
         );
     }

fili-core/src/main/java/com/yahoo/bard/webservice/util/AllPagesPagination.java

@@ -41,7 +41,7 @@ public class AllPagesPagination<T> implements Pagination<T> {
     public AllPagesPagination(Collection<T> entireCollection, PaginationParameters paginationParameters)
             throws PageNotFoundException {
         this.collectionSize = entireCollection.size();
-        this.pageToFetch = paginationParameters.getPage();
+        this.pageToFetch = paginationParameters.getPage(entireCollection.size());
         this.countPerPage = paginationParameters.getPerPage();
         this.lastPage = (collectionSize > countPerPage) ? (collectionSize - 1) / countPerPage + 1 : 1;
 

fili-core/src/main/java/com/yahoo/bard/webservice/util/SinglePagePagination.java

@@ -28,7 +28,7 @@ public class SinglePagePagination<T> implements Pagination<T> {
      * @param totalMatch  The total number of results found. The single page collection is part of these results
      */
     public SinglePagePagination(List<T> entirePage, PaginationParameters paginationParameters, int totalMatch) {
-        this.pageToFetch = paginationParameters.getPage();
+        this.pageToFetch = paginationParameters.getPage(entirePage.size());
         this.countPerPage = paginationParameters.getPerPage();
         this.totalMatch = totalMatch;
         this.lastPage = (totalMatch > countPerPage) ? (totalMatch - 1) / countPerPage + 1 : 1;

fili-core/src/main/java/com/yahoo/bard/webservice/web/util/PaginationParameters.java

@@ -21,6 +21,9 @@ public class PaginationParameters {
     private static final SystemConfig SYSTEM_CONFIG = SystemConfigProvider.getInstance();
     private static final Logger LOG = LoggerFactory.getLogger(PaginationParameters.class);
     private static final int MINIMAL_VALUE = 1;
+    private static final int LAST_PAGE = -1;
+    private static final String FIRST = "first";
+    private static final String LAST = "last";
 
     private static final int DEFAULT_MAX_RESULTS_WITHOUT_FILTERS = 10000;
     private static final int MAX_RESULTS_WITHOUT_FILTER = SYSTEM_CONFIG.getIntProperty(
@@ -53,25 +56,18 @@ public class PaginationParameters {
      * @throws BadPaginationException If at least one of 'perPage' or 'page' is not a positive integer.
      */
     public PaginationParameters(String perPage, String page) throws BadPaginationException {
-        this.perPage = parseParameter(perPage, "perPage");
-        this.page = parseParameter(page, "page");
-        validate(this.perPage, "perPage");
-        validate(this.page, "page");
+        this(parseParameter(perPage, "perPage"), parseParameter(page, "page"));
     }
 
     /**
      * Constructor for already-parsed pagination parameters.
      *
      * @param perPage  The number of rows to be displayed on each page.
      * @param page  The page to be displayed
-     *
-     * @throws BadPaginationException If at least one of 'perPage' or 'page' is not positive.
      */
-    public PaginationParameters(int perPage, int page) throws BadPaginationException {
+    public PaginationParameters(int perPage, int page) {
         this.perPage = perPage;
         this.page = page;
-        validate(this.perPage, "perPage");
-        validate(this.page, "page");
     }
 
     /**
@@ -83,14 +79,23 @@ public PaginationParameters(int perPage, int page) throws BadPaginationException
      * @return the parsed integer
      * @throws BadPaginationException If 'parameter' cannot be parsed as an integer.
      */
-    private int parseParameter (String parameter, String parameterName) throws BadPaginationException {
+    private static int parseParameter (String parameter, String parameterName) throws BadPaginationException {
         if (parameter.equals("")) {
             ErrorMessageFormat errorMessage = ErrorMessageFormat.PAGINATION_PARAMETER_MISSING;
             LOG.debug(errorMessage.logFormat(parameterName));
             throw new BadPaginationException(errorMessage.format(parameterName));
         }
         try {
-            return Integer.parseInt(parameter);
+            if (parameterName.equals("page")) {
+                if (parameter.equals(FIRST)) {
+                    return 1;
+                } else if (parameter.equals(LAST)) {
+                    return LAST_PAGE;
+                }
+            }
+            int parsedParameter = Integer.parseInt(parameter);
+            validate(parsedParameter, parameterName);
+            return parsedParameter;
         } catch (NumberFormatException ignored) {
             ErrorMessageFormat errorMessage = ErrorMessageFormat.PAGINATION_PARAMETER_INVALID;
             LOG.debug(errorMessage.logFormat(parameterName, parameter));
@@ -106,7 +111,7 @@ private int parseParameter (String parameter, String parameterName) throws BadPa
      *
      * @throws BadPaginationException if 'parameter' is not greater than 0.
      */
-    private void validate(int parameter, String parameterName) throws BadPaginationException {
+    private static void validate(int parameter, String parameterName) throws BadPaginationException {
         if (parameter < MINIMAL_VALUE) {
             ErrorMessageFormat errorMessage = ErrorMessageFormat.PAGINATION_PARAMETER_INVALID;
             LOG.debug(errorMessage.logFormat(parameterName, parameter));
@@ -118,7 +123,17 @@ public int getPerPage() {
         return perPage;
     }
 
-    public int getPage() {
+    /**
+     * Returns the requested page number.
+     *
+     * @param resultSize  The number of rows in the result set
+     *
+     * @return The request page number
+     */
+    public int getPage(int resultSize) {
+        if (page == -1) {
+            return resultSize == 0 ? 1 : (int) Math.ceil(((double) resultSize) / perPage);
+        }
         return page;
     }
 

fili-core/src/test/groovy/com/yahoo/bard/webservice/data/dimension/impl/SearchProviderSpec.groovy

@@ -514,7 +514,7 @@ abstract class SearchProviderSpec<T extends SearchProvider> extends Specificatio
                 buildFilter("animal|desc-notin[this is an owl]")
         ]
         and: "We get the second page, where each page has two rows (so the last page has to have only one result)"
-        PaginationParameters parameters = new PaginationParameters(2, 2)
+        PaginationParameters parameters = new PaginationParameters("2", "last")
 
         when: "We query the search provider"
         Pagination<DimensionRow> resultsPage = searchProvider.findFilteredDimensionRowsPaged(filters, parameters)

fili-core/src/test/groovy/com/yahoo/bard/webservice/web/endpoints/DataPaginationSpec.groovy

@@ -144,7 +144,7 @@ class DataPaginationSpec extends BaseDataServletComponentSpec {
 
 
     @Unroll
-    def "Page #page of #numPages with the correct headers and #rowsPerPage rows per page of data, is returned"() {
+    def "Page #pageParam of #numPages with the correct headers and #rowsPerPage rows per page of data, is returned"() {
         given: "A known Druid response, and the expected API response"
         String druidResponse = getFakeDruidResponse(numPages * rowsPerPage)
         validateJson(druidResponse)
@@ -154,21 +154,23 @@ class DataPaginationSpec extends BaseDataServletComponentSpec {
         injectDruidResponse(druidResponse)
 
         when: "We send a request"
-        Response response = makeAbstractRequest {getQueryParams("$rowsPerPage", "$page")}
+        Response response = makeAbstractRequest {getQueryParams("$rowsPerPage", pageParam)}
 
         then:
         headersAreCorrect(response.getHeaders(), ROWS_PER_PAGE, page, numPages, true)
         GroovyTestUtils.compareJson(response.readEntity(String), apiResponse)
 
         where:
         rowsPerPage = ROWS_PER_PAGE
-        numPages | page
-        1        |  1
-        2        |  1
-        2        |  2
-        3        |  1
-        3        |  2
-        3        |  3
+        numPages | page | pageParam
+        1        |  1   | "1"
+        2        |  1   | "1"
+        2        |  2   | "2"
+        3        |  1   | "1"
+        3        |  2   | "2"
+        3        |  3   | "3"
+        3        |  1   | "first"
+        3        |  3   | "last"
     }
 
     @Unroll

fili-core/src/test/groovy/com/yahoo/bard/webservice/web/endpoints/DimensionsServletComponentSpec.groovy

@@ -349,9 +349,11 @@ class DimensionsServletComponentSpec extends Specification {
         GroovyTestUtils.compareJson(result, expectedResponse)
 
         where:
-        paginating | page | perPage | explicitlyNotExplicitly
-        true       | "1"  | "5"     | "explicitly"
-        false      | ""   | ""      | "not explicitly"
+        paginating |  page   | perPage | explicitlyNotExplicitly
+        true       |   "1"   |   "5"   | "explicitly"
+        false      |   ""    |   ""    | "not explicitly"
+        true       | "first" |   "5"   | "explicitly"
+        true       | "last"  |   "5"   | "explicitly"
     }
 
     def "test dimension value endpoint filter-chain"() {

fili-core/src/test/groovy/com/yahoo/bard/webservice/web/util/PaginationParametersSpec.groovy

@@ -19,12 +19,19 @@ class PaginationParametersSpec extends Specification {
 
         then: "The handler's perPage and page are as expected"
         handler.getPerPage() == expectedPerPage
-        handler.getPage() == expectedPage
+        handler.getPage(resultSize) == expectedPage
 
         where:
-        perPage | page || expectedPerPage   || expectedPage
-        "1"     | "2"  || 1                 || 2
-        "2"     | "1"  || 2                 || 1
+        perPage | page    || expectedPerPage   || expectedPage  || resultSize
+        "1"     | "2"     || 1                 || 2             || 10
+        "2"     | "1"     || 2                 || 1             || 10
+        "3"     | "last"  || 3                 || 4             || 10
+        "5"     | "last"  || 5                 || 2             || 10
+        "2"     | "first" || 2                 || 1             || 10
+        "3"     | "1"     || 3                 || 1             || 3
+        "3"     | "first" || 3                 || 1             || 3
+        "3"     | "last"  || 3                 || 1             || 3
+        "3"     | "last"  || 3                 || 1             || 0
     }
 
     @Unroll
@@ -38,11 +45,11 @@ class PaginationParametersSpec extends Specification {
 
         where:
         perPage | page  || expectedError
-        "-1"  | "-1"    || errorMessage("perPage", "-1")
+        "-1" | "-1"     || errorMessage("perPage", "-1")
         "0"   | "-1"    || errorMessage("perPage", "0")
         "1"   | "-1"    || errorMessage("page", "-1")
-        "-1"  | "0"     || errorMessage("perPage", "-1")
-        "-1"  | "1"     || errorMessage("perPage", "-1")
+        "-1" | "0"      || errorMessage("perPage", "-1")
+        "-1" | "1"      || errorMessage("perPage", "-1")
         "1a"  | "1a"    || errorMessage("perPage", "1a")
         "1a"  | "1"     || errorMessage("perPage", "1a")
         "1"   | "1a"    || errorMessage("page", "1a")