diff options
Diffstat (limited to 'src/java/com/healthmarketscience/jackcess/IndexCursor.java')
| -rw-r--r-- | src/java/com/healthmarketscience/jackcess/IndexCursor.java | 175 |
1 files changed, 135 insertions, 40 deletions
diff --git a/src/java/com/healthmarketscience/jackcess/IndexCursor.java b/src/java/com/healthmarketscience/jackcess/IndexCursor.java index 2529c40..6d02fa2 100644 --- a/src/java/com/healthmarketscience/jackcess/IndexCursor.java +++ b/src/java/com/healthmarketscience/jackcess/IndexCursor.java @@ -20,7 +20,9 @@ USA package com.healthmarketscience.jackcess; import java.io.IOException; +import java.util.Collection; import java.util.HashSet; +import java.util.Iterator; import java.util.LinkedHashMap; import java.util.Map; import java.util.Set; @@ -156,9 +158,8 @@ public class IndexCursor extends Cursor /** * Moves to the first row (as defined by the cursor) where the index entries - * match the given values (only valid for index-backed cursors). If a match - * is not found (or an exception is thrown), the cursor is restored to its - * previous state. + * match the given values. If a match is not found (or an exception is + * thrown), the cursor is restored to its previous state. * * @param entryValues the column values for the index's columns. * @return {@code true} if a valid row was found with the given values, @@ -171,7 +172,7 @@ public class IndexCursor extends Cursor Position prevPos = _prevPos; boolean found = false; try { - found = findRowByEntryImpl(entryValues, true); + found = findRowByEntryImpl(toRowValues(entryValues), true); return found; } finally { if(!found) { @@ -186,8 +187,8 @@ public class IndexCursor extends Cursor /** * Moves to the first row (as defined by the cursor) where the index entries - * are >= the given values (only valid for index-backed cursors). If a an - * exception is thrown, the cursor is restored to its previous state. + * are >= the given values. If a an exception is thrown, the cursor is + * restored to its previous state. * * @param entryValues the column values for the index's columns. */ @@ -198,7 +199,7 @@ public class IndexCursor extends Cursor Position prevPos = _prevPos; boolean found = false; try { - findRowByEntryImpl(entryValues, false); + findRowByEntryImpl(toRowValues(entryValues), false); found = true; } finally { if(!found) { @@ -210,7 +211,69 @@ public class IndexCursor extends Cursor } } } - + + /** + * Returns {@code true} if the current row matches the given index entries. + * + * @param entryValues the column values for the index's columns. + */ + public boolean currentRowMatchesEntry(Object... entryValues) + throws IOException + { + return currentRowMatchesEntryImpl(toRowValues(entryValues)); + } + + /** + * Returns a modifiable Iterator which will iterate through all the rows of + * this table which match the given index entries. + * @throws IllegalStateException if an IOException is thrown by one of the + * operations, the actual exception will be contained within + */ + public Iterator<Map<String,Object>> entryIterator(Object... entryValues) + { + return entryIterator((Collection<String>)null, entryValues); + } + + /** + * Returns a modifiable Iterator which will iterate through all the rows of + * this table which match the given index entries, returning only the given + * columns. + * @throws IllegalStateException if an IOException is thrown by one of the + * operations, the actual exception will be contained within + */ + public Iterator<Map<String,Object>> entryIterator( + Collection<String> columnNames, Object... entryValues) + { + return new EntryIterator(columnNames, toRowValues(entryValues)); + } + + /** + * Returns an Iterable whose iterator() method returns the result of a call + * to {@link #entryIterator(Object...)} + * @throws IllegalStateException if an IOException is thrown by one of the + * operations, the actual exception will be contained within + */ + public Iterable<Map<String,Object>> entryIterable(Object... entryValues) + { + return entryIterable((Collection<String>)null, entryValues); + } + + /** + * Returns an Iterable whose iterator() method returns the result of a call + * to {@link #entryIterator(Collection,Object...)} + * @throws IllegalStateException if an IOException is thrown by one of the + * operations, the actual exception will be contained within + */ + public Iterable<Map<String,Object>> entryIterable( + final Collection<String> columnNames, final Object... entryValues) + { + return new Iterable<Map<String, Object>>() { + public Iterator<Map<String, Object>> iterator() { + return new EntryIterator(columnNames, toRowValues(entryValues)); + } + }; + } + @Override protected IndexDirHandler getDirHandler(boolean moveForward) { return (moveForward ? _forwardDirHandler : _reverseDirHandler); @@ -267,19 +330,15 @@ public class IndexCursor extends Cursor * Moves to the first row (as defined by the cursor) where the index entries * match the given values. Caller manages save/restore on failure. * - * @param entryValues the column values for the index's columns. + * @param rowValues the column values built from the index column values * @param requireMatch whether or not an exact match is found * @return {@code true} if a valid row was found with the given values, * {@code false} if no row was found */ - protected boolean findRowByEntryImpl(Object[] entryValues, - boolean requireMatch) + protected boolean findRowByEntryImpl(Object[] rowValues, + boolean requireMatch) throws IOException { - Object[] rowValues = _entryCursor.getIndexData() - .constructIndexRowFromEntry(entryValues); - - // sweet, we can use our index if(!findPotentialRow(rowValues, requireMatch)) { return false; } else if(!requireMatch) { @@ -287,28 +346,7 @@ public class IndexCursor extends Cursor return true; } - if(_indexEntryPattern == null) { - // init our set of index column names - _indexEntryPattern = new HashSet<String>(); - for(IndexData.ColumnDescriptor col : getIndex().getColumns()) { - _indexEntryPattern.add(col.getName()); - } - } - - // check the next row to see if it actually matches - Map<String,Object> row = getCurrentRow(_indexEntryPattern); - - for(IndexData.ColumnDescriptor col : getIndex().getColumns()) { - String columnName = col.getName(); - Object patValue = rowValues[col.getColumnIndex()]; - Object rowValue = row.get(columnName); - if(!_columnMatcher.matches(getTable(), columnName, - patValue, rowValue)) { - return false; - } - } - - return true; + return currentRowMatchesEntryImpl(rowValues); } @Override @@ -338,8 +376,7 @@ public class IndexCursor extends Cursor } else { // the rowPattern has more columns than just the index, so we need to // do more work when testing below - indexRowPattern = - new LinkedHashMap<String,Object>(); + indexRowPattern = new LinkedHashMap<String,Object>(); for(IndexData.ColumnDescriptor idxCol : indexData.getColumns()) { indexRowPattern.put(idxCol.getName(), rowValues[idxCol.getColumnIndex()]); @@ -368,7 +405,34 @@ public class IndexCursor extends Cursor // none of the potential rows matched return false; } - + + private boolean currentRowMatchesEntryImpl(Object[] rowValues) + throws IOException + { + if(_indexEntryPattern == null) { + // init our set of index column names + _indexEntryPattern = new HashSet<String>(); + for(IndexData.ColumnDescriptor col : getIndex().getColumns()) { + _indexEntryPattern.add(col.getName()); + } + } + + // check the next row to see if it actually matches + Map<String,Object> row = getCurrentRow(_indexEntryPattern); + + for(IndexData.ColumnDescriptor col : getIndex().getColumns()) { + String columnName = col.getName(); + Object patValue = rowValues[col.getColumnIndex()]; + Object rowValue = row.get(columnName); + if(!_columnMatcher.matches(getTable(), columnName, + patValue, rowValue)) { + return false; + } + } + + return true; + } + private boolean findPotentialRow(Object[] rowValues, boolean requireMatch) throws IOException { @@ -383,6 +447,11 @@ public class IndexCursor extends Cursor return true; } + private Object[] toRowValues(Object[] entryValues) + { + return _entryCursor.getIndexData().constructIndexRowFromEntry(entryValues); + } + @Override protected Position findAnotherPosition(RowState rowState, Position curPos, boolean moveForward) @@ -480,5 +549,31 @@ public class IndexCursor extends Cursor return "Entry = " + getEntry(); } } + + /** + * Row iterator (by matching entry) for this cursor, modifiable. + */ + private final class EntryIterator extends BaseIterator + { + private final Object[] _rowValues; + + private EntryIterator(Collection<String> columnNames, Object[] rowValues) + { + super(columnNames); + _rowValues = rowValues; + try { + _hasNext = findRowByEntryImpl(rowValues, true); + _validRow = _hasNext; + } catch(IOException e) { + throw new IllegalStateException(e); + } + } + + @Override + protected boolean findNext() throws IOException { + return (moveToNextRow() && currentRowMatchesEntryImpl(_rowValues)); + } + } + } |