diff options
Diffstat (limited to 'callback.go')
-rw-r--r-- | callback.go | 52 |
1 files changed, 49 insertions, 3 deletions
diff --git a/callback.go b/callback.go index ee9d40c..e2bf3c6 100644 --- a/callback.go +++ b/callback.go @@ -24,29 +24,75 @@ import ( "fmt" "math" "reflect" + "sync" "unsafe" ) //export callbackTrampoline func callbackTrampoline(ctx *C.sqlite3_context, argc int, argv **C.sqlite3_value) { args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:argc:argc] - fi := (*functionInfo)(unsafe.Pointer(C.sqlite3_user_data(ctx))) + fi := lookupHandle(uintptr(C.sqlite3_user_data(ctx))).(*functionInfo) fi.Call(ctx, args) } //export stepTrampoline func stepTrampoline(ctx *C.sqlite3_context, argc int, argv **C.sqlite3_value) { args := (*[(math.MaxInt32 - 1) / unsafe.Sizeof((*C.sqlite3_value)(nil))]*C.sqlite3_value)(unsafe.Pointer(argv))[:argc:argc] - ai := (*aggInfo)(unsafe.Pointer(C.sqlite3_user_data(ctx))) + ai := lookupHandle(uintptr(C.sqlite3_user_data(ctx))).(*aggInfo) ai.Step(ctx, args) } //export doneTrampoline func doneTrampoline(ctx *C.sqlite3_context) { - ai := (*aggInfo)(unsafe.Pointer(C.sqlite3_user_data(ctx))) + handle := uintptr(C.sqlite3_user_data(ctx)) + ai := lookupHandle(handle).(*aggInfo) ai.Done(ctx) } +// Use handles to avoid passing Go pointers to C. + +type handleVal struct { + db *SQLiteConn + val interface{} +} + +var handleLock sync.Mutex +var handleVals = make(map[uintptr]handleVal) +var handleIndex uintptr = 100 + +func newHandle(db *SQLiteConn, v interface{}) uintptr { + handleLock.Lock() + defer handleLock.Unlock() + i := handleIndex + handleIndex++ + handleVals[i] = handleVal{db, v} + return i +} + +func lookupHandle(handle uintptr) interface{} { + handleLock.Lock() + defer handleLock.Unlock() + r, ok := handleVals[handle] + if !ok { + if handle >= 100 && handle < handleIndex { + panic("deleted handle") + } else { + panic("invalid handle") + } + } + return r.val +} + +func deleteHandles(db *SQLiteConn) { + handleLock.Lock() + defer handleLock.Unlock() + for handle, val := range handleVals { + if val.db == db { + delete(handleVals, handle) + } + } +} + // This is only here so that tests can refer to it. type callbackArgRaw C.sqlite3_value |