SQLite

# 2013 July 04
#
# The author disclaims copyright to this source code.  In place of
# a legal notice, here is a blessing:
#
#    May you do good and not evil.
#    May you find forgiveness for yourself and forgive others.
#    May you share freely, never taking more than you give.
#
#***********************************************************************
#
# This file tests that the sessions module handles foreign key constraint
# violations when applying changesets as required.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
} 
source [file join [file dirname [info script]] session_common.tcl]
source $testdir/tester.tcl
ifcapable !session {finish_test; return}
set testprefix sessionA


forcedelete test.db2
sqlite3 db2 test.db2
foreach {tn db} {1 db 2 db2} {
  do_test 1.$tn.1 {
    execsql {
      CREATE TABLE t1(a PRIMARY KEY, b);
      CREATE TABLE t2(a PRIMARY KEY, b);
      CREATE TABLE t3(a PRIMARY KEY, b);
    } $db
  } {}
}

proc tbl_filter {zTbl} {
  return $::table_filter($zTbl)
}

do_test 2.1 {
  set ::table_filter(t1) 1
  set ::table_filter(t2) 0
  set ::table_filter(t3) 1

  sqlite3session S db main
  S table_filter tbl_filter 

  execsql {
    INSERT INTO t1 VALUES('a', 'b');
    INSERT INTO t2 VALUES('c', 'd');
    INSERT INTO t3 VALUES('e', 'f');
  }

  set changeset [S changeset]
  S delete
  sqlite3changeset_apply db2 $changeset xConflict

  execsql {
    SELECT * FROM t1;
    SELECT * FROM t2;
    SELECT * FROM t3;
  } db2
} {a b e f}


finish_test

struct sqlite3_session {
  sqlite3 *db;                    /* Database handle session is attached to */
  char *zDb;                      /* Name of database session is attached to */
  int bEnable;                    /* True if currently recording */
  int bIndirect;                  /* True if all changes are indirect */
  int bAutoAttach;                /* True to auto-attach tables */
  int rc;                         /* Non-zero if an error has occurred */
  void *pFilterCtx;               /* First argument to pass to xTableFilter */
  int (*xTableFilter)(void *pCtx, const char *zTab);
  sqlite3_session *pNext;         /* Next session object on same db. */
  SessionTable *pTable;           /* List of attached tables */
};

/*
** Structure for changeset iterators.
*/

    if( pSession->rc ) continue;
    if( sqlite3_strnicmp(zDb, pSession->zDb, nDb+1) ) continue;

    for(pTab=pSession->pTable; pTab || pSession->bAutoAttach; pTab=pTab->pNext){
      if( !pTab ){
        /* This branch is taken if table zName has not yet been attached to
        ** this session and the auto-attach flag is set.  */

        /* If there is a table-filter configured, invoke it. If it returns 0,
        ** this change will not be recorded. Break out of the loop early in
        ** this case.  */
        if( pSession->xTableFilter 
         && pSession->xTableFilter(pSession->pFilterCtx, zName)==0
        ){
          break;
        }

        pSession->rc = sqlite3session_attach(pSession,zName);
        if( pSession->rc ) break;
        pTab = pSession->pTable;
        assert( 0==sqlite3_strnicmp(pTab->zName, zName, nName+1) );
      }

      if( 0==sqlite3_strnicmp(pTab->zName, zName, nName+1) ){

  /* Delete all attached table objects. And the contents of their 
  ** associated hash-tables. */
  sessionDeleteTable(pSession->pTable);

  /* Free the session object itself. */
  sqlite3_free(pSession);
}

/*
** Set a table filter on a Session Object.
*/
void sqlite3session_table_filter(
  sqlite3_session *pSession, 
  int(*xFilter)(void*, const char*),
  void *pCtx                      /* First argument passed to xFilter */
){
  pSession->bAutoAttach = 1;
  pSession->pFilterCtx = pCtx;
  pSession->xTableFilter = xFilter;
}

/*
** Attach a table to a session. All subsequent changes made to the table
** while the session object is enabled will be recorded.
**
** Only tables that have a PRIMARY KEY defined may be attached. It does
** not matter if the PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias)

** function are undefined.
**
** Session objects must be deleted before the database handle to which they
** are attached is closed. Refer to the documentation for 
** [sqlite3session_create()] for details.
*/
void sqlite3session_delete(sqlite3_session *pSession);


/*
** CAPI3REF: Enable Or Disable A Session Object
**
** Enable or disable the recording of changes by a session object. When
** enabled, a session object records changes made to the database. When
** disabled - it does not. A newly created session object is enabled.

** SQLITE_OK is returned if the call completes without error. Or, if an error 
** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
*/
int sqlite3session_attach(
  sqlite3_session *pSession,      /* Session object */
  const char *zTab                /* Table name */
);

/*
** CAPI3REF: Set a table filter on a Session Object.
**
** The second argument (xFilter) is the "filter callback". For changes to rows 
** in tables that are not attached to the Session oject, the filter is called
** to determine whether changes to the table's rows should be tracked or not. 
** If xFilter returns 0, changes is not tracked. Note that once a table is 
** attached, xFilter will not be called again.
*/
void sqlite3session_table_filter(
  sqlite3_session *pSession,      /* Session object */
  int(*xFilter)(
    void *pCtx,                   /* Copy of third arg to _filter_table() */
    const char *zTab              /* Table name */
  ),
  void *pCtx                      /* First argument passed to xFilter */
);

/*
** CAPI3REF: Generate A Changeset From A Session Object
**
** Obtain a changeset containing changes to the tables attached to the 
** session object passed as the first argument. If successful, 
** set *ppChangeset to point to a buffer containing the changeset 

#if defined(SQLITE_TEST) && defined(SQLITE_ENABLE_SESSION) \
 && defined(SQLITE_ENABLE_PREUPDATE_HOOK)

#include "sqlite3session.h"
#include <assert.h>
#include <string.h>
#include <tcl.h>

typedef struct TestSession TestSession;
struct TestSession {
  sqlite3_session *pSession;
  Tcl_Interp *interp;
  Tcl_Obj *pFilterScript;
};

static int test_session_error(Tcl_Interp *interp, int rc){
  extern const char *sqlite3ErrName(int);
  Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
  return TCL_ERROR;
}

static int test_table_filter(void *pCtx, const char *zTbl){
  TestSession *p = (TestSession*)pCtx;
  Tcl_Obj *pEval;
  int rc;
  int bRes = 0;

  pEval = Tcl_DuplicateObj(p->pFilterScript);
  Tcl_IncrRefCount(pEval);
  rc = Tcl_ListObjAppendElement(p->interp, pEval, Tcl_NewStringObj(zTbl, -1));
  if( rc==TCL_OK ){
    rc = Tcl_EvalObjEx(p->interp, pEval, TCL_EVAL_GLOBAL);
  }
  if( rc==TCL_OK ){
    rc = Tcl_GetBooleanFromObj(p->interp, Tcl_GetObjResult(p->interp), &bRes);
  }
  if( rc!=TCL_OK ){
    /* printf("error: %s\n", Tcl_GetStringResult(p->interp)); */
    Tcl_BackgroundError(p->interp);
  }
  Tcl_DecrRefCount(pEval);

  return bRes;
}

/*
** Tclcmd:  $session attach TABLE
**          $session changeset
**          $session delete
**          $session enable BOOL
**          $session indirect INTEGER
**          $session table_filter SCRIPT
*/
static int test_session_cmd(
  void *clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  TestSession *p = (TestSession*)clientData;
  sqlite3_session *pSession = p->pSession;
  struct SessionSubcmd {
    const char *zSub;
    int nArg;
    const char *zMsg;
    int iSub;
  } aSub[] = {
    { "attach",       1, "TABLE",  }, /* 0 */
    { "changeset",    0, "",       }, /* 1 */
    { "delete",       0, "",       }, /* 2 */
    { "enable",       1, "BOOL",   }, /* 3 */
    { "indirect",     1, "BOOL",   }, /* 4 */
    { "isempty",      0, "",       }, /* 5 */
    { "table_filter", 1, "SCRIPT", }, /* 6 */
    { 0 }
  };
  int iSub;
  int rc;

  if( objc<2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "SUBCOMMAND ...");

    case 0: {      /* attach */
      char *zArg = Tcl_GetString(objv[2]);
      if( zArg[0]=='*' && zArg[1]=='\0' ) zArg = 0;
      rc = sqlite3session_attach(pSession, zArg);
      if( rc!=SQLITE_OK ){
        return test_session_error(interp, rc);
      }

      break;
    }

    case 1: {      /* changeset */
      int nChange;
      void *pChange;
      rc = sqlite3session_changeset(pSession, &nChange, &pChange);
      if( rc==SQLITE_OK ){
        Tcl_SetObjResult(interp, Tcl_NewByteArrayObj(pChange, nChange)); 

    case 5: {      /* isempty */
      int val;
      val = sqlite3session_isempty(pSession);
      Tcl_SetObjResult(interp, Tcl_NewBooleanObj(val));
      break;
    }
            
    case 6: {      /* table_filter */
      if( p->pFilterScript ) Tcl_DecrRefCount(p->pFilterScript);
      p->interp = interp;
      p->pFilterScript = Tcl_DuplicateObj(objv[2]);
      Tcl_IncrRefCount(p->pFilterScript);
      sqlite3session_table_filter(pSession, test_table_filter, clientData);
      break;
    }
  }

  return TCL_OK;
}

static void test_session_del(void *clientData){
  TestSession *p = (TestSession*)clientData;
  if( p->pFilterScript ) Tcl_DecrRefCount(p->pFilterScript);
  sqlite3session_delete(p->pSession);
  ckfree(p);
}

/*
** Tclcmd:  sqlite3session CMD DB-HANDLE DB-NAME
*/
static int test_sqlite3session(
  void * clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  sqlite3 *db;
  Tcl_CmdInfo info;
  int rc;                         /* sqlite3session_create() return code */
  TestSession *p;                 /* New wrapper object */

  if( objc!=4 ){
    Tcl_WrongNumArgs(interp, 1, objv, "CMD DB-HANDLE DB-NAME");
    return TCL_ERROR;
  }

  if( 0==Tcl_GetCommandInfo(interp, Tcl_GetString(objv[2]), &info) ){
    Tcl_AppendResult(interp, "no such handle: ", Tcl_GetString(objv[2]), 0);
    return TCL_ERROR;
  }
  db = *(sqlite3 **)info.objClientData;

  p = (TestSession*)ckalloc(sizeof(TestSession));
  memset(p, 0, sizeof(TestSession));
  rc = sqlite3session_create(db, Tcl_GetString(objv[3]), &p->pSession);
  if( rc!=SQLITE_OK ){
    ckfree(p);
    return test_session_error(interp, rc);
  }

  Tcl_CreateObjCommand(
      interp, Tcl_GetString(objv[1]), test_session_cmd, (ClientData)p,
      test_session_del
  );
  Tcl_SetObjResult(interp, objv[1]);
  return TCL_OK;
}

static void test_append_value(Tcl_Obj *pList, sqlite3_value *pVal){