From: drh <drh@noemail.net>
Date: Wed, 14 Mar 2018 14:53:50 +0000 (+0000)
Subject: Add the SQLITE_DBSTATUS_CACHE_SPILL option to sqlite3_db_status()
X-Git-Tag: version-3.23.0~58^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=ffc78a41ea2e13fb17a2528e53551342d3957e15;p=thirdparty%2Fsqlite.git

Add the SQLITE_DBSTATUS_CACHE_SPILL option to sqlite3_db_status()

FossilOrigin-Name: 3faeb851374471a6f94a6fab3a62c73d03330eae6fc72cd1a277b03ad12dcdd0
---

diff --git a/manifest b/manifest
index 9a05c02d0e..ed2f8c84a0 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Improve\sdetection\sof\sout-of-range\sparameters\sin\ssqlite3_stmt_status()\sfor\nSQLITE_ENABLE_API_ARMOR\sbuilds.
-D 2018-03-14T08:27:39.022
+C Add\sthe\sSQLITE_DBSTATUS_CACHE_SPILL\soption\sto\ssqlite3_db_status()
+D 2018-03-14T14:53:50.744
 F .fossil-settings/empty-dirs dbb81e8fc0401ac46a1491ab34a7f2c7c0452f2f06b54ebb845d024ca8283ef1
 F .fossil-settings/ignore-glob 35175cdfcf539b2318cb04a9901442804be81cd677d8b889fcc9149c21f239ea
 F Makefile.in 7016fc56c6b9bfe5daac4f34be8be38d8c0b5fab79ccbfb764d3b23bf1c6fff3
@@ -476,7 +476,7 @@ F src/os_setup.h 0dbaea40a7d36bf311613d31342e0b99e2536586
 F src/os_unix.c 928586cbde31890538854f1657463392d63b2d7794f577774573ae53ec283d7b
 F src/os_win.c eb03c6d52f893bcd7fdd4c6006674c13c1b5e49543fec98d605201af2997171c
 F src/os_win.h 7b073010f1451abe501be30d12f6bc599824944a
-F src/pager.c aa764a01a5548e633ea083521f48c2b128245fae1a8157a16a3490b9b9718f55
+F src/pager.c 3e3b659b6b3f40b5a5efef6b8890ced490c397a81d96feb5266fde1f7362e608
 F src/pager.h 581698f2177e8bd4008fe4760898ce20b6133d1df22139b9101b5155f900df7a
 F src/parse.y 3be4b2b5e33ef7dab3128b765898ee786fc6cd698a7f053f756a68f2f238f0aa
 F src/pcache.c 135ef0bc6fb2e3b7178d49ab5c9176254c8a691832c1bceb1156b2fbdd0869bd
@@ -490,13 +490,13 @@ F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 66c73fcb7719b8ff0e841b58338f13604ff3e2b50a723f9b8f383595735262f6
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
 F src/select.c f02352ac5cbb6fad3804add825743b924cfb6c742ba2e8666d726828a9985d73
-F src/shell.c.in b0aad8855b1c04ff4637c9f244a5537255f5d3dc6625e334454f5bd7d9794c61
-F src/sqlite.h.in 49d776d536076894e38de837a6c999e5150949baf008aa02d91fea70471eae78
+F src/shell.c.in 9b7e7ac1ccdbc045e285e745ff6d21dbec6ce91330f2bdd5db50d5c39f40679e
+F src/sqlite.h.in 6283ece8dbc3749d78593415a2373f4e7050afce7d18f87acea3b9a48f6fa576
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 83a3c4ce93d650bedfd1aa558cb85a516bd6d094445ee989740827d0d944368d
 F src/sqliteInt.h 2ef60a6d9a50e6eef224e9eae71b29a9fb91c301e882d9fbbb77afd50b6cf815
 F src/sqliteLimit.h 1513bfb7b20378aa0041e7022d04acb73525de35b80b252f1b83fedb4de6a76b
-F src/status.c 9737ed017279a9e0c5da748701c3c7bf1e8ae0dae459aad20dd64fcff97a7e35
+F src/status.c 46e7aec11f79dad50965a5ca5fa9de009f7d6bde08be2156f1538a0a296d4d0e
 F src/table.c b46ad567748f24a326d9de40e5b9659f96ffff34
 F src/tclsqlite.c 916a92de77ec5cbe27818ca194d8cf0c58aa7ad5b87527098f6aa5a6068800ce
 F src/test1.c 1ab7cbbb6693e08364c1a9241e2aee17f8c4925e4cc52396be77ae6845a05828
@@ -526,7 +526,7 @@ F src/test_intarray.c 988fc61cb0ff539f4172c0d95f15287c92516f64
 F src/test_intarray.h f3b7672f5d1056eac563c0d6ea8480a660b1475c
 F src/test_journal.c 619f2aa10e0d7a5f87c0f06825bc61dfce1c6b9c7f3ad990fb13de6c3b8874a3
 F src/test_loadext.c 337056bae59f80b9eb00ba82088b39d0f4fe6dfd
-F src/test_malloc.c 4f06a805de86be5216a127b3777ca2d5a1ff99d1a9238374ce136a47411be36c
+F src/test_malloc.c 5201422e2403e66a7a9c2b7d8df806acd8d2a0429822adb7e932f324e7b5b3c6
 F src/test_md5.c 7268e1e8c399d4a5e181b64ac20e1e6f3bc4dd9fc87abac02db145a3d951fa8c
 F src/test_multiplex.c e054459f7633f3ff8ce1245da724f9a8be189e4e
 F src/test_multiplex.h 5436d03f2d0501d04f3ed50a75819e190495b635
@@ -742,7 +742,7 @@ F test/date2.test 74c234bece1b016e94dd4ef9c8cc7a199a8806c0e2291cab7ba64bace6350b
 F test/dbfuzz.c 73047c920d6210e5912c87cdffd9a1c281d4252e
 F test/dbpage.test dbf50a4d361f9e45a979432c727506065113124478a7d2db12074fa655e65d6c
 F test/dbstatus.test 76e317d26476ffba00faa724f383b97e6f9b7d037270fc924f15b6cd4d0bd99d
-F test/dbstatus2.test e93ab03bfae6d62d4d935f20de928c19ca0ed0ab
+F test/dbstatus2.test 35a987036fefbbc696e65b6a3fbd860864cfd54941c52f50c61b55d4778ac66c
 F test/default.test 0cb49b1c315a0d81c81d775e407f66906a2a604d
 F test/delete.test acc38fca8ee4851467705b1c2cfea64cd26667e5
 F test/delete2.test 3a03f2cca1f9a67ec469915cb8babd6485db43fa
@@ -1712,7 +1712,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 0171d4a71ca7911a9fd409a42eeed0eda4521b6e48df5cd058364c0a736313b7
-R a2badd15fc27350d38828fa175bb36a1
-U dan
-Z 1e5c4dfa2e88b466a3e12b606bfaedf6
+P 21ecbce1378f3cc4b1051628b8c1580bb807c8745a1f525bc089036af93a54af
+R d33a89781051cd16ed43afc1ec7bbcef
+T *branch * dbstatus-cache-spill
+T *sym-dbstatus-cache-spill *
+T -sym-trunk *
+U drh
+Z ec7615ff5aac967dc56fabc66432aa1b
diff --git a/manifest.uuid b/manifest.uuid
index a5dc53cc26..5d0cc6dacb 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-21ecbce1378f3cc4b1051628b8c1580bb807c8745a1f525bc089036af93a54af
\ No newline at end of file
+3faeb851374471a6f94a6fab3a62c73d03330eae6fc72cd1a277b03ad12dcdd0
\ No newline at end of file
diff --git a/src/pager.c b/src/pager.c
index f4ac88c206..e3881c6a89 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -699,7 +699,7 @@ struct Pager {
   char *zJournal;             /* Name of the journal file */
   int (*xBusyHandler)(void*); /* Function to call when busy */
   void *pBusyHandlerArg;      /* Context argument for xBusyHandler */
-  int aStat[3];               /* Total cache hits, misses and writes */
+  int aStat[4];               /* Total cache hits, misses, writes, spills */
 #ifdef SQLITE_TEST
   int nRead;                  /* Database pages read */
 #endif
@@ -727,6 +727,7 @@ struct Pager {
 #define PAGER_STAT_HIT   0
 #define PAGER_STAT_MISS  1
 #define PAGER_STAT_WRITE 2
+#define PAGER_STAT_SPILL 3
 
 /*
 ** The following global variables hold counters used for
@@ -4618,6 +4619,7 @@ static int pagerStress(void *p, PgHdr *pPg){
     return SQLITE_OK;
   }
 
+  pPager->aStat[PAGER_STAT_SPILL]++;
   pPg->pDirty = 0;
   if( pagerUseWal(pPager) ){
     /* Write a single frame for this page to the log. */
@@ -6738,8 +6740,12 @@ int *sqlite3PagerStats(Pager *pPager){
 #endif
 
 /*
-** Parameter eStat must be either SQLITE_DBSTATUS_CACHE_HIT or
-** SQLITE_DBSTATUS_CACHE_MISS. Before returning, *pnVal is incremented by the
+** Parameter eStat must be one of SQLITE_DBSTATUS_CACHE_HIT, _MISS, _WRITE,
+** or _WRITE+1.  The SQLITE_DBSTATUS_CACHE_WRITE+1 case is a translation
+** of SQLITE_DBSTATUS_CACHE_SPILL.  The _SPILL case is not contiguous because
+** it was added later.
+**
+** Before returning, *pnVal is incremented by the
 ** current cache hit or miss count, according to the value of eStat. If the 
 ** reset parameter is non-zero, the cache hit or miss count is zeroed before 
 ** returning.
@@ -6749,15 +6755,18 @@ void sqlite3PagerCacheStat(Pager *pPager, int eStat, int reset, int *pnVal){
   assert( eStat==SQLITE_DBSTATUS_CACHE_HIT
        || eStat==SQLITE_DBSTATUS_CACHE_MISS
        || eStat==SQLITE_DBSTATUS_CACHE_WRITE
+       || eStat==SQLITE_DBSTATUS_CACHE_WRITE+1
   );
 
   assert( SQLITE_DBSTATUS_CACHE_HIT+1==SQLITE_DBSTATUS_CACHE_MISS );
   assert( SQLITE_DBSTATUS_CACHE_HIT+2==SQLITE_DBSTATUS_CACHE_WRITE );
-  assert( PAGER_STAT_HIT==0 && PAGER_STAT_MISS==1 && PAGER_STAT_WRITE==2 );
+  assert( PAGER_STAT_HIT==0 && PAGER_STAT_MISS==1
+           && PAGER_STAT_WRITE==2 && PAGER_STAT_SPILL==3 );
 
-  *pnVal += pPager->aStat[eStat - SQLITE_DBSTATUS_CACHE_HIT];
+  eStat -= SQLITE_DBSTATUS_CACHE_HIT;
+  *pnVal += pPager->aStat[eStat];
   if( reset ){
-    pPager->aStat[eStat - SQLITE_DBSTATUS_CACHE_HIT] = 0;
+    pPager->aStat[eStat] = 0;
   }
 }
 
diff --git a/src/shell.c.in b/src/shell.c.in
index 7cdd361779..f7389f3097 100644
--- a/src/shell.c.in
+++ b/src/shell.c.in
@@ -2353,6 +2353,9 @@ static int display_stats(
     sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_WRITE, &iCur, &iHiwtr, 1);
     raw_printf(pArg->out, "Page cache writes:                   %d\n", iCur);
     iHiwtr = iCur = -1;
+    sqlite3_db_status(db, SQLITE_DBSTATUS_CACHE_SPILL, &iCur, &iHiwtr, 1);
+    raw_printf(pArg->out, "Page cache spills:                   %d\n", iCur);
+    iHiwtr = iCur = -1;
     sqlite3_db_status(db, SQLITE_DBSTATUS_SCHEMA_USED, &iCur, &iHiwtr, bReset);
     raw_printf(pArg->out, "Schema Heap Usage:                   %d bytes\n",
             iCur);
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 1d7e191442..9b477d84bc 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -7230,6 +7230,15 @@ int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
 ** </dd>
 **
+** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
+** <dd>This parameter returns the number of dirty cache entries that have
+** been written to disk in the middle of a transaction due to the page
+** cache overflowing. Transactions are more efficient if they are written
+** to disk all at once. When pages spill mid-transaction, that introduces
+** additional overhead. This parameter can be used help identify
+** inefficiencies that can be resolve by increasing the cache size.
+** </dd>
+**
 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
 ** <dd>This parameter returns zero for the current value if and only if
 ** all foreign key constraints (deferred or immediate) have been
@@ -7249,7 +7258,8 @@ int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
 #define SQLITE_DBSTATUS_CACHE_WRITE          9
 #define SQLITE_DBSTATUS_DEFERRED_FKS        10
 #define SQLITE_DBSTATUS_CACHE_USED_SHARED   11
-#define SQLITE_DBSTATUS_MAX                 11   /* Largest defined DBSTATUS */
+#define SQLITE_DBSTATUS_CACHE_SPILL         12
+#define SQLITE_DBSTATUS_MAX                 12   /* Largest defined DBSTATUS */
 
 
 /*
diff --git a/src/status.c b/src/status.c
index 6e5b0e573b..a5a39f4c18 100644
--- a/src/status.c
+++ b/src/status.c
@@ -337,6 +337,9 @@ int sqlite3_db_status(
     ** pagers the database handle is connected to. *pHighwater is always set 
     ** to zero.
     */
+    case SQLITE_DBSTATUS_CACHE_SPILL:
+      op = SQLITE_DBSTATUS_CACHE_WRITE+1;
+      /* Fall through into the next case */
     case SQLITE_DBSTATUS_CACHE_HIT:
     case SQLITE_DBSTATUS_CACHE_MISS:
     case SQLITE_DBSTATUS_CACHE_WRITE:{
diff --git a/src/test_malloc.c b/src/test_malloc.c
index b13d9b2b2c..33bc3807ba 100644
--- a/src/test_malloc.c
+++ b/src/test_malloc.c
@@ -1383,6 +1383,7 @@ static int SQLITE_TCLAPI test_db_status(
     { "CACHE_WRITE",         SQLITE_DBSTATUS_CACHE_WRITE         },
     { "DEFERRED_FKS",        SQLITE_DBSTATUS_DEFERRED_FKS        },
     { "CACHE_USED_SHARED",   SQLITE_DBSTATUS_CACHE_USED_SHARED   },
+    { "CACHE_SPILL",         SQLITE_DBSTATUS_CACHE_SPILL         },
   };
   Tcl_Obj *pResult;
   if( objc!=4 ){
diff --git a/test/dbstatus2.test b/test/dbstatus2.test
index eff4b0207f..b75f40b062 100644
--- a/test/dbstatus2.test
+++ b/test/dbstatus2.test
@@ -37,6 +37,10 @@ proc db_write {db {reset 0}} {
   sqlite3_db_status $db CACHE_WRITE $reset
 }
 
+proc db_spill {db {reset 0}} {
+  sqlite3_db_status $db CACHE_SPILL $reset
+}
+
 do_test 1.1 {
   db close
   sqlite3 db test.db
@@ -98,5 +102,14 @@ do_test 2.7 {
 } {0 4 0}
 do_test 2.8 { db_write db 1 } {0 4 0}
 do_test 2.9 { db_write db 0 } {0 0 0}
+
+do_test 3.0 { db_spill db 1 } {0 0 0}
+do_test 3.1 { db_spill db 0 } {0 0 0}
+do_execsql_test 3.2 {
+  PRAGMA journal_mode=DELETE;
+  PRAGMA cache_size=3;
+  UPDATE t1 SET b=randomblob(1000);
+} {delete}
+do_test 3.2 { db_spill db 0 } {0 8 0}
  
 finish_test