Fossil

**    May you find forgiveness for yourself and forgive others.
**    May you share freely, never taking more than you give.
**
******************************************************************************
**
** This SQLite extension implements functions that compute SHA3 hashes
** in the way described by the (U.S.) NIST FIPS 202 SHA-3 Standard.
** Three SQL functions are implemented:
**
**     sha3(X,SIZE)
**     sha3_agg(Y,SIZE)
**     sha3_query(Z,SIZE)
**
** The sha3(X) function computes the SHA3 hash of the input X, or NULL if
** X is NULL.  If inputs X is text, the UTF-8 rendering of that text is

    if( zType[0]=='v' || zType[1]=='r' || bVirtual ){
      /* A view. Or a trigger on a view. */
      if( zSql ) rc = expertSchemaSql(p->dbv, zSql, pzErrmsg);
    }else{
      IdxTable *pTab;
      rc = idxGetTableInfo(p->db, zName, &pTab, pzErrmsg);
      if( rc==SQLITE_OK && ALWAYS(pTab!=0) ){
        int i;
        char *zInner = 0;
        char *zOuter = 0;
        pTab->pNext = p->pTable;
        p->pTable = pTab;

        /* The statement the vtab will pass to sqlite3_declare_vtab() */

**         -DSQLITE_THREADSAFE=0 -DSQLITE_ENABLE_VFSTRACE \
**         shell.c test_vfstrace.c sqlite3.c
**
** Similar compiler commands will work on different systems.  The key
** invariants are (1) you must have -DSQLITE_ENABLE_VFSTRACE so that
** the shell.c source file will know to include the -vfstrace command-line
** option and (2) you must compile and link the three source files
** shell,c, test_vfstrace.c, and sqlite3.c.
**
** RUNTIME CONTROL OF VFSTRACE OUTPUT
**
** The application can use the "vfstrace" pragma to control which VFS
** APIs are traced.  To disable all output:
**
**    PRAGMA vfstrace('-all');
**
** To enable all output (which is the default setting):
**
**    PRAGMA vfstrace('+all');
**
** Individual APIs can be enabled or disabled by name, with or without
** the initial "x" character.  For example, to set up for tracing lock
** primatives only:
**
**    PRAGMA vfstrace('-all, +Lock,Unlock,ShmLock');
**
** The argument to the vfstrace pragma ignores capitalization and any
** characters other than alphabetics, '+', and '-'.
*/
#include <stdlib.h>
#include <string.h>
/* #include "sqlite3.h" */

/*
** An instance of this structure is attached to the each trace VFS to
** provide auxiliary information.
*/
typedef struct vfstrace_info vfstrace_info;
struct vfstrace_info {
  sqlite3_vfs *pRootVfs;              /* The underlying real VFS */
  int (*xOut)(const char*, void*);    /* Send output here */
  unsigned int mTrace;                /* Mask of interfaces to trace */
  u8 bOn;                             /* Tracing on/off */
  void *pOutArg;                      /* First argument to xOut */
  const char *zVfsName;               /* Name of this trace-VFS */
  sqlite3_vfs *pTraceVfs;             /* Pointer back to the trace VFS */
};

/*
** The sqlite3_file object for the trace VFS
*/
typedef struct vfstrace_file vfstrace_file;
struct vfstrace_file {
  sqlite3_file base;        /* Base class.  Must be first */
  vfstrace_info *pInfo;     /* The trace-VFS to which this file belongs */
  const char *zFName;       /* Base name of the file */
  sqlite3_file *pReal;      /* The real underlying file */
};

/*
** Bit values for vfstrace_info.mTrace.
*/
#define VTR_CLOSE           0x00000001
#define VTR_READ            0x00000002
#define VTR_WRITE           0x00000004
#define VTR_TRUNC           0x00000008
#define VTR_SYNC            0x00000010
#define VTR_FSIZE           0x00000020
#define VTR_LOCK            0x00000040
#define VTR_UNLOCK          0x00000080
#define VTR_CRL             0x00000100
#define VTR_FCTRL           0x00000200
#define VTR_SECSZ           0x00000400
#define VTR_DEVCHAR         0x00000800
#define VTR_SHMLOCK         0x00001000
#define VTR_SHMMAP          0x00002000
#define VTR_SHMBAR          0x00004000
#define VTR_SHMUNMAP        0x00008000
#define VTR_OPEN            0x00010000
#define VTR_DELETE          0x00020000
#define VTR_ACCESS          0x00040000
#define VTR_FULLPATH        0x00080000
#define VTR_DLOPEN          0x00100000
#define VTR_DLERR           0x00200000
#define VTR_DLSYM           0x00400000
#define VTR_DLCLOSE         0x00800000
#define VTR_RAND            0x01000000
#define VTR_SLEEP           0x02000000
#define VTR_CURTIME         0x04000000
#define VTR_LASTERR         0x08000000

/*
** Method declarations for vfstrace_file.
*/
static int vfstraceClose(sqlite3_file*);
static int vfstraceRead(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
static int vfstraceWrite(sqlite3_file*,const void*,int iAmt, sqlite3_int64);
static int vfstraceTruncate(sqlite3_file*, sqlite3_int64 size);

static void vfstrace_printf(
  vfstrace_info *pInfo,
  const char *zFormat,
  ...
){
  va_list ap;
  char *zMsg;
  if( pInfo->bOn ){
    va_start(ap, zFormat);
    zMsg = sqlite3_vmprintf(zFormat, ap);
    va_end(ap);
    pInfo->xOut(zMsg, pInfo->pOutArg);
    sqlite3_free(zMsg);
  }
}

/*
** Try to convert an error code into a symbolic name for that error code.
*/
static const char *vfstrace_errcode_name(int rc ){
  const char *zVal = 0;

*/
static void strappend(char *z, int *pI, const char *zAppend){
  int i = *pI;
  while( zAppend[0] ){ z[i++] = *(zAppend++); }
  z[i] = 0;
  *pI = i;
}

/*
** Turn tracing output on or off according to mMask.
*/
static void vfstraceOnOff(vfstrace_info *pInfo, unsigned int mMask){
  pInfo->bOn = (pInfo->mTrace & mMask)!=0;
}

/*
** Close an vfstrace-file.
*/
static int vfstraceClose(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_CLOSE);
  vfstrace_printf(pInfo, "%s.xClose(%s)", pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xClose(p->pReal);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  if( rc==SQLITE_OK ){
    sqlite3_free((void*)p->base.pMethods);
    p->base.pMethods = 0;
  }

  void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_READ);
  vfstrace_printf(pInfo, "%s.xRead(%s,n=%d,ofst=%lld)",
                  pInfo->zVfsName, p->zFName, iAmt, iOfst);
  rc = p->pReal->pMethods->xRead(p->pReal, zBuf, iAmt, iOfst);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Write data to an vfstrace-file.
*/
static int vfstraceWrite(
  sqlite3_file *pFile, 
  const void *zBuf, 
  int iAmt, 
  sqlite_int64 iOfst
){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_WRITE);
  vfstrace_printf(pInfo, "%s.xWrite(%s,n=%d,ofst=%lld)",
                  pInfo->zVfsName, p->zFName, iAmt, iOfst);
  rc = p->pReal->pMethods->xWrite(p->pReal, zBuf, iAmt, iOfst);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Truncate an vfstrace-file.
*/
static int vfstraceTruncate(sqlite3_file *pFile, sqlite_int64 size){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_TRUNC);
  vfstrace_printf(pInfo, "%s.xTruncate(%s,%lld)", pInfo->zVfsName, p->zFName,
                  size);
  rc = p->pReal->pMethods->xTruncate(p->pReal, size);
  vfstrace_printf(pInfo, " -> %d\n", rc);
  return rc;
}

  i = 0;
  if( flags & SQLITE_SYNC_FULL )        strappend(zBuf, &i, "|FULL");
  else if( flags & SQLITE_SYNC_NORMAL ) strappend(zBuf, &i, "|NORMAL");
  if( flags & SQLITE_SYNC_DATAONLY )    strappend(zBuf, &i, "|DATAONLY");
  if( flags & ~(SQLITE_SYNC_FULL|SQLITE_SYNC_DATAONLY) ){
    sqlite3_snprintf(sizeof(zBuf)-i, &zBuf[i], "|0x%x", flags);
  }
  vfstraceOnOff(pInfo, VTR_SYNC);
  vfstrace_printf(pInfo, "%s.xSync(%s,%s)", pInfo->zVfsName, p->zFName,
                  &zBuf[1]);
  rc = p->pReal->pMethods->xSync(p->pReal, flags);
  vfstrace_printf(pInfo, " -> %d\n", rc);
  return rc;
}

/*
** Return the current file-size of an vfstrace-file.
*/
static int vfstraceFileSize(sqlite3_file *pFile, sqlite_int64 *pSize){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_FSIZE);
  vfstrace_printf(pInfo, "%s.xFileSize(%s)", pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xFileSize(p->pReal, pSize);
  vfstrace_print_errcode(pInfo, " -> %s,", rc);
  vfstrace_printf(pInfo, " size=%lld\n", *pSize);
  return rc;
}

/*
** Lock an vfstrace-file.
*/
static int vfstraceLock(sqlite3_file *pFile, int eLock){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_LOCK);
  vfstrace_printf(pInfo, "%s.xLock(%s,%s)", pInfo->zVfsName, p->zFName,
                  lockName(eLock));
  rc = p->pReal->pMethods->xLock(p->pReal, eLock);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Unlock an vfstrace-file.
*/
static int vfstraceUnlock(sqlite3_file *pFile, int eLock){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_UNLOCK);
  vfstrace_printf(pInfo, "%s.xUnlock(%s,%s)", pInfo->zVfsName, p->zFName,
                  lockName(eLock));
  rc = p->pReal->pMethods->xUnlock(p->pReal, eLock);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Check if another file-handle holds a RESERVED lock on an vfstrace-file.
*/
static int vfstraceCheckReservedLock(sqlite3_file *pFile, int *pResOut){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_CRL);
  vfstrace_printf(pInfo, "%s.xCheckReservedLock(%s,%d)", 
                  pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xCheckReservedLock(p->pReal, pResOut);
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  vfstrace_printf(pInfo, ", out=%d\n", *pResOut);
  return rc;
}

/*
** File control method. For custom operations on an vfstrace-file.
*/
static int vfstraceFileControl(sqlite3_file *pFile, int op, void *pArg){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  char zBuf[100];
  char zBuf2[100];
  char *zOp;
  char *zRVal = 0;
  vfstraceOnOff(pInfo, VTR_FCTRL);
  switch( op ){
    case SQLITE_FCNTL_LOCKSTATE:           zOp = "LOCKSTATE";           break;
    case SQLITE_GET_LOCKPROXYFILE:         zOp = "GET_LOCKPROXYFILE";   break;
    case SQLITE_SET_LOCKPROXYFILE:         zOp = "SET_LOCKPROXYFILE";   break;
    case SQLITE_LAST_ERRNO:                zOp = "LAST_ERRNO";          break;
    case SQLITE_FCNTL_SIZE_HINT: {
      sqlite3_snprintf(sizeof(zBuf), zBuf, "SIZE_HINT,%lld",

       break;
    }
    case SQLITE_FCNTL_OVERWRITE:           zOp = "OVERWRITE";           break;
    case SQLITE_FCNTL_VFSNAME:             zOp = "VFSNAME";             break;
    case SQLITE_FCNTL_POWERSAFE_OVERWRITE: zOp = "POWERSAFE_OVERWRITE"; break;
    case SQLITE_FCNTL_PRAGMA: {
      const char *const* a = (const char*const*)pArg;
      if( a[1] && strcmp(a[1],"vfstrace")==0 && a[2] ){
        const u8 *zArg = (const u8*)a[2];
        if( zArg[0]>='0' && zArg[0]<=9 ){
          pInfo->mTrace = (sqlite3_uint64)strtoll(a[2], 0, 0);
        }else{
          static const struct {
            const char *z;
            unsigned int m;
          } aKw[] = {
            { "all",                   0xffffffff   },
            { "close",                 VTR_CLOSE    },
            { "read",                  VTR_READ     },
            { "write",                 VTR_WRITE    },
            { "truncate",              VTR_TRUNC    },
            { "sync",                  VTR_SYNC     },
            { "filesize",              VTR_FSIZE    },
            { "lock",                  VTR_LOCK     },
            { "unlock",                VTR_UNLOCK   },
            { "checkreservedlock",     VTR_CRL      },
            { "filecontrol",           VTR_FCTRL    },
            { "sectorsize",            VTR_SECSZ    },
            { "devicecharacteristics", VTR_DEVCHAR  },
            { "shmlock",               VTR_SHMLOCK  },
            { "shmmap",                VTR_SHMMAP   },
            { "shmummap",              VTR_SHMUNMAP },
            { "shmbarrier",            VTR_SHMBAR   },
            { "open",                  VTR_OPEN     },
            { "delete",                VTR_DELETE   },
            { "access",                VTR_ACCESS   },
            { "fullpathname",          VTR_FULLPATH },
            { "dlopen",                VTR_DLOPEN   },
            { "dlerror",               VTR_DLERR    },
            { "dlsym",                 VTR_DLSYM    },
            { "dlclose",               VTR_DLCLOSE  },
            { "randomness",            VTR_RAND     },
            { "sleep",                 VTR_SLEEP    },
            { "currenttime",           VTR_CURTIME  },
            { "currenttimeint64",      VTR_CURTIME  },
            { "getlasterror",          VTR_LASTERR  },
          };
          int onOff = 1;
          while( zArg[0] ){
            int jj, n;
            while( zArg[0]!=0 && zArg[0]!='-' && zArg[0]!='+'
                   && !isalpha(zArg[0]) ) zArg++;
            if( zArg[0]==0 ) break;
            if( zArg[0]=='-' ){
              onOff = 0;
              zArg++;
            }else if( zArg[0]=='+' ){
              onOff = 1;
              zArg++;
            }
            while( !isalpha(zArg[0]) ){
              if( zArg[0]==0 ) break;
              zArg++;
            }
            if( zArg[0]=='x' && isalpha(zArg[1]) ) zArg++;
            for(n=0; isalpha(zArg[n]); n++){}
            for(jj=0; jj<(int)(sizeof(aKw)/sizeof(aKw[0])); jj++){
              if( sqlite3_strnicmp(aKw[jj].z,(const char*)zArg,n)==0 ){
                if( onOff ){
                  pInfo->mTrace |= aKw[jj].m;
                }else{
                  pInfo->mTrace &= ~aKw[jj].m;
                }
                break;
              }
            }
            zArg += n;
          }
        }
      }
      sqlite3_snprintf(sizeof(zBuf), zBuf, "PRAGMA,[%s,%s]",a[1],a[2]);
      zOp = zBuf;
      break;
    }
    case SQLITE_FCNTL_BUSYHANDLER:         zOp = "BUSYHANDLER";         break;
    case SQLITE_FCNTL_TEMPFILENAME:        zOp = "TEMPFILENAME";        break;
    case SQLITE_FCNTL_MMAP_SIZE: {

/*
** Return the sector-size in bytes for an vfstrace-file.
*/
static int vfstraceSectorSize(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_SECSZ);
  vfstrace_printf(pInfo, "%s.xSectorSize(%s)", pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xSectorSize(p->pReal);
  vfstrace_printf(pInfo, " -> %d\n", rc);
  return rc;
}

/*
** Return the device characteristic flags supported by an vfstrace-file.
*/
static int vfstraceDeviceCharacteristics(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_DEVCHAR);
  vfstrace_printf(pInfo, "%s.xDeviceCharacteristics(%s)",
                  pInfo->zVfsName, p->zFName);
  rc = p->pReal->pMethods->xDeviceCharacteristics(p->pReal);
  vfstrace_printf(pInfo, " -> 0x%08x\n", rc);
  return rc;
}

     "READ4",
  };
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  char zLck[100];
  int i = 0;
  vfstraceOnOff(pInfo, VTR_SHMLOCK);
  memcpy(zLck, "|0", 3);
  if( flags & SQLITE_SHM_UNLOCK )    strappend(zLck, &i, "|UNLOCK");
  if( flags & SQLITE_SHM_LOCK )      strappend(zLck, &i, "|LOCK");
  if( flags & SQLITE_SHM_SHARED )    strappend(zLck, &i, "|SHARED");
  if( flags & SQLITE_SHM_EXCLUSIVE ) strappend(zLck, &i, "|EXCLUSIVE");
  if( flags & ~(0xf) ){
     sqlite3_snprintf(sizeof(zLck)-i, &zLck[i], "|0x%x", flags);
  }
  if( ofst>=0 && ofst<(int)(sizeof(azLockName)/sizeof(azLockName[0])) ){
    vfstrace_printf(pInfo, "%s.xShmLock(%s,ofst=%d(%s),n=%d,%s)",
                  pInfo->zVfsName, p->zFName, ofst, azLockName[ofst],
                  n, &zLck[1]);
  }else{
    vfstrace_printf(pInfo, "%s.xShmLock(%s,ofst=5d,n=%d,%s)",
                  pInfo->zVfsName, p->zFName, ofst,
                  n, &zLck[1]);

  int szRegion, 
  int isWrite, 
  void volatile **pp
){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_SHMMAP);
  vfstrace_printf(pInfo, "%s.xShmMap(%s,iRegion=%d,szRegion=%d,isWrite=%d,*)",
                  pInfo->zVfsName, p->zFName, iRegion, szRegion, isWrite);
  rc = p->pReal->pMethods->xShmMap(p->pReal, iRegion, szRegion, isWrite, pp);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}
static void vfstraceShmBarrier(sqlite3_file *pFile){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  vfstraceOnOff(pInfo, VTR_SHMBAR);
  vfstrace_printf(pInfo, "%s.xShmBarrier(%s)\n", pInfo->zVfsName, p->zFName);
  p->pReal->pMethods->xShmBarrier(p->pReal);
}
static int vfstraceShmUnmap(sqlite3_file *pFile, int delFlag){
  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = p->pInfo;
  int rc;
  vfstraceOnOff(pInfo, VTR_SHMUNMAP);
  vfstrace_printf(pInfo, "%s.xShmUnmap(%s,delFlag=%d)",
                  pInfo->zVfsName, p->zFName, delFlag);
  rc = p->pReal->pMethods->xShmUnmap(p->pReal, delFlag);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

  vfstrace_file *p = (vfstrace_file *)pFile;
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  p->pInfo = pInfo;
  p->zFName = zName ? fileTail(zName) : "<temp>";
  p->pReal = (sqlite3_file *)&p[1];
  rc = pRoot->xOpen(pRoot, zName, p->pReal, flags, pOutFlags);
  vfstraceOnOff(pInfo, VTR_OPEN);
  vfstrace_printf(pInfo, "%s.xOpen(%s,flags=0x%x)",
                  pInfo->zVfsName, p->zFName, flags);
  if( p->pReal->pMethods ){
    sqlite3_io_methods *pNew = sqlite3_malloc( sizeof(*pNew) );
    const sqlite3_io_methods *pSub = p->pReal->pMethods;
    memset(pNew, 0, sizeof(*pNew));
    pNew->iVersion = pSub->iVersion;

** ensure the file-system modifications are synced to disk before
** returning.
*/
static int vfstraceDelete(sqlite3_vfs *pVfs, const char *zPath, int dirSync){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_DELETE);
  vfstrace_printf(pInfo, "%s.xDelete(\"%s\",%d)",
                  pInfo->zVfsName, zPath, dirSync);
  rc = pRoot->xDelete(pRoot, zPath, dirSync);
  vfstrace_print_errcode(pInfo, " -> %s\n", rc);
  return rc;
}

/*
** Test for access permissions. Return true if the requested permission
** is available, or false otherwise.
*/
static int vfstraceAccess(
  sqlite3_vfs *pVfs, 
  const char *zPath, 
  int flags, 
  int *pResOut
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_ACCESS);
  vfstrace_printf(pInfo, "%s.xAccess(\"%s\",%d)",
                  pInfo->zVfsName, zPath, flags);
  rc = pRoot->xAccess(pRoot, zPath, flags, pResOut);
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  vfstrace_printf(pInfo, ", out=%d\n", *pResOut);
  return rc;
}

  const char *zPath, 
  int nOut, 
  char *zOut
){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_FULLPATH);
  vfstrace_printf(pInfo, "%s.xFullPathname(\"%s\")",
                  pInfo->zVfsName, zPath);
  rc = pRoot->xFullPathname(pRoot, zPath, nOut, zOut);
  vfstrace_print_errcode(pInfo, " -> %s", rc);
  vfstrace_printf(pInfo, ", out=\"%.*s\"\n", nOut, zOut);
  return rc;
}

/*
** Open the dynamic library located at zPath and return a handle.
*/
static void *vfstraceDlOpen(sqlite3_vfs *pVfs, const char *zPath){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_DLOPEN);
  vfstrace_printf(pInfo, "%s.xDlOpen(\"%s\")\n", pInfo->zVfsName, zPath);
  return pRoot->xDlOpen(pRoot, zPath);
}

/*
** Populate the buffer zErrMsg (size nByte bytes) with a human readable
** utf-8 string describing the most recent error encountered associated 
** with dynamic libraries.
*/
static void vfstraceDlError(sqlite3_vfs *pVfs, int nByte, char *zErrMsg){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_DLERR);
  vfstrace_printf(pInfo, "%s.xDlError(%d)", pInfo->zVfsName, nByte);
  pRoot->xDlError(pRoot, nByte, zErrMsg);
  vfstrace_printf(pInfo, " -> \"%s\"", zErrMsg);
}

/*
** Return a pointer to the symbol zSymbol in the dynamic library pHandle.

/*
** Close the dynamic library handle pHandle.
*/
static void vfstraceDlClose(sqlite3_vfs *pVfs, void *pHandle){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_DLCLOSE);
  vfstrace_printf(pInfo, "%s.xDlOpen()\n", pInfo->zVfsName);
  pRoot->xDlClose(pRoot, pHandle);
}

/*
** Populate the buffer pointed to by zBufOut with nByte bytes of 
** random data.
*/
static int vfstraceRandomness(sqlite3_vfs *pVfs, int nByte, char *zBufOut){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_RAND);
  vfstrace_printf(pInfo, "%s.xRandomness(%d)\n", pInfo->zVfsName, nByte);
  return pRoot->xRandomness(pRoot, nByte, zBufOut);
}

/*
** Sleep for nMicro microseconds. Return the number of microseconds 
** actually slept.
*/
static int vfstraceSleep(sqlite3_vfs *pVfs, int nMicro){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  vfstraceOnOff(pInfo, VTR_SLEEP);
  vfstrace_printf(pInfo, "%s.xSleep(%d)\n", pInfo->zVfsName, nMicro);
  return pRoot->xSleep(pRoot, nMicro);
}

/*
** Return the current time as a Julian Day number in *pTimeOut.
*/
static int vfstraceCurrentTime(sqlite3_vfs *pVfs, double *pTimeOut){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_CURTIME);
  vfstrace_printf(pInfo, "%s.xCurrentTime()", pInfo->zVfsName);
  rc = pRoot->xCurrentTime(pRoot, pTimeOut);
  vfstrace_printf(pInfo, " -> %.17g\n", *pTimeOut);
  return rc;
}
static int vfstraceCurrentTimeInt64(sqlite3_vfs *pVfs, sqlite3_int64 *pTimeOut){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_CURTIME);
  vfstrace_printf(pInfo, "%s.xCurrentTimeInt64()", pInfo->zVfsName);
  rc = pRoot->xCurrentTimeInt64(pRoot, pTimeOut);
  vfstrace_printf(pInfo, " -> %lld\n", *pTimeOut);
  return rc;
}

/*
** Return the most recent error code and message
*/
static int vfstraceGetLastError(sqlite3_vfs *pVfs, int nErr, char *zErr){
  vfstrace_info *pInfo = (vfstrace_info*)pVfs->pAppData;
  sqlite3_vfs *pRoot = pInfo->pRootVfs;
  int rc;
  vfstraceOnOff(pInfo, VTR_LASTERR);
  vfstrace_printf(pInfo, "%s.xGetLastError(%d,zBuf)", pInfo->zVfsName, nErr);
  if( nErr ) zErr[0] = 0;
  rc = pRoot->xGetLastError(pRoot, nErr, zErr);
  vfstrace_printf(pInfo, " -> zBuf[] = \"%s\", rc = %d\n", nErr?zErr:"", rc);
  return rc;
}

/*
** Override system calls.
*/
static int vfstraceSetSystemCall(
  sqlite3_vfs *pVfs,

    }
  }
  pInfo->pRootVfs = pRoot;
  pInfo->xOut = xOut;
  pInfo->pOutArg = pOutArg;
  pInfo->zVfsName = pNew->zName;
  pInfo->pTraceVfs = pNew;
  pInfo->mTrace = 0xffffffff;
  pInfo->bOn = 1;
  vfstrace_printf(pInfo, "%s.enabled_for(\"%s\")\n",
       pInfo->zVfsName, pRoot->zName);
  return sqlite3_vfs_register(pNew, makeDefault);
}

/*
** Look for the named VFS.  If it is a TRACEVFS, then unregister it

# define output_redir(SS,pfO)
# define output_reset(SS)
#endif

/*
** Run an SQL command and return the single integer result.
*/
static int db_int(sqlite3 *db, const char *zSql, ...){
  sqlite3_stmt *pStmt;
  int res = 0;
  char *z;
  va_list ap;
  va_start(ap, zSql);
  z = sqlite3_vmprintf(zSql, ap);
  va_end(ap);
  sqlite3_prepare_v2(db, z, -1, &pStmt, 0);
  if( pStmt && sqlite3_step(pStmt)==SQLITE_ROW ){
    res = sqlite3_column_int(pStmt,0);
  }
  sqlite3_finalize(pStmt);
  sqlite3_free(z);
  return res;
}

#if SQLITE_SHELL_HAVE_RECOVER
/*
** Convert a 2-byte or 4-byte big-endian integer into a native integer
*/

    zSchemaTab = sqlite3_mprintf("main.sqlite_schema");
  }else if( cli_strcmp(zDb,"temp")==0 ){
    zSchemaTab = sqlite3_mprintf("%s", "sqlite_temp_schema");
  }else{
    zSchemaTab = sqlite3_mprintf("\"%w\".sqlite_schema", zDb);
  }
  for(i=0; i<ArraySize(aQuery); i++){

    int val = db_int(p->db, aQuery[i].zSql, zSchemaTab);

    sqlite3_fprintf(p->out, "%-20s %d\n", aQuery[i].zName, val);
  }
  sqlite3_free(zSchemaTab);
  sqlite3_file_control(p->db, zDb, SQLITE_FCNTL_DATA_VERSION, &iDataVersion);
  sqlite3_fprintf(p->out, "%-20s %u\n", "data version", iDataVersion);
  return 0;
}
#endif /* SQLITE_SHELL_HAVE_RECOVER */

/*
** Implementation of the ".dbtotxt" command.
**
** Return 1 on error, 2 to exit, and 0 otherwise.
*/
static int shell_dbtotxt_command(ShellState *p, int nArg, char **azArg){
  sqlite3_stmt *pStmt = 0;
  sqlite3_int64 nPage = 0;
  int pgSz = 0;

  const char *zTail;
  char *zName = 0;
  int rc, i, j;
  unsigned char bShow[256];   /* Characters ok to display */

  UNUSED_PARAMETER(nArg);
  UNUSED_PARAMETER(azArg);
  memset(bShow, '.', sizeof(bShow));
  for(i=' '; i<='~'; i++){
    if( i!='{' && i!='}' && i!='"' && i!='\\' ) bShow[i] = (unsigned char)i;
  }
  rc = sqlite3_prepare_v2(p->db, "PRAGMA page_size", -1, &pStmt, 0);
  if( rc ) goto dbtotxt_error;
  rc = 0;

  if( sqlite3_step(pStmt)!=SQLITE_ROW ) goto dbtotxt_error;
  nPage = sqlite3_column_int64(pStmt, 0);
  sqlite3_finalize(pStmt);
  pStmt = 0;
  if( nPage<1 ) goto dbtotxt_error;
  rc = sqlite3_prepare_v2(p->db, "PRAGMA databases", -1, &pStmt, 0);
  if( rc ) goto dbtotxt_error;

  if( sqlite3_step(pStmt)!=SQLITE_ROW ){
    zTail = "unk.db";
  }else{
    const char *zFilename = (const char*)sqlite3_column_text(pStmt, 2);
    if( zFilename==0 || zFilename[0]==0 ) zFilename = "unk.db";
    zTail = strrchr(zFilename, '/');
#if defined(_WIN32)
    if( zTail==0 ) zTail = strrchr(zFilename, '\\');
#endif

  }
  zName = strdup(zTail);
  shell_check_oom(zName);
  sqlite3_fprintf(p->out, "| size %lld pagesize %d filename %s\n",
                  nPage*pgSz, pgSz, zName);
  sqlite3_finalize(pStmt);
  pStmt = 0;
  rc = sqlite3_prepare_v2(p->db,
           "SELECT pgno, data FROM sqlite_dbpage ORDER BY pgno", -1, &pStmt, 0);
  if( rc ) goto dbtotxt_error;

  while( sqlite3_step(pStmt)==SQLITE_ROW ){
    sqlite3_int64 pgno = sqlite3_column_int64(pStmt, 0);
    const u8 *aData = sqlite3_column_blob(pStmt, 1);
    int seenPageLabel = 0;
    for(i=0; i<pgSz; i+=16){
      const u8 *aLine = aData+i;
      for(j=0; j<16 && aLine[j]==0; j++){}

    sqlite3_finalize(pStmt);
    return 0;
  }else if( *pDb==0 ){
    return 0;
  }else{
    /* Formulate the columns spec, close the DB, zero *pDb. */
    char *zColsSpec = 0;
    int hasDupes = db_int(*pDb, "%s", zHasDupes);
    int nDigits = (hasDupes)? db_int(*pDb, "%s", zColDigits) : 0;
    if( hasDupes ){
#ifdef SHELL_COLUMN_RENAME_CLEAN
      rc = sqlite3_exec(*pDb, zDedoctor, 0, 0, 0);
      rc_err_oom_die(rc);
#endif
      rc = sqlite3_exec(*pDb, zSetReps, 0, 0, 0);
      rc_err_oom_die(rc);
      rc = sqlite3_prepare_v2(*pDb, zRenameRank, -1, &pStmt, 0);
      rc_err_oom_die(rc);
      sqlite3_bind_int(pStmt, 1, nDigits);
      rc = sqlite3_step(pStmt);
      sqlite3_finalize(pStmt);
      if( rc!=SQLITE_DONE ) rc_err_oom_die(SQLITE_NOMEM);
    }
    assert(db_int(*pDb, "%s", zHasDupes)==0); /* Consider: remove this */
    rc = sqlite3_prepare_v2(*pDb, zCollectVar, -1, &pStmt, 0);
    rc_err_oom_die(rc);
    rc = sqlite3_step(pStmt);
    if( rc==SQLITE_ROW ){
      zColsSpec = sqlite3_mprintf("%s", sqlite3_column_text(pStmt, 0));
    }else{
      zColsSpec = 0;

      shell_out_of_memory();
    }
    /* Below, resources must be freed before exit. */
    while( (nSkip--)>0 ){
      while( xRead(&sCtx) && sCtx.cTerm==sCtx.cColSep ){}
    }
    import_append_char(&sCtx, 0);    /* To ensure sCtx.z is allocated */
    if( sqlite3_table_column_metadata(p->db, zSchema, zTable,0,0,0,0,0,0) 
     && 0==db_int(p->db, "SELECT count(*) FROM \"%w\".sqlite_schema"
                         " WHERE name=%Q AND type='view'",
                         zSchema ? zSchema : "main", zTable)
    ){
      /* Table does not exist.  Create it. */
      sqlite3 *dbCols = 0;
      char *zRenames = 0;
      char *zColDefs;
      zCreate = sqlite3_mprintf("CREATE TABLE \"%w\".\"%w\"", 
                    zSchema ? zSchema : "main", zTable);
      while( xRead(&sCtx) ){

      shellDatabaseError(p->db);
      rc = 1;
    }
    close_db(pSrc);
  }else
#endif /* !defined(SQLITE_SHELL_FIDDLE) */

  if( c=='s' &&
     (cli_strncmp(azArg[0], "scanstats",  n)==0 ||
      cli_strncmp(azArg[0], "scanstatus", n)==0)
  ){
    if( nArg==2 ){
      if( cli_strcmp(azArg[1], "vm")==0 ){
        p->scanstatsOn = 3;
      }else
      if( cli_strcmp(azArg[1], "est")==0 ){
        p->scanstatsOn = 2;
      }else{

            { 0x04000000, 1, "NullUnusedCols" },
            { 0x08000000, 1, "OnePass" },
            { 0x10000000, 1, "OrderBySubq" },
            { 0xffffffff, 0, "All" },
          };
          unsigned int curOpt;
          unsigned int newOpt;
          unsigned int m;
          int ii;
          int nOff;
          sqlite3_test_control(SQLITE_TESTCTRL_GETOPT, p->db, &curOpt);
          newOpt = curOpt;
          for(ii=2; ii<nArg; ii++){
            const char *z = azArg[ii];
            int useLabel = 0;
            const char *zLabel = 0;
            if( (z[0]=='+'|| z[0]=='-') && !IsDigit(z[1]) ){

              }else{
                newOpt |= aLabel[jj].mask;
              }
            }
          }
          if( curOpt!=newOpt ){
            sqlite3_test_control(SQLITE_TESTCTRL_OPTIMIZATIONS,p->db,newOpt);

          }
          for(ii=nOff=0, m=1; ii<32; ii++, m <<= 1){
            if( m & newOpt ) nOff++;
          }
          if( nOff<12 ){
            sqlite3_fputs("+All", p->out);
            for(ii=0; ii<ArraySize(aLabel); ii++){
              if( !aLabel[ii].bDsply  ) continue;
              if( (newOpt & aLabel[ii].mask)!=0 ){
                sqlite3_fprintf(p->out, " -%s", aLabel[ii].zLabel);
              }
            }
          }else{

            sqlite3_fputs("-All", p->out);
            for(ii=0; ii<ArraySize(aLabel); ii++){

              if( !aLabel[ii].bDsply  ) continue;
              if( (newOpt & aLabel[ii].mask)==0 ){
                sqlite3_fprintf(p->out, " +%s", aLabel[ii].zLabel);

              }
            }
          }
          sqlite3_fputs("\n", p->out);
          rc2 = isOk = 3;
          break;
        }

        /* sqlite3_test_control(int, db, int) */
        case SQLITE_TESTCTRL_FK_NO_ACTION:
          if( nArg==3 ){

*/
static QuickScanState quickscan(char *zLine, QuickScanState qss,
                                SCAN_TRACKER_REFTYPE pst){
  char cin;
  char cWait = (char)qss; /* intentional narrowing loss */
  if( cWait==0 ){
  PlainScan:

    while( (cin = *zLine++)!=0 ){
      if( IsSpace(cin) )
        continue;
      switch (cin){
      case '-':
        if( *zLine!='-' )
          break;

    while( (cin = *zLine++)!=0 ){
      if( cin==cWait ){
        switch( cWait ){
        case '*':
          if( *zLine != '/' )
            continue;
          ++zLine;

          CONTINUE_PROMPT_AWAITC(pst, 0);
          qss = QSS_SETV(qss, 0);
          goto PlainScan;
        case '`': case '\'': case '"':
          if(*zLine==cWait){
            /* Swallow doubled end-delimiter.*/
            ++zLine;
            continue;
          }
          deliberate_fall_through;
        case ']':

          CONTINUE_PROMPT_AWAITC(pst, 0);
          qss = QSS_SETV(qss, 0);
          goto PlainScan;
        default: assert(0);
        }
      }
    }

  }

  if( doAutoDetectRestore(p, zSql) ) return 1;
  return 0;
}

static void echo_group_input(ShellState *p, const char *zDo){
  if( ShellHasFlag(p, SHFLG_Echo) ){
    sqlite3_fprintf(p->out, "%s\n", zDo);
    fflush(p->out);
  }
}

#ifdef SQLITE_SHELL_FIDDLE
/*
** Alternate one_input_line() impl for wasm mode. This is not in the primary
** impl because we need the global shellState and cannot access it from that
** function without moving lots of code around (creating a larger/messier diff).

  }
  return argv[i];
}

static void sayAbnormalExit(void){
  if( seenInterrupt ) eputz("Program interrupted.\n");
}

/* Routine to output from vfstrace
*/
static int vfstraceOut(const char *z, void *pArg){
  ShellState *p = (ShellState*)pArg;
  sqlite3_fputs(z, p->out);
  fflush(p->out);
  return 1;
}

#ifndef SQLITE_SHELL_IS_UTF8
#  if (defined(_WIN32) || defined(WIN32)) \
   && (defined(_MSC_VER) || (defined(UNICODE) && defined(__GNUC__)))
#    define SQLITE_SHELL_IS_UTF8          (0)
#  else
#    define SQLITE_SHELL_IS_UTF8          (1)

      verify_uninitialized();
      switch( n ){
         case 0:  sqlite3_config(SQLITE_CONFIG_SINGLETHREAD);  break;
         case 2:  sqlite3_config(SQLITE_CONFIG_MULTITHREAD);   break;
         default: sqlite3_config(SQLITE_CONFIG_SERIALIZED);    break;
      }
    }else if( cli_strcmp(z,"-vfstrace")==0 ){


      bEnableVfstrace = 1;
#ifdef SQLITE_ENABLE_MULTIPLEX
    }else if( cli_strcmp(z,"-multiplex")==0 ){
      extern int sqlite3_multiplex_initialize(const char*,int);
      sqlite3_multiplex_initialize(0, 1);
#endif
    }else if( cli_strcmp(z,"-mmap")==0 ){

#else
    sqlite3_fprintf(stderr,
                    "%s: Error: no database filename specified\n", Argv0);
    return 1;
#endif
  }
  data.out = stdout;
  if( bEnableVfstrace ){
    vfstrace_register("trace",0,vfstraceOut, &data, 1);
  }
#ifndef SQLITE_SHELL_FIDDLE
  sqlite3_appendvfs_init(0,0,0);
#endif

  /* Go ahead and open the database file if it already exists.  If the
  ** file does not exist, delay opening it.  This prevents empty database
  ** files from being created if a user mistypes the database name argument