SQLite4  Check-in [a1399dac00]

** File-system interface.
*/
typedef struct bt_env bt_env;
typedef struct bt_file bt_file;

struct bt_env {
  void *pVfsCtx;
  int (*xFullpath)(sqlite4_env*,bt_env*, const char *, char **);
  int (*xOpen)(sqlite4_env*,bt_env*, const char *, int flags, bt_file**);
  int (*xRead)(bt_file*, i64, void *, int);
  int (*xWrite)(bt_file*, i64, void *, int);
  int (*xTruncate)(bt_file*, i64);
  int (*xSync)(bt_file*);
  int (*xSectorSize)(bt_file*);
  int (*xClose)(bt_file*);
  int (*xUnlink)(sqlite4_env*,bt_env*, const char *);
  int (*xLock)(bt_file*, int, int);
  int (*xTestLock)(bt_file*, int, int, int);
  int (*xShmMap)(bt_file*, int, int, void **);
  void (*xShmBarrier)(bt_file*);
  int (*xShmUnmap)(bt_file*, int);
};

/* Flags for the 3rd argument to xOpen */
#define BT_OPEN_READONLY 0x0001

/* Candidate values for the 3rd argument to bt_env.xLock() */
#define BT_LOCK_UNLOCK 0
#define BT_LOCK_SHARED 1
#define BT_LOCK_EXCL   2

/* Size of shared-memory chunks - 48KB. */
#define BT_SHM_CHUNK_SIZE (48*1024)

/* Find the default VFS */
bt_env *sqlite4BtEnvDefault(void);

/*
** End of file system interface.
*************************************************************************/

**    May you share freely, never taking more than you give.
**
*************************************************************************
**
*/

#include "bt.h"

struct bt_db {
  BtPager *pPager;
};

int sqlite4BtNew(lsm_env *pEnv, int nExtra, bt_db **ppDb){
  return SQLITE4_OK;
}

int sqlite4BtClose(bt_db *db){
  return SQLITE4_OK;

}

int sqlite4BtRollback(bt_db *db, int iLevel){
  return SQLITE4_OK;
}

int sqlite4BtTransactionLevel(bt_db *db){
  return sqlite4BtPagerTransactionLevel(db->pPager);
}

int sqlite4BtCsrOpen(bt_db *db, int nExtra, bt_cursor **ppCsr){
  return SQLITE4_OK;
}

int sqlite4BtCsrClose(bt_cursor *pCsr){

#endif

/*
** An open file is an instance of the following object
*/
typedef struct PosixFile PosixFile;
struct PosixFile {
  sqlite4_env *pSqlEnv;
  bt_env *pEnv;                   /* The run-time environment */
  const char *zName;              /* Full path to file */
  int fd;                         /* The open file descriptor */
  int shmfd;                      /* Shared memory file-descriptor */
  int nShm;                       /* Number of entries in array apShm[] */
  void **apShm;                   /* Array of 32K shared memory segments */
};

static char *posixShmFile(PosixFile *p){
  char *zShm;
  int nName = strlen(p->zName);
  zShm = (char*)btMalloc(nName+4+1);
  if( zShm ){
    memcpy(zShm, p->zName, nName);
    memcpy(&zShm[nName], "-shm", 5);
  }
  return zShm;
}

static int btPosixOsOpen(
  sqlite4_env *pSqlEnv,
  bt_env *pEnv,
  const char *zFile,
  int flags,
  bt_file **ppFile
){
  int rc = SQLITE4_OK;
  PosixFile *p;

  p = (PosixFile*)sqlite4_malloc(pSqlEnv, sizeof(PosixFile));
  if( p==0 ){
    rc = btErrorBkpt(SQLITE4_NOMEM);
  }else{
    int bReadonly = (flags & BT_OPEN_READONLY);
    int oflags = (bReadonly ? O_RDONLY : (O_RDWR|O_CREAT));
    memset(p, 0, sizeof(PosixFile));
    p->zName = zFile;
    p->pEnv = pEnv;
    p->pSqlEnv = pSqlEnv;
    p->fd = open(zFile, oflags, 0644);
    if( p->fd<0 ){
      sqlite4_free(pSqlEnv, p);
      p = 0;
      rc = btErrorBkpt(SQLITE4_IOERR);
    }
  }

  *ppFile = (bt_file*)p;
  return rc;
}

static int btPosixOsWrite(
  bt_file *pFile,                 /* File to write to */
  i64 iOff,                       /* Offset to write to */
  void *pData,                    /* Write data from this buffer */

}

static int btPosixOsSectorSize(bt_file *pFile){
  return 512;
}

static int btPosixOsFullpath(
  sqlite4_env *pSqlEnv,
  bt_env *pEnv,
  const char *zName,
  char **pzOut

){
  int rc = SQLITE4_OK;
  char *zOut = 0;
  char *zCwd = 0;
  int nCwd = 0;

  if( zName[0]!='/' ){


    int nTmp = 512;
    char *zTmp = (char*)sqlite4_malloc(pSqlEnv, nTmp);
    while( zTmp ){
      zCwd = getcwd(zTmp, nTmp);
      if( zCwd || errno!=ERANGE ) break;
      sqlite4_free(pSqlEnv, zTmp);
      nTmp = nTmp*2;
      zTmp = sqlite4_malloc(pSqlEnv, nTmp);
    }
    if( zTmp==0 ){
      rc = btErrorBkpt(SQLITE4_NOMEM);
    }else if( zCwd==0 ){
      rc = btErrorBkpt(SQLITE4_IOERR);
    }else{
      assert( zCwd==zTmp );
      nCwd = strlen(zCwd);
    }
  }

  if( rc==SQLITE4_OK ){
    int nReq = nCwd + 1 + strlen(zName) + 1;
    zOut = sqlite4_malloc(pSqlEnv, nReq);
    if( zOut ){
      int nName = strlen(zName);
      if( nCwd ){
        memcpy(zOut, zCwd, nCwd);
        zOut[nCwd] = '/';
        memcpy(&zOut[nCwd+1], zName, nName+1);
      }else{
        memcpy(zOut, zName, nName+1);
      }

    }else{
      rc = btErrorBkpt(SQLITE4_NOMEM);


    }
  }

  sqlite4_free(pSqlEnv, zCwd);
  *pzOut = zOut;
  return rc;
}

static int btPosixOsUnlink(bt_env *pEnv, const char *zFile){
  int prc = unlink(zFile);
  return prc ? btErrorBkpt(SQLITE4_IOERR) : SQLITE4_OK;
}

    if( p->apShm[iChunk]==0 ) return btErrorBkpt(SQLITE4_IOERR);
  }

  *ppShm = p->apShm[iChunk];
  return SQLITE4_OK;
}

void btPosixOsShmBarrier(bt_file *pFile){
}

int btPosixOsShmUnmap(bt_file *pFile, int bDelete){
  PosixFile *p = (PosixFile *)pFile;
  if( p->shmfd>0 ){
    int i;
    for(i=0; i<p->nShm; i++){

   btPosixOsShmUnmap(pFile, 0);
   close(p->fd);
   btFree(p->apShm);
   btFree(p);
   return SQLITE4_OK;
}

bt_env *sqlite4BtEnvDefault(void){
  static bt_env posix_env = {
    0,                            /* pVfsCtx */
    btPosixOsFullpath,            /* xFullpath */
    btPosixOsOpen,                /* xOpen */
    btPosixOsRead,                /* xRead */
    btPosixOsWrite,               /* xWrite */
    btPosixOsTruncate,            /* xTruncate */