SQLite

	$(LTLINK) -o $@ $(TOP)/tool/sqldiff.c sqlite3.lo $(TLIBS)

dbhash$(TEXE):	$(TOP)/tool/dbhash.c sqlite3.lo sqlite3.h
	$(LTLINK) -o $@ $(TOP)/tool/dbhash.c sqlite3.lo $(TLIBS)

RSYNC_SRC = \
  $(TOP)/tool/sqlite3-rsync.c \

  sqlite3.c

RSYNC_OPT = \
  -DSQLITE_ENABLE_DBPAGE_VTAB \
  -USQLITE_THREADSAFE \
  -DSQLITE_THREADSAFE=0 \
  -DSQLITE_OMIT_LOAD_EXTENSION \

	$(LTLINK) $(NO_WARN) -I$(TOP)\ext\consio $(TOP)\tool\sqldiff.c $(TOP)\ext\consio\console_io.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS) $(LIBRESOBJS)

dbhash.exe:	$(TOP)\tool\dbhash.c $(SQLITE3C) $(SQLITE3H)
	$(LTLINK) $(NO_WARN) $(TOP)\tool\dbhash.c $(SQLITE3C) /link $(LDFLAGS) $(LTLINKOPTS)

RSYNC_SRC = \
  $(TOP)\tool\sqlite3-rsync.c \

  $(SQLITE3C)

RSYNC_OPT = \
  -DSQLITE_ENABLE_DBPAGE_VTAB \
  -DSQLITE_THREADSAFE=0 \
  -DSQLITE_OMIT_LOAD_EXTENSION \
  -DSQLITE_OMIT_DEPRECATED

dbhash$(EXE):	$(TOP)/tool/dbhash.c sqlite3.c sqlite3.h
	$(TCCX) -o dbhash$(EXE) -DSQLITE_THREADSAFE=0 \
		$(TOP)/tool/dbhash.c sqlite3.c $(TLIBS) $(THREADLIB)

RSYNC_SRC = \
  $(TOP)/tool/sqlite3-rsync.c \

  sqlite3.c

RSYNC_OPT = \
  -DSQLITE_ENABLE_DBPAGE_VTAB \
  -DSQLITE_THREADSAFE=0 \
  -DSQLITE_OMIT_LOAD_EXTENSION \
  -DSQLITE_OMIT_DEPRECATED

  }
  return 0;
}
/*****************************************************************************
** End of the append_escaped_arg() routine, adapted from the Fossil         **
*****************************************************************************/

/*****************************************************************************
** The Hash Engine
**
** This is basically SHA3, though with a 160-bit hash, and reducing the
** number of rounds in the KeccakF1600 step function from 24 to 6.
*/
/*
** Macros to determine whether the machine is big or little endian,
** and whether or not that determination is run-time or compile-time.
**
** For best performance, an attempt is made to guess at the byte-order
** using C-preprocessor macros.  If that is unsuccessful, or if
** -DHash_BYTEORDER=0 is set, then byte-order is determined
** at run-time.
*/
#ifndef Hash_BYTEORDER
# if defined(i386)     || defined(__i386__)   || defined(_M_IX86) ||    \
     defined(__x86_64) || defined(__x86_64__) || defined(_M_X64)  ||    \
     defined(_M_AMD64) || defined(_M_ARM)     || defined(__x86)   ||    \
     defined(__arm__)
#   define Hash_BYTEORDER    1234
# elif defined(sparc)    || defined(__ppc__)
#   define Hash_BYTEORDER    4321
# else
#   define Hash_BYTEORDER 0
# endif
#endif

typedef sqlite3_uint64 u64;

/*
** State structure for a Hash hash in progress
*/
typedef struct HashContext HashContext;
struct HashContext {
  union {
    u64 s[25];                /* Keccak state. 5x5 lines of 64 bits each */
    unsigned char x[1600];    /* ... or 1600 bytes */
  } u;
  unsigned nRate;        /* Bytes of input accepted per Keccak iteration */
  unsigned nLoaded;      /* Input bytes loaded into u.x[] so far this cycle */
  unsigned ixMask;       /* Insert next input into u.x[nLoaded^ixMask]. */
  unsigned iSize;        /* 224, 256, 358, or 512 */
};

/*
** A single step of the Keccak mixing function for a 1600-bit state
*/
static void KeccakF1600Step(HashContext *p){
  int i;
  u64 b0, b1, b2, b3, b4;
  u64 c0, c1, c2, c3, c4;
  u64 d0, d1, d2, d3, d4;
  static const u64 RC[] = {
    0x0000000000000001ULL,  0x0000000000008082ULL,
    0x800000000000808aULL,  0x8000000080008000ULL,
    0x000000000000808bULL,  0x0000000080000001ULL,
    0x8000000080008081ULL,  0x8000000000008009ULL,
    0x000000000000008aULL,  0x0000000000000088ULL,
    0x0000000080008009ULL,  0x000000008000000aULL,
    0x000000008000808bULL,  0x800000000000008bULL,
    0x8000000000008089ULL,  0x8000000000008003ULL,
    0x8000000000008002ULL,  0x8000000000000080ULL,
    0x000000000000800aULL,  0x800000008000000aULL,
    0x8000000080008081ULL,  0x8000000000008080ULL,
    0x0000000080000001ULL,  0x8000000080008008ULL
  };
# define a00 (p->u.s[0])
# define a01 (p->u.s[1])
# define a02 (p->u.s[2])
# define a03 (p->u.s[3])
# define a04 (p->u.s[4])
# define a10 (p->u.s[5])
# define a11 (p->u.s[6])
# define a12 (p->u.s[7])
# define a13 (p->u.s[8])
# define a14 (p->u.s[9])
# define a20 (p->u.s[10])
# define a21 (p->u.s[11])
# define a22 (p->u.s[12])
# define a23 (p->u.s[13])
# define a24 (p->u.s[14])
# define a30 (p->u.s[15])
# define a31 (p->u.s[16])
# define a32 (p->u.s[17])
# define a33 (p->u.s[18])
# define a34 (p->u.s[19])
# define a40 (p->u.s[20])
# define a41 (p->u.s[21])
# define a42 (p->u.s[22])
# define a43 (p->u.s[23])
# define a44 (p->u.s[24])
# define ROL64(a,x) ((a<<x)|(a>>(64-x)))

  /*         v---- Number of rounds.  SHA3 has 24 here. */
  for(i=0; i<6; i+=4){
    c0 = a00^a10^a20^a30^a40;
    c1 = a01^a11^a21^a31^a41;
    c2 = a02^a12^a22^a32^a42;
    c3 = a03^a13^a23^a33^a43;
    c4 = a04^a14^a24^a34^a44;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a11^d1), 44);
    b2 = ROL64((a22^d2), 43);
    b3 = ROL64((a33^d3), 21);
    b4 = ROL64((a44^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i];
    a11 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a20^d0), 3);
    b3 = ROL64((a31^d1), 45);
    b4 = ROL64((a42^d2), 61);
    b0 = ROL64((a03^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a20 =   b0 ^((~b1)&  b2 );
    a31 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a40^d0), 18);
    b0 = ROL64((a01^d1), 1);
    b1 = ROL64((a12^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a34^d4), 8);
    a40 =   b0 ^((~b1)&  b2 );
    a01 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a10^d0), 36);
    b2 = ROL64((a21^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a43^d3), 56);
    b0 = ROL64((a04^d4), 27);
    a10 =   b0 ^((~b1)&  b2 );
    a21 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a30^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a02^d2), 62);
    b1 = ROL64((a13^d3), 55);
    b2 = ROL64((a24^d4), 39);
    a30 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    c0 = a00^a20^a40^a10^a30;
    c1 = a11^a31^a01^a21^a41;
    c2 = a22^a42^a12^a32^a02;
    c3 = a33^a03^a23^a43^a13;
    c4 = a44^a14^a34^a04^a24;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a31^d1), 44);
    b2 = ROL64((a12^d2), 43);
    b3 = ROL64((a43^d3), 21);
    b4 = ROL64((a24^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i+1];
    a31 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a40^d0), 3);
    b3 = ROL64((a21^d1), 45);
    b4 = ROL64((a02^d2), 61);
    b0 = ROL64((a33^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a40 =   b0 ^((~b1)&  b2 );
    a21 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a30^d0), 18);
    b0 = ROL64((a11^d1), 1);
    b1 = ROL64((a42^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a04^d4), 8);
    a30 =   b0 ^((~b1)&  b2 );
    a11 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a20^d0), 36);
    b2 = ROL64((a01^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a13^d3), 56);
    b0 = ROL64((a44^d4), 27);
    a20 =   b0 ^((~b1)&  b2 );
    a01 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a10^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a22^d2), 62);
    b1 = ROL64((a03^d3), 55);
    b2 = ROL64((a34^d4), 39);
    a10 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    c0 = a00^a40^a30^a20^a10;
    c1 = a31^a21^a11^a01^a41;
    c2 = a12^a02^a42^a32^a22;
    c3 = a43^a33^a23^a13^a03;
    c4 = a24^a14^a04^a44^a34;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a21^d1), 44);
    b2 = ROL64((a42^d2), 43);
    b3 = ROL64((a13^d3), 21);
    b4 = ROL64((a34^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i+2];
    a21 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a30^d0), 3);
    b3 = ROL64((a01^d1), 45);
    b4 = ROL64((a22^d2), 61);
    b0 = ROL64((a43^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a30 =   b0 ^((~b1)&  b2 );
    a01 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a10^d0), 18);
    b0 = ROL64((a31^d1), 1);
    b1 = ROL64((a02^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a44^d4), 8);
    a10 =   b0 ^((~b1)&  b2 );
    a31 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a40^d0), 36);
    b2 = ROL64((a11^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a03^d3), 56);
    b0 = ROL64((a24^d4), 27);
    a40 =   b0 ^((~b1)&  b2 );
    a11 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a20^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a12^d2), 62);
    b1 = ROL64((a33^d3), 55);
    b2 = ROL64((a04^d4), 39);
    a20 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    c0 = a00^a30^a10^a40^a20;
    c1 = a21^a01^a31^a11^a41;
    c2 = a42^a22^a02^a32^a12;
    c3 = a13^a43^a23^a03^a33;
    c4 = a34^a14^a44^a24^a04;
    d0 = c4^ROL64(c1, 1);
    d1 = c0^ROL64(c2, 1);
    d2 = c1^ROL64(c3, 1);
    d3 = c2^ROL64(c4, 1);
    d4 = c3^ROL64(c0, 1);

    b0 = (a00^d0);
    b1 = ROL64((a01^d1), 44);
    b2 = ROL64((a02^d2), 43);
    b3 = ROL64((a03^d3), 21);
    b4 = ROL64((a04^d4), 14);
    a00 =   b0 ^((~b1)&  b2 );
    a00 ^= RC[i+3];
    a01 =   b1 ^((~b2)&  b3 );
    a02 =   b2 ^((~b3)&  b4 );
    a03 =   b3 ^((~b4)&  b0 );
    a04 =   b4 ^((~b0)&  b1 );

    b2 = ROL64((a10^d0), 3);
    b3 = ROL64((a11^d1), 45);
    b4 = ROL64((a12^d2), 61);
    b0 = ROL64((a13^d3), 28);
    b1 = ROL64((a14^d4), 20);
    a10 =   b0 ^((~b1)&  b2 );
    a11 =   b1 ^((~b2)&  b3 );
    a12 =   b2 ^((~b3)&  b4 );
    a13 =   b3 ^((~b4)&  b0 );
    a14 =   b4 ^((~b0)&  b1 );

    b4 = ROL64((a20^d0), 18);
    b0 = ROL64((a21^d1), 1);
    b1 = ROL64((a22^d2), 6);
    b2 = ROL64((a23^d3), 25);
    b3 = ROL64((a24^d4), 8);
    a20 =   b0 ^((~b1)&  b2 );
    a21 =   b1 ^((~b2)&  b3 );
    a22 =   b2 ^((~b3)&  b4 );
    a23 =   b3 ^((~b4)&  b0 );
    a24 =   b4 ^((~b0)&  b1 );

    b1 = ROL64((a30^d0), 36);
    b2 = ROL64((a31^d1), 10);
    b3 = ROL64((a32^d2), 15);
    b4 = ROL64((a33^d3), 56);
    b0 = ROL64((a34^d4), 27);
    a30 =   b0 ^((~b1)&  b2 );
    a31 =   b1 ^((~b2)&  b3 );
    a32 =   b2 ^((~b3)&  b4 );
    a33 =   b3 ^((~b4)&  b0 );
    a34 =   b4 ^((~b0)&  b1 );

    b3 = ROL64((a40^d0), 41);
    b4 = ROL64((a41^d1), 2);
    b0 = ROL64((a42^d2), 62);
    b1 = ROL64((a43^d3), 55);
    b2 = ROL64((a44^d4), 39);
    a40 =   b0 ^((~b1)&  b2 );
    a41 =   b1 ^((~b2)&  b3 );
    a42 =   b2 ^((~b3)&  b4 );
    a43 =   b3 ^((~b4)&  b0 );
    a44 =   b4 ^((~b0)&  b1 );
  }
}

/*
** Initialize a new hash.  iSize determines the size of the hash
** in bits and should be one of 224, 256, 384, or 512.  Or iSize
** can be zero to use the default hash size of 256 bits.
*/
static void HashInit(HashContext *p, int iSize){
  memset(p, 0, sizeof(*p));
  p->iSize = iSize;
  if( iSize>=128 && iSize<=512 ){
    p->nRate = (1600 - ((iSize + 31)&~31)*2)/8;
  }else{
    p->nRate = (1600 - 2*256)/8;
  }
#if Hash_BYTEORDER==1234
  /* Known to be little-endian at compile-time. No-op */
#elif Hash_BYTEORDER==4321
  p->ixMask = 7;  /* Big-endian */
#else
  {
    static unsigned int one = 1;
    if( 1==*(unsigned char*)&one ){
      /* Little endian.  No byte swapping. */
      p->ixMask = 0;
    }else{
      /* Big endian.  Byte swap. */
      p->ixMask = 7;
    }
  }
#endif
}

/*
** Make consecutive calls to the HashUpdate function to add new content
** to the hash
*/
static void HashUpdate(
  HashContext *p,
  const unsigned char *aData,
  unsigned int nData
){
  unsigned int i = 0;
  if( aData==0 ) return;
#if Hash_BYTEORDER==1234
  if( (p->nLoaded % 8)==0 && ((aData - (const unsigned char*)0)&7)==0 ){
    for(; i+7<nData; i+=8){
      p->u.s[p->nLoaded/8] ^= *(u64*)&aData[i];
      p->nLoaded += 8;
      if( p->nLoaded>=p->nRate ){
        KeccakF1600Step(p);
        p->nLoaded = 0;
      }
    }
  }
#endif
  for(; i<nData; i++){
#if Hash_BYTEORDER==1234
    p->u.x[p->nLoaded] ^= aData[i];
#elif Hash_BYTEORDER==4321
    p->u.x[p->nLoaded^0x07] ^= aData[i];
#else
    p->u.x[p->nLoaded^p->ixMask] ^= aData[i];
#endif
    p->nLoaded++;
    if( p->nLoaded==p->nRate ){
      KeccakF1600Step(p);
      p->nLoaded = 0;
    }
  }
}

/*
** After all content has been added, invoke HashFinal() to compute
** the final hash.  The function returns a pointer to the binary
** hash value.
*/
static unsigned char *HashFinal(HashContext *p){
  unsigned int i;
  if( p->nLoaded==p->nRate-1 ){
    const unsigned char c1 = 0x86;
    HashUpdate(p, &c1, 1);
  }else{
    const unsigned char c2 = 0x06;
    const unsigned char c3 = 0x80;
    HashUpdate(p, &c2, 1);
    p->nLoaded = p->nRate - 1;
    HashUpdate(p, &c3, 1);
  }
  for(i=0; i<p->nRate; i++){
    p->u.x[i+p->nRate] = p->u.x[i^p->ixMask];
  }
  return &p->u.x[p->nRate];
}

/*
** Implementation of the hash(X) function.
**
** Return a 160-bit BLOB which is the hash of X.
*/
static void hashFunc(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  HashContext cx;
  int eType = sqlite3_value_type(argv[0]);
  int nByte = sqlite3_value_bytes(argv[0]);
  if( eType==SQLITE_NULL ) return;
  HashInit(&cx, 160);
  if( eType==SQLITE_BLOB ){
    HashUpdate(&cx, sqlite3_value_blob(argv[0]), nByte);
  }else{
    HashUpdate(&cx, sqlite3_value_text(argv[0]), nByte);
  }
  sqlite3_result_blob(context, HashFinal(&cx), 160/8, SQLITE_TRANSIENT);
}

/* Register the hash function */
static int hashRegister(sqlite3 *db){
   return sqlite3_create_function(db, "hash", 1,
                SQLITE_UTF8 | SQLITE_INNOCUOUS | SQLITE_DETERMINISTIC,
                0, hashFunc, 0, 0);
}

/* End of the hashing logic
*****************************************************************************/

/*
** Return the tail of a file pathname.  The tail is the last component
** of the path.  For example, the tail of "/a/b/c.d" is "c.d".
*/
const char *file_tail(const char *z){
  const char *zTail = z;
  if( !zTail ) return 0;

    rc = sqlite3_open_v2(p->zOrigin, &p->db, SQLITE_OPEN_READWRITE, 0);
    if( rc ){
      reportError(p, "unable to open origin database file \"%s\": %s",
                  sqlite3_errmsg(p->db));
      closeDb(p);
      return;
    }
    hashRegister(p->db);
    runSql(p, "BEGIN");
    runSqlReturnText(p, buf, "PRAGMA journal_mode");
    if( sqlite3_stricmp(buf,"wal")!=0 ){
      reportError(p, "Origin database is not in WAL mode");
    }
    runSqlReturnUInt(p, &nPage, "PRAGMA page_count");
    runSqlReturnUInt(p, &szPg, "PRAGMA page_size");

        break;
      }
      case REPLICA_HASH: {
        if( pCkHash==0 ){
          runSql(p, "CREATE TEMP TABLE badHash(pgno INTEGER PRIMARY KEY)");
          pCkHash = prepareStmt(p,
            "INSERT INTO badHash SELECT pgno FROM sqlite_dbpage('main')"
            " WHERE pgno=?1 AND hash(data)!=?2"
          );
          if( pCkHash==0 ) break;
        }
        p->nHashSent++;
        iPage++;
        sqlite3_bind_int64(pCkHash, 1, iPage);
        readBytes(p, 20, buf);

        rc = sqlite3_open(p->zReplica, &p->db);
        if( rc ){
          reportError(p, "cannot open replica database \"%s\": %s",
                      p->zReplica, sqlite3_errmsg(p->db));
          closeDb(p);
          break;
        }
        hashRegister(p->db);
        if( runSqlReturnUInt(p, &nRPage, "PRAGMA page_count") ){
          break;
        }
        if( nRPage==0 ){
          runSql(p, "PRAGMA page_size=%u", szOPage);
          runSql(p, "PRAGMA journal_mode=WAL");
          runSql(p, "SELECT * FROM sqlite_schema");

        if( szRPage!=szOPage ){
          reportError(p, "page size mismatch; origin is %d bytes and "
                         "replica is %d bytes", szOPage, szRPage);
          break;
        }

        pStmt = prepareStmt(p,
                   "SELECT hash(data) FROM sqlite_dbpage"
                   " WHERE pgno<=min(%d,%d)"
                   " ORDER BY pgno", nRPage, nOPage);
        while( sqlite3_step(pStmt)==SQLITE_ROW && p->nErr==0 ){
          const unsigned char *a = sqlite3_column_blob(pStmt, 0);
          writeByte(p, REPLICA_HASH);
          writeBytes(p, 20, a);
          p->nHashSent++;