SQLite

  u16 mDate;
  u32 crc32;
  u32 szCompressed;
  u32 szUncompressed;
  u16 nFile;
  u16 nExtra;
};

typedef struct ZipfileEntry ZipfileEntry;
struct ZipfileEntry {
  char *zPath;               /* Path of zipfile entry */
  i64 iRowid;                /* Rowid for this value if queried */
  u8 *aCdsEntry;             /* Buffer containing entire CDS entry */
  int nCdsEntry;             /* Size of buffer aCdsEntry[] in bytes */
  int bDeleted;              /* True if entry has been deleted */
  ZipfileEntry *pNext;       /* Next element in in-memory CDS */
};

/* 
** Cursor type for recursively iterating through a directory structure.
*/
typedef struct ZipfileCsr ZipfileCsr;

struct ZipfileCsr {
  sqlite3_vtab_cursor base;  /* Base class - must be first */
  int bEof;                  /* True when at EOF */

  /* Used outside of write transactions */
  FILE *pFile;               /* Zip file */


  i64 iNextOff;              /* Offset of next record in central directory */
  ZipfileEOCD eocd;          /* Parse of central directory record */

  /* Used inside write transactions */
  ZipfileEntry *pCurrent;

  ZipfileCDS cds;            /* Central Directory Structure */
  ZipfileLFH lfh;            /* Local File Header for current entry */
  i64 iDataOff;              /* Offset in zipfile to data */
  u32 mTime;                 /* Extended mtime value */
  int flags;                 /* Flags byte (see below for bits) */
  ZipfileCsr *pCsrNext;      /* Next cursor on same virtual table */
};

/*
** Values for ZipfileCsr.flags.
*/
#define ZIPFILE_MTIME_VALID 0x0001










typedef struct ZipfileTab ZipfileTab;
struct ZipfileTab {
  sqlite3_vtab base;         /* Base class - must be first */
  char *zFile;               /* Zip file this table accesses (may be NULL) */
  u8 *aBuffer;               /* Temporary buffer used for various tasks */

  /* The following are used by write transactions only */
  ZipfileCsr *pCsrList;      /* List of cursors */
  ZipfileEntry *pFirstEntry; /* Linked list of all files (if pWriteFd!=0) */
  ZipfileEntry *pLastEntry;  /* Last element in pFirstEntry list */
  FILE *pWriteFd;            /* File handle open on zip archive */
  i64 szCurrent;             /* Current size of zip archive */
  i64 szOrig;                /* Size of archive at start of transaction */
};

}

/*
** Reset a cursor back to the state it was in when first returned
** by zipfileOpen().
*/
static void zipfileResetCursor(ZipfileCsr *pCsr){
  ZipfileTab *pTab = (ZipfileTab*)(pCsr->base.pVtab);
  ZipfileCsr **pp;

  /* Remove this cursor from the ZipfileTab.pCsrList list. */
  for(pp=&pTab->pCsrList; *pp; pp=&((*pp)->pCsrNext)){
    if( *pp==pCsr ) *pp = pCsr->pCsrNext;
  }

  sqlite3_free(pCsr->cds.zFile);
  pCsr->cds.zFile = 0;

  pCsr->bEof = 0;
  if( pCsr->pFile ){
    fclose(pCsr->pFile);
    pCsr->pFile = 0;
  }
}

** Magic numbers used to read CDS records.
*/
#define ZIPFILE_CDS_FIXED_SZ  46
#define ZIPFILE_CDS_NFILE_OFF 28

static int zipfileReadCDS(ZipfileCsr *pCsr){
  char **pzErr = &pCsr->base.pVtab->zErrMsg;
  u8 *aRead;
  int rc = SQLITE_OK;

  sqlite3_free(pCsr->cds.zFile);
  pCsr->cds.zFile = 0;

  if( pCsr->pCurrent==0 ){
    aRead = zipfileCsrBuffer(pCsr);
    rc = zipfileReadData(
        pCsr->pFile, aRead, ZIPFILE_CDS_FIXED_SZ, pCsr->iNextOff, pzErr
    );
  }else{
    aRead = pCsr->pCurrent->aCdsEntry;
  }

  if( rc==SQLITE_OK ){
    u32 sig = zipfileRead32(aRead);
    if( sig!=ZIPFILE_SIGNATURE_CDS ){
      assert( pCsr->pCurrent==0 );
      zipfileSetErrmsg(pCsr,"failed to read CDS at offset %lld",pCsr->iNextOff);
      rc = SQLITE_ERROR;
    }else{
      int nRead;
      pCsr->cds.iVersionMadeBy = zipfileRead16(aRead);
      pCsr->cds.iVersionExtract = zipfileRead16(aRead);
      pCsr->cds.flags = zipfileRead16(aRead);
      pCsr->cds.iCompression = zipfileRead16(aRead);
      pCsr->cds.mTime = zipfileRead16(aRead);
      pCsr->cds.mDate = zipfileRead16(aRead);
      pCsr->cds.crc32 = zipfileRead32(aRead);
      pCsr->cds.szCompressed = zipfileRead32(aRead);
      pCsr->cds.szUncompressed = zipfileRead32(aRead);
      assert( pCsr->pCurrent 
           || aRead==zipfileCsrBuffer(pCsr)+ZIPFILE_CDS_NFILE_OFF 
      );
      pCsr->cds.nFile = zipfileRead16(aRead);
      pCsr->cds.nExtra = zipfileRead16(aRead);
      pCsr->cds.nComment = zipfileRead16(aRead);
      pCsr->cds.iDiskStart = zipfileRead16(aRead);
      pCsr->cds.iInternalAttr = zipfileRead16(aRead);
      pCsr->cds.iExternalAttr = zipfileRead32(aRead);
      pCsr->cds.iOffset = zipfileRead32(aRead);
      assert( pCsr->pCurrent 
           || aRead==zipfileCsrBuffer(pCsr)+ZIPFILE_CDS_FIXED_SZ
      );

      if( pCsr->pCurrent==0 ){
        nRead = pCsr->cds.nFile + pCsr->cds.nExtra;
        aRead = zipfileCsrBuffer(pCsr);
        pCsr->iNextOff += ZIPFILE_CDS_FIXED_SZ;
        rc = zipfileReadData(pCsr->pFile, aRead, nRead, pCsr->iNextOff, pzErr);
      }

      if( rc==SQLITE_OK ){
        pCsr->cds.zFile = sqlite3_mprintf("%.*s", (int)pCsr->cds.nFile, aRead);
        pCsr->iNextOff += pCsr->cds.nFile;
        pCsr->iNextOff += pCsr->cds.nExtra;
        pCsr->iNextOff += pCsr->cds.nComment;
      }

        }
      }
    }
  }

  return rc;
}

static FILE *zipfileGetFd(ZipfileCsr *pCsr){
  if( pCsr->pFile ) return pCsr->pFile;
  return ((ZipfileTab*)(pCsr->base.pVtab))->pWriteFd;
}

static int zipfileReadLFH(ZipfileCsr *pCsr){
  FILE *pFile = zipfileGetFd(pCsr);
  char **pzErr = &pCsr->base.pVtab->zErrMsg;
  static const int szFix = ZIPFILE_LFH_FIXED_SZ;
  u8 *aRead = zipfileCsrBuffer(pCsr);
  int rc;

  rc = zipfileReadData(pFile, aRead, szFix, pCsr->cds.iOffset, pzErr);
  if( rc==SQLITE_OK ){
    u32 sig = zipfileRead32(aRead);
    if( sig!=ZIPFILE_SIGNATURE_LFH ){
      zipfileSetErrmsg(pCsr, "failed to read LFH at offset %d", 
          (int)pCsr->cds.iOffset
      );
      rc = SQLITE_ERROR;

/*
** Advance an ZipfileCsr to its next row of output.
*/
static int zipfileNext(sqlite3_vtab_cursor *cur){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;

  int rc = SQLITE_OK;
  pCsr->flags = 0;

  if( pCsr->pCurrent==0 ){
    i64 iEof = pCsr->eocd.iOffset + pCsr->eocd.nSize;
    if( pCsr->iNextOff>=iEof ){
      pCsr->bEof = 1;
    }
  }else{
    assert( pCsr->pFile==0 );
    do {
      pCsr->pCurrent = pCsr->pCurrent->pNext;
    }while( pCsr->pCurrent && pCsr->pCurrent->bDeleted );
    if( pCsr->pCurrent==0 ){
      pCsr->bEof = 1;
    }
  }

  if( pCsr->bEof==0 ){
    rc = zipfileReadCDS(pCsr);
    if( rc==SQLITE_OK ){
      rc = zipfileReadLFH(pCsr);
    }
  }

  return rc;
}

/*
** "Standard" MS-DOS time format:
**
**   File modification time:

    case 4: { /* data */
      int sz = pCsr->cds.szCompressed;
      if( sz>0 ){
        u8 *aBuf = sqlite3_malloc(sz);
        if( aBuf==0 ){
          rc = SQLITE_NOMEM;
        }else{
          FILE *pFile = zipfileGetFd(pCsr);
          rc = zipfileReadData(pFile, aBuf, sz, pCsr->iDataOff,
              &pCsr->base.pVtab->zErrMsg
          );
        }
        if( rc==SQLITE_OK ){
          sqlite3_result_blob(ctx, aBuf, sz, SQLITE_TRANSIENT);
          sqlite3_free(aBuf);
        }
      }
      break;
    }
    case 5:   /* method */
      sqlite3_result_int(ctx, pCsr->cds.iCompression);
      break;
  }

  return SQLITE_OK;
}

/*
** Return the rowid for the current row.


*/
static int zipfileRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  if( pCsr->pCurrent ){
    *pRowid = pCsr->pCurrent->iRowid;
  }else{
    *pRowid = pCsr->cds.iOffset;
  }
  return SQLITE_OK;
}

/*
** Return TRUE if the cursor has been moved off of the last
** row of output.
*/

  ZipfileTab *pTab = (ZipfileTab*)cur->pVtab;
  ZipfileCsr *pCsr = (ZipfileCsr*)cur;
  const char *zFile;              /* Zip file to scan */
  int rc = SQLITE_OK;             /* Return Code */

  zipfileResetCursor(pCsr);


  if( pTab->zFile ){

    zFile = pTab->zFile;
  }else if( idxNum==0 ){
    /* Error. This is an eponymous virtual table and the user has not 
    ** supplied a file name. */
    zipfileSetErrmsg(pCsr, "table function zipfile() requires an argument");
    return SQLITE_ERROR;

  }else{
    zFile = (const char*)sqlite3_value_text(argv[0]);
  }

  if( pTab->pWriteFd==0 ){
    pCsr->pFile = fopen(zFile, "rb");
    if( pCsr->pFile==0 ){
      zipfileSetErrmsg(pCsr, "cannot open file: %s", zFile);
      rc = SQLITE_ERROR;
    }else{
      rc = zipfileReadEOCD(pTab, pCsr->pFile, &pCsr->eocd);
      if( rc==SQLITE_OK ){
        pCsr->iNextOff = pCsr->eocd.iOffset;
        rc = zipfileNext(cur);
      }else if( rc==SQLITE_EMPTY ){
        rc = SQLITE_OK;
        pCsr->bEof = 1;
      }
    }
  }else{
    ZipfileEntry e;
    memset(&e, 0, sizeof(e));
    e.pNext = pTab->pFirstEntry;
    pCsr->pCurrent = &e;
    rc = zipfileNext(cur);
    assert( pCsr->pCurrent!=&e );
  }

  return rc;
}

/*
** xBestIndex callback.

** Add object pNew to the end of the linked list that begins at
** ZipfileTab.pFirstEntry and ends with pLastEntry.
*/
static void zipfileAddEntry(ZipfileTab *pTab, ZipfileEntry *pNew){
  assert( (pTab->pFirstEntry==0)==(pTab->pLastEntry==0) );
  assert( pNew->pNext==0 );
  if( pTab->pFirstEntry==0 ){
    pNew->iRowid = 1;
    pTab->pFirstEntry = pTab->pLastEntry = pNew;
  }else{
    assert( pTab->pLastEntry->pNext==0 );
    pNew->iRowid = pTab->pLastEntry->iRowid+1;
    pTab->pLastEntry->pNext = pNew;
    pTab->pLastEntry = pNew;
  }
}

static int zipfileLoadDirectory(ZipfileTab *pTab){
  ZipfileEOCD eocd;

          sizeof(ZipfileEntry) 
        + nFile+1 
        + ZIPFILE_CDS_FIXED_SZ+nFile+nExtra+nComment
      );
      if( pNew==0 ){
        rc = SQLITE_NOMEM;
      }else{
        memset(pNew, 0, sizeof(ZipfileEntry));
        pNew->zPath = (char*)&pNew[1];
        memcpy(pNew->zPath, &aBuf[ZIPFILE_CDS_FIXED_SZ], nFile);
        pNew->zPath[nFile] = '\0';
        pNew->aCdsEntry = (u8*)&pNew->zPath[nFile+1];
        pNew->nCdsEntry = ZIPFILE_CDS_FIXED_SZ+nFile+nExtra+nComment;

        memcpy(pNew->aCdsEntry, aRec, pNew->nCdsEntry);
        zipfileAddEntry(pTab, pNew);
      }

      iOff += ZIPFILE_CDS_FIXED_SZ+nFile+nExtra+nComment;
    }

  pNew = (ZipfileEntry*)sqlite3_malloc(
    sizeof(ZipfileEntry) + 
    nPath+1 + 
    ZIPFILE_CDS_FIXED_SZ + nPath + pCds->nExtra
  );

  if( pNew ){
    memset(pNew, 0, sizeof(ZipfileEntry));
    pNew->zPath = (char*)&pNew[1];
    pNew->aCdsEntry = (u8*)&pNew->zPath[nPath+1];
    pNew->nCdsEntry = ZIPFILE_CDS_FIXED_SZ + nPath + pCds->nExtra;

    memcpy(pNew->zPath, zPath, nPath+1);

    aWrite = pNew->aCdsEntry;
    zipfileWrite32(aWrite, ZIPFILE_SIGNATURE_CDS);
    zipfileWrite16(aWrite, pCds->iVersionMadeBy);
    zipfileWrite16(aWrite, pCds->iVersionExtract);
    zipfileWrite16(aWrite, pCds->flags);

  int nPath;                      /* strlen(zPath) */
  const u8 *pData;                /* Pointer to buffer containing content */
  int nData;                      /* Size of pData buffer in bytes */
  int iMethod = 0;                /* Compression method for new entry */
  u8 *pFree = 0;                  /* Free this */
  ZipfileCDS cds;                 /* New Central Directory Structure entry */


  assert( pTab->zFile );

  assert( pTab->pWriteFd );


  if( sqlite3_value_type(apVal[0])!=SQLITE_NULL ){



    i64 iDelete = sqlite3_value_int64(apVal[0]);
    ZipfileEntry *p;

    for(p=pTab->pFirstEntry; p; p=p->pNext){
      if( p->iRowid==iDelete ){
        p->bDeleted = 1;
        break;
      }
    }










    if( nVal==1 ) return SQLITE_OK;





  }

  zPath = (const char*)sqlite3_value_text(apVal[2]);
  nPath = strlen(zPath);
  rc = zipfileGetMode(pTab, apVal[3], &mode);
  if( rc!=SQLITE_OK ) return rc;
  mTime = sqlite3_value_int64(apVal[4]);

  fclose(pTab->pWriteFd);
  pTab->pWriteFd = 0;
  pTab->szCurrent = 0;
  pTab->szOrig = 0;
}

static int zipfileBegin(sqlite3_vtab *pVtab){
  ZipfileTab *pTab = (ZipfileTab*)pVtab;
  int rc = SQLITE_OK;

  assert( pTab->pWriteFd==0 );

  /* This table is only writable if a default archive path was specified 
  ** as part of the CREATE VIRTUAL TABLE statement. */
  if( pTab->zFile==0 ){
    pTab->base.zErrMsg = sqlite3_mprintf(
        "zipfile: writing requires a default archive"
    );
    return SQLITE_ERROR;
  }

  /* Open a write fd on the file. Also load the entire central directory
  ** structure into memory. During the transaction any new file data is 
  ** appended to the archive file, but the central directory is accumulated
  ** in main-memory until the transaction is committed.  */
  pTab->pWriteFd = fopen(pTab->zFile, "ab+");
  if( pTab->pWriteFd==0 ){
    pTab->base.zErrMsg = sqlite3_mprintf(
        "zipfile: failed to open file %s for writing", pTab->zFile
    );
    rc = SQLITE_ERROR;
  }else{
    fseek(pTab->pWriteFd, 0, SEEK_END);
    pTab->szCurrent = pTab->szOrig = (i64)ftell(pTab->pWriteFd);
    rc = zipfileLoadDirectory(pTab);
  }

  if( rc!=SQLITE_OK ){
    zipfileCleanupTransaction(pTab);
  }

  return rc;
}

static int zipfileCommit(sqlite3_vtab *pVtab){
  ZipfileTab *pTab = (ZipfileTab*)pVtab;
  int rc = SQLITE_OK;
  if( pTab->pWriteFd ){
    i64 iOffset = pTab->szCurrent;
    ZipfileEntry *p;
    ZipfileEOCD eocd;
    int nEntry = 0;

    /* Write out all undeleted entries */
    for(p=pTab->pFirstEntry; rc==SQLITE_OK && p; p=p->pNext){
      if( p->bDeleted ) continue;
      rc = zipfileAppendData(pTab, p->aCdsEntry, p->nCdsEntry);
      nEntry++;
    }

    /* Write out the EOCD record */
    eocd.iDisk = 0;
    eocd.iFirstDisk = 0;

  1 mode {} 0 {} 0 
  2 mtime {} 0 {} 0 
  3 sz {} 0 {} 0 
  4 data {} 0 {} 0
  5 method {} 0 {} 0
}

do_execsql_test 1.1.1 {
  INSERT INTO zz VALUES('f.txt', '-rw-r--r--', 1000000000, 5, 'abcde', 0);
}
do_execsql_test 1.1.2 {
  INSERT INTO zz VALUES('g.txt', '-rw-r--r--', 1000000002, 5, '12345', 0);
}

do_execsql_test 1.2 {
  SELECT name, mtime, data FROM zipfile('test.zip')
} {
  f.txt 1000000000 abcde 
  g.txt 1000000002 12345
}

do_execsql_test 1.3 {
  INSERT INTO zz VALUES('h.txt', 
    '-rw-r--r--', 1000000004, 20, 'aaaaaaaaaabbbbbbbbbb', NULL
  );
}

do_execsql_test 1.4 {
  SELECT name, mtime, zipfile_uncompress(data, sz, method), method
  FROM zipfile('test.zip');
} {
  f.txt 1000000000 abcde 0
  g.txt 1000000002 12345 0
  h.txt 1000000004 aaaaaaaaaabbbbbbbbbb 8
}

do_execsql_test 1.5.1 {
  BEGIN;
    INSERT INTO zz VALUES('i.txt', '-rw-r--r--', 1000000006, 5, 'zxcvb', 0);
    SELECT name FROM zz;
  COMMIT;
} {f.txt g.txt h.txt i.txt}
do_execsql_test 1.5.2 {
  SELECT name FROM zz;
} {f.txt g.txt h.txt i.txt}

do_execsql_test 1.6.0 {
  DELETE FROM zz WHERE name='g.txt';
  SELECT name FROM zz;
} {f.txt h.txt i.txt}

finish_test