PLT-8131 (part2) Add plugin key value store support (#7902)

* Add plugin key value store support

* Add localization strings

* Updates per feedback

store/sqlstore/plugin_store.go

@@ -0,0 +1,92 @@
+// Copyright (c) 2017-present Mattermost, Inc. All Rights Reserved.
+// See License.txt for license information.
+
+package sqlstore
+
+import (
+	"database/sql"
+	"fmt"
+	"net/http"
+
+	"github.com/mattermost/mattermost-server/model"
+	"github.com/mattermost/mattermost-server/store"
+)
+
+type SqlPluginStore struct {
+	SqlStore
+}
+
+func NewSqlPluginStore(sqlStore SqlStore) store.PluginStore {
+	s := &SqlPluginStore{sqlStore}
+
+	for _, db := range sqlStore.GetAllConns() {
+		table := db.AddTableWithName(model.PluginKeyValue{}, "PluginKeyValueStore").SetKeys(false, "PluginId", "Key")
+		table.ColMap("Value").SetMaxSize(8192)
+	}
+
+	return s
+}
+
+func (ps SqlPluginStore) CreateIndexesIfNotExists() {
+}
+
+func (ps SqlPluginStore) SaveOrUpdate(kv *model.PluginKeyValue) store.StoreChannel {
+	return store.Do(func(result *store.StoreResult) {
+		if result.Err = kv.IsValid(); result.Err != nil {
+			return
+		}
+
+		if ps.DriverName() == model.DATABASE_DRIVER_POSTGRES {
+			// Unfortunately PostgreSQL pre-9.5 does not have an atomic upsert, so we use
+			// separate update and insert queries to accomplish our upsert
+			if rowsAffected, err := ps.GetMaster().Update(kv); err != nil {
+				result.Err = model.NewAppError("SqlPluginStore.SaveOrUpdate", "store.sql_plugin_store.save.app_error", nil, err.Error(), http.StatusInternalServerError)
+				return
+			} else if rowsAffected == 0 {
+				// No rows were affected by the update, so let's try an insert
+				if err := ps.GetMaster().Insert(kv); err != nil {
+					// If the error is from unique constraints violation, it's the result of a
+					// valid race and we can report success. Otherwise we have a real error and
+					// need to return it
+					if !IsUniqueConstraintError(err, []string{"PRIMARY", "PluginId", "Key", "PKey"}) {
+						result.Err = model.NewAppError("SqlPluginStore.SaveOrUpdate", "store.sql_plugin_store.save.app_error", nil, err.Error(), http.StatusInternalServerError)
+						return
+					}
+				}
+			}
+		} else if ps.DriverName() == model.DATABASE_DRIVER_MYSQL {
+			if _, err := ps.GetMaster().Exec("INSERT INTO PluginKeyValueStore (PluginId, PKey, PValue) VALUES(:PluginId, :Key, :Value) ON DUPLICATE KEY UPDATE PValue = :Value", map[string]interface{}{"PluginId": kv.PluginId, "Key": kv.Key, "Value": kv.Value}); err != nil {
+				result.Err = model.NewAppError("SqlPluginStore.SaveOrUpdate", "store.sql_plugin_store.save.app_error", nil, err.Error(), http.StatusInternalServerError)
+				return
+			}
+		}
+
+		result.Data = kv
+	})
+}
+
+func (ps SqlPluginStore) Get(pluginId, key string) store.StoreChannel {
+	return store.Do(func(result *store.StoreResult) {
+		var kv *model.PluginKeyValue
+
+		if err := ps.GetReplica().SelectOne(&kv, "SELECT * FROM PluginKeyValueStore WHERE PluginId = :PluginId AND PKey = :Key", map[string]interface{}{"PluginId": pluginId, "Key": key}); err != nil {
+			if err == sql.ErrNoRows {
+				result.Err = model.NewAppError("SqlPluginStore.Get", "store.sql_plugin_store.get.app_error", nil, fmt.Sprintf("plugin_id=%v, key=%v, err=%v", pluginId, key, err.Error()), http.StatusNotFound)
+			} else {
+				result.Err = model.NewAppError("SqlPluginStore.Get", "store.sql_plugin_store.get.app_error", nil, fmt.Sprintf("plugin_id=%v, key=%v, err=%v", pluginId, key, err.Error()), http.StatusInternalServerError)
+			}
+		} else {
+			result.Data = kv
+		}
+	})
+}
+
+func (ps SqlPluginStore) Delete(pluginId, key string) store.StoreChannel {
+	return store.Do(func(result *store.StoreResult) {
+		if _, err := ps.GetMaster().Exec("DELETE FROM PluginKeyValueStore WHERE PluginId = :PluginId AND PKey = :Key", map[string]interface{}{"PluginId": pluginId, "Key": key}); err != nil {
+			result.Err = model.NewAppError("SqlPluginStore.Delete", "store.sql_plugin_store.delete.app_error", nil, fmt.Sprintf("plugin_id=%v, key=%v, err=%v", pluginId, key, err.Error()), http.StatusInternalServerError)
+		} else {
+			result.Data = true
+		}
+	})
+}