Add the immutable=TRUE query parameter and SQLITE_IOCAP_IMMUTABLE, either

of which prevents locking of the database and omits tests for existance
of journal files.

FossilOrigin-Name: 71f152c85d79ebd9ca48bc9c4c71fc4debaf2437

manifest

@@ -1,5 +1,5 @@
-C Merge\sin\sall\srecent\schanges\sand\senhancements\sfrom\strunk.
-D 2014-04-30T20:32:41.139
+C Add\sthe\simmutable=TRUE\squery\sparameter\sand\sSQLITE_IOCAP_IMMUTABLE,\seither\nof\swhich\sprevents\slocking\sof\sthe\sdatabase\sand\somits\stests\sfor\sexistance\nof\sjournal\sfiles.
+D 2014-05-01T01:13:08.624
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 2ef13430cd359f7b361bb863504e227b25cc7f81
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -206,7 +206,7 @@ F src/os.h 4a46270a64e9193af4a0aaa3bc2c66dc07c29b3f
 F src/os_common.h 92815ed65f805560b66166e3583470ff94478f04
 F src/os_unix.c ae4b5240af4619d711301d7992396e182585269f
 F src/os_win.c 1662c40d22be162698a31725e836eede09e841ed
-F src/pager.c ab62a24218d87dda1be641f6c5ad291bff78fd94
+F src/pager.c 5c296b584df0d675e2377196472ff8a993ad079d
 F src/pager.h ffd5607f7b3e4590b415b007a4382f693334d428
 F src/parse.y 22d6a074e5f5a7258947a1dc55a9bf946b765dd0
 F src/pcache.c d8eafac28290d4bb80332005435db44991d07fc2
@@ -220,7 +220,7 @@ F src/resolve.c 273d5f47c4e2c05b2d3d2bffeda939551ab59e66
 F src/rowset.c a9c9aae3234b44a6d7c6f5a3cadf90dce1e627be
 F src/select.c ed459f7f478a1e533d19c4b953693b3ffa2efd15
 F src/shell.c 2afe7a7154e97be0c74c5feacf09626bda8493be
-F src/sqlite.h.in bde98816e1ba0c9ffef50afe7b32f4e5a8f54fe0
+F src/sqlite.h.in ad2bbeb6a41c228f6a9dbf24df62e4d3eff79ee5
 F src/sqlite3.rc 11094cc6a157a028b301a9f06b3d03089ea37c3e
 F src/sqlite3ext.h 886f5a34de171002ad46fae8c36a7d8051c190fc
 F src/sqliteInt.h b2947801eccefd7ba3e5f14e1353289351a83cf3
@@ -1166,7 +1166,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix 030f3eeaf2cb811a3692ab9c14d021a75ce41fff
-P ffceacf61905dc3553978ba5f68e133947eca2fa 9bbca48b42e4fe16f2188e18dc736da30a96435c
-R de599c68866896adcd34d6a6ff4634e0
+P 84243f844417f888ab731841f7dbf95749f6e034
+R 5c0369593ee1e8996babaee6957b771b
 U drh
-Z adbf9541c1c60ea64244c304cb7bb6d4
+Z 54ea9e774afb5e969c7607c1ec92b0eb

manifest.uuid

@@ -1 +1 @@
-84243f844417f888ab731841f7dbf95749f6e034
+71f152c85d79ebd9ca48bc9c4c71fc4debaf2437

src/pager.c

@@ -4674,30 +4674,37 @@ int sqlite3PagerOpen(
     **    + The value returned by sqlite3OsSectorSize()
     **    + The largest page size that can be written atomically.
     */
-    if( rc==SQLITE_OK && !readOnly ){
-      setSectorSize(pPager);
-      assert(SQLITE_DEFAULT_PAGE_SIZE<=SQLITE_MAX_DEFAULT_PAGE_SIZE);
-      if( szPageDflt<pPager->sectorSize ){
-        if( pPager->sectorSize>SQLITE_MAX_DEFAULT_PAGE_SIZE ){
-          szPageDflt = SQLITE_MAX_DEFAULT_PAGE_SIZE;
-        }else{
-          szPageDflt = (u32)pPager->sectorSize;
-        }
-      }
-#ifdef SQLITE_ENABLE_ATOMIC_WRITE
-      {
+    if( rc==SQLITE_OK ){
+      if( !readOnly ){
         int iDc = sqlite3OsDeviceCharacteristics(pPager->fd);
-        int ii;
-        assert(SQLITE_IOCAP_ATOMIC512==(512>>8));
-        assert(SQLITE_IOCAP_ATOMIC64K==(65536>>8));
-        assert(SQLITE_MAX_DEFAULT_PAGE_SIZE<=65536);
-        for(ii=szPageDflt; ii<=SQLITE_MAX_DEFAULT_PAGE_SIZE; ii=ii*2){
-          if( iDc&(SQLITE_IOCAP_ATOMIC|(ii>>8)) ){
-            szPageDflt = ii;
+        setSectorSize(pPager);
+        assert(SQLITE_DEFAULT_PAGE_SIZE<=SQLITE_MAX_DEFAULT_PAGE_SIZE);
+        if( szPageDflt<pPager->sectorSize ){
+          if( pPager->sectorSize>SQLITE_MAX_DEFAULT_PAGE_SIZE ){
+            szPageDflt = SQLITE_MAX_DEFAULT_PAGE_SIZE;
+          }else{
+            szPageDflt = (u32)pPager->sectorSize;
+          }
+        }
+#ifdef SQLITE_ENABLE_ATOMIC_WRITE
+        {
+          int ii;
+          assert(SQLITE_IOCAP_ATOMIC512==(512>>8));
+          assert(SQLITE_IOCAP_ATOMIC64K==(65536>>8));
+          assert(SQLITE_MAX_DEFAULT_PAGE_SIZE<=65536);
+          for(ii=szPageDflt; ii<=SQLITE_MAX_DEFAULT_PAGE_SIZE; ii=ii*2){
+            if( iDc&(SQLITE_IOCAP_ATOMIC|(ii>>8)) ){
+              szPageDflt = ii;
+            }
           }
         }
-      }
 #endif
+        if( (iDc & SQLITE_IOCAP_IMMUTABLE)!=0
+         || sqlite3_uri_boolean(zFilename, "immutable", 0) ){
+            vfsFlags |= SQLITE_OPEN_READONLY;
+            goto act_like_temp_file;
+        }
+      }
     }
   }else{
     /* If a temporary file is requested, it is not opened immediately.
@@ -4708,6 +4715,7 @@ int sqlite3PagerOpen(
     ** database is the same as a temp-file that is never written out to
     ** disk and uses an in-memory rollback journal.
     */ 
+act_like_temp_file:
     tempFile = 1;
     pPager->eState = PAGER_READER;
     pPager->eLock = EXCLUSIVE_LOCK;
@@ -4751,9 +4759,6 @@ int sqlite3PagerOpen(
   /* pPager->nPage = 0; */
   pPager->mxPgno = SQLITE_MAX_PAGE_COUNT;
   /* pPager->state = PAGER_UNLOCK; */
-#if 0
-  assert( pPager->state == (tempFile ? PAGER_EXCLUSIVE : PAGER_UNLOCK) );
-#endif
   /* pPager->errMask = 0; */
   pPager->tempFile = (u8)tempFile;
   assert( tempFile==PAGER_LOCKINGMODE_NORMAL 

src/sqlite.h.in

@@ -555,7 +555,10 @@ int sqlite3_exec(
 ** file that were written at the application level might have changed
 ** and that adjacent bytes, even bytes within the same sector are
 ** guaranteed to be unchanged.  The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
-** flag indicate that a file cannot be deleted when open.
+** flag indicate that a file cannot be deleted when open.  The
+** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
+** read-only media and cannot be changed even by processes with
+** elevated privileges.
 */
 #define SQLITE_IOCAP_ATOMIC                 0x00000001
 #define SQLITE_IOCAP_ATOMIC512              0x00000002
@@ -570,6 +573,7 @@ int sqlite3_exec(
 #define SQLITE_IOCAP_SEQUENTIAL             0x00000400
 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN  0x00000800
 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE    0x00001000
+#define SQLITE_IOCAP_IMMUTABLE              0x00002000
 
 /*
 ** CAPI3REF: File Locking Levels