SQLite

#include "sqlite3ext.h"
#endif
SQLITE_EXTENSION_INIT1
#include <assert.h>
#include <string.h>

#ifndef SQLITE_OMIT_VIRTUALTABLE

/*
** The following macros are used to cast pointers to integers.
** The way you do this varies from one compiler
** to the next, so we have developed the following set of #if statements
** to generate appropriate macros for a wide range of compilers.
*/
#if defined(__PTRDIFF_TYPE__)  /* This case should work for GCC */
# define SQLITE_PTR_TO_INT64(X)  ((sqlite3_int64)(__PTRDIFF_TYPE__)(X))
#elif !defined(__GNUC__)       /* Works for compilers other than LLVM */
# define SQLITE_PTR_TO_INT64(X)  ((sqlite3_int64)(((char*)X)-(char*)0))
#elif defined(HAVE_STDINT_H)   /* Use this case if we have ANSI headers */
# define SQLITE_PTR_TO_INT64(X)  ((sqlite3_int64)(intptr_t)(X))
#else                          /* Generates a warning - but it always works */
# define SQLITE_PTR_TO_INT64(X)  ((sqlite3_int64)(X))
#endif


/* stmt_vtab is a subclass of sqlite3_vtab which will
** serve as the underlying representation of a stmt virtual table
*/
typedef struct stmt_vtab stmt_vtab;
struct stmt_vtab {
  sqlite3_vtab base;  /* Base class - must be first */

  sqlite3_vtab **ppVtab,
  char **pzErr
){
  stmt_vtab *pNew;
  int rc;

/* Column numbers */
#define STMT_COLUMN_PTR     0   /* Numeric value of the statement pointer */
#define STMT_COLUMN_SQL     1   /* SQL for the statement */
#define STMT_COLUMN_NCOL    2   /* Number of result columns */
#define STMT_COLUMN_RO      3   /* True if read-only */
#define STMT_COLUMN_BUSY    4   /* True if currently busy */
#define STMT_COLUMN_NSCAN   5   /* SQLITE_STMTSTATUS_FULLSCAN_STEP */
#define STMT_COLUMN_NSORT   6   /* SQLITE_STMTSTATUS_SORT */
#define STMT_COLUMN_NAIDX   7   /* SQLITE_STMTSTATUS_AUTOINDEX */
#define STMT_COLUMN_NSTEP   8   /* SQLITE_STMTSTATUS_VM_STEP */
#define STMT_COLUMN_REPREP  9   /* SQLITE_STMTSTATUS_REPREPARE */
#define STMT_COLUMN_RUN    10   /* SQLITE_STMTSTATUS_RUN */
#define STMT_COLUMN_MEM    11   /* SQLITE_STMTSTATUS_MEMUSED */


  rc = sqlite3_declare_vtab(db,
     "CREATE TABLE x(ptr,sql,ncol,ro,busy,nscan,nsort,naidx,nstep,"
                    "reprep,run,mem)");
  if( rc==SQLITE_OK ){
    pNew = sqlite3_malloc( sizeof(*pNew) );
    *ppVtab = (sqlite3_vtab*)pNew;
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
    pNew->db = db;

static int stmtColumn(
  sqlite3_vtab_cursor *cur,   /* The cursor */
  sqlite3_context *ctx,       /* First argument to sqlite3_result_...() */
  int i                       /* Which column to return */
){
  stmt_cursor *pCur = (stmt_cursor*)cur;
  switch( i ){
    case STMT_COLUMN_PTR: {
      sqlite3_result_int64(ctx, SQLITE_PTR_TO_INT64(pCur->pStmt));
      break;
    }
    case STMT_COLUMN_SQL: {
      sqlite3_result_text(ctx, sqlite3_sql(pCur->pStmt), -1, SQLITE_TRANSIENT);
      break;
    }
    case STMT_COLUMN_NCOL: {
      sqlite3_result_int(ctx, sqlite3_column_count(pCur->pStmt));
      break;

};

#endif /* SQLITE_OMIT_VIRTUALTABLE */

int sqlite3StmtVtabInit(sqlite3 *db){
  int rc = SQLITE_OK;
#ifndef SQLITE_OMIT_VIRTUALTABLE
  rc = sqlite3_create_module(db, "stmt", &stmtModule, 0);
#endif
  return rc;
}

#ifndef SQLITE_CORE
#ifdef _WIN32
__declspec(dllexport)

set x giraffe
set y mango
set z alabama
do_execsql_test stmtvtab1-100 {
  CREATE TABLE t1(a,b,c);
  INSERT INTO t1 VALUES($a,$b,$c);
  CREATE INDEX t1a ON t1(a);
  SELECT run, sql FROM stmt ORDER BY 1;
} {1 {SELECT run, sql FROM stmt ORDER BY 1;} 1 {CREATE INDEX t1a ON t1(a);} 1 {INSERT INTO t1 VALUES($a,$b,$c);} 1 {CREATE TABLE t1(a,b,c);}}
set x neon
set y event
set z future
do_execsql_test stmtvtab1-110 {
  INSERT INTO t1 VALUES($a,$b,$c);
  SELECT reprep,run,SQL FROM stmt WHERE sql LIKE '%INSERT%' AND NOT busy;
} {1 2 {INSERT INTO t1 VALUES($a,$b,$c);}}
set x network
set y fit
set z metal
do_execsql_test stmtvtab1-120 {
  INSERT INTO t1 VALUES($a,$b,$c);
  SELECT reprep,run,SQL FROM stmt WHERE sql LIKE '%INSERT%' AND NOT busy;
} {1 3 {INSERT INTO t1 VALUES($a,$b,$c);}}
set x history
set y detail
set z grace
do_execsql_test stmtvtab1-130 {
  CREATE INDEX t1b ON t1(b);
  INSERT INTO t1 VALUES($a,$b,$c);
  SELECT reprep,run,SQL FROM stmt WHERE sql LIKE '%INSERT%' AND NOT busy;
} {2 4 {INSERT INTO t1 VALUES($a,$b,$c);}}

# All statements are still in cache
#
do_execsql_test stmtvtab1-140 {
  SELECT count(*) FROM stmt WHERE NOT busy;
} {6}

# None of the prepared statements should use more than a couple thousand
# bytes of memory
#
#db eval {SELECT mem, sql FROM stmt} {puts [format {%5d %s} $mem $sql]}
do_execsql_test stmtvtab1-150 {
  SELECT count(*) FROM stmt WHERE mem>5000;
} {0}

# Flushing the cache clears all of the prepared statements.
#
db cache flush
do_execsql_test stmtvtab1-160 {
  SELECT * FROM stmt WHERE NOT busy;
} {}