Moved redis client from tilemapper to common.

common/redisclient.go

@@ -0,0 +1,138 @@
+// Copyright 2014 by Sascha L. Teichmann
+// Use of this source code is governed by the MIT license
+// that can be found in the LICENSE file.
+
+package common
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+)
+
+type RedisClient struct {
+	conn   net.Conn
+	reader *bufio.Reader
+}
+
+func NewRedisClient(network, address string) (client *RedisClient, err error) {
+	var conn net.Conn
+	if conn, err = net.Dial(network, address); err != nil {
+		return
+	}
+
+	client = &RedisClient{conn: conn, reader: bufio.NewReaderSize(conn, 8*1024)}
+	return
+}
+
+func (client *RedisClient) Close() error {
+	return client.conn.Close()
+}
+
+func (client *RedisClient) writeArray(size int) (err error) {
+	_, err = client.conn.Write([]byte(fmt.Sprintf("*%d\r\n", size)))
+	return
+}
+
+func (client *RedisClient) writeBulkString(data []byte) (err error) {
+	if _, err = client.conn.Write([]byte(fmt.Sprintf("$%d\r\n", len(data)))); err != nil {
+		return
+	}
+	if _, err = client.conn.Write(data); err != nil {
+		return
+	}
+	_, err = client.conn.Write([]byte("\r\n"))
+	return
+}
+
+func (client *RedisClient) writeHSpatial(p1, p2 int64) (err error) {
+	if err = client.writeArray(4); err != nil {
+		return
+	}
+	if err = client.writeBulkString([]byte("HSPATIAL")); err != nil {
+		return
+	}
+	if err = client.writeBulkString([]byte("IGNORE")); err != nil {
+		return
+	}
+	if err = client.writeBulkString(StringToBytes(p1)); err != nil {
+		return
+	}
+	err = client.writeBulkString(StringToBytes(p2))
+	return
+}
+
+func (client *RedisClient) readLine() (data []byte, err error) {
+	return client.reader.ReadBytes('\n')
+}
+
+func isError(line []byte) error {
+	if len(line) > 0 && line[0] == '-' {
+		return fmt.Errorf("error: %s", line[1:])
+	}
+	return nil
+}
+
+func (client *RedisClient) readBulkString(data *[]byte) (size int, err error) {
+	var line []byte
+	if line, err = client.readLine(); err != nil {
+		return
+	}
+	if err = isError(line); err != nil {
+		return
+	}
+	if _, err = fmt.Sscanf(string(line), "$%d\r\n", &size); err != nil {
+		return
+	}
+	if size <= 0 {
+		return
+	}
+	if cap(*data) < size {
+		*data = make([]byte, size)
+	}
+	for rest := size; rest > 0; {
+		var n int
+		if n, err = client.reader.Read((*data)[size-rest : size]); err != nil {
+			return
+		}
+		rest -= n
+	}
+	if _, err = client.reader.ReadBytes('\n'); err != nil {
+		return
+	}
+	return
+}
+
+func (client *RedisClient) QueryCuboid(cuboid Cuboid, fn func(*Block)) (err error) {
+	p1 := CoordToPlain(cuboid.P1)
+	p2 := CoordToPlain(cuboid.P2)
+	if err = client.writeHSpatial(p1, p2); err != nil {
+		return
+	}
+	var (
+		data  = make([]byte, 8*1024)
+		block = Block{}
+		size  int
+		key   int64
+	)
+
+	for {
+		if size, err = client.readBulkString(&data); err != nil {
+			return
+		}
+		if size <= 0 {
+			break
+		}
+		if key, err = DecodeStringFromBytes(data[0:size]); err != nil {
+			return
+		}
+		block.Coord = PlainToCoord(key)
+		if size, err = client.readBulkString(&data); err != nil {
+			return
+		}
+		block.Data = data[0:size]
+		fn(&block)
+	}
+
+	return
+}