Add the sqlite3_create_function_v2() API, a version of create_function that allows a destructor to be specified.

FossilOrigin-Name: 9a724dfbe822c77e76721abe3443c9cb018bb2e2

1 files changed, 25 insertions, 1 deletions

diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 6c41315f8..90d900d69 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -600,6 +600,7 @@ typedef struct Expr Expr;
 typedef struct ExprList ExprList;
 typedef struct ExprSpan ExprSpan;
 typedef struct FKey FKey;
+typedef struct FuncDestructor FuncDestructor;
 typedef struct FuncDef FuncDef;
 typedef struct FuncDefHash FuncDefHash;
 typedef struct IdList IdList;
@@ -956,6 +957,27 @@ struct FuncDef {
   void (*xFinalize)(sqlite3_context*);                /* Aggregate finalizer */
   char *zName;         /* SQL name of the function. */
   FuncDef *pHash;      /* Next with a different name but the same hash */
+  FuncDestructor *pDestructor;   /* Reference counted destructor function */
+};
+
+/*
+** This structure encapsulates a user-function destructor callback (as
+** configured using create_function_v2()) and a reference counter. When
+** create_function_v2() is called to create a function with a destructor,
+** a single object of this type is allocated. FuncDestructor.nRef is set to 
+** the number of FuncDef objects created (either 1 or 3, depending on whether
+** or not the specified encoding is SQLITE_ANY). The FuncDef.pDestructor
+** member of each of the new FuncDef objects is set to point to the allocated
+** FuncDestructor.
+**
+** Thereafter, when one of the FuncDef objects is deleted, the reference
+** count on this object is decremented. When it reaches 0, the destructor
+** is invoked and the FuncDestructor structure freed.
+*/
+struct FuncDestructor {
+  int nRef;
+  void (*xDestroy)(void *);
+  void *pUserData;
 };
 
 /*
@@ -2921,7 +2943,9 @@ int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *, 
   void (*)(sqlite3_context*,int,sqlite3_value **),
-  void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*));
+  void (*)(sqlite3_context*,int,sqlite3_value **), void (*)(sqlite3_context*),
+  FuncDestructor *pDestructor
+);
 int sqlite3ApiExit(sqlite3 *db, int);
 int sqlite3OpenTempDatabase(Parse *);