From b2273fcf645879d564c2e5518f4172defdf82027 Mon Sep 17 00:00:00 2001
From: Ahoo Wang <ahoowang@qq.com>
Date: Sat, 8 May 2021 00:41:04 +0800
Subject: [PATCH] add ServiceDiscovery#getInstance impl add
 ServiceDiscovery#getInstanceTtl impl

---
 .../redis/DiscoveryRedisScripts.java          | 10 +++++++
 .../redis/RedisServiceDiscovery.java          | 18 +++++++++--
 .../resources/discovery_get_instance_ttl.lua  | 30 +++++++++++++++++++
 3 files changed, 56 insertions(+), 2 deletions(-)
 create mode 100644 discovery/src/main/resources/discovery_get_instance_ttl.lua

diff --git a/discovery/src/main/java/me/ahoo/govern/discovery/redis/DiscoveryRedisScripts.java b/discovery/src/main/java/me/ahoo/govern/discovery/redis/DiscoveryRedisScripts.java
index 3242bc14..af1c29c1 100644
--- a/discovery/src/main/java/me/ahoo/govern/discovery/redis/DiscoveryRedisScripts.java
+++ b/discovery/src/main/java/me/ahoo/govern/discovery/redis/DiscoveryRedisScripts.java
@@ -14,6 +14,8 @@ public final class DiscoveryRedisScripts {
     public static final String REGISTRY_RENEW = "registry_renew.lua";
     public static final String REGISTRY_SET_METADATA = "registry_set_metadata.lua";
     public static final String DISCOVERY_GET_INSTANCES = "discovery_get_instances.lua";
+    public static final String DISCOVERY_GET_INSTANCE = "discovery_get_instance.lua";
+    public static final String DISCOVERY_GET_INSTANCE_TTL = "discovery_get_instance_ttl.lua";
     public static final String SERVICE_STAT = "service_stat.lua";
 
     public static CompletableFuture<String> loadRegistryRegister(RedisScriptingAsyncCommands<String, String> scriptingCommands) {
@@ -36,6 +38,14 @@ public static CompletableFuture<String> loadDiscoveryGetInstances(RedisScripting
         return RedisScripts.loadScript(DISCOVERY_GET_INSTANCES, scriptingCommands);
     }
 
+    public static CompletableFuture<String> loadDiscoveryGetInstance(RedisScriptingAsyncCommands<String, String> scriptingCommands) {
+        return RedisScripts.loadScript(DISCOVERY_GET_INSTANCE, scriptingCommands);
+    }
+
+    public static CompletableFuture<String> loadDiscoveryGetInstanceTtl(RedisScriptingAsyncCommands<String, String> scriptingCommands) {
+        return RedisScripts.loadScript(DISCOVERY_GET_INSTANCE_TTL, scriptingCommands);
+    }
+
     public static CompletableFuture<String> loadServiceStat(RedisScriptingAsyncCommands<String, String> scriptingCommands) {
         return RedisScripts.loadScript(SERVICE_STAT, scriptingCommands);
     }
diff --git a/discovery/src/main/java/me/ahoo/govern/discovery/redis/RedisServiceDiscovery.java b/discovery/src/main/java/me/ahoo/govern/discovery/redis/RedisServiceDiscovery.java
index 236400df..66d015a8 100644
--- a/discovery/src/main/java/me/ahoo/govern/discovery/redis/RedisServiceDiscovery.java
+++ b/discovery/src/main/java/me/ahoo/govern/discovery/redis/RedisServiceDiscovery.java
@@ -50,12 +50,26 @@ public CompletableFuture<List<ServiceInstance>> getInstances(String namespace, S
 
     @Override
     public CompletableFuture<ServiceInstance> getInstance(String namespace, String serviceId, String instanceId) {
-        return null;
+        return DiscoveryRedisScripts.loadDiscoveryGetInstance(redisCommands)
+                .thenCompose(sha -> {
+                    RedisFuture<List<String>> redisFuture = redisCommands.evalsha(sha, ScriptOutputType.MULTI, namespace, serviceId, instanceId);
+                    return redisFuture;
+                })
+                .thenApply(instanceData -> {
+                    if (Objects.isNull(instanceData)) {
+                        return null;
+                    }
+                    return ServiceInstanceCodec.decode(instanceData);
+                });
     }
 
     @Override
     public CompletableFuture<Integer> getInstanceTtl(String namespace, String serviceId, String instanceId) {
-        return null;
+        return DiscoveryRedisScripts.loadDiscoveryGetInstance(redisCommands)
+                .thenCompose(sha -> {
+                    RedisFuture<Integer> redisFuture = redisCommands.evalsha(sha, ScriptOutputType.INTEGER, namespace, serviceId, instanceId);
+                    return redisFuture;
+                });
     }
 
     @Override
diff --git a/discovery/src/main/resources/discovery_get_instance_ttl.lua b/discovery/src/main/resources/discovery_get_instance_ttl.lua
new file mode 100644
index 00000000..ced7fb44
--- /dev/null
+++ b/discovery/src/main/resources/discovery_get_instance_ttl.lua
@@ -0,0 +1,30 @@
+local namespace = KEYS[1];
+local serviceId = KEYS[2];
+local instanceId = KEYS[3];
+local instanceIdxKey = namespace .. ':svc_itc_idx:' .. serviceId;
+
+local function getInstanceKey(instanceId)
+    return namespace .. ":svc_itc:" .. instanceId;
+end
+
+local function ensureNotExpired(instanceIdxKey, instanceId)
+    local instanceKey = getInstanceKey(instanceId);
+    local instanceTtl = redis.call("ttl", instanceKey);
+    -- -2: The key doesn't exist | -1: The key is fixed | >0: ttl(second)
+    if instanceTtl == -2 then
+        redis.call("srem", instanceIdxKey, instanceId);
+        redis.call("del", instanceKey);
+        redis.call("publish", instanceKey, "expired");
+    end
+
+    return instanceTtl;
+end
+
+local instanceTtl = ensureNotExpired(instanceIdxKey, instanceId);
+if instanceTtl == -1 or instanceTtl == -2 then
+    return instanceTtl;
+else
+    local nowTime = redis.call('time')[1];
+    local ttlAt = nowTime + instanceTtl;
+    return ttlAt;
+end