Comment improvements in pcache1.c. No changes to code.

FossilOrigin-Name: 9660a0a22547656cc3765b673d0cee9e1dd829ef

diff --git a/manifest b/manifest
index 118063a23418a871e7d400dbe603c671cf433c77..f9bb697af73533b7c45c73f26a4c1c049e15d159 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,8 +1,8 @@
 -----BEGIN PGP SIGNED MESSAGE-----
 Hash: SHA1
 
-C Do\snot\suse\smutexes\sin\sthe\spcache\simplementation\sunless\nSQLITE_ENABLE_MEMORY_MANAGMENT\sis\sdefined.\s\sThis\sis\sa\sperformance\senhancement.\nA\sside\seffect\sis\sthat\spcaches\swill\snot\ssteal\spages\sfrom\sone\sanother\sunless\nENABLE_MEMORY_MANAGEMENT\sis\sset,\sor\sunless\sSQLITE_THREADSAFE=0.
-D 2011-01-18T17:03:26.554
+C Comment\simprovements\sin\spcache1.c.\s\sNo\schanges\sto\scode.
+D 2011-01-19T21:58:56.344
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in de6498556d536ae60bb8bb10e8c1ba011448658c
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -170,7 +170,7 @@ F src/pager.h 0ea59db2a33bc6c2c02cae34de33367e1effdf76
 F src/parse.y 12b7ebd61ea54f0e1b1083ff69cc2c8ce9353d58
 F src/pcache.c 09d38c44ab275db581f7a2f6ff8b9bc7f8c0faaa
 F src/pcache.h c683390d50f856d4cd8e24342ae62027d1bb6050
-F src/pcache1.c b02aafb8e6e83cf1e49321bdd53926f430beb4b6
+F src/pcache1.c 2610bcebf127df5ff82730c0c130cb35d4d6debe
 F src/pragma.c 8a6cd3c787f882fa44f6490d2411fc26839ce8f3
 F src/prepare.c c8b877b80721d70b68053fd9ae30ec6d63eeeadc
 F src/printf.c 37e8bfd4c5a04eae4960adbe776b0f1fc4cad674
@@ -899,14 +899,14 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 56417a3386fc84dd36bf1488e88149b1ac6a0d02 2dc98d29995bef51108e99aa8f7a56427cf9e1d7
-R ae7dd673c03c5cec18f064cfaf72f5a8
+P e5ca59e63b18ac45a8c82ca39dc8cce1c4ce903c
+R 246c042190fbeb83b3f1f3c471b7048c
 U drh
-Z 325abbc955397207600330822401f3ff
+Z d4b4af53a8b712c86792c5f30e91ad66
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1.4.6 (GNU/Linux)
 
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-=JG+V
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diff --git a/manifest.uuid b/manifest.uuid
index 08777730f0c05407397a45d74e30566cd0fae8db..96c640d6cfa1f71bb3aaa24432acd86a70081565 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e5ca59e63b18ac45a8c82ca39dc8cce1c4ce903c
\ No newline at end of file
+9660a0a22547656cc3765b673d0cee9e1dd829ef
\ No newline at end of file

diff --git a/src/pcache1.c b/src/pcache1.c
index 7c046c20d38a9703ca5118ab7a84d6b8b9cfdbb2..4af41407f9d0af39e0d90ecd1bebaf34dddec2a9 100644 (file)
--- a/src/pcache1.c
+++ b/src/pcache1.c
@@ -674,18 +674,19 @@ static void *pcache1Fetch(sqlite3_pcache *p, unsigned int iKey, int createFlag){
   pcache1EnterMutex(pGroup);
   if( createFlag==1 ) sqlite3BeginBenignMalloc();
 
-  /* Search the hash table for an existing entry. */
+  /* Step 1: Search the hash table for an existing entry. */
   if( pCache->nHash>0 ){
     unsigned int h = iKey % pCache->nHash;
     for(pPage=pCache->apHash[h]; pPage&&pPage->iKey!=iKey; pPage=pPage->pNext);
   }
 
+  /* Step 2: Abort if no existing page is found and createFlag is 0 */
   if( pPage || createFlag==0 ){
     pcache1PinPage(pPage);
     goto fetch_out;
   }
 
-  /* Step 3 of header comment. */
+  /* Step 3: Abort if createFlag is 1 but the cache is nearly full */
   nPinned = pCache->nPage - pCache->nRecyclable;
   if( createFlag==1 && (
         nPinned>=(pGroup->nMaxPage+pCache->nMin-pGroup->nMinPage)
@@ -699,7 +700,7 @@ static void *pcache1Fetch(sqlite3_pcache *p, unsigned int iKey, int createFlag){
     goto fetch_out;
   }
 
-  /* Step 4. Try to recycle a page buffer if appropriate. */
+  /* Step 4. Try to recycle a page. */
   if( pCache->bPurgeable && pGroup->pLruTail && (
          (pCache->nPage+1>=pCache->nMax)
       || pGroup->nCurrentPage>=pGroup->nMaxPage