hunt.redis.util.RedisClusterHashTagUtil source code

1 /*
2  * Hunt - A redis client library for D programming language.
3  *
4  * Copyright (C) 2018-2019 HuntLabs
5  *
6  * Website: https://www.huntlabs.net/
7  *
8  * Licensed under the Apache-2.0 License.
9  *
10  */
11 
12 module hunt.redis.util.RedisClusterHashTagUtil;
13 
14 import hunt.redis.util.SafeEncoder;
15 
16 import hunt.Exceptions;
17 
18 import std.array;
19 import std.range;
20 import std.string;
21 
22 /**
23  * Holds various methods/utilities to manipualte and parse redis hash-tags. See <a
24  * href="http://redis.io/topics/cluster-spec">Cluster-Spec : Keys hash tags</a>
25  */
26 class RedisClusterHashTagUtil {
27 
28     private this() {
29         throw new InstantiationError("Must not instantiate this class");
30     }
31 
32     static string getHashTag(string key) {
33         return extractHashTag(key, true);
34     }
35 
36     static bool isClusterCompliantMatchPattern(const(ubyte)[] matchPattern) {
37         return isClusterCompliantMatchPattern(SafeEncoder.encode(matchPattern));
38     }
39 
40     static bool isClusterCompliantMatchPattern(string matchPattern) {
41         string tag = extractHashTag(matchPattern, false);
42         return !tag.empty();
43     }
44 
45     private static string extractHashTag(string key, bool returnKeyOnAbsence) {
46         ptrdiff_t s = key.indexOf("{");
47         if (s > -1) {
48             ptrdiff_t e = key.indexOf("}", s + 1);
49             if (e > -1 && e != s + 1) {
50                 return key[s + 1 .. e];
51             }
52         }
53         return returnKeyOnAbsence ? key : null;
54     }
55 }