LCOV - code coverage report
Current view: directory - storage/src - FileSystemModule.cpp (source / functions) Found Hit Coverage
Test: app.info Lines: 103 64 62.1 %
Date: 2012-06-02 Functions: 19 14 73.7 %

       1                 : /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
       2                 :  * vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
       3                 :  * ***** BEGIN LICENSE BLOCK *****
       4                 :  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
       5                 :  *
       6                 :  * The contents of this file are subject to the Mozilla Public License Version
       7                 :  * 1.1 (the "License"); you may not use this file except in compliance with
       8                 :  * the License. You may obtain a copy of the License at
       9                 :  * http://www.mozilla.org/MPL/
      10                 :  *
      11                 :  * Software distributed under the License is distributed on an "AS IS" basis,
      12                 :  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
      13                 :  * for the specific language governing rights and limitations under the
      14                 :  * License.
      15                 :  *
      16                 :  * The Original Code is Mozilla.
      17                 :  *
      18                 :  * The Initial Developer of the Original Code is Mozilla Foundation.
      19                 :  * Portions created by the Initial Developer are Copyright (C) 2011
      20                 :  * the Initial Developer. All Rights Reserved.
      21                 :  *
      22                 :  * Contributor(s):
      23                 :  *
      24                 :  * Alternatively, the contents of this file may be used under the terms of
      25                 :  * either the GNU General Public License Version 2 or later (the "GPL"), or
      26                 :  * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
      27                 :  * in which case the provisions of the GPL or the LGPL are applicable instead
      28                 :  * of those above. If you wish to allow use of your version of this file only
      29                 :  * under the terms of either the GPL or the LGPL, and not to allow others to
      30                 :  * use your version of this file under the terms of the MPL, indicate your
      31                 :  * decision by deleting the provisions above and replace them with the notice
      32                 :  * and other provisions required by the GPL or the LGPL. If you do not delete
      33                 :  * the provisions above, a recipient may use your version of this file under
      34                 :  * the terms of any one of the MPL, the GPL or the LGPL.
      35                 :  *
      36                 :  * ***** END LICENSE BLOCK ***** */
      37                 : 
      38                 : #include "FileSystemModule.h"
      39                 : 
      40                 : #include "sqlite3.h"
      41                 : #include "nsString.h"
      42                 : #include "nsISimpleEnumerator.h"
      43                 : #include "nsIFile.h"
      44                 : #include "nsILocalFile.h"
      45                 : 
      46                 : namespace {
      47                 : 
      48                 : struct VirtualTableCursorBase
      49                 : {
      50              52 :   VirtualTableCursorBase()
      51                 :   {
      52              52 :     memset(&mBase, 0, sizeof(mBase));
      53              52 :   }
      54                 : 
      55                 :   sqlite3_vtab_cursor mBase;
      56                 : };
      57                 : 
      58                 : struct VirtualTableCursor : public VirtualTableCursorBase
      59              52 : {
      60                 : public:
      61              52 :   VirtualTableCursor()
      62              52 :   : mRowId(-1)
      63                 :   {
      64              52 :     mCurrentFileName.SetIsVoid(true);
      65              52 :   }
      66                 : 
      67               0 :   const nsString& DirectoryPath() const
      68                 :   {
      69               0 :     return mDirectoryPath;
      70                 :   }
      71                 : 
      72              52 :   const nsString& CurrentFileName() const
      73                 :   {
      74              52 :     return mCurrentFileName;
      75                 :   }
      76                 : 
      77               0 :   PRInt64 RowId() const
      78                 :   {
      79               0 :     return mRowId;
      80                 :   }
      81                 : 
      82                 :   nsresult Init(const nsAString& aPath);
      83                 :   nsresult NextFile();
      84                 : 
      85                 : private:
      86                 :   nsCOMPtr<nsISimpleEnumerator> mEntries;
      87                 : 
      88                 :   nsString mDirectoryPath;
      89                 :   nsString mCurrentFileName;
      90                 : 
      91                 :   PRInt64 mRowId;
      92                 : };
      93                 : 
      94                 : nsresult
      95              52 : VirtualTableCursor::Init(const nsAString& aPath)
      96                 : {
      97                 :   nsCOMPtr<nsILocalFile> directory =
      98             104 :     do_CreateInstance(NS_LOCAL_FILE_CONTRACTID);
      99              52 :   NS_ENSURE_TRUE(directory, NS_ERROR_FAILURE);
     100                 : 
     101              52 :   nsresult rv = directory->InitWithPath(aPath);
     102              52 :   NS_ENSURE_SUCCESS(rv, rv);
     103                 : 
     104              52 :   rv = directory->GetPath(mDirectoryPath);
     105              52 :   NS_ENSURE_SUCCESS(rv, rv);
     106                 : 
     107              52 :   rv = directory->GetDirectoryEntries(getter_AddRefs(mEntries));
     108              52 :   NS_ENSURE_SUCCESS(rv, rv);
     109                 : 
     110              52 :   rv = NextFile();
     111              52 :   NS_ENSURE_SUCCESS(rv, rv);
     112                 : 
     113              52 :   return NS_OK;
     114                 : }
     115                 : 
     116                 : nsresult
     117              52 : VirtualTableCursor::NextFile()
     118                 : {
     119                 :   bool hasMore;
     120              52 :   nsresult rv = mEntries->HasMoreElements(&hasMore);
     121              52 :   NS_ENSURE_SUCCESS(rv, rv);
     122                 : 
     123              52 :   if (!hasMore) {
     124              52 :     mCurrentFileName.SetIsVoid(true);
     125              52 :     return NS_OK;
     126                 :   }
     127                 : 
     128               0 :   nsCOMPtr<nsISupports> entry;
     129               0 :   rv = mEntries->GetNext(getter_AddRefs(entry));
     130               0 :   NS_ENSURE_SUCCESS(rv, rv);
     131                 : 
     132               0 :   nsCOMPtr<nsIFile> file = do_QueryInterface(entry);
     133               0 :   NS_ENSURE_TRUE(file, NS_ERROR_FAILURE);
     134                 : 
     135               0 :   rv = file->GetLeafName(mCurrentFileName);
     136               0 :   NS_ENSURE_SUCCESS(rv, rv);
     137                 : 
     138               0 :   mRowId++;
     139                 : 
     140               0 :   return NS_OK;
     141                 : }
     142                 : 
     143              52 : int Connect(sqlite3* aDB, void* aAux, int aArgc, const char* const* aArgv,
     144                 :             sqlite3_vtab** aVtab, char** aErr)
     145                 : {
     146                 :   static const char virtualTableSchema[] =
     147                 :     "CREATE TABLE fs ("
     148                 :       "name TEXT, "
     149                 :       "path TEXT"
     150                 :     ")";
     151                 : 
     152              52 :   int rc = sqlite3_declare_vtab(aDB, virtualTableSchema);
     153              52 :   if (rc != SQLITE_OK) {
     154               0 :     return rc;
     155                 :   }
     156                 : 
     157              52 :   sqlite3_vtab* vt = new sqlite3_vtab();
     158              52 :   memset(vt, 0, sizeof(*vt));
     159                 : 
     160              52 :   *aVtab = vt;
     161                 : 
     162              52 :   return SQLITE_OK;
     163                 : }
     164                 : 
     165              52 : int Disconnect(sqlite3_vtab* aVtab )
     166                 : {
     167                 :   delete aVtab;
     168                 : 
     169              52 :   return SQLITE_OK;
     170                 : }
     171                 : 
     172              52 : int BestIndex(sqlite3_vtab* aVtab, sqlite3_index_info* aInfo)
     173                 : {
     174                 :   // Here we specify what index constraints we want to handle. That is, there
     175                 :   // might be some columns with particular constraints in which we can help
     176                 :   // SQLite narrow down the result set.
     177                 :   //
     178                 :   // For example, take the "path = x" where x is a directory. In this case,
     179                 :   // we can narrow our search to just this directory instead of the entire file
     180                 :   // system. This can be a significant optimization. So, we want to handle that
     181                 :   // constraint. To do so, we would look for two specific input conditions:
     182                 :   //
     183                 :   // 1. aInfo->aConstraint[i].iColumn == 1
     184                 :   // 2. aInfo->aConstraint[i].op == SQLITE_INDEX_CONSTRAINT_EQ
     185                 :   //
     186                 :   // The first states that the path column is being used in one of the input
     187                 :   // constraints and the second states that the constraint involves the equal
     188                 :   // operator.
     189                 :   //
     190                 :   // An even more specific search would be for name='xxx', in which case we
     191                 :   // can limit the search to a single file, if it exists.
     192                 :   //
     193                 :   // What we have to do here is look for all of our index searches and select
     194                 :   // the narrowest. We can only pick one, so obviously we want the one that
     195                 :   // is the most specific, which leads to the smallest result set.
     196                 : 
     197              52 :   for(int i = 0; i < aInfo->nConstraint; i++) {
     198              52 :     if (aInfo->aConstraint[i].iColumn == 1 && aInfo->aConstraint[i].usable) {
     199              52 :       if (aInfo->aConstraint[i].op & SQLITE_INDEX_CONSTRAINT_EQ) {
     200              52 :         aInfo->aConstraintUsage[i].argvIndex = 1;
     201                 :       }
     202              52 :       break;
     203                 :     }
     204                 : 
     205                 :     // TODO: handle single files (constrained also by the name column)
     206                 :   }
     207                 : 
     208              52 :   return SQLITE_OK;
     209                 : }
     210                 : 
     211              52 : int Open(sqlite3_vtab* aVtab, sqlite3_vtab_cursor** aCursor)
     212                 : {
     213              52 :   VirtualTableCursor* cursor = new VirtualTableCursor();
     214                 : 
     215              52 :   *aCursor = reinterpret_cast<sqlite3_vtab_cursor*>(cursor);
     216                 : 
     217              52 :   return SQLITE_OK;
     218                 : }
     219                 : 
     220              52 : int Close(sqlite3_vtab_cursor* aCursor)
     221                 : {
     222              52 :   VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
     223                 : 
     224              52 :   delete cursor;
     225                 : 
     226              52 :   return SQLITE_OK;
     227                 : }
     228                 : 
     229              52 : int Filter(sqlite3_vtab_cursor* aCursor, int aIdxNum, const char* aIdxStr,
     230                 :            int aArgc, sqlite3_value** aArgv)
     231                 : {
     232              52 :   VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
     233                 : 
     234              52 :   if(aArgc <= 0) {
     235               0 :     return SQLITE_OK;
     236                 :   }
     237                 : 
     238                 :   nsDependentString path(
     239             104 :     reinterpret_cast<const PRUnichar*>(::sqlite3_value_text16(aArgv[0])));
     240                 : 
     241              52 :   nsresult rv = cursor->Init(path);
     242              52 :   NS_ENSURE_SUCCESS(rv, SQLITE_ERROR);
     243                 : 
     244              52 :   return SQLITE_OK;
     245                 : }
     246                 : 
     247               0 : int Next(sqlite3_vtab_cursor* aCursor)
     248                 : {
     249               0 :   VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
     250                 : 
     251               0 :   nsresult rv = cursor->NextFile();
     252               0 :   NS_ENSURE_SUCCESS(rv, SQLITE_ERROR);
     253                 : 
     254               0 :   return SQLITE_OK;
     255                 : }
     256                 : 
     257              52 : int Eof(sqlite3_vtab_cursor* aCursor)
     258                 : {
     259              52 :   VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
     260              52 :   return cursor->CurrentFileName().IsVoid() ? 1 : 0;
     261                 : }
     262                 : 
     263               0 : int Column(sqlite3_vtab_cursor* aCursor, sqlite3_context* aContext,
     264                 :            int aColumnIndex)
     265                 : {
     266               0 :   VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
     267                 : 
     268               0 :   switch (aColumnIndex) {
     269                 :     // name
     270                 :     case 0: {
     271               0 :       const nsString& name = cursor->CurrentFileName();
     272               0 :       sqlite3_result_text16(aContext, name.get(),
     273               0 :                             name.Length() * sizeof(PRUnichar),
     274               0 :                             SQLITE_TRANSIENT);
     275               0 :       break;
     276                 :     }
     277                 : 
     278                 :     // path
     279                 :     case 1: {
     280               0 :       const nsString& path = cursor->DirectoryPath();
     281               0 :       sqlite3_result_text16(aContext, path.get(),
     282               0 :                             path.Length() * sizeof(PRUnichar),
     283               0 :                             SQLITE_TRANSIENT);
     284               0 :       break;
     285                 :     }
     286                 :     default:
     287               0 :       NS_NOTREACHED("Unsupported column!");
     288                 :   }
     289                 : 
     290               0 :   return SQLITE_OK;
     291                 : }
     292                 : 
     293               0 : int RowId(sqlite3_vtab_cursor* aCursor, sqlite3_int64* aRowid)
     294                 : {
     295               0 :   VirtualTableCursor* cursor = reinterpret_cast<VirtualTableCursor*>(aCursor);
     296                 : 
     297               0 :   *aRowid = cursor->RowId();
     298                 : 
     299               0 :   return SQLITE_OK;
     300                 : }
     301                 : 
     302                 : } // anonymous namespace
     303                 : 
     304                 : namespace mozilla {
     305                 : namespace storage {
     306                 : 
     307              76 : int RegisterFileSystemModule(sqlite3* aDB, const char* aName)
     308                 : {
     309                 :   static sqlite3_module module = {
     310                 :     1,
     311                 :     Connect,
     312                 :     Connect,
     313                 :     BestIndex,
     314                 :     Disconnect,
     315                 :     Disconnect,
     316                 :     Open,
     317                 :     Close,
     318                 :     Filter,
     319                 :     Next,
     320                 :     Eof,
     321                 :     Column,
     322                 :     RowId,
     323                 :     nsnull,
     324                 :     nsnull,
     325                 :     nsnull,
     326                 :     nsnull,
     327                 :     nsnull,
     328                 :     nsnull,
     329                 :     nsnull
     330                 :   };
     331                 : 
     332              76 :   return sqlite3_create_module(aDB, aName, &module, nsnull);
     333                 : }
     334                 : 
     335                 : } // namespace storage
     336                 : } // namespace mozilla

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