@@ -6,6 +6,12 @@ package db
66import (
77 "context"
88 "database/sql"
9+ "errors"
10+ "runtime"
11+ "slices"
12+ "sync"
13+
14+ "code.gitea.io/gitea/modules/setting"
915
1016 "xorm.io/builder"
1117 "xorm.io/xorm"
@@ -15,76 +21,85 @@ import (
1521// will be overwritten by Init with HammerContext
1622var DefaultContext context.Context
1723
18- // contextKey is a value for use with context.WithValue.
19- type contextKey struct {
20- name string
21- }
24+ type engineContextKeyType struct {}
2225
23- // enginedContextKey is a context key. It is used with context.Value() to get the current Engined for the context
24- var (
25- enginedContextKey = & contextKey {"engined" }
26- _ Engined = & Context {}
27- )
26+ var engineContextKey = engineContextKeyType {}
2827
2928// Context represents a db context
3029type Context struct {
3130 context.Context
32- e Engine
33- transaction bool
31+ engine Engine
3432}
3533
36- func newContext (ctx context.Context , e Engine , transaction bool ) * Context {
37- return & Context {
38- Context : ctx ,
39- e : e ,
40- transaction : transaction ,
41- }
42- }
43-
44- // InTransaction if context is in a transaction
45- func (ctx * Context ) InTransaction () bool {
46- return ctx .transaction
47- }
48-
49- // Engine returns db engine
50- func (ctx * Context ) Engine () Engine {
51- return ctx .e
34+ func newContext (ctx context.Context , e Engine ) * Context {
35+ return & Context {Context : ctx , engine : e }
5236}
5337
5438// Value shadows Value for context.Context but allows us to get ourselves and an Engined object
5539func (ctx * Context ) Value (key any ) any {
56- if key == enginedContextKey {
40+ if key == engineContextKey {
5741 return ctx
5842 }
5943 return ctx .Context .Value (key )
6044}
6145
6246// WithContext returns this engine tied to this context
6347func (ctx * Context ) WithContext (other context.Context ) * Context {
64- return newContext (ctx , ctx .e .Context (other ), ctx . transaction )
48+ return newContext (ctx , ctx .engine .Context (other ))
6549}
6650
67- // Engined structs provide an Engine
68- type Engined interface {
69- Engine () Engine
51+ var contextSafetyOnce sync.Once
52+ var contextSafetyDeniedFuncPCs []uintptr
53+
54+ func contextSafetyCheck (e Engine ) {
55+ if setting .IsProd && ! setting .IsInTesting {
56+ return
57+ }
58+ // Only do this check for non-end-users. If the problem could be fixed in the future, this code could be removed.
59+ contextSafetyOnce .Do (func () {
60+ // try to figure out the bad functions to deny
61+ type m struct {}
62+ _ = e .SQL ("SELECT 1" ).Iterate (& m {}, func (int , any ) error {
63+ callers := make ([]uintptr , 32 )
64+ callerNum := runtime .Callers (1 , callers )
65+ for i := 0 ; i < callerNum ; i ++ {
66+ if funcName := runtime .FuncForPC (callers [i ]).Name (); funcName == "xorm.io/xorm.(*Session).Iterate" {
67+ contextSafetyDeniedFuncPCs = append (contextSafetyDeniedFuncPCs , callers [i ])
68+ }
69+ }
70+ return nil
71+ })
72+ if len (contextSafetyDeniedFuncPCs ) != 1 {
73+ panic (errors .New ("unable to determine the functions to deny" ))
74+ }
75+ })
76+
77+ // it should be very fast: xxxx ns/op
78+ callers := make ([]uintptr , 32 )
79+ callerNum := runtime .Callers (3 , callers ) // skip 3: runtime.Callers, contextSafetyCheck, GetEngine
80+ for i := 0 ; i < callerNum ; i ++ {
81+ if slices .Contains (contextSafetyDeniedFuncPCs , callers [i ]) {
82+ panic (errors .New ("using database context in an iterator would cause corrupted results" ))
83+ }
84+ }
7085}
7186
72- // GetEngine will get a db Engine from this context or return an Engine restricted to this context
87+ // GetEngine gets an existing db Engine/Statement or creates a new Session
7388func GetEngine (ctx context.Context ) Engine {
74- if e := getEngine (ctx ); e != nil {
89+ if e := getExistingEngine (ctx ); e != nil {
7590 return e
7691 }
7792 return x .Context (ctx )
7893}
7994
80- // getEngine will get a db Engine from this context or return nil
81- func getEngine (ctx context.Context ) Engine {
82- if engined , ok := ctx .(Engined ); ok {
83- return engined .Engine ()
95+ // getExistingEngine gets an existing db Engine/Statement from this context or returns nil
96+ func getExistingEngine (ctx context.Context ) (e Engine ) {
97+ defer func () { contextSafetyCheck (e ) }()
98+ if engined , ok := ctx .(* Context ); ok {
99+ return engined .engine
84100 }
85- enginedInterface := ctx .Value (enginedContextKey )
86- if enginedInterface != nil {
87- return enginedInterface .(Engined ).Engine ()
101+ if engined , ok := ctx .Value (engineContextKey ).(* Context ); ok {
102+ return engined .engine
88103 }
89104 return nil
90105}
@@ -132,23 +147,23 @@ func (c *halfCommitter) Close() error {
132147// d. It doesn't mean rollback is forbidden, but always do it only when there is an error, and you do want to rollback.
133148func TxContext (parentCtx context.Context ) (* Context , Committer , error ) {
134149 if sess , ok := inTransaction (parentCtx ); ok {
135- return newContext (parentCtx , sess , true ), & halfCommitter {committer : sess }, nil
150+ return newContext (parentCtx , sess ), & halfCommitter {committer : sess }, nil
136151 }
137152
138153 sess := x .NewSession ()
139154 if err := sess .Begin (); err != nil {
140- sess .Close ()
155+ _ = sess .Close ()
141156 return nil , nil , err
142157 }
143158
144- return newContext (DefaultContext , sess , true ), sess , nil
159+ return newContext (DefaultContext , sess ), sess , nil
145160}
146161
147162// WithTx represents executing database operations on a transaction, if the transaction exist,
148163// this function will reuse it otherwise will create a new one and close it when finished.
149164func WithTx (parentCtx context.Context , f func (ctx context.Context ) error ) error {
150165 if sess , ok := inTransaction (parentCtx ); ok {
151- err := f (newContext (parentCtx , sess , true ))
166+ err := f (newContext (parentCtx , sess ))
152167 if err != nil {
153168 // rollback immediately, in case the caller ignores returned error and tries to commit the transaction.
154169 _ = sess .Close ()
@@ -165,7 +180,7 @@ func txWithNoCheck(parentCtx context.Context, f func(ctx context.Context) error)
165180 return err
166181 }
167182
168- if err := f (newContext (parentCtx , sess , true )); err != nil {
183+ if err := f (newContext (parentCtx , sess )); err != nil {
169184 return err
170185 }
171186
@@ -312,7 +327,7 @@ func InTransaction(ctx context.Context) bool {
312327}
313328
314329func inTransaction (ctx context.Context ) (* xorm.Session , bool ) {
315- e := getEngine (ctx )
330+ e := getExistingEngine (ctx )
316331 if e == nil {
317332 return nil , false
318333 }
0 commit comments