SQLite

# 2014 November 20
#
# 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.
#
#***********************************************************************
#
# Test the ota_delta() feature.
#

if {![info exists testdir]} {
  set testdir [file join [file dirname [info script]] .. .. test]
}
source $testdir/tester.tcl
set ::testprefix ota8

do_execsql_test 1.0 {
  CREATE TABLE t1(x, y PRIMARY KEY, z);
  INSERT INTO t1 VALUES(NULL, 1, 'one');
  INSERT INTO t1 VALUES(NULL, 2, 'two');
  INSERT INTO t1 VALUES(NULL, 3, 'three');
  CREATE INDEX i1z ON t1(z, x);
}

do_test 1.1 {
  forcedelete ota.db
  sqlite3 db2 ota.db
  db2 eval {
    CREATE TABLE data_t1(x, y, z, ota_control);
    INSERT INTO data_t1 VALUES('a',    1, '_i'      , 'x.d');
    INSERT INTO data_t1 VALUES('b',    2, 2         , '..x');
    INSERT INTO data_t1 VALUES('_iii', 3, '-III'    , 'd.d');
  }
  db2 close
} {}

do_test 1.2.1 {
  sqlite3ota ota test.db ota.db
  ota step
} {SQLITE_ERROR}
do_test 1.2.2 {
  list [catch {ota close} msg] $msg
} {1 {SQLITE_ERROR - no such function: ota_delta}}

proc ota_delta {orig new} {
 return "${orig}${new}"
}

do_test 1.3.1 {
  while 1 {
    sqlite3ota ota test.db ota.db
    ota create_ota_delta
    set rc [ota step]
    if {$rc != "SQLITE_OK"} break
    ota close
  }
  ota close
} {SQLITE_DONE}

do_execsql_test 1.3.2 {
  SELECT * FROM t1
} {
  a    1 one_i
  {}   2 2
  _iii 3 three-III
}
integrity_check 1.3.3


finish_test

      p->zErrmsg = sqlite3_mprintf("table %s has no PRIMARY KEY", pIter->zTbl);
      p->rc = SQLITE_ERROR;
    }
  }

  return p->rc;
}

/*
** This is a wrapper around "sqlite3_mprintf(zFmt, ...)". If an OOM occurs,
** an error code is stored in the OTA handle passed as the first argument.
*/
static char *otaMPrintfAndCollectError(sqlite3ota *p, const char *zFmt, ...){
  char *zSql = 0;
  va_list ap;
  va_start(ap, zFmt);
  if( p->rc==SQLITE_OK ){
    zSql = sqlite3_vmprintf(zFmt, ap);
    if( zSql==0 ) p->rc = SQLITE_NOMEM;
  }
  va_end(ap);
  return zSql;
}

/*
** This function constructs and returns a pointer to a nul-terminated 
** string containing some SQL clause or list based on one or more of the 
** column names currently stored in the pIter->azTblCol[] array.
**
** If an OOM error is encountered, NULL is returned and an error code

** stored in the (p->nCol+1)'th column. Set the error code and error message
** of the OTA handle to something reflecting this.
*/
static void otaBadControlError(sqlite3ota *p){
  p->rc = SQLITE_ERROR;
  p->zErrmsg = sqlite3_mprintf("Invalid ota_control value");
}


static char *otaObjIterGetSetlist(
  sqlite3ota *p,
  OtaObjIter *pIter,
  const char *zMask
){
  char *zList = 0;
  if( p->rc==SQLITE_OK ){
    int i;

    if( strlen(zMask)!=pIter->nTblCol ){
      otaBadControlError(p);
    }else{
      const char *zSep = "";
      for(i=0; i<pIter->nTblCol; i++){
        char c = zMask[i];
        if( c=='x' ){
          zList = otaMPrintfAndCollectError(p, "%z%s%s=?%d", 
              zList, zSep, pIter->azTblCol[i], i+1
          );

          zSep = ", ";

        }
        if( c=='d' ){
          zList = otaMPrintfAndCollectError(p, "%z%s%s=ota_delta(%s, ?%d)", 
              zList, zSep, pIter->azTblCol[i], pIter->azTblCol[i], i+1
          );
          zSep = ", ";
        }
      }
    }
  }
  return zList;
}

    }

    otaFreeState(pState);
  }

  return p;
}

/*
** Return the database handle used by pOta.
*/
sqlite3 *sqlite3ota_db(sqlite3ota *pOta){
  return (pOta ? pOta->db : 0);
}

/*
** Close the OTA handle.
*/
int sqlite3ota_close(sqlite3ota *p, char **pzErrmsg){
  int rc;
  if( p ){

#ifdef SQLITE_TEST 

#include <tcl.h>

/* From main.c (apparently...) */
extern const char *sqlite3ErrName(int);

void test_ota_delta(sqlite3_context *pCtx, int nArg, sqlite3_value **apVal){
  Tcl_Interp *interp = (Tcl_Interp*)sqlite3_user_data(pCtx);
  Tcl_Obj *pScript;
  int i;

  pScript = Tcl_NewObj();
  Tcl_IncrRefCount(pScript);
  Tcl_ListObjAppendElement(0, pScript, Tcl_NewStringObj("ota_delta", -1));
  for(i=0; i<nArg; i++){
    sqlite3_value *pIn = apVal[i];
    const char *z = (const char*)sqlite3_value_text(pIn);
    Tcl_ListObjAppendElement(0, pScript, Tcl_NewStringObj(z, -1));
  }

  if( TCL_OK==Tcl_EvalObjEx(interp, pScript, TCL_GLOBAL_ONLY) ){
    const char *z = Tcl_GetStringResult(interp);
    sqlite3_result_text(pCtx, z, -1, SQLITE_TRANSIENT);
  }else{
    Tcl_BackgroundError(interp);
  }

  Tcl_DecrRefCount(pScript);
}


static int test_sqlite3ota_cmd(
  ClientData clientData,
  Tcl_Interp *interp,
  int objc,
  Tcl_Obj *CONST objv[]
){
  int ret = TCL_OK;
  sqlite3ota *pOta = (sqlite3ota*)clientData;
  const char *azMethod[] = { "step", "close", "create_ota_delta", 0 };
  int iMethod;

  if( objc!=2 ){
    Tcl_WrongNumArgs(interp, 1, objv, "METHOD");
    return TCL_ERROR;
  }
  if( Tcl_GetIndexFromObj(interp, objv[1], azMethod, "method", 0, &iMethod) ){

          Tcl_AppendResult(interp, " - ", zErrmsg, 0);
          sqlite3_free(zErrmsg);
        }
        ret = TCL_ERROR;
      }
      break;
    }

    case 2: /* create_ota_delta */ {
      sqlite3 *db = sqlite3ota_db(pOta);
      int rc = sqlite3_create_function(
          db, "ota_delta", -1, SQLITE_UTF8, (void*)interp, test_ota_delta, 0, 0
      );
      Tcl_SetObjResult(interp, Tcl_NewStringObj(sqlite3ErrName(rc), -1));
      ret = (rc==SQLITE_OK ? TCL_OK : TCL_ERROR);
      break;
    }

    default: /* seems unlikely */
      assert( !"cannot happen" );
      break;
  }

  return ret;

**
**   UPDATE t1 SET c = 'usa' WHERE a = 4;
**
** is represented by the data_t1 row created by:
**
**   INSERT INTO data_t1(a, b, c, ota_control) VALUES(4, NULL, 'usa', '..x');
**
** Instead of an 'x' character, characters of the ota_control value specified
** for UPDATEs may also be set to 'd'. In this case, instead of updating the
** target table with the value stored in the corresponding data_% column, the
** user-defined SQL function "ota_delta()" is invoked and the result stored in
** the target table column. ota_delta() is invoked with two arguments - the
** original value currently stored in the target table column and the 
** value specified in the data_xxx table.
**
** For example, this row:
**
**   INSERT INTO data_t1(a, b, c, ota_control) VALUES(4, NULL, 'usa', '..d');
**
** is similar to an UPDATE statement such as: 
**
**   UPDATE t1 SET c = ota_delta(c, 'usa') WHERE a = 4;
**
** USAGE
**
** The API declared below allows an application to apply an OTA update 
** stored on disk to an existing target database. Essentially, the 
** application:
**

**
** Argument zTarget is the path to the target database. Argument zOta is
** the path to the OTA database. Each call to this function must be matched
** by a call to sqlite3ota_close().
*/
sqlite3ota *sqlite3ota_open(const char *zTarget, const char *zOta);

/*
** Obtain the underlying database handle used by the OTA extension.
**
** The only argument passed to this function must be a valid, open, OTA
** handle. This function returns the database handle used by OTA for all
** operations on the target and source databases. This may be useful in 
** two scenarios:
**
**   * If the data_xxx tables in the OTA source database are virtual 
**     tables, or if any of the tables being updated are virtual tables,
**     the application may need to call sqlite3_create_module() on
**     the db handle to register the required virtual table implementations.
**
**   * If the application uses the "ota_delta()" feature described above,
**     it must use sqlite3_create_function() or similar to register the
**     ota_delta() implementation with OTA.
*/
sqlite3 *sqlite3ota_db(sqlite3ota*);

/*
** Do some work towards applying the OTA update to the target db. 
**
** Return SQLITE_DONE if the update has been completely applied, or 
** SQLITE_OK if no error occurs but there remains work to do to apply
** the OTA update. If an error does occur, some other error code is 
** returned.