0
0
Fork 0
mirror of https://github.com/go-gitea/gitea synced 2024-12-24 01:44:57 +01:00
gitea/modules/gitgraph/graph_models.go
Lunny Xiao bd820aa9c5
Add context cache as a request level cache (#22294)
To avoid duplicated load of the same data in an HTTP request, we can set
a context cache to do that. i.e. Some pages may load a user from a
database with the same id in different areas on the same page. But the
code is hidden in two different deep logic. How should we share the
user? As a result of this PR, now if both entry functions accept
`context.Context` as the first parameter and we just need to refactor
`GetUserByID` to reuse the user from the context cache. Then it will not
be loaded twice on an HTTP request.

But of course, sometimes we would like to reload an object from the
database, that's why `RemoveContextData` is also exposed.

The core context cache is here. It defines a new context
```go
type cacheContext struct {
	ctx  context.Context
	data map[any]map[any]any
        lock sync.RWMutex
}

var cacheContextKey = struct{}{}

func WithCacheContext(ctx context.Context) context.Context {
	return context.WithValue(ctx, cacheContextKey, &cacheContext{
		ctx:  ctx,
		data: make(map[any]map[any]any),
	})
}
```

Then you can use the below 4 methods to read/write/del the data within
the same context.

```go
func GetContextData(ctx context.Context, tp, key any) any
func SetContextData(ctx context.Context, tp, key, value any)
func RemoveContextData(ctx context.Context, tp, key any)
func GetWithContextCache[T any](ctx context.Context, cacheGroupKey string, cacheTargetID any, f func() (T, error)) (T, error)
```

Then let's take a look at how `system.GetString` implement it.

```go
func GetSetting(ctx context.Context, key string) (string, error) {
	return cache.GetWithContextCache(ctx, contextCacheKey, key, func() (string, error) {
		return cache.GetString(genSettingCacheKey(key), func() (string, error) {
			res, err := GetSettingNoCache(ctx, key)
			if err != nil {
				return "", err
			}
			return res.SettingValue, nil
		})
	})
}
```

First, it will check if context data include the setting object with the
key. If not, it will query from the global cache which may be memory or
a Redis cache. If not, it will get the object from the database. In the
end, if the object gets from the global cache or database, it will be
set into the context cache.

An object stored in the context cache will only be destroyed after the
context disappeared.
2023-02-15 21:37:34 +08:00

256 lines
6.3 KiB
Go

// Copyright 2020 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package gitgraph
import (
"bytes"
"context"
"fmt"
"strings"
asymkey_model "code.gitea.io/gitea/models/asymkey"
"code.gitea.io/gitea/models/db"
git_model "code.gitea.io/gitea/models/git"
repo_model "code.gitea.io/gitea/models/repo"
user_model "code.gitea.io/gitea/models/user"
"code.gitea.io/gitea/modules/git"
"code.gitea.io/gitea/modules/log"
)
// NewGraph creates a basic graph
func NewGraph() *Graph {
graph := &Graph{}
graph.relationCommit = &Commit{
Row: -1,
Column: -1,
}
graph.Flows = map[int64]*Flow{}
return graph
}
// Graph represents a collection of flows
type Graph struct {
Flows map[int64]*Flow
Commits []*Commit
MinRow int
MinColumn int
MaxRow int
MaxColumn int
relationCommit *Commit
}
// Width returns the width of the graph
func (graph *Graph) Width() int {
return graph.MaxColumn - graph.MinColumn + 1
}
// Height returns the height of the graph
func (graph *Graph) Height() int {
return graph.MaxRow - graph.MinRow + 1
}
// AddGlyph adds glyph to flows
func (graph *Graph) AddGlyph(row, column int, flowID int64, color int, glyph byte) {
flow, ok := graph.Flows[flowID]
if !ok {
flow = NewFlow(flowID, color, row, column)
graph.Flows[flowID] = flow
}
flow.AddGlyph(row, column, glyph)
if row < graph.MinRow {
graph.MinRow = row
}
if row > graph.MaxRow {
graph.MaxRow = row
}
if column < graph.MinColumn {
graph.MinColumn = column
}
if column > graph.MaxColumn {
graph.MaxColumn = column
}
}
// AddCommit adds a commit at row, column on flowID with the provided data
func (graph *Graph) AddCommit(row, column int, flowID int64, data []byte) error {
commit, err := NewCommit(row, column, data)
if err != nil {
return err
}
commit.Flow = flowID
graph.Commits = append(graph.Commits, commit)
graph.Flows[flowID].Commits = append(graph.Flows[flowID].Commits, commit)
return nil
}
// LoadAndProcessCommits will load the git.Commits for each commit in the graph,
// the associate the commit with the user author, and check the commit verification
// before finally retrieving the latest status
func (graph *Graph) LoadAndProcessCommits(ctx context.Context, repository *repo_model.Repository, gitRepo *git.Repository) error {
var err error
var ok bool
emails := map[string]*user_model.User{}
keyMap := map[string]bool{}
for _, c := range graph.Commits {
if len(c.Rev) == 0 {
continue
}
c.Commit, err = gitRepo.GetCommit(c.Rev)
if err != nil {
return fmt.Errorf("GetCommit: %s Error: %w", c.Rev, err)
}
if c.Commit.Author != nil {
email := c.Commit.Author.Email
if c.User, ok = emails[email]; !ok {
c.User, _ = user_model.GetUserByEmail(ctx, email)
emails[email] = c.User
}
}
c.Verification = asymkey_model.ParseCommitWithSignature(ctx, c.Commit)
_ = asymkey_model.CalculateTrustStatus(c.Verification, repository.GetTrustModel(), func(user *user_model.User) (bool, error) {
return repo_model.IsOwnerMemberCollaborator(repository, user.ID)
}, &keyMap)
statuses, _, err := git_model.GetLatestCommitStatus(db.DefaultContext, repository.ID, c.Commit.ID.String(), db.ListOptions{})
if err != nil {
log.Error("GetLatestCommitStatus: %v", err)
} else {
c.Status = git_model.CalcCommitStatus(statuses)
}
}
return nil
}
// NewFlow creates a new flow
func NewFlow(flowID int64, color, row, column int) *Flow {
return &Flow{
ID: flowID,
ColorNumber: color,
MinRow: row,
MinColumn: column,
MaxRow: row,
MaxColumn: column,
}
}
// Flow represents a series of glyphs
type Flow struct {
ID int64
ColorNumber int
Glyphs []Glyph
Commits []*Commit
MinRow int
MinColumn int
MaxRow int
MaxColumn int
}
// Color16 wraps the color numbers around mod 16
func (flow *Flow) Color16() int {
return flow.ColorNumber % 16
}
// AddGlyph adds glyph at row and column
func (flow *Flow) AddGlyph(row, column int, glyph byte) {
if row < flow.MinRow {
flow.MinRow = row
}
if row > flow.MaxRow {
flow.MaxRow = row
}
if column < flow.MinColumn {
flow.MinColumn = column
}
if column > flow.MaxColumn {
flow.MaxColumn = column
}
flow.Glyphs = append(flow.Glyphs, Glyph{
row,
column,
glyph,
})
}
// Glyph represents a co-ordinate and glyph
type Glyph struct {
Row int
Column int
Glyph byte
}
// RelationCommit represents an empty relation commit
var RelationCommit = &Commit{
Row: -1,
}
// NewCommit creates a new commit from a provided line
func NewCommit(row, column int, line []byte) (*Commit, error) {
data := bytes.SplitN(line, []byte("|"), 5)
if len(data) < 5 {
return nil, fmt.Errorf("malformed data section on line %d with commit: %s", row, string(line))
}
return &Commit{
Row: row,
Column: column,
// 0 matches git log --pretty=format:%d => ref names, like the --decorate option of git-log(1)
Refs: newRefsFromRefNames(data[0]),
// 1 matches git log --pretty=format:%H => commit hash
Rev: string(data[1]),
// 2 matches git log --pretty=format:%ad => author date (format respects --date= option)
Date: string(data[2]),
// 3 matches git log --pretty=format:%h => abbreviated commit hash
ShortRev: string(data[3]),
// 4 matches git log --pretty=format:%s => subject
Subject: string(data[4]),
}, nil
}
func newRefsFromRefNames(refNames []byte) []git.Reference {
refBytes := bytes.Split(refNames, []byte{',', ' '})
refs := make([]git.Reference, 0, len(refBytes))
for _, refNameBytes := range refBytes {
if len(refNameBytes) == 0 {
continue
}
refName := string(refNameBytes)
if strings.HasPrefix(refName, "tag: ") {
refName = strings.TrimPrefix(refName, "tag: ")
} else {
refName = strings.TrimPrefix(refName, "HEAD -> ")
}
refs = append(refs, git.Reference{
Name: refName,
})
}
return refs
}
// Commit represents a commit at co-ordinate X, Y with the data
type Commit struct {
Commit *git.Commit
User *user_model.User
Verification *asymkey_model.CommitVerification
Status *git_model.CommitStatus
Flow int64
Row int
Column int
Refs []git.Reference
Rev string
Date string
ShortRev string
Subject string
}
// OnlyRelation returns whether this a relation only commit
func (c *Commit) OnlyRelation() bool {
return c.Row == -1
}