Tweaks to comments in pager.c. Fix two compiler warnings.

FossilOrigin-Name: 68a49f7fe382e4d36e1259cdeec956c942906ddb

manifest

@@ -1,5 +1,8 @@
-C Add\stest\scases\sto\se_expr.test.
+-----BEGIN PGP SIGNED MESSAGE-----
-D 2010-08-14T12:25:18
+Hash: SHA1
+
+C Tweaks\sto\scomments\sin\spager.c.\s\sFix\stwo\scompiler\swarnings.
+D 2010-08-14T12:42:45
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in ec08dc838fd8110fe24c92e5130bcd91cbb1ff2e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -156,7 +159,7 @@ F src/os_common.h a8f95b81eca8a1ab8593d23e94f8a35f35d4078f
 F src/os_os2.c 72d0b2e562952a2464308c4ce5f7913ac10bef3e
 F src/os_unix.c 11194cbcf6a57456e58022dc537ab8c3497d9bb9
 F src/os_win.c 51cb62f76262d961ea4249489383d714501315a7
-F src/pager.c 4e144b452545838fdb226755a16d109e0198f513
+F src/pager.c afcd1f6f707f3bff2e214f326fcdcdebe1ef8203
 F src/pager.h 985a83d35b0cfa8e1c23ef91ed5cdb9bde73695a
 F src/parse.y 12b7ebd61ea54f0e1b1083ff69cc2c8ce9353d58
 F src/pcache.c 1e9aa2dbc0845b52e1b51cc39753b6d1e041cb07
@@ -207,7 +210,7 @@ F src/test_osinst.c f408c6a181f2fb04c56273afd5c3e1e82f60392c
 F src/test_pcache.c 7bf828972ac0d2403f5cfa4cd14da41f8ebe73d8
 F src/test_schema.c 8c06ef9ddb240c7a0fcd31bc221a6a2aade58bf0
 F src/test_server.c bbba05c144b5fc4b52ff650a4328027b3fa5fcc6
-F src/test_stat.c dcabb7d39da058cbfc9ddc427cd92fbf14822b28
+F src/test_stat.c f682704b5d1ba8e1d4e7e882a6d7922e2dcf066c
 F src/test_tclvar.c f4dc67d5f780707210d6bb0eb6016a431c04c7fa
 F src/test_thread.c bedd05cad673dba53326f3aa468cc803038896c0
 F src/test_vfs.c 702e52636113f6b9721da90ef1bf26e07fff414d
@@ -843,7 +846,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P d4ec61e2547200aa92a26c1f270682ed67edc241
+P d8bbab78fa56b076dfafb36daa7d6ef0b07f9a44
-R e84bb46a139cdce66b3551c38c0d1297
+R 00ed3364cfce8a4105ed9a3a25cad7ed
-U dan
+U drh
-Z bd338cd57dbe432375897c27c0c4e355
+Z 25d17dd4620d7e65e11d0b88322d1479
+-----BEGIN PGP SIGNATURE-----
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+d6d5VsCmNb5RNvHYenT8x/U=
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manifest.uuid

@@ -1 +1 @@
-d8bbab78fa56b076dfafb36daa7d6ef0b07f9a44
+68a49f7fe382e4d36e1259cdeec956c942906ddb

src/pager.c

@@ -22,8 +22,12 @@
 #include "sqliteInt.h"
 #include "wal.h"
 
-/*
+
-******************** NOTES ON THE DESIGN OF THE PAGER ************************
+/******************* NOTES ON THE DESIGN OF THE PAGER ************************
+**
+** This comment block describes invariants that hold when using a rollback
+** journal.  These invariants do not apply for journal_mode=WAL,
+** journal_mode=MEMORY, or journal_mode=OFF.
 **
 ** Within this comment block, a page is deemed to have been synced
 ** automatically as soon as it is written when PRAGMA synchronous=OFF.
@@ -57,7 +61,7 @@
 **     transaction.
 ** 
 ** (3) Writes to the database file are an integer multiple of the page size
-**     in length and are aligned to a page boundary.
+**     in length and are aligned on a page boundary.
 ** 
 ** (4) Reads from the database file are either aligned on a page boundary and
 **     an integer multiple of the page size in length or are taken from the
@@ -88,7 +92,8 @@
 ** 
 ** (9) Whenever the database file is modified, at least one bit in the range
 **     of bytes from 24 through 39 inclusive will be changed prior to releasing
-**     the EXCLUSIVE lock.
+**     the EXCLUSIVE lock, thus signaling other connections on the same
+**     database to flush their caches.
 **
 ** (10) The pattern of bits in bytes 24 through 39 shall not repeat in less
 **      than one billion transactions.
@@ -101,7 +106,8 @@
 **
 ** (13) A SHARED lock is held on the database file while reading any
 **      content out of the database file.
-*/
+**
+******************************************************************************/
 
 /*
 ** Macros for troubleshooting.  Normally turned off
@@ -625,16 +631,14 @@ struct Pager {
   u8 readOnly;                /* True for a read-only database */
   u8 memDb;                   /* True to inhibit all file I/O */
 
-  /* The following block contains those class members that are dynamically
+  /**************************************************************************
-  ** modified during normal operations. The other variables in this structure
+  ** The following block contains those class members that change during
-  ** are either constant throughout the lifetime of the pager, or else
+  ** routine opertion.  Class members not in this block are either fixed
-  ** used to store configuration parameters that affect the way the pager 
+  ** when the pager is first created or else only change when there is a
-  ** operates.
+  ** significant mode change (such as changing the page_size, locking_mode,
-  **
+  ** or the journal_mode).  From another view, these class members describe
-  ** The 'state' variable is described in more detail along with the
+  ** the "state" of the pager, while other class members describe the
-  ** descriptions of the values it may take - PAGER_UNLOCK etc. Many of the
+  ** "configuration" of the pager.
-  ** other variables in this block are described in the comment directly 
-  ** above this class definition.
   */
   u8 eState;                  /* Pager state (OPEN, READER, WRITER_LOCKED..) */
   u8 eLock;                   /* Current lock held on database file */
@@ -657,17 +661,21 @@ struct Pager {
   sqlite3_file *sjfd;         /* File descriptor for sub-journal */
   i64 journalOff;             /* Current write offset in the journal file */
   i64 journalHdr;             /* Byte offset to previous journal header */
-  i64 journalSizeLimit;       /* Size limit for persistent journal files */
+  sqlite3_backup *pBackup;    /* Pointer to list of ongoing backup processes */
   PagerSavepoint *aSavepoint; /* Array of active savepoints */
   int nSavepoint;             /* Number of elements in aSavepoint[] */
   char dbFileVers[16];        /* Changes whenever database file changes */
-  u32 sectorSize;             /* Assumed sector size during rollback */
+  /*
+  ** End of the routinely-changing class members
+  ***************************************************************************/
 
   u16 nExtra;                 /* Add this many bytes to each in-memory page */
   i16 nReserve;               /* Number of unused bytes at end of each page */
   u32 vfsFlags;               /* Flags for sqlite3_vfs.xOpen() */
+  u32 sectorSize;             /* Assumed sector size during rollback */
   int pageSize;               /* Number of bytes in a page */
   Pgno mxPgno;                /* Maximum allowed size of the database */
+  i64 journalSizeLimit;       /* Size limit for persistent journal files */
   char *zFilename;            /* Name of the database file */
   char *zJournal;             /* Name of the journal file */
   int (*xBusyHandler)(void*); /* Function to call when busy */
@@ -685,7 +693,6 @@ struct Pager {
 #endif
   char *pTmpSpace;            /* Pager.pageSize bytes of space for tmp use */
   PCache *pPCache;            /* Pointer to page cache object */
-  sqlite3_backup *pBackup;    /* Pointer to list of ongoing backup processes */
 #ifndef SQLITE_OMIT_WAL
   Wal *pWal;                  /* Write-ahead log used by "journal_mode=wal" */
   char *zWal;                 /* File name for write-ahead log */
@@ -6370,6 +6377,13 @@ int sqlite3PagerLockingMode(Pager *pPager, int eMode){
 int sqlite3PagerSetJournalMode(Pager *pPager, int eMode){
   u8 eOld = pPager->journalMode;    /* Prior journalmode */
 
+#ifdef SQLITE_DEBUG
+  /* The print_pager_state() routine is intended to be used by the debugger
+  ** only.  We invoke it once here to suppress a compiler warning. */
+  print_pager_state(pPager);
+#endif
+
+
   /* The eMode parameter is always valid */
   assert(      eMode==PAGER_JOURNALMODE_DELETE
             || eMode==PAGER_JOURNALMODE_TRUNCATE

src/test_stat.c

@@ -494,7 +494,7 @@ static int statFilter(
 ){
   StatCursor *pCsr = (StatCursor *)pCursor;
 
-  statResetCsr((StatCursor *)pCursor);
+  statResetCsr(pCsr);
   return statNext(pCursor);
 }