Protocol implementation

2010-06-11 02:57:11 -03:00
commit 7e6ed0af41
5 changed files with 370 additions and 0 deletions
--- a/src/main/java/redis/clients/jedis/Protocol.java
+++ b/src/main/java/redis/clients/jedis/Protocol.java
@@ -0,0 +1,116 @@
+package redis.clients.jedis;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.List;
+
+public class Protocol {
+    public static final String DOLLAR = "$";
+    public static final String ASTERISK = "*";
+    public static final String PLUS = "+";
+    public static final String COLON = ":";
+    public static final String COMMAND_DELIMITER = "\r\n";
+    public static final int DEFAULT_PORT = 6379;
+
+    public static final byte DOLLAR_BYTE = DOLLAR.getBytes()[0];
+    public static final byte ASTERISK_BYTE = ASTERISK.getBytes()[0];
+    public static final byte PLUS_BYTE = PLUS.getBytes()[0];
+    public static final byte COLON_BYTE = COLON.getBytes()[0];
+
+    public String buildCommand(String name, String... args) {
+	StringBuilder builder = new StringBuilder();
+	builder.append(ASTERISK).append(args.length + 1).append(
+		COMMAND_DELIMITER);
+	builder.append(DOLLAR).append(name.length()).append(COMMAND_DELIMITER);
+	builder.append(name).append(COMMAND_DELIMITER);
+	for (String arg : args) {
+	    builder.append(DOLLAR).append(arg.length()).append(
+		    COMMAND_DELIMITER).append(arg).append(COMMAND_DELIMITER);
+	}
+	return builder.toString();
+    }
+
+    public String getBulkReply(InputStream is) {
+	String ret = null;
+	try {
+	    if ((byte) is.read() == DOLLAR_BYTE) {
+		int len = Integer.parseInt(readLine(is));
+		if (len == -1) {
+		    return null;
+		}
+		byte[] read = new byte[len];
+		is.read(read);
+		// read 2 more bytes for the command delimiter
+		is.read();
+		is.read();
+
+		ret = new String(read);
+
+	    }
+	} catch (IOException e) {
+	    // TODO Not sure that I should return null
+	    return null;
+	}
+	return ret;
+    }
+
+    private String readLine(InputStream is) throws IOException {
+	byte b;
+	StringBuilder sb = new StringBuilder();
+
+	while ((b = (byte) is.read()) != -1) {
+	    if (b == '\r') {
+		b = (byte) is.read();
+		if (b == '\n') {
+		    break;
+		}
+	    }
+	    sb.append((char) b);
+	}
+	return sb.toString();
+    }
+
+    public String getSingleLineReply(InputStream is) {
+	String ret = null;
+	try {
+	    if ((byte) is.read() == PLUS_BYTE) {
+		ret = readLine(is);
+	    }
+	} catch (IOException e) {
+	    // TODO Not sure that I should return null
+	    return null;
+	}
+	return ret;
+    }
+
+    public int getIntegerReply(InputStream is) {
+	int ret = 0;
+	try {
+	    if ((byte) is.read() == COLON_BYTE) {
+		String num = readLine(is);
+		ret = Integer.parseInt(num);
+	    }
+	} catch (IOException e) {
+	    // TODO Not sure that I should return 0
+	    return 0;
+	}
+	return ret;
+    }
+
+    public List<String> getMultiBulkReply(InputStream is) {
+	List<String> ret = new ArrayList<String>();
+	try {
+	    if ((byte) is.read() == ASTERISK_BYTE) {
+		int num = Integer.parseInt(readLine(is));
+		for (int i = 0; i < num; i++) {
+		    ret.add(getBulkReply(is));
+		}
+	    }
+	} catch (IOException e) {
+	    // TODO Not sure that I should return null
+	    return null;
+	}
+	return ret;
+    }
+}