SQLite

#  define VVA(X) X
#endif

/* Objects */
typedef struct JsonString JsonString;
typedef struct JsonNode JsonNode;
typedef struct JsonParse JsonParse;
typedef struct JsonCleanup JsonCleanup;

/* An instance of this object represents a JSON string
** under construction.  Really, this is a generic string accumulator
** that can be and is used to create strings other than JSON.
*/
struct JsonString {
  sqlite3_context *pCtx;   /* Function context - put error messages here */
  char *zBuf;              /* Append JSON content here */
  u64 nAlloc;              /* Bytes of storage available in zBuf[] */
  u64 nUsed;               /* Bytes of zBuf[] currently used */
  u8 bStatic;              /* True if zBuf is static space */
  u8 bErr;                 /* True if an error has been encountered */
  char zSpace[100];        /* Initial static space */
};

/* A deferred cleanup task.  A list of JsonCleanup objects might be
** run when the JsonParse object is destroyed.
*/
struct JsonCleanup {
  JsonCleanup *pJCNext;    /* Next in a list */
  void (*xOp)(void*);      /* Routine to run */
  void *pArg;              /* Argument to xOp() */
};

/* JSON type values
*/
#define JSON_SUBST    0    /* Special edit node.  Uses u.iPrev */
#define JSON_NULL     1
#define JSON_TRUE     2
#define JSON_FALSE    3
#define JSON_INT      4
#define JSON_REAL     5
#define JSON_STRING   6
#define JSON_ARRAY    7
#define JSON_OBJECT   8

/* The "subtype" set for JSON values */
#define JSON_SUBTYPE  74    /* Ascii for "J" */

/*
** Names of the various JSON types:
*/
static const char * const jsonType[] = {
  "subst",
  "null", "true", "false", "integer", "real", "text", "array", "object"
};

/* Bit values for the JsonNode.jnFlag field
*/
#define JNODE_RAW     0x01  /* Content is raw, not JSON encoded */
#define JNODE_ESCAPE  0x02  /* Content is text with \ escapes */
#define JNODE_REMOVE  0x04  /* Do not output */
#define JNODE_REPLACE 0x08  /* Target of a JSON_SUBST node */

#define JNODE_APPEND  0x10  /* More ARRAY/OBJECT entries at u.iAppend */
#define JNODE_LABEL   0x20  /* Is a label of an object */
#define JNODE_JSON5   0x40  /* Node contains JSON5 enhancements */


/* A single node of parsed JSON.  An array of these nodes describes
** a parse of JSON + edits.
**
** Use the json_parse() SQL function (available when compiled with
** -DSQLITE_DEBUG) to see a dump of complete JsonParse objects, including
** a complete listing and decoding of the array of JsonNodes.
*/
struct JsonNode {
  u8 eType;              /* One of the JSON_ type values */
  u8 jnFlags;            /* JNODE flags */
  u8 eU;                 /* Which union element to use */
  u32 n;                 /* Bytes of content for INT, REAL or STRING
                         ** Number of sub-nodes for ARRAY and OBJECT
                         ** Node that SUBST applies to */
  union {
    const char *zJContent; /* 1: Content for INT, REAL, and STRING */
    u32 iAppend;           /* 2: More terms for ARRAY and OBJECT */
    u32 iKey;              /* 3: Key for ARRAY objects in json_tree() */
    u32 iPrev;             /* 4: Previous SUBST node, or 0 */

  } u;
};


/* A parsed and possibly edited JSON string.  Lifecycle:
**
**   1.  JSON comes in and is parsed into an array aNode[].  The original
**       JSON text is stored in zJson.  This object may or may not be the
**       owner of the input JSON - the bOwnsJson variables determines which.
**
**   2.  Zero or more changes are made (via json_remove() or json_replace()
**       or similar) to the aNode[] array.
**
**   3.  A new, edited and mimified JSON string is generated from aNode
**       and stored in zAlt.  The JsonParse object always owns zAlt.
**
** Step 1 always happens.  Step 2 and 3 may or may not happen, depending
** on the operation.
**
** aNode[].u.zJContent entries typically point into zJson.  Hence zJson
** must remain valid for the lifespan of the parse.  For edits,
** aNode[].u.zJContent might point to malloced space other than zJson.
** Entries in pClup are responsible for freeing that extra malloced space.
**
** When walking the parse tree in aNode[], edits are ignored if useMod is
** false.
*/
struct JsonParse {
  u32 nNode;         /* Number of slots of aNode[] used */
  u32 nAlloc;        /* Number of slots of aNode[] allocated */
  JsonNode *aNode;   /* Array of nodes containing the parse */
  char *zJson;       /* Original JSON string (before edits) */
  char *zAlt;        /* Revised and/or mimified JSON */
  u32 *aUp;          /* Index of parent of each node */
  JsonCleanup *pClup;/* Cleanup operations prior to freeing this object */
  u16 iDepth;        /* Nesting depth */
  u8 nErr;           /* Number of errors seen */
  u8 oom;            /* Set to true if out of memory */
  u8 hasNonstd;      /* True if input uses non-standard features like JSON5 */
  u8 bOwnsJson;      /* This object owns zJson and response for freeing it */
  u8 useMod;         /* Actually use the edits contain inside aNode */
  u8 hasMod;         /* aNode contains edits from the original zJson */
  u32 nJPRef;        /* Number of references to this object */
  int nJson;         /* Length of the zJson string in bytes */
  int nAlt;          /* Length of alternative JSON string zAlt, in bytes */
  u32 iErr;          /* Error location in zJson[] */
  u32 iSubst;        /* Last JSON_SUBST entry in aNode[] */
  u32 iHold;         /* Age of this entry in the cache for LRU replacement */
};

/*
** Maximum nesting depth of JSON for this implementation.
**
** This limit is needed to avoid a stack overflow in the recursive
** descent parser.  A depth of 1000 is far deeper than any sane JSON

*/
static void jsonInit(JsonString *p, sqlite3_context *pCtx){
  p->pCtx = pCtx;
  p->bErr = 0;
  jsonZero(p);
}


/* Free all allocated memory and reset the JsonString object back to its
** initial state.
*/
static void jsonReset(JsonString *p){
  if( !p->bStatic ) sqlite3RCStrUnref(p->zBuf);
  jsonZero(p);
}


/* Report an out-of-memory (OOM) condition
*/
static void jsonOom(JsonString *p){
  p->bErr = 1;
  sqlite3_result_error_nomem(p->pCtx);
  jsonReset(p);
}

/* Enlarge pJson->zBuf so that it can hold at least N more bytes.
** Return zero on success.  Return non-zero on an OOM error
*/
static int jsonGrow(JsonString *p, u32 N){
  u64 nTotal = N<p->nAlloc ? p->nAlloc*2 : p->nAlloc+N+10;
  char *zNew;
  if( p->bStatic ){
    if( p->bErr ) return 1;
    zNew = sqlite3RCStrNew(nTotal);
    if( zNew==0 ){
      jsonOom(p);
      return SQLITE_NOMEM;
    }
    memcpy(zNew, p->zBuf, (size_t)p->nUsed);
    p->zBuf = zNew;
    p->bStatic = 0;
  }else{
    p->zBuf = sqlite3RCStrResize(p->zBuf, nTotal);
    if( p->zBuf==0 ){
      p->bErr = 1;
      jsonZero(p);
      return SQLITE_NOMEM;
    }

  }
  p->nAlloc = nTotal;
  return SQLITE_OK;
}

/* Append N bytes from zIn onto the end of the JsonString string.
*/

static void jsonAppendChar(JsonString *p, char c){
  if( p->nUsed>=p->nAlloc ){
    jsonAppendCharExpand(p,c);
  }else{
    p->zBuf[p->nUsed++] = c;
  }
}

/* Try to force the string to be a zero-terminated RCStr string.
**
** Return true on success.  Return false if an OOM prevents this
** from happening.
*/
static int jsonForceRCStr(JsonString *p){
  jsonAppendChar(p, 0);
  if( p->bErr ) return 0;
  p->nUsed--;
  if( p->bStatic==0 ) return 1;
  p->nAlloc = 0;
  p->nUsed++;
  jsonGrow(p, p->nUsed);
  p->nUsed--;
  return p->bStatic==0;
}


/* Append a comma separator to the output buffer, if the previous
** character is not '[' or '{'.
*/
static void jsonAppendSeparator(JsonString *p){
  char c;
  if( p->nUsed==0 ) return;

  N -= 2;
  while( N>0 ){
    for(i=0; i<N && zIn[i]!='\\'; i++){}
    if( i>0 ){
      jsonAppendRawNZ(p, zIn, i);
      zIn += i;
      N -= i;
      if( N==0 ) break;
    }
    assert( zIn[0]=='\\' );
    switch( (u8)zIn[1] ){
      case '\'':
        jsonAppendChar(p, '\'');
        break;
      case 'v':

    jsonAppendRawNZ(p, zIn, N);
  }
}



/*
** Append a function parameter value to the JSON string under
** construction.
*/
static void jsonAppendValue(
  JsonString *p,                 /* Append to this JSON string */
  sqlite3_value *pValue          /* Value to append */
){
  switch( sqlite3_value_type(pValue) ){

      break;
    }
  }
}


/* Make the JSON in p the result of the SQL function.
**
** The JSON string is reset.
*/
static void jsonResult(JsonString *p){
  if( p->bErr==0 && jsonForceRCStr(p) ){

    sqlite3RCStrRef(p->zBuf);
    sqlite3_result_text64(p->pCtx, p->zBuf, p->nUsed,
                          (void(*)(void*))sqlite3RCStrUnref,
                          SQLITE_UTF8);

  }else if( p->bErr==1 ){
    sqlite3_result_error_nomem(p->pCtx);
  }
  jsonReset(p);
}

/**************************************************************************
** Utility routines for dealing with JsonNode and JsonParse objects
**************************************************************************/

/*

}

/*
** Reclaim all memory allocated by a JsonParse object.  But do not
** delete the JsonParse object itself.
*/
static void jsonParseReset(JsonParse *pParse){
  while( pParse->pClup ){
    JsonCleanup *pTask = pParse->pClup;
    pParse->pClup = pTask->pJCNext;
    pTask->xOp(pTask->pArg);
    sqlite3_free(pTask);
  }
  assert( pParse->nJPRef<=1 );
  if( pParse->aNode ){
    sqlite3_free(pParse->aNode);
    pParse->aNode = 0;
  }
  pParse->nNode = 0;
  pParse->nAlloc = 0;
  if( pParse->aUp ){
    sqlite3_free(pParse->aUp);
    pParse->aUp = 0;
  }
  if( pParse->zAlt ){
    sqlite3RCStrUnref(pParse->zAlt);
    pParse->zAlt = 0;
  }
  if( pParse->bOwnsJson ){
    pParse->bOwnsJson = 0;
    sqlite3RCStrUnref(pParse->zJson);
    pParse->zJson = 0;
  }
}

/*
** Free a JsonParse object that was obtained from sqlite3_malloc().
**
** Note that destroying JsonParse might call sqlite3RCStrUnref() to
** destroy the zJson value.  The RCStr object might recursively invoke
** JsonParse to destroy this pParse object again.  Take care to ensure
** that this recursive destructor sequence terminates harmlessly.
*/
static void jsonParseFree(JsonParse *pParse){
  if( pParse->nJPRef>1 ){
    pParse->nJPRef--;
  }else{
    jsonParseReset(pParse);
    sqlite3_free(pParse);
  }
}

/*
** Add a cleanup task to the JsonParse object.
**
** If an OOM occurs, the cleanup operation happens immediately
** and this function returns SQLITE_NOMEM.
*/
static int jsonParseAddCleanup(
  JsonParse *pParse,          /* Add the cleanup task to this parser */
  void(*xOp)(void*),          /* The cleanup task */
  void *pArg                  /* Argument to the cleanup */
){
  JsonCleanup *pTask = sqlite3_malloc64( sizeof(*pTask) );
  if( pTask==0 ){
    pParse->oom = 1;
    xOp(pArg);
    return SQLITE_ERROR;
  }
  pTask->pJCNext = pParse->pClup;
  pParse->pClup = pTask;
  pTask->xOp = xOp;
  pTask->pArg = pArg;
  return SQLITE_OK;
}

/*
** Convert the JsonNode pNode into a pure JSON string and
** append to pOut.  Subsubstructure is also included.  Return
** the number of JsonNode objects that are encoded.
*/
static void jsonRenderNode(
  JsonParse *pParse,             /* the complete parse of the JSON */
  JsonNode *pNode,               /* The node to render */
  JsonString *pOut               /* Write JSON here */

){
  assert( pNode!=0 );

  while( (pNode->jnFlags & JNODE_REPLACE)!=0 && pParse->useMod ){
    u32 idx = (u32)(pNode - pParse->aNode);
    u32 i = pParse->iSubst;
    while( 1 /*exit-by-break*/ ){
      assert( i<pParse->nNode );
      assert( pParse->aNode[i].eType==JSON_SUBST );
      assert( pParse->aNode[i].eU==4 );
      assert( pParse->aNode[i].u.iPrev<i );
      if( pParse->aNode[i].n==idx ){
        pNode = &pParse->aNode[i+1];
        break;
      }
      i = pParse->aNode[i].u.iPrev;

    }
  }
  switch( pNode->eType ){
    default: {
      assert( pNode->eType==JSON_NULL );
      jsonAppendRawNZ(pOut, "null", 4);
      break;
    }

      break;
    }
    case JSON_ARRAY: {
      u32 j = 1;
      jsonAppendChar(pOut, '[');
      for(;;){
        while( j<=pNode->n ){
          if( (pNode[j].jnFlags & JNODE_REMOVE)==0 || pParse->useMod==0 ){
            jsonAppendSeparator(pOut);
            jsonRenderNode(pParse, &pNode[j], pOut);
          }
          j += jsonNodeSize(&pNode[j]);
        }
        if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;
        if( pParse->useMod==0 ) break;
        assert( pNode->eU==2 );
        pNode = &pParse->aNode[pNode->u.iAppend];
        j = 1;
      }
      jsonAppendChar(pOut, ']');
      break;
    }
    case JSON_OBJECT: {
      u32 j = 1;
      jsonAppendChar(pOut, '{');
      for(;;){
        while( j<=pNode->n ){
          if( (pNode[j+1].jnFlags & JNODE_REMOVE)==0 || pParse->useMod==0 ){
            jsonAppendSeparator(pOut);
            jsonRenderNode(pParse, &pNode[j], pOut);
            jsonAppendChar(pOut, ':');
            jsonRenderNode(pParse, &pNode[j+1], pOut);
          }
          j += 1 + jsonNodeSize(&pNode[j+1]);
        }
        if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;
        if( pParse->useMod==0 ) break;
        assert( pNode->eU==2 );
        pNode = &pParse->aNode[pNode->u.iAppend];
        j = 1;
      }
      jsonAppendChar(pOut, '}');
      break;
    }
  }
}

/*
** Return a JsonNode and all its descendants as a JSON string.
*/
static void jsonReturnJson(
  JsonParse *pParse,          /* The complete JSON */
  JsonNode *pNode,            /* Node to return */
  sqlite3_context *pCtx,      /* Return value for this function */

  int bGenerateAlt            /* Also store the rendered text in zAlt */
){
  JsonString s;
  if( pParse->oom ){
    sqlite3_result_error_nomem(pCtx);
    return;
  }
  if( pParse->nErr==0 ){
    jsonInit(&s, pCtx);
    jsonRenderNode(pParse, pNode, &s);
    if( bGenerateAlt && pParse->zAlt==0 && jsonForceRCStr(&s) ){
      pParse->zAlt = sqlite3RCStrRef(s.zBuf);
      pParse->nAlt = s.nUsed;
    }
    jsonResult(&s);
    sqlite3_result_subtype(pCtx, JSON_SUBTYPE);
  }
}

/*
** Translate a single byte of Hex into an integer.
** This routine only works if h really is a valid hexadecimal
** character:  0..9a..fA..F
*/

  return v;
}

/*
** Make the JsonNode the return value of the function.
*/
static void jsonReturn(
  JsonParse *pParse,          /* Complete JSON parse tree */
  JsonNode *pNode,            /* Node to return */
  sqlite3_context *pCtx       /* Return value for this function */

){
  switch( pNode->eType ){
    default: {
      assert( pNode->eType==JSON_NULL );
      sqlite3_result_null(pCtx);
      break;
    }
    case JSON_TRUE: {
      sqlite3_result_int(pCtx, 1);
      break;
    }
    case JSON_FALSE: {
      sqlite3_result_int(pCtx, 0);
      break;
    }
    case JSON_INT: {
      sqlite3_int64 i = 0;
      int rc;
      int bNeg = 0;
      const char *z;


      assert( pNode->eU==1 );
      z = pNode->u.zJContent;
      if( z[0]=='-' ){ z++; bNeg = 1; }
      else if( z[0]=='+' ){ z++; }
      rc = sqlite3DecOrHexToI64(z, &i);
      if( rc<=1 ){
        sqlite3_result_int64(pCtx, bNeg ? -i : i);

        zOut[j] = 0;
        sqlite3_result_text(pCtx, zOut, j, sqlite3_free);
      }
      break;
    }
    case JSON_ARRAY:
    case JSON_OBJECT: {
      jsonReturnJson(pParse, pNode, pCtx, 0);
      break;
    }
  }
}

/* Forward reference */
static int jsonParseAddNode(JsonParse*,u32,u32,const char*);

#elif defined(_MSC_VER) && _MSC_VER>=1310
#  define JSON_NOINLINE  __declspec(noinline)
#else
#  define JSON_NOINLINE
#endif


/*
** Add a single node to pParse->aNode after first expanding the
** size of the aNode array.  Return the index of the new node.
**
** If an OOM error occurs, set pParse->oom and return -1.
*/
static JSON_NOINLINE int jsonParseAddNodeExpand(
  JsonParse *pParse,        /* Append the node to this object */
  u32 eType,                /* Node type */
  u32 n,                    /* Content size or sub-node count */
  const char *zContent      /* Content */
){
  u32 nNew;
  JsonNode *pNew;
  assert( pParse->nNode>=pParse->nAlloc );
  if( pParse->oom ) return -1;
  nNew = pParse->nAlloc*2 + 10;
  pNew = sqlite3_realloc64(pParse->aNode, sizeof(JsonNode)*nNew);
  if( pNew==0 ){
    pParse->oom = 1;
    return -1;
  }
  pParse->nAlloc = sqlite3_msize(pNew)/sizeof(JsonNode);
  pParse->aNode = pNew;
  assert( pParse->nNode<pParse->nAlloc );
  return jsonParseAddNode(pParse, eType, n, zContent);
}

/*
** Create a new JsonNode instance based on the arguments and append that

  p->eType = (u8)(eType & 0xff);
  p->jnFlags = (u8)(eType >> 8);
  VVA( p->eU = zContent ? 1 : 0 );
  p->n = n;
  p->u.zJContent = zContent;
  return pParse->nNode++;
}

/*
** Add an array of new nodes to the current pParse->aNode array.
** Return the index of the first node added.
**
** If an OOM error occurs, set pParse->oom.
*/
static void jsonParseAddNodeArray(
  JsonParse *pParse,        /* Append the node to this object */
  JsonNode *aNode,          /* Array of nodes to add */
  u32 nNode                 /* Number of elements in aNew */
){
  if( pParse->nNode + nNode > pParse->nAlloc ){
    u32 nNew = pParse->nNode + nNode;
    JsonNode *aNew = sqlite3_realloc64(pParse->aNode, nNew*sizeof(JsonNode));
    if( aNew==0 ){
      pParse->oom = 1;
      return;
    }
    pParse->nAlloc = sqlite3_msize(aNew)/sizeof(JsonNode);
    pParse->aNode = aNew;
  }
  memcpy(&pParse->aNode[pParse->nNode], aNode, nNode*sizeof(JsonNode));
  pParse->nNode += nNode;
}

/*
** Add a new JSON_SUBST node.  The node immediately following
** this new node will be the substitute content for iNode.
*/
static int jsonParseAddSubstNode(
  JsonParse *pParse,       /* Add the JSON_SUBST here */
  u32 iNode                /* References this node */
){
  int idx = jsonParseAddNode(pParse, JSON_SUBST, iNode, 0);
  if( pParse->oom ) return -1;
  pParse->aNode[iNode].jnFlags |= JNODE_REPLACE;
  pParse->aNode[idx].eU = 4;
  pParse->aNode[idx].u.iPrev = pParse->iSubst;
  pParse->iSubst = idx;
  pParse->hasMod = 1;
  pParse->useMod = 1;
  return idx;
}

/*
** Return true if z[] begins with 2 (or more) hexadecimal digits
*/
static int jsonIs2Hex(const char *z){
  return sqlite3Isxdigit(z[0]) && sqlite3Isxdigit(z[1]);
}

/*
** Parse a single JSON value which begins at pParse->zJson[i].  Return the
** index of the first character past the end of the value parsed.
**
** Special return values:
**
**      0    End of input
**     -1    Syntax error
**     -2    '}' seen
**     -3    ']' seen
**     -4    ',' seen
**     -5    ':' seen
*/
static int jsonParseValue(JsonParse *pParse, u32 i){

  case '"':
    /* Parse string */
    jnFlags = 0;
  parse_string:
    cDelim = z[i];
    for(j=i+1; 1; j++){
      static const char aOk[256] = {
          0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
          0, 0, 0, 0, 0, 0, 0, 0,  0, 0, 0, 0, 0, 0, 0, 0,
          1, 1, 0, 1, 1, 1, 1, 0,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 0, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,

          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
          1, 1, 1, 1, 1, 1, 1, 1,  1, 1, 1, 1, 1, 1, 1, 1,
      };
      if( aOk[(unsigned char)z[j]] ) continue;
      c = z[j];
      if( c==cDelim ){
        break;
      }else if( c=='\\' ){
        c = z[++j];

    return -1;  /* Syntax error */
  }
  } /* End switch(z[i]) */
}

/*
** Parse a complete JSON string.  Return 0 on success or non-zero if there
** are any errors.  If an error occurs, free all memory held by pParse,
** but not pParse itself.
**
** pParse is uninitialized when this routine is called.
**
** pParse->nJPRef set to 1.  The caller becomes the owner of the
** the JsonParse object.
**
** pParse->bOwnsJson is set to bTakeJson.  If bTakeJson is 1, the newly
** initialized JsonParse object will become the owner of the zJson input
** string.  If bTakeJson is 0, then the caller is responsible for
** preserving zJson for the lifetime of the JsonParse object.
*/
static int jsonParse(
  JsonParse *pParse,           /* Initialize and fill this JsonParse object */
  sqlite3_context *pCtx,       /* Report errors here */
  char *zJson,                 /* Input JSON text to be parsed */
  int bTakeJson                /* Assume ownership of zJson if true */
){
  int i;
  memset(pParse, 0, sizeof(*pParse));
  if( zJson==0 ) return 1;
  pParse->zJson = zJson;
  pParse->bOwnsJson = bTakeJson;
  pParse->nJPRef = 1;
  i = jsonParseValue(pParse, 0);
  if( pParse->oom ) i = -1;
  if( i>0 ){
    assert( pParse->iDepth==0 );
    while( fast_isspace(zJson[i]) ) i++;
    if( zJson[i] ){
      i += json5Whitespace(&zJson[i]);

      }
    }
    jsonParseReset(pParse);
    return 1;
  }
  return 0;
}


/* Mark node i of pParse as being a child of iParent.  Call recursively
** to fill in all the descendants of node i.
*/
static void jsonParseFillInParentage(JsonParse *pParse, u32 i, u32 iParent){
  JsonNode *pNode = &pParse->aNode[i];
  u32 j;

/*
** Magic number used for the JSON parse cache in sqlite3_get_auxdata()
*/
#define JSON_CACHE_ID  (-429938)  /* First cache entry */
#define JSON_CACHE_SZ  4          /* Max number of cache entries */

/*
** Obtain a complete parse of the JSON found in the pJson argument
**
** Use the sqlite3_get_auxdata() cache to find a preexisting parse
** if it is available.  If the cache is not available or if it
** is no longer valid, parse the JSON again and return the new parse.
** Also register the new parse so that it will be available for
** future sqlite3_get_auxdata() calls.
**
** If an error occurs and pErrCtx!=0 then report the error on pErrCtx
** and return NULL.
**
** The returned pointer (if it is not NULL) is owned by the cache in
** most cases, not the caller.  The caller does NOT need to invoke
** jsonParseFree(), in most cases.
**
** Except, if an error occurs and pErrCtx==0 then return the JsonParse
** object with JsonParse.nErr non-zero and the caller will own the JsonParse

** object.  In that case, it will be the responsibility of the caller to
** invoke jsonParseFree().  To summarize:
**
**   pErrCtx!=0 || p->nErr==0      ==>   Return value p is owned by the
**                                       cache.  Call does not need to
**                                       free it.
**
**   pErrCtx==0 && p->nErr!=0      ==>   Return value is owned by the caller
**                                       and so the caller must free it.
*/
static JsonParse *jsonParseCached(
  sqlite3_context *pCtx,         /* Context to use for cache search */
  sqlite3_value *pJson,          /* Function param containing JSON text */
  sqlite3_context *pErrCtx,      /* Write parse errors here if not NULL */
  int bUnedited                  /* No prior edits allowed */
){
  char *zJson = (char*)sqlite3_value_text(pJson);
  int nJson = sqlite3_value_bytes(pJson);
  JsonParse *p;
  JsonParse *pMatch = 0;
  int iKey;
  int iMinKey = 0;
  u32 iMinHold = 0xffffffff;
  u32 iMaxHold = 0;

  if( zJson==0 ) return 0;
  for(iKey=0; iKey<JSON_CACHE_SZ; iKey++){
    p = (JsonParse*)sqlite3_get_auxdata(pCtx, JSON_CACHE_ID+iKey);
    if( p==0 ){
      iMinKey = iKey;
      break;
    }
    if( pMatch==0
     && p->nJson==nJson
     && (p->hasMod==0 || bUnedited==0)
     && memcmp(p->zJson,zJson,nJson)==0
    ){
      p->nErr = 0;
      p->useMod = 0;
      pMatch = p;
    }else
    if( pMatch==0
     && p->zAlt!=0
     && bUnedited==0
     && p->nAlt==nJson
     && memcmp(p->zAlt, zJson, nJson)==0
    ){
      p->nErr = 0;
      p->useMod = 1;
      pMatch = p;
    }else if( p->iHold<iMinHold ){
      iMinHold = p->iHold;
      iMinKey = iKey;
    }
    if( p->iHold>iMaxHold ){
      iMaxHold = p->iHold;
    }
  }
  if( pMatch ){
    /* The input JSON text was found in the cache.  Use the preexisting
    ** parse of this JSON */
    pMatch->nErr = 0;
    pMatch->iHold = iMaxHold+1;
    assert( pMatch->nJPRef>0 ); /* pMatch is owned by the cache */
    return pMatch;
  }

  /* The input JSON was not found anywhere in the cache.  We will need
  ** to parse it ourselves and generate a new JsonParse object.
  */
  p = sqlite3_malloc64( sizeof(*p) );
  if( p==0 ){
    sqlite3_result_error_nomem(pCtx);
    return 0;
  }
  memset(p, 0, sizeof(*p));
  p->zJson = sqlite3RCStrNew( nJson );
  if( p->zJson==0 ){
    sqlite3_free(p);
    sqlite3_result_error_nomem(pCtx);
    return 0;
  }
  memcpy(p->zJson, zJson, nJson);
  p->zJson[nJson] = 0;
  if( jsonParse(p, pErrCtx, p->zJson, 1) ){
    if( pErrCtx==0 ){
      p->nErr = 1;
      assert( p->nJPRef==1 ); /* Caller will own the new JsonParse object p */
      return p;
    }
    jsonParseFree(p);
    return 0;
  }
  p->nJson = nJson;
  p->iHold = iMaxHold+1;
  /* Transfer ownership of the new JsonParse to the cache */
  sqlite3_set_auxdata(pCtx, JSON_CACHE_ID+iMinKey, p,
                      (void(*)(void*))jsonParseFree);
  return (JsonParse*)sqlite3_get_auxdata(pCtx, JSON_CACHE_ID+iMinKey);
}

/*
** Compare the OBJECT label at pNode against zKey,nKey.  Return true on

  u32 iRoot,              /* Begin the search at this node */
  const char *zPath,      /* The path to search */
  int *pApnd,             /* Append nodes to complete path if not NULL */
  const char **pzErr      /* Make *pzErr point to any syntax error in zPath */
){
  u32 i, j, nKey;
  const char *zKey;
  JsonNode *pRoot;
  if( pParse->oom ) return 0;
  pRoot = &pParse->aNode[iRoot];
  while( (pRoot->jnFlags & JNODE_REPLACE)!=0 && pParse->useMod ){
    u32 idx = (u32)(pRoot - pParse->aNode);
    i = pParse->iSubst;
    while( 1 /*exit-by-break*/ ){
      assert( i<pParse->nNode );
      assert( pParse->aNode[i].eType==JSON_SUBST );
      assert( pParse->aNode[i].eU==4 );
      assert( pParse->aNode[i].u.iPrev<i );
      if( pParse->aNode[i].n==idx ){
        pRoot = &pParse->aNode[i+1];
        iRoot = i+1;
        break;
      }
      i = pParse->aNode[i].u.iPrev;
    }
  }
  if( zPath[0]==0 ) return pRoot;

  if( zPath[0]=='.' ){
    if( pRoot->eType!=JSON_OBJECT ) return 0;
    zPath++;
    if( zPath[0]=='"' ){
      zKey = zPath + 1;
      for(i=1; zPath[i] && zPath[i]!='"'; i++){}
      nKey = i-1;

        if( jsonLabelCompare(pRoot+j, zKey, nKey) ){
          return jsonLookupStep(pParse, iRoot+j+1, &zPath[i], pApnd, pzErr);
        }
        j++;
        j += jsonNodeSize(&pRoot[j]);
      }
      if( (pRoot->jnFlags & JNODE_APPEND)==0 ) break;
      if( pParse->useMod==0 ) break;
      assert( pRoot->eU==2 );
      iRoot = pRoot->u.iAppend;
      pRoot = &pParse->aNode[iRoot];
      j = 1;
    }
    if( pApnd ){
      u32 iStart, iLabel;
      JsonNode *pNode;
      assert( pParse->useMod );
      iStart = jsonParseAddNode(pParse, JSON_OBJECT, 2, 0);
      iLabel = jsonParseAddNode(pParse, JSON_STRING, nKey, zKey);
      zPath += i;
      pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);
      if( pParse->oom ) return 0;
      if( pNode ){
        pRoot = &pParse->aNode[iRoot];
        assert( pRoot->eU==0 );
        pRoot->u.iAppend = iStart;
        pRoot->jnFlags |= JNODE_APPEND;
        VVA( pRoot->eU = 2 );
        pParse->aNode[iLabel].jnFlags |= JNODE_RAW;
      }
      return pNode;
    }
  }else if( zPath[0]=='[' ){
    i = 0;
    j = 1;
    while( sqlite3Isdigit(zPath[j]) ){
      i = i*10 + zPath[j] - '0';
      j++;
    }
    if( j<2 || zPath[j]!=']' ){
      if( zPath[1]=='#' ){
        JsonNode *pBase = pRoot;
        int iBase = iRoot;
        if( pRoot->eType!=JSON_ARRAY ) return 0;
        for(;;){
          while( j<=pBase->n ){
            if( (pBase[j].jnFlags & JNODE_REMOVE)==0 || pParse->useMod==0 ) i++;
            j += jsonNodeSize(&pBase[j]);
          }
          if( (pBase->jnFlags & JNODE_APPEND)==0 ) break;
          if( pParse->useMod==0 ) break;
          assert( pBase->eU==2 );
          iBase = pBase->u.iAppend;
          pBase = &pParse->aNode[iBase];
          j = 1;
        }
        j = 2;
        if( zPath[2]=='-' && sqlite3Isdigit(zPath[3]) ){
          unsigned int x = 0;
          j = 3;

        return 0;
      }
    }
    if( pRoot->eType!=JSON_ARRAY ) return 0;
    zPath += j + 1;
    j = 1;
    for(;;){
      while( j<=pRoot->n
         && (i>0 || ((pRoot[j].jnFlags & JNODE_REMOVE)!=0 && pParse->useMod))
      ){
        if( (pRoot[j].jnFlags & JNODE_REMOVE)==0 || pParse->useMod==0 ) i--;
        j += jsonNodeSize(&pRoot[j]);
      }
      if( (pRoot->jnFlags & JNODE_APPEND)==0 ) break;
      if( pParse->useMod==0 ) break;
      assert( pRoot->eU==2 );
      iRoot = pRoot->u.iAppend;
      pRoot = &pParse->aNode[iRoot];
      j = 1;
    }
    if( j<=pRoot->n ){
      return jsonLookupStep(pParse, iRoot+j, zPath, pApnd, pzErr);
    }
    if( i==0 && pApnd ){
      u32 iStart;
      JsonNode *pNode;
      assert( pParse->useMod );
      iStart = jsonParseAddNode(pParse, JSON_ARRAY, 1, 0);
      pNode = jsonLookupAppend(pParse, zPath, pApnd, pzErr);
      if( pParse->oom ) return 0;
      if( pNode ){
        pRoot = &pParse->aNode[iRoot];
        assert( pRoot->eU==0 );
        pRoot->u.iAppend = iStart;
        pRoot->jnFlags |= JNODE_APPEND;
        VVA( pRoot->eU = 2 );
      }
      return pNode;
    }
  }else{
    *pzErr = zPath;

static void jsonWrongNumArgs(
  sqlite3_context *pCtx,
  const char *zFuncName
){
  char *zMsg = sqlite3_mprintf("json_%s() needs an odd number of arguments",
                               zFuncName);
  sqlite3_result_error(pCtx, zMsg, -1);
  sqlite3_free(zMsg);
}

/*
** Mark all NULL entries in the Object passed in as JNODE_REMOVE.
*/
static void jsonRemoveAllNulls(JsonNode *pNode){
  int i, n;

  }
}


/****************************************************************************
** SQL functions used for testing and debugging
****************************************************************************/

#if SQLITE_DEBUG
/*
** Print N node entries.
*/
static void jsonDebugPrintNodeEntries(
  JsonNode *aNode,  /* First node entry to print */
  int N             /* Number of node entries to print */
){
  int i;
  for(i=0; i<N; i++){
    const char *zType;
    if( aNode[i].jnFlags & JNODE_LABEL ){
      zType = "label";
    }else{
      zType = jsonType[aNode[i].eType];
    }
    printf("node %4u: %-7s n=%-5d", i, zType, aNode[i].n);
    if( (aNode[i].jnFlags & ~JNODE_LABEL)!=0 ){
      u8 f = aNode[i].jnFlags;
      if( f & JNODE_RAW )     printf(" RAW");
      if( f & JNODE_ESCAPE )  printf(" ESCAPE");
      if( f & JNODE_REMOVE )  printf(" REMOVE");
      if( f & JNODE_REPLACE ) printf(" REPLACE");
      if( f & JNODE_APPEND )  printf(" APPEND");
      if( f & JNODE_JSON5 )   printf(" JSON5");
    }
    switch( aNode[i].eU ){
      case 1:  printf(" zJContent=[%.*s]\n",
                      aNode[i].n, aNode[i].u.zJContent);           break;
      case 2:  printf(" iAppend=%u\n", aNode[i].u.iAppend);        break;
      case 3:  printf(" iKey=%u\n", aNode[i].u.iKey);              break;
      case 4:  printf(" iPrev=%u\n", aNode[i].u.iPrev);            break;
      default: printf("\n");
    }
  }
}
#endif /* SQLITE_DEBUG */


#if 0  /* 1 for debugging.  0 normally.  Requires -DSQLITE_DEBUG too */
static void jsonDebugPrintParse(JsonParse *p){
  jsonDebugPrintNodeEntries(p->aNode, p->nNode);
}
static void jsonDebugPrintNode(JsonNode *pNode){
  jsonDebugPrintNodeEntries(pNode, jsonNodeSize(pNode));
}
#else
   /* The usual case */
# define jsonDebugPrintNode(X)
# define jsonDebugPrintParse(X)
#endif

#ifdef SQLITE_DEBUG
/*
** SQL function:   json_parse(JSON)
**
** Parse JSON using jsonParseCached().  Then print a dump of that
** parse on standard output.  Return the mimified JSON result, just
** like the json() function.
*/
static void jsonParseFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){

  JsonParse *p;        /* The parse */


  assert( argc==1 );
  p = jsonParseCached(ctx, argv[0], ctx, 0);
  if( p==0 ) return;

  printf("nNode     = %u\n", p->nNode);
  printf("nAlloc    = %u\n", p->nAlloc);
  printf("nJson     = %d\n", p->nJson);
  printf("nAlt      = %d\n", p->nAlt);
  printf("nErr      = %u\n", p->nErr);
  printf("oom       = %u\n", p->oom);
  printf("hasNonstd = %u\n", p->hasNonstd);
  printf("bOwnsJson = %u\n", p->bOwnsJson);
  printf("useMod    = %u\n", p->useMod);
  printf("hasMod    = %u\n", p->hasMod);

  printf("nJPRef    = %u\n", p->nJPRef);
  printf("iSubst    = %u\n", p->iSubst);
  printf("iHold     = %u\n", p->iHold);


  jsonDebugPrintNodeEntries(p->aNode, p->nNode);








  jsonReturnJson(p, p->aNode, ctx, 1);
}

/*
** The json_test1(JSON) function return true (1) if the input is JSON
** text generated by another json function.  It returns (0) if the input
** is not known to be JSON.
*/

/****************************************************************************
** Scalar SQL function implementations
****************************************************************************/

/*
** Implementation of the json_QUOTE(VALUE) function.  Return a JSON value
** corresponding to the SQL value input.  Mostly this means putting
** double-quotes around strings and returning the unquoted string "null"
** when given a NULL input.
*/
static void jsonQuoteFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv

}


/*
** json_array_length(JSON)
** json_array_length(JSON, PATH)
**
** Return the number of elements in the top-level JSON array.
** Return 0 if the input is not a well-formed JSON array.
*/
static void jsonArrayLengthFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *p;          /* The parse */
  sqlite3_int64 n = 0;
  u32 i;
  JsonNode *pNode;

  p = jsonParseCached(ctx, argv[0], ctx, 0);
  if( p==0 ) return;
  assert( p->nNode );
  if( argc==2 ){
    const char *zPath = (const char*)sqlite3_value_text(argv[1]);
    pNode = jsonLookup(p, zPath, 0, ctx);
  }else{
    pNode = p->aNode;
  }
  if( pNode==0 ){
    return;
  }
  if( pNode->eType==JSON_ARRAY ){
    while( 1 /*exit-by-break*/ ){
      for(i=1; i<=pNode->n; n++){
        i += jsonNodeSize(&pNode[i]);
      }
      if( (pNode->jnFlags & JNODE_APPEND)==0 ) break;
      if( p->useMod==0 ) break;
      assert( pNode->eU==2 );
      pNode = &p->aNode[pNode->u.iAppend];
    }
  }
  sqlite3_result_int64(ctx, n);
}

/*
** Bit values for the flags passed into jsonExtractFunc() or

  JsonParse *p;          /* The parse */
  JsonNode *pNode;
  const char *zPath;
  int flags = SQLITE_PTR_TO_INT(sqlite3_user_data(ctx));
  JsonString jx;

  if( argc<2 ) return;
  p = jsonParseCached(ctx, argv[0], ctx, 0);
  if( p==0 ) return;
  if( argc==2 ){
    /* With a single PATH argument */
    zPath = (const char*)sqlite3_value_text(argv[1]);
    if( zPath==0 ) return;
    if( flags & JSON_ABPATH ){
      if( zPath[0]!='$' || (zPath[1]!='.' && zPath[1]!='[' && zPath[1]!=0) ){

        pNode = jx.bErr ? 0 : jsonLookup(p, jx.zBuf, 0, ctx);
        jsonReset(&jx);
      }else{
        pNode = jsonLookup(p, zPath, 0, ctx);
      }
      if( pNode ){
        if( flags & JSON_JSON ){
          jsonReturnJson(p, pNode, ctx, 0);
        }else{
          jsonReturn(p, pNode, ctx);
          sqlite3_result_subtype(ctx, 0);
        }
      }
    }else{
      pNode = jsonLookup(p, zPath, 0, ctx);
      if( p->nErr==0 && pNode ) jsonReturn(p, pNode, ctx);
    }
  }else{
    /* Two or more PATH arguments results in a JSON array with each
    ** element of the array being the value selected by one of the PATHs */
    int i;
    jsonInit(&jx, ctx);
    jsonAppendChar(&jx, '[');
    for(i=1; i<argc; i++){
      zPath = (const char*)sqlite3_value_text(argv[i]);
      pNode = jsonLookup(p, zPath, 0, ctx);
      if( p->nErr ) break;
      jsonAppendSeparator(&jx);
      if( pNode ){
        jsonRenderNode(p, pNode, &jx);
      }else{
        jsonAppendRawNZ(&jx, "null", 4);
      }
    }
    if( i==argc ){
      jsonAppendChar(&jx, ']');
      jsonResult(&jx);

    assert( pPatch[i].eU==1 );
    nKey = pPatch[i].n;
    zKey = pPatch[i].u.zJContent;
    for(j=1; j<pTarget->n; j += jsonNodeSize(&pTarget[j+1])+1 ){
      assert( pTarget[j].eType==JSON_STRING );
      assert( pTarget[j].jnFlags & JNODE_LABEL );
      if( jsonSameLabel(&pPatch[i], &pTarget[j]) ){
        if( pTarget[j+1].jnFlags & (JNODE_REMOVE|JNODE_REPLACE) ) break;
        if( pPatch[i+1].eType==JSON_NULL ){
          pTarget[j+1].jnFlags |= JNODE_REMOVE;
        }else{
          JsonNode *pNew = jsonMergePatch(pParse, iTarget+j+1, &pPatch[i+1]);
          if( pNew==0 ) return 0;
          if( pNew!=&pParse->aNode[iTarget+j+1] ){


            jsonParseAddSubstNode(pParse, iTarget+j+1);




            jsonParseAddNodeArray(pParse, pNew, jsonNodeSize(pNew));

          }
          pTarget = &pParse->aNode[iTarget];
        }
        break;
      }
    }
    if( j>=pTarget->n && pPatch[i+1].eType!=JSON_NULL ){
      int iStart;
      JsonNode *pApnd;
      u32 nApnd;
      iStart = jsonParseAddNode(pParse, JSON_OBJECT, 0, 0);
      jsonParseAddNode(pParse, JSON_STRING, nKey, zKey);
      pApnd = &pPatch[i+1];
      if( pApnd->eType==JSON_OBJECT ) jsonRemoveAllNulls(pApnd);
      nApnd = jsonNodeSize(pApnd);
      jsonParseAddNodeArray(pParse, pApnd, jsonNodeSize(pApnd));
      if( pParse->oom ) return 0;

      pParse->aNode[iStart].n = 1+nApnd;

      pParse->aNode[iRoot].jnFlags |= JNODE_APPEND;
      pParse->aNode[iRoot].u.iAppend = iStart;
      VVA( pParse->aNode[iRoot].eU = 2 );

      iRoot = iStart;

      pTarget = &pParse->aNode[iTarget];


    }
  }
  return pTarget;
}

/*
** Implementation of the json_mergepatch(JSON1,JSON2) function.  Return a JSON
** object that is the result of running the RFC 7396 MergePatch() algorithm
** on the two arguments.
*/
static void jsonPatchFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse x;     /* The JSON that is being patched */
  JsonParse y;     /* The patch */
  JsonNode *pResult;   /* The result of the merge */

  UNUSED_PARAMETER(argc);
  if( jsonParse(&x, ctx, (char*)sqlite3_value_text(argv[0]), 0) ) return;
  if( jsonParse(&y, ctx, (char*)sqlite3_value_text(argv[1]), 0) ){
    jsonParseReset(&x);
    return;
  }
  x.useMod = 1;
  y.useMod = 1;
  pResult = jsonMergePatch(&x, 0, y.aNode);
  assert( pResult!=0 || x.oom );
  if( pResult && x.oom==0 ){
    jsonDebugPrintParse(&x);
    jsonDebugPrintNode(pResult);
    jsonReturnJson(&x, pResult, ctx, 0);
  }else{
    sqlite3_result_error_nomem(ctx);
  }
  jsonParseReset(&x);
  jsonParseReset(&y);
}

** JSON or PATH arguments result in an error.
*/
static void jsonRemoveFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *pParse;          /* The parse */
  JsonNode *pNode;
  const char *zPath;
  u32 i;

  if( argc<1 ) return;
  pParse = jsonParseCached(ctx, argv[0], ctx, argc>1);
  if( pParse==0 ) return;
  for(i=1; i<(u32)argc; i++){
    zPath = (const char*)sqlite3_value_text(argv[i]);
    if( zPath==0 ) goto remove_done;
    pNode = jsonLookup(pParse, zPath, 0, ctx);
    if( pParse->nErr ) goto remove_done;
    if( pNode ){
      pNode->jnFlags |= JNODE_REMOVE;
      pParse->hasMod = 1;
      pParse->useMod = 1;
    }
  }
  if( (pParse->aNode[0].jnFlags & JNODE_REMOVE)==0 ){
    jsonReturnJson(pParse, pParse->aNode, ctx, 1);
  }
remove_done:
  jsonDebugPrintParse(p);
}

/*
** Substitute the value at iNode with the pValue parameter.
*/
static void jsonReplaceNode(
  sqlite3_context *pCtx,
  JsonParse *p,
  int iNode,
  sqlite3_value *pValue
){
  int idx = jsonParseAddSubstNode(p, iNode);
  if( idx<=0 ){
    assert( p->oom );
    return;
  }
  switch( sqlite3_value_type(pValue) ){
    case SQLITE_NULL: {
      jsonParseAddNode(p, JSON_NULL, 0, 0);
      break;
    }
    case SQLITE_FLOAT: {
      char *z = sqlite3_mprintf("%!0.15g", sqlite3_value_double(pValue));
      int n;
      if( z==0 ){
        p->oom = 1;
        break;
      }
      n = sqlite3Strlen30(z);
      jsonParseAddNode(p, JSON_REAL, n, z);
      jsonParseAddCleanup(p, sqlite3_free, z);
      break;
    }
    case SQLITE_INTEGER: {
      char *z = sqlite3_mprintf("%lld", sqlite3_value_int64(pValue));
      int n;
      if( z==0 ){
        p->oom = 1;
        break;
      }
      n = sqlite3Strlen30(z);
      jsonParseAddNode(p, JSON_INT, n, z);
      jsonParseAddCleanup(p, sqlite3_free, z);

      break;
    }
    case SQLITE_TEXT: {
      const char *z = (const char*)sqlite3_value_text(pValue);
      u32 n = (u32)sqlite3_value_bytes(pValue);
      if( z==0 ){
         p->oom = 1;
         break;
      }
      if( sqlite3_value_subtype(pValue)!=JSON_SUBTYPE ){
        int k = jsonParseAddNode(p, JSON_STRING, n, z);
        char *zCopy = sqlite3DbStrDup(0, z);
        if( k>0 ) p->aNode[k].jnFlags |= JNODE_RAW;
        if( zCopy ){
          jsonParseAddCleanup(p, sqlite3_free, zCopy);
        }else{
          sqlite3_result_error_nomem(pCtx);
        }
      }else{
        JsonParse *pPatch = jsonParseCached(pCtx, pValue, pCtx, 1);
        if( pPatch==0 ){
          p->oom = 1;
          break;
        }
        jsonParseAddNodeArray(p, pPatch->aNode, pPatch->nNode);
        /* The nodes copied out of pPatch and into p likely contain
        ** u.zJContent pointers into pPatch->zJson.  So preserve the
        ** content of pPatch until p is destroyed. */
        assert( pPatch->nJPRef>=1 );
        pPatch->nJPRef++;
        jsonParseAddCleanup(p, (void(*)(void*))jsonParseFree, pPatch);
      }
      break;
    }
    case SQLITE_BLOB: {
      sqlite3_result_error(pCtx, "JSON cannot hold BLOB values", -1);
      p->nErr++;
      break;
    }
  }
}

/*
** json_replace(JSON, PATH, VALUE, ...)
**
** Replace the value at PATH with VALUE.  If PATH does not already exist,
** this routine is a no-op.  If JSON or PATH is malformed, throw an error.
*/
static void jsonReplaceFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *pParse;          /* The parse */
  JsonNode *pNode;
  const char *zPath;
  u32 i;

  if( argc<1 ) return;
  if( (argc&1)==0 ) {
    jsonWrongNumArgs(ctx, "replace");
    return;
  }
  pParse = jsonParseCached(ctx, argv[0], ctx, argc>1);
  if( pParse==0 ) return;
  for(i=1; i<(u32)argc; i+=2){
    zPath = (const char*)sqlite3_value_text(argv[i]);
    pParse->useMod = 1;
    pNode = jsonLookup(pParse, zPath, 0, ctx);
    if( pParse->nErr ) goto replace_err;
    if( pNode ){




      jsonReplaceNode(ctx, pParse, (u32)(pNode - pParse->aNode), argv[i+1]);
    }
  }




  jsonReturnJson(pParse, pParse->aNode, ctx, 1);

replace_err:
  jsonDebugPrintParse(pParse);
}


/*
** json_set(JSON, PATH, VALUE, ...)
**
** Set the value at PATH to VALUE.  Create the PATH if it does not already
** exist.  Overwrite existing values that do exist.
** If JSON or PATH is malformed, throw an error.
**
** json_insert(JSON, PATH, VALUE, ...)
**
** Create PATH and initialize it to VALUE.  If PATH already exists, this
** routine is a no-op.  If JSON or PATH is malformed, throw an error.
*/
static void jsonSetFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *pParse;       /* The parse */
  JsonNode *pNode;
  const char *zPath;
  u32 i;
  int bApnd;
  int bIsSet = sqlite3_user_data(ctx)!=0;

  if( argc<1 ) return;
  if( (argc&1)==0 ) {
    jsonWrongNumArgs(ctx, bIsSet ? "set" : "insert");
    return;
  }
  pParse = jsonParseCached(ctx, argv[0], ctx, argc>1);
  if( pParse==0 ) return;
  for(i=1; i<(u32)argc; i+=2){
    zPath = (const char*)sqlite3_value_text(argv[i]);
    bApnd = 0;
    pParse->useMod = 1;
    pNode = jsonLookup(pParse, zPath, &bApnd, ctx);
    if( pParse->oom ){
      sqlite3_result_error_nomem(ctx);
      goto jsonSetDone;
    }else if( pParse->nErr ){
      goto jsonSetDone;
    }else if( pNode && (bApnd || bIsSet) ){




      jsonReplaceNode(ctx, pParse, (u32)(pNode - pParse->aNode), argv[i+1]);
    }
  }



  jsonDebugPrintParse(pParse);
  jsonReturnJson(pParse, pParse->aNode, ctx, 1);

jsonSetDone:

  /* no cleanup required */;
}

/*
** json_type(JSON)
** json_type(JSON, PATH)
**
** Return the top-level "type" of a JSON string.  json_type() raises an
** error if either the JSON or PATH inputs are not well-formed.
*/
static void jsonTypeFunc(
  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *p;          /* The parse */
  const char *zPath;
  JsonNode *pNode;

  p = jsonParseCached(ctx, argv[0], ctx, 0);
  if( p==0 ) return;
  if( argc==2 ){
    zPath = (const char*)sqlite3_value_text(argv[1]);
    pNode = jsonLookup(p, zPath, 0, ctx);
  }else{
    pNode = p->aNode;
  }

  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *p;          /* The parse */
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  p = jsonParseCached(ctx, argv[0], 0, 0);
  if( p==0 || p->oom ){
    sqlite3_result_error_nomem(ctx);
    sqlite3_free(p);
  }else{
    sqlite3_result_int(ctx, p->nErr==0 && (p->hasNonstd==0 || p->useMod));
    if( p->nErr ) jsonParseFree(p);
  }
}

/*
** json_error_position(JSON)
**

  sqlite3_context *ctx,
  int argc,
  sqlite3_value **argv
){
  JsonParse *p;          /* The parse */
  UNUSED_PARAMETER(argc);
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  p = jsonParseCached(ctx, argv[0], 0, 0);
  if( p==0 || p->oom ){
    sqlite3_result_error_nomem(ctx);
    sqlite3_free(p);
  }else if( p->nErr==0 ){
    sqlite3_result_int(ctx, 0);
  }else{
    int n = 1;
    u32 i;
    const char *z = (const char*)sqlite3_value_text(argv[0]);
    for(i=0; i<p->iErr && ALWAYS(z[i]); i++){
      if( (z[i]&0xc0)!=0x80 ) n++;
    }
    sqlite3_result_int(ctx, n);
    jsonParseFree(p);
  }
}

    pStr->pCtx = ctx;
    jsonAppendChar(pStr, ']');
    if( pStr->bErr ){
      if( pStr->bErr==1 ) sqlite3_result_error_nomem(ctx);
      assert( pStr->bStatic );
    }else if( isFinal ){
      sqlite3_result_text(ctx, pStr->zBuf, (int)pStr->nUsed,
                          pStr->bStatic ? SQLITE_TRANSIENT :
                              (void(*)(void*))sqlite3RCStrUnref);
      pStr->bStatic = 1;
    }else{
      sqlite3_result_text(ctx, pStr->zBuf, (int)pStr->nUsed, SQLITE_TRANSIENT);
      pStr->nUsed--;
    }
  }else{
    sqlite3_result_text(ctx, "[]", 2, SQLITE_STATIC);

  if( pStr ){
    jsonAppendChar(pStr, '}');
    if( pStr->bErr ){
      if( pStr->bErr==1 ) sqlite3_result_error_nomem(ctx);
      assert( pStr->bStatic );
    }else if( isFinal ){
      sqlite3_result_text(ctx, pStr->zBuf, (int)pStr->nUsed,
                          pStr->bStatic ? SQLITE_TRANSIENT :
                          (void(*)(void*))sqlite3RCStrUnref);
      pStr->bStatic = 1;
    }else{
      sqlite3_result_text(ctx, pStr->zBuf, (int)pStr->nUsed, SQLITE_TRANSIENT);
      pStr->nUsed--;
    }
  }else{
    sqlite3_result_text(ctx, "{}", 2, SQLITE_STATIC);

#define JEACH_JSON    8
#define JEACH_ROOT    9

  UNUSED_PARAMETER(pzErr);
  UNUSED_PARAMETER(argv);
  UNUSED_PARAMETER(argc);
  UNUSED_PARAMETER(pAux);
  rc = sqlite3_declare_vtab(db,
     "CREATE TABLE x(key,value,type,atom,id,parent,fullkey,path,"
                    "json HIDDEN,root HIDDEN)");
  if( rc==SQLITE_OK ){
    pNew = *ppVtab = sqlite3_malloc( sizeof(*pNew) );
    if( pNew==0 ) return SQLITE_NOMEM;
    memset(pNew, 0, sizeof(*pNew));
    sqlite3_vtab_config(db, SQLITE_VTAB_INNOCUOUS);

){
  JsonEachCursor *p = (JsonEachCursor*)cur;
  JsonNode *pThis = &p->sParse.aNode[p->i];
  switch( i ){
    case JEACH_KEY: {
      if( p->i==0 ) break;
      if( p->eType==JSON_OBJECT ){
        jsonReturn(&p->sParse, pThis, ctx);
      }else if( p->eType==JSON_ARRAY ){
        u32 iKey;
        if( p->bRecursive ){
          if( p->iRowid==0 ) break;
          assert( p->sParse.aNode[p->sParse.aUp[p->i]].eU==3 );
          iKey = p->sParse.aNode[p->sParse.aUp[p->i]].u.iKey;
        }else{
          iKey = p->iRowid;
        }
        sqlite3_result_int64(ctx, (sqlite3_int64)iKey);
      }
      break;
    }
    case JEACH_VALUE: {
      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
      jsonReturn(&p->sParse, pThis, ctx);
      break;
    }
    case JEACH_TYPE: {
      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
      sqlite3_result_text(ctx, jsonType[pThis->eType], -1, SQLITE_STATIC);
      break;
    }
    case JEACH_ATOM: {
      if( pThis->jnFlags & JNODE_LABEL ) pThis++;
      if( pThis->eType>=JSON_ARRAY ) break;
      jsonReturn(&p->sParse, pThis, ctx);
      break;
    }
    case JEACH_ID: {
      sqlite3_result_int64(ctx,
         (sqlite3_int64)p->i + ((pThis->jnFlags & JNODE_LABEL)!=0));
      break;
    }
    case JEACH_PARENT: {
      if( p->i>p->iBegin && p->bRecursive ){
        sqlite3_result_int64(ctx, (sqlite3_int64)p->sParse.aUp[p->i]);
      }

    if( pConstraint->usable==0 ){
      unusableMask |= iMask;
    }else if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){
      aIdx[iCol] = i;
      idxMask |= iMask;
    }
  }
  if( pIdxInfo->nOrderBy>0
   && pIdxInfo->aOrderBy[0].iColumn<0
   && pIdxInfo->aOrderBy[0].desc==0
  ){
    pIdxInfo->orderByConsumed = 1;
  }

  if( (unusableMask & ~idxMask)!=0 ){
    /* If there are any unusable constraints on JSON or ROOT, then reject

  if( idxNum==0 ) return SQLITE_OK;
  z = (const char*)sqlite3_value_text(argv[0]);
  if( z==0 ) return SQLITE_OK;
  n = sqlite3_value_bytes(argv[0]);
  p->zJson = sqlite3_malloc64( n+1 );
  if( p->zJson==0 ) return SQLITE_NOMEM;
  memcpy(p->zJson, z, (size_t)n+1);
  if( jsonParse(&p->sParse, 0, p->zJson, 0) ){
    int rc = SQLITE_NOMEM;
    if( p->sParse.oom==0 ){
      sqlite3_free(cur->pVtab->zErrMsg);
      cur->pVtab->zErrMsg = sqlite3_mprintf("malformed JSON");
      if( cur->pVtab->zErrMsg ) rc = SQLITE_ERROR;
    }
    jsonEachCursorReset(p);

    JFUNCTION(json_type,          1, 0,  jsonTypeFunc),
    JFUNCTION(json_type,          2, 0,  jsonTypeFunc),
    JFUNCTION(json_valid,         1, 0,  jsonValidFunc),
#if SQLITE_DEBUG
    JFUNCTION(json_parse,         1, 0,  jsonParseFunc),
    JFUNCTION(json_test1,         1, 0,  jsonTest1Func),
#endif
    WAGGREGATE(json_group_array,  1, 0, 0,
       jsonArrayStep, jsonArrayFinal, jsonArrayValue, jsonGroupInverse,
       SQLITE_SUBTYPE|SQLITE_UTF8|SQLITE_DETERMINISTIC),
    WAGGREGATE(json_group_object, 2, 0, 0,
       jsonObjectStep, jsonObjectFinal, jsonObjectValue, jsonGroupInverse,
       SQLITE_SUBTYPE|SQLITE_UTF8|SQLITE_DETERMINISTIC)
  };
  sqlite3InsertBuiltinFuncs(aJsonFunc, ArraySize(aJsonFunc));
#endif
}

*/
void sqlite3_str_appendf(StrAccum *p, const char *zFormat, ...){
  va_list ap;
  va_start(ap,zFormat);
  sqlite3_str_vappendf(p, zFormat, ap);
  va_end(ap);
}


/*****************************************************************************
** Reference counted string storage
*****************************************************************************/

/*
** Increase the reference count of the string by one.
**
** The input parameter is returned.
*/
char *sqlite3RCStrRef(char *z){
  RCStr *p = (RCStr*)z;
  assert( p!=0 );
  p--;
  p->nRCRef++;
  return z;
}

/*
** Decrease the reference count by one.  Free the string when the
** reference count reaches zero.
*/
void sqlite3RCStrUnref(char *z){
  RCStr *p = (RCStr*)z;
  assert( p!=0 );
  p--;
  assert( p->nRCRef>0 );
  if( p->nRCRef>=2 ){
    p->nRCRef--;
  }else{
    sqlite3_free(p);
  }
}

/*
** Create a new string that is capable of holding N bytes of text, not counting
** the zero byte at the end.  The string is uninitialized.
**
** The reference count is initially 1.  Call sqlite3RCStrUnref() to free the
** newly allocated string.
**
** This routine returns 0 on an OOM.
*/
char *sqlite3RCStrNew(u64 N){
  RCStr *p = sqlite3_malloc64( N + sizeof(*p) + 1 );
  if( p==0 ) return 0;
  p->nRCRef = 1;
  return (char*)&p[1];
}

/*
** Change the size of the string so that it is able to hold N bytes.
** The string might be reallocated, so return the new allocation.
*/
char *sqlite3RCStrResize(char *z, u64 N){
  RCStr *p = (RCStr*)z;
  RCStr *pNew;
  assert( p!=0 );
  p--;
  assert( p->nRCRef==1 );
  pNew = sqlite3_realloc64(p, N+sizeof(RCStr)+1);
  if( pNew==0 ){
    sqlite3_free(p);
    return 0;
  }else{
    return (char*)&pNew[1];
  }
}

typedef struct Module Module;
typedef struct NameContext NameContext;
typedef struct OnOrUsing OnOrUsing;
typedef struct Parse Parse;
typedef struct ParseCleanup ParseCleanup;
typedef struct PreUpdate PreUpdate;
typedef struct PrintfArguments PrintfArguments;
typedef struct RCStr RCStr;
typedef struct RenameToken RenameToken;
typedef struct Returning Returning;
typedef struct RowSet RowSet;
typedef struct Savepoint Savepoint;
typedef struct Select Select;
typedef struct SQLiteThread SQLiteThread;
typedef struct SelectDest SelectDest;

};
#define SQLITE_PRINTF_INTERNAL 0x01  /* Internal-use-only converters allowed */
#define SQLITE_PRINTF_SQLFUNC  0x02  /* SQL function arguments to VXPrintf */
#define SQLITE_PRINTF_MALLOCED 0x04  /* True if xText is allocated space */

#define isMalloced(X)  (((X)->printfFlags & SQLITE_PRINTF_MALLOCED)!=0)

/*
** The following object is the header for an "RCStr" or "reference-counted
** string".  An RCStr is passed around and used like any other char*
** that has been dynamically allocated.  The important interface
** differences:
**
**   1.  RCStr strings are reference counted.  They are deallocated
**       when the reference count reaches zero.
**
**   2.  Use sqlite3RCStrUnref() to free an RCStr string rather than
**       sqlite3_free()
**
**   3.  Make a (read-only) copy of a read-only RCStr string using
**       sqlite3RCStrRef().
*/
struct RCStr {
  u64 nRCRef;            /* Number of references */
  /* Total structure size should be a multiple of 8 bytes for alignment */
};

/*
** A pointer to this structure is used to communicate information
** from sqlite3Init and OP_ParseSchema into the sqlite3InitCallback.
*/
typedef struct {
  sqlite3 *db;        /* The database being initialized */

);
void sqlite3NoopDestructor(void*);
void *sqlite3OomFault(sqlite3*);
void sqlite3OomClear(sqlite3*);
int sqlite3ApiExit(sqlite3 *db, int);
int sqlite3OpenTempDatabase(Parse *);

char *sqlite3RCStrRef(char*);
void sqlite3RCStrUnref(char*);
char *sqlite3RCStrNew(u64);
char *sqlite3RCStrResize(char*,u64);

void sqlite3StrAccumInit(StrAccum*, sqlite3*, char*, int, int);
int sqlite3StrAccumEnlarge(StrAccum*, i64);
char *sqlite3StrAccumFinish(StrAccum*);
void sqlite3StrAccumSetError(StrAccum*, u8);
void sqlite3ResultStrAccum(sqlite3_context*,StrAccum*);
void sqlite3SelectDestInit(SelectDest*,int,int);
Expr *sqlite3CreateColumnExpr(sqlite3 *, SrcList *, int, int);

  if( pMem->flags & MEM_Dyn ){
    if( pMem->xDel==sqlite3_free
     && sqlite3_msize(pMem->z) >= (u64)(pMem->n+1)
    ){
      pMem->z[pMem->n] = 0;
      pMem->flags |= MEM_Term;
      return;
    }
    if( pMem->xDel==(void(*)(void*))sqlite3RCStrUnref ){
      /* Blindly assume that all RCStr objects are zero-terminated */
      pMem->flags |= MEM_Term;
      return;
    }
  }else if( pMem->szMalloc>0 && pMem->szMalloc >= pMem->n+1 ){
    pMem->z[pMem->n] = 0;
    pMem->flags |= MEM_Term;
    return;
  }
}