Keep track of the optimal number of reserved bytes (by looking at reserve

byte requests in calls to sqlite3BtreeSetPageSize()) and then change the
reserve byte count to the optimal when doing a VACUUM or when using the
backup API.

FossilOrigin-Name: 28c2b726285ea88b334acfd6390a057d2d244838

diff --git a/manifest b/manifest
index 116b2466ba7487e69bcfa07d58b2988c98a4a624..18ce942edbd66039c96628b4021bd1cadf66b61e 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\serrors\sin\sthe\sEBCDIC\supper-case\sto\slower-case\stranslation\stable.
-D 2015-02-19T17:16:14.345
+C Keep\strack\sof\sthe\soptimal\snumber\sof\sreserved\sbytes\s(by\slooking\sat\sreserve\nbyte\srequests\sin\scalls\sto\ssqlite3BtreeSetPageSize())\sand\sthen\schange\sthe\nreserve\sbyte\scount\sto\sthe\soptimal\swhen\sdoing\sa\sVACUUM\sor\swhen\susing\sthe\nbackup\sAPI.
+D 2015-02-21T00:19:25.084
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 6b9e7677829aa94b9f30949656e27312aefb9a46
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -168,14 +168,14 @@ F sqlite3.1 fc7ad8990fc8409983309bb80de8c811a7506786
 F sqlite3.pc.in 48fed132e7cb71ab676105d2a4dc77127d8c1f3a
 F src/alter.c ba266a779bc7ce10e52e59e7d3dc79fa342e8fdb
 F src/analyze.c 91540f835163d5369ccbae78e2e6c74d0dd53c1d
-F src/attach.c 7f6b3fafa2290b407e4a94dcf1afda7ec0fe394b
+F src/attach.c 880f9b8641a829c563e52dd13c452ce457ae4dd8
 F src/auth.c b56c78ebe40a2110fd361379f7e8162d23f92240
-F src/backup.c 7ddee9c7d505e07e959a575b18498f17c71e53ea
+F src/backup.c ff743689c4d6c5cb55ad42ed9d174b2b3e71f1e3
 F src/bitvec.c 19a4ba637bd85f8f63fc8c9bae5ade9fb05ec1cb
 F src/btmutex.c 49ca66250c7dfa844a4d4cb8272b87420d27d3a5
-F src/btree.c 2a1245df0356a229bcd0fd87a8536b5067f16e82
-F src/btree.h 94277c1d30c0b75705974bcc8b0c05e79c03d474
-F src/btreeInt.h a3d0ae1d511365e1a2b76ad10960dbe55c286f34
+F src/btree.c a31ac00e30fb7bb49e90e48ce29ef8a61591be96
+F src/btree.h 9cbbb92aab22ef8b50493c40aa3f8de87c43a2fb
+F src/btreeInt.h 2bfefc01875d8da066504c233ec259fcb3b2ef72
 F src/build.c ba45ebd02904e84d98839a6ea74c3eb948596587
 F src/callback.c 7b44ce59674338ad48b0e84e7b72f935ea4f68b0
 F src/complete.c 198a0066ba60ab06fc00fba1998d870a4d575463
@@ -278,7 +278,7 @@ F src/test_rtree.c bfe6f4386517f70054311109f3528adffec34485
 F src/test_schema.c 2bdba21b82f601da69793e1f1d11bf481a79b091
 F src/test_server.c a2615049954cbb9cfb4a62e18e2f0616e4dc38fe
 F src/test_sqllog.c b690c12933f50ff46491e0d56a251f84ae16e914
-F src/test_stat.c 9898687a6c2beca733b0dd6fe19163d987826d31
+F src/test_stat.c ffc8177f6e69de32a8a89fa6bca73facb6c5face
 F src/test_superlock.c 06797157176eb7085027d9dd278c0d7a105e3ec9
 F src/test_syscall.c 2e21ca7f7dc54a028f1967b63f1e76155c356f9b
 F src/test_tclvar.c f4dc67d5f780707210d6bb0eb6016a431c04c7fa
@@ -292,7 +292,7 @@ F src/trigger.c 25571661fdeae8c7f975ff40ffec205520a3f92f
 F src/update.c 3c4ecc282accf12d39edb8d524cf089645e55a13
 F src/utf.c fc6b889ba0779b7722634cdeaa25f1930d93820c
 F src/util.c 98a7627ca48ad3265b6940915a1d08355eb3fc7e
-F src/vacuum.c 9b30ec729337dd012ed88d4c292922c8ef9cf00c
+F src/vacuum.c 9460b9de7b2d4e34b0d374894aa6c8a0632be8ec
 F src/vdbe.c ddfc977981cd6324668aa6b114045eb1c677421a
 F src/vdbe.h 6fc69d9c5e146302c56e163cb4b31d1ee64a18c3
 F src/vdbeInt.h bb56fd199d8af1a2c1b9639ee2f70724b4338e3a
@@ -1239,7 +1239,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh 0abfd78ceb09b7f7c27c688c8e3fe93268a13b32
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 8215727dda384351765ab1d5c53ea80775b4ec65
-R ed42099f889d81b7ba10262d93840087
+P 905009f6723040d4da4776b6fd07e83c628dea2b
+R 9a7352553472f105646c8fe233cf7b38
 U drh
-Z c9abd15eefd1ceffcd5e72613bc587bc
+Z d63bd336672b94104d11cd96538a1a36

diff --git a/manifest.uuid b/manifest.uuid
index e2d70db74c630a91737d0940e8949beb70dde3db..67f04903f94683a1666b83fe97fbd90dc44f40af 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-905009f6723040d4da4776b6fd07e83c628dea2b
\ No newline at end of file
+28c2b726285ea88b334acfd6390a057d2d244838
\ No newline at end of file

diff --git a/src/attach.c b/src/attach.c
index de8742938b5f53979494391921df76aafd5d020e..7e35fa67c61ce235cca38b581a484dd23111ae06 100644 (file)
--- a/src/attach.c
+++ b/src/attach.c
@@ -191,7 +191,7 @@ static void attachFunc(
       case SQLITE_NULL:
         /* No key specified.  Use the key from the main database */
         sqlite3CodecGetKey(db, 0, (void**)&zKey, &nKey);
-        if( nKey>0 || sqlite3BtreeGetReserve(db->aDb[0].pBt)>0 ){
+        if( nKey>0 || sqlite3BtreeGetOptimalReserve(db->aDb[0].pBt)>0 ){
           rc = sqlite3CodecAttach(db, db->nDb-1, zKey, nKey);
         }
         break;

diff --git a/src/backup.c b/src/backup.c
index e3f869035eef1e537ac435fdc3835d174e6ad1e8..81c8b5c5f4f111e81eec4728c07b74f4076b544c 100644 (file)
--- a/src/backup.c
+++ b/src/backup.c
@@ -247,7 +247,7 @@ static int backupOnePage(
   ** guaranteed that the shared-mutex is held by this thread, handle
   ** p->pSrc may not actually be the owner.  */
   int nSrcReserve = sqlite3BtreeGetReserveNoMutex(p->pSrc);
-  int nDestReserve = sqlite3BtreeGetReserve(p->pDest);
+  int nDestReserve = sqlite3BtreeGetOptimalReserve(p->pDest);
 #endif
   int rc = SQLITE_OK;
   i64 iOff;

diff --git a/src/btree.c b/src/btree.c
index eb5151351c68d3b4815da028b35d2e61588da34e..8957b74c19e41729febab722cfc8ed976a7af961 100644 (file)
--- a/src/btree.c
+++ b/src/btree.c
@@ -2405,6 +2405,9 @@ int sqlite3BtreeSetPageSize(Btree *p, int pageSize, int nReserve, int iFix){
   BtShared *pBt = p->pBt;
   assert( nReserve>=-1 && nReserve<=255 );
   sqlite3BtreeEnter(p);
+#if SQLITE_HAS_CODEC
+  if( nReserve>pBt->optimalReserve ) pBt->optimalReserve = (u8)nReserve;
+#endif
   if( pBt->btsFlags & BTS_PAGESIZE_FIXED ){
     sqlite3BtreeLeave(p);
     return SQLITE_READONLY;
@@ -2434,7 +2437,6 @@ int sqlite3BtreeGetPageSize(Btree *p){
   return p->pBt->pageSize;
 }
 
-#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_DEBUG)
 /*
 ** This function is similar to sqlite3BtreeGetReserve(), except that it
 ** may only be called if it is guaranteed that the b-tree mutex is already
@@ -2447,25 +2449,33 @@ int sqlite3BtreeGetPageSize(Btree *p){
 ** database handle that owns *p, causing undefined behavior.
 */
 int sqlite3BtreeGetReserveNoMutex(Btree *p){
+  int n;
   assert( sqlite3_mutex_held(p->pBt->mutex) );
-  return p->pBt->pageSize - p->pBt->usableSize;
+  n = p->pBt->pageSize - p->pBt->usableSize;
+  return n;
 }
-#endif /* SQLITE_HAS_CODEC || SQLITE_DEBUG */
 
-#if !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM)
 /*
 ** Return the number of bytes of space at the end of every page that
 ** are intentually left unused.  This is the "reserved" space that is
 ** sometimes used by extensions.
+**
+** If SQLITE_HAS_MUTEX is defined then the number returned is the
+** greater of the current reserved space and the maximum requested
+** reserve space.
 */
-int sqlite3BtreeGetReserve(Btree *p){
+int sqlite3BtreeGetOptimalReserve(Btree *p){
   int n;
   sqlite3BtreeEnter(p);
-  n = p->pBt->pageSize - p->pBt->usableSize;
+  n = sqlite3BtreeGetReserveNoMutex(p);
+#ifdef SQLITE_HAS_CODEC
+  if( n<p->pBt->optimalReserve ) n = p->pBt->optimalReserve;
+#endif
   sqlite3BtreeLeave(p);
   return n;
 }
 
+
 /*
 ** Set the maximum page count for a database if mxPage is positive.
 ** No changes are made if mxPage is 0 or negative.
@@ -2496,7 +2506,6 @@ int sqlite3BtreeSecureDelete(Btree *p, int newFlag){
   sqlite3BtreeLeave(p);
   return b;
 }
-#endif /* !defined(SQLITE_OMIT_PAGER_PRAGMAS) || !defined(SQLITE_OMIT_VACUUM) */
 
 /*
 ** Change the 'auto-vacuum' property of the database. If the 'autoVacuum'

diff --git a/src/btree.h b/src/btree.h
index b57d500c779f33961c586c9d59d793642fa809d5..77d12f78d3698c051fa7af37ccab43a90525f351 100644 (file)
--- a/src/btree.h
+++ b/src/btree.h
@@ -73,10 +73,8 @@ int sqlite3BtreeGetPageSize(Btree*);
 int sqlite3BtreeMaxPageCount(Btree*,int);
 u32 sqlite3BtreeLastPage(Btree*);
 int sqlite3BtreeSecureDelete(Btree*,int);
-int sqlite3BtreeGetReserve(Btree*);
-#if defined(SQLITE_HAS_CODEC) || defined(SQLITE_DEBUG)
+int sqlite3BtreeGetOptimalReserve(Btree*);
 int sqlite3BtreeGetReserveNoMutex(Btree *p);
-#endif
 int sqlite3BtreeSetAutoVacuum(Btree *, int);
 int sqlite3BtreeGetAutoVacuum(Btree *);
 int sqlite3BtreeBeginTrans(Btree*,int);

diff --git a/src/btreeInt.h b/src/btreeInt.h
index ed4d75ee9f0b972b88073110d929a8c78d1a9916..87d0ef1bb82b9e06a42ca0e8e139c782c7b521a6 100644 (file)
--- a/src/btreeInt.h
+++ b/src/btreeInt.h
@@ -418,6 +418,9 @@ struct BtShared {
 #endif
   u8 inTransaction;     /* Transaction state */
   u8 max1bytePayload;   /* Maximum first byte of cell for a 1-byte payload */
+#ifdef SQLITE_HAS_CODEC
+  u8 optimalReserve;    /* Desired amount of reserved space per page */
+#endif
   u16 btsFlags;         /* Boolean parameters.  See BTS_* macros below */
   u16 maxLocal;         /* Maximum local payload in non-LEAFDATA tables */
   u16 minLocal;         /* Minimum local payload in non-LEAFDATA tables */

diff --git a/src/test_stat.c b/src/test_stat.c
index 615df3d80fe155847516cf00b5a5c0f0e129ea25..daa84de2c05bfe767343503be5e57d84812a7d29 100644 (file)
--- a/src/test_stat.c
+++ b/src/test_stat.c
@@ -301,8 +301,11 @@ static int statDecodePage(Btree *pBt, StatPage *p){
 
   if( p->nCell ){
     int i;                        /* Used to iterate through cells */
-    int nUsable = szPage - sqlite3BtreeGetReserve(pBt);
+    int nUsable;                  /* Usable bytes per page */
 
+    sqlite3BtreeEnter(pBt);
+    nUsable = szPage - sqlite3BtreeGetReserveNoMutex(pBt);
+    sqlite3BtreeLeave(pBt);
     p->aCell = sqlite3_malloc((p->nCell+1) * sizeof(StatCell));
     memset(p->aCell, 0, (p->nCell+1) * sizeof(StatCell));
 
@@ -425,7 +428,11 @@ statNextRestart:
     while( p->iCell<p->nCell ){
       StatCell *pCell = &p->aCell[p->iCell];
       if( pCell->iOvfl<pCell->nOvfl ){
-        int nUsable = sqlite3BtreeGetPageSize(pBt)-sqlite3BtreeGetReserve(pBt);
+        int nUsable;
+        sqlite3BtreeEnter(pBt);
+        nUsable = sqlite3BtreeGetPageSize(pBt) - 
+                        sqlite3BtreeGetReserveNoMutex(pBt);
+        sqlite3BtreeLeave(pBt);
         pCsr->zName = (char *)sqlite3_column_text(pCsr->pStmt, 0);
         pCsr->iPageno = pCell->aOvfl[pCell->iOvfl];
         pCsr->zPagetype = "overflow";

diff --git a/src/vacuum.c b/src/vacuum.c
index 9df8e08b2285098805f5aa9c193bc60f0f1c5dd6..dca43e217e885636cb2bae713d0ba15c9c5cf896 100644 (file)
--- a/src/vacuum.c
+++ b/src/vacuum.c
@@ -184,7 +184,7 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
   ** cause problems for the call to BtreeSetPageSize() below.  */
   sqlite3BtreeCommit(pTemp);
 
-  nRes = sqlite3BtreeGetReserve(pMain);
+  nRes = sqlite3BtreeGetOptimalReserve(pMain);
 
   /* A VACUUM cannot change the pagesize of an encrypted database. */
 #ifdef SQLITE_HAS_CODEC