refactor: reduce sql query in retrieveFeeds (#3547)

2 files changed, 108 insertions, 1 deletions

diff --git a/models/action.go b/models/action.go
index 5333f62772..b551d79bb8 100644
--- a/models/action.go
+++ b/models/action.go
@@ -742,5 +742,14 @@ func GetFeeds(opts GetFeedsOptions) ([]*Action, error) {
 	}
 
 	actions := make([]*Action, 0, 20)
-	return actions, x.Limit(20).Desc("id").Where(cond).Find(&actions)
+
+	if err := x.Limit(20).Desc("id").Where(cond).Find(&actions); err != nil {
+		return nil, fmt.Errorf("Find: %v", err)
+	}
+
+	if err := ActionList(actions).LoadAttributes(); err != nil {
+		return nil, fmt.Errorf("LoadAttributes: %v", err)
+	}
+
+	return actions, nil
 }
diff --git a/models/action_list.go b/models/action_list.go
new file mode 100644
index 0000000000..6f726f4b34
--- /dev/null
+++ b/models/action_list.go
@@ -0,0 +1,98 @@
+// Copyright 2018 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package models
+
+import "fmt"
+
+// ActionList defines a list of actions
+type ActionList []*Action
+
+func (actions ActionList) getUserIDs() []int64 {
+	userIDs := make(map[int64]struct{}, len(actions))
+	for _, action := range actions {
+		if _, ok := userIDs[action.ActUserID]; !ok {
+			userIDs[action.ActUserID] = struct{}{}
+		}
+	}
+	return keysInt64(userIDs)
+}
+
+func (actions ActionList) loadUsers(e Engine) ([]*User, error) {
+	if len(actions) == 0 {
+		return nil, nil
+	}
+
+	userIDs := actions.getUserIDs()
+	userMaps := make(map[int64]*User, len(userIDs))
+	err := e.
+		In("id", userIDs).
+		Find(&userMaps)
+	if err != nil {
+		return nil, fmt.Errorf("find user: %v", err)
+	}
+
+	for _, action := range actions {
+		action.ActUser = userMaps[action.ActUserID]
+	}
+	return valuesUser(userMaps), nil
+}
+
+// LoadUsers loads actions' all users
+func (actions ActionList) LoadUsers() ([]*User, error) {
+	return actions.loadUsers(x)
+}
+
+func (actions ActionList) getRepoIDs() []int64 {
+	repoIDs := make(map[int64]struct{}, len(actions))
+	for _, action := range actions {
+		if _, ok := repoIDs[action.RepoID]; !ok {
+			repoIDs[action.RepoID] = struct{}{}
+		}
+	}
+	return keysInt64(repoIDs)
+}
+
+func (actions ActionList) loadRepositories(e Engine) ([]*Repository, error) {
+	if len(actions) == 0 {
+		return nil, nil
+	}
+
+	repoIDs := actions.getRepoIDs()
+	repoMaps := make(map[int64]*Repository, len(repoIDs))
+	err := e.
+		In("id", repoIDs).
+		Find(&repoMaps)
+	if err != nil {
+		return nil, fmt.Errorf("find repository: %v", err)
+	}
+
+	for _, action := range actions {
+		action.Repo = repoMaps[action.RepoID]
+	}
+	return valuesRepository(repoMaps), nil
+}
+
+// LoadRepositories loads actions' all repositories
+func (actions ActionList) LoadRepositories() ([]*Repository, error) {
+	return actions.loadRepositories(x)
+}
+
+// loadAttributes loads all attributes
+func (actions ActionList) loadAttributes(e Engine) (err error) {
+	if _, err = actions.loadUsers(e); err != nil {
+		return
+	}
+
+	if _, err = actions.loadRepositories(e); err != nil {
+		return
+	}
+
+	return nil
+}
+
+// LoadAttributes loads attributes of the actions
+func (actions ActionList) LoadAttributes() error {
+	return actions.loadAttributes(x)
+}