Merge pull request #41 from zzgab/feature_36_scan

issue #36 : basic support for SCAN

src/main/java/com/fiftyonred/mock_jedis/MockJedis.java

@@ -3,11 +3,15 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.ArrayList;
+import java.util.Collection;
 
 import redis.clients.jedis.*;
 import redis.clients.util.Pool;
 import redis.clients.util.Slowlog;
 
+import static redis.clients.jedis.Protocol.Keyword.MATCH;
+
 public class MockJedis extends Jedis {
 
 	public static final String NOT_IMPLEMENTED = "Not implemented";
@@ -1320,14 +1324,46 @@ public ScanResult<Tuple> zscan(String key, int cursor, ScanParams params) {
 
 	@Override
 	public ScanResult<String> scan(String cursor) {
-		throw new UnsupportedOperationException(NOT_IMPLEMENTED);
+		return scan(cursor, (new ScanParams()).match("*"));
 	}
 
+	/**
+	 * In this simple proposal, we're not testing complex iterations
+	 * of scan cursor. SCAN is simply a wrapper for KEYS, and the result
+	 * is given in one single response, no matter the COUNT argument.
+	 */
 	@Override
 	public ScanResult<String> scan(String cursor, ScanParams params) {
-		throw new UnsupportedOperationException(NOT_IMPLEMENTED);
-	}
-
+		// We need to extract the MATCH argument from the scan params
+		Collection<byte[]> rawParams = params.getParams();
+
+		// Raw collection is a list of byte[], made of: key1, value1, key2, value2, etc.
+		boolean isKey = true;
+		String match = null;
+		boolean foundMatchKey = false;
+
+		// So, we run over the list, where any even index is a key, and the following data is its value.
+		for (byte[] raw : rawParams) {
+			if (isKey) {
+				String key = new String(raw);
+				if (key.equals(new String(MATCH.raw))) {
+					// What really interests us is the MATCH key.
+					foundMatchKey = true;
+				}
+			}
+			// As soon as we've found the MATCH key, we can stop searching.
+			else if (foundMatchKey) {
+				match = new String(raw);
+				break;
+			}
+			isKey = !isKey;
+		}
+
+		// Our simple implementation of SCAN is really a plain wrapper for KEYS,
+		// relying on the current mock implementation of the pattern search.
+		return new ScanResult<String>("0", new ArrayList<String>(keys(match)));
+	}
+
 	@Override
 	public ScanResult<Map.Entry<String, String>> hscan(String key, String cursor) {
 		throw new UnsupportedOperationException(NOT_IMPLEMENTED);

src/test/java/com/fiftyonred/mock_jedis/MockJedisTest.java

@@ -5,6 +5,8 @@
 import redis.clients.jedis.Jedis;
 import redis.clients.jedis.SortingParams;
 import redis.clients.jedis.exceptions.JedisDataException;
+import redis.clients.jedis.ScanParams;
+import redis.clients.jedis.ScanResult;
 
 import java.util.*;
 
@@ -216,4 +218,25 @@ public void testMultipleDB() {
 		j.select(5);
 		assertEquals(1L, j.dbSize().longValue());
 	}
+
+	/**
+	 * In this simple proposal, we're not testing complex iterations
+	 * of scan cursor. SCAN is simply a wrapper for KEYS, and the result
+	 * is given in one single response, no matter the COUNT argument.
+	 */
+	@Test
+	public void testScan() {
+		j.set("key1", "val1");
+		j.set("key2", "val2");
+		j.set("kk", "val3");
+
+		ScanParams scanParams = new ScanParams();
+		scanParams.count(100).match("key*");
+		ScanResult<String> scanResult;
+		scanResult = j.scan("0", scanParams);
+
+
+		assertEquals(2L, scanResult.getResult().size());
+		assertEquals("0", scanResult.getStringCursor());
+	}
 }