Bug 385066 - "Remove preloading from mozStorage" [p=comrade693+bmo@gmail.com (Shawn Wilsher [sdwilsh]) r=gavin a=blocking1.9+]

git-svn-id: svn://10.0.0.236/trunk@241625 18797224-902f-48f8-a5cc-f745e15eee43

mozilla/db/sqlite3/README.MOZILLA

@@ -18,13 +18,6 @@ Simply copy the sqlite3.h and sqlite3.c files from the amalgamation of sqlite.
 Then you need to update sqlite3file.h, which pulls out random bits of the
 internal files that we need to export. If any of these internal structures
 change, they need to be changed in sqlite3file.h as well.  This may involve
-downloading the whole souce (not the amalgamation) to check.
+downloading the whole source (not the amalgamation) to check.
 
 -- Shawn Wilsher <me@shawnwilsher.com> 06/2007
-
-XXX: This is temporarily obsolete (See Bug 385066)
-You also need to apply preload-cache.patch. This patch provides the preload
-functionality used by mozIStorageConnection.preload to fill the cache with
-pages from the disk.
-
--- Brett Wilson <brettw@gmail.com> 04/2006

mozilla/db/sqlite3/preload-cache.patch

@@ -1,307 +0,0 @@
-Index: build.c
-===================================================================
-RCS file: /cvsroot/mozilla/db/sqlite3/src/build.c,v
-retrieving revision 1.4.8.3
-diff -u -u -8 -p -r1.4.8.3 build.c
---- build.c	22 Feb 2006 20:56:28 -0000	1.4.8.3
-+++ build.c	11 Apr 2006 17:28:51 -0000
-@@ -22,16 +22,19 @@
- **     COMMIT
- **     ROLLBACK
- **
- ** $Id: preload-cache.patch,v 1.2 2006-04-11 17:35:25 brettw%gmail.com Exp $
- */
- #include "sqliteInt.h"
- #include <ctype.h>
- 
-+#include "pager.h"
-+#include "btree.h"
-+
- /*
- ** This routine is called when a new SQL statement is beginning to
- ** be parsed.  Initialize the pParse structure as needed.
- */
- void sqlite3BeginParse(Parse *pParse, int explainFlag){
-   pParse->explain = explainFlag;
-   pParse->nVar = 0;
- }
-@@ -3214,8 +3217,34 @@ KeyInfo *sqlite3IndexKeyinfo(Parse *pPar
-   }
- 
-   if( pParse->nErr ){
-     sqliteFree(pKey);
-     pKey = 0;
-   }
-   return pKey;
- }
-+
-+
-+/* See declaration in sqlite3.h for information */
-+int sqlite3Preload(sqlite3* db)
-+{
-+  Pager* pPager;
-+  Btree* pBt;
-+  int rc;
-+  int i;
-+  int dbsLoaded = 0;
-+
-+  for (i = 0; i < db->nDb; i ++) {
-+    pBt = db->aDb[i].pBt;
-+    if (! pBt)
-+      continue;
-+    pPager = sqlite3BtreePager(pBt);
-+    if (pPager) {
-+      rc = sqlite3pager_loadall(pPager);
-+      if (rc == SQLITE_OK)
-+        dbsLoaded ++;
-+    }
-+  }
-+  if (dbsLoaded == 0)
-+    return SQLITE_ERROR;
-+  return SQLITE_OK;
-+}
-Index: pager.c
-===================================================================
-RCS file: /cvsroot/mozilla/db/sqlite3/src/pager.c,v
-retrieving revision 1.3.8.3
-diff -u -u -8 -p -r1.3.8.3 pager.c
---- pager.c	22 Feb 2006 20:56:28 -0000	1.3.8.3
-+++ pager.c	11 Apr 2006 17:28:51 -0000
-@@ -2521,16 +2521,30 @@ int sqlite3pager_release_memory(int nReq
- ** to find a page in the in-memory cache first.  If the page is not already
- ** in memory, this routine goes to disk to read it in whereas _lookup()
- ** just returns 0.  This routine acquires a read-lock the first time it
- ** has to go to disk, and could also playback an old journal if necessary.
- ** Since _lookup() never goes to disk, it never has to deal with locks
- ** or journal files.
- */
- int sqlite3pager_get(Pager *pPager, Pgno pgno, void **ppPage){
-+  /* This just passes through to our modified version with a NULL data pointer */
-+  return sqlite3pager_get2(pPager, pgno, ppPage, 0);
-+}
-+
-+
-+/*
-+** This is an internal version of pager_get that takes an extra parameter of
-+** data to use to fill the page with. This allows more efficient filling for
-+** preloaded data. If this extra parameter is NULL, we'll go to the file.
-+**
-+** See sqlite3pager_loadall which uses this function.
-+*/
-+int sqlite3pager_get2(Pager *pPager, Pgno pgno, void **ppPage,
-+                      unsigned char* pDataToFill) {
-   PgHdr *pPg;
-   int rc;
- 
-   /* The maximum page number is 2^31. Return SQLITE_CORRUPT if a page
-   ** number greater than this, or zero, is requested.
-   */
-   if( pgno>PAGER_MAX_PGNO || pgno==0 || pgno==PAGER_MJ_PGNO(pPager) ){
-     return SQLITE_CORRUPT_BKPT;
-@@ -2676,39 +2690,46 @@ int sqlite3pager_get(Pager *pPager, Pgno
-     }
- 
-     /* Populate the page with data, either by reading from the database
-     ** file, or by setting the entire page to zero.
-     */
-     if( sqlite3pager_pagecount(pPager)<(int)pgno || MEMDB ){
-       memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
-     }else{
--      assert( MEMDB==0 );
--      rc = sqlite3OsSeek(pPager->fd, (pgno-1)*(i64)pPager->pageSize);
--      if( rc==SQLITE_OK ){
--        rc = sqlite3OsRead(pPager->fd, PGHDR_TO_DATA(pPg),
--                              pPager->pageSize);
--      }
--      TRACE3("FETCH %d page %d\n", PAGERID(pPager), pPg->pgno);
--      CODEC(pPager, PGHDR_TO_DATA(pPg), pPg->pgno, 3);
--      if( rc!=SQLITE_OK ){
--        i64 fileSize;
--        int rc2 = sqlite3OsFileSize(pPager->fd, &fileSize);
--        if( rc2!=SQLITE_OK || fileSize>=pgno*pPager->pageSize ){
--	  /* An IO error occured in one of the the sqlite3OsSeek() or
--          ** sqlite3OsRead() calls above. */
--          pPg->pgno = 0;
--          sqlite3pager_unref(PGHDR_TO_DATA(pPg));
--          return rc;
-+      if (pDataToFill) {
-+        /* Just copy from the given memory */
-+        memcpy(PGHDR_TO_DATA(pPg), pDataToFill, pPager->pageSize);
-+        CODEC(pPager, PGHDR_TO_DATA(pPg), pPg->pgno, 3);
-+      } else {
-+        /* Load from disk */
-+        assert( MEMDB==0 );
-+        rc = sqlite3OsSeek(pPager->fd, (pgno-1)*(i64)pPager->pageSize);
-+        if( rc==SQLITE_OK ){
-+          rc = sqlite3OsRead(pPager->fd, PGHDR_TO_DATA(pPg),
-+                                pPager->pageSize);
-+        }
-+        TRACE3("FETCH %d page %d\n", PAGERID(pPager), pPg->pgno);
-+        CODEC(pPager, PGHDR_TO_DATA(pPg), pPg->pgno, 3);
-+        if( rc!=SQLITE_OK ){
-+          i64 fileSize;
-+          int rc2 = sqlite3OsFileSize(pPager->fd, &fileSize);
-+          if( rc2!=SQLITE_OK || fileSize>=pgno*pPager->pageSize ){
-+            /* An IO error occured in one of the the sqlite3OsSeek() or
-+            ** sqlite3OsRead() calls above. */
-+            pPg->pgno = 0;
-+            sqlite3pager_unref(PGHDR_TO_DATA(pPg));
-+            return rc;
-+          }else{
-+            clear_simulated_io_error();
-+            memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
-+          }
-         }else{
--          clear_simulated_io_error();
--          memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
-+          TEST_INCR(pPager->nRead);
-         }
--      }else{
--        TEST_INCR(pPager->nRead);
-       }
-     }
- 
-     /* Link the page into the page hash table */
-     h = pager_hash(pgno);
-     pPg->pNextHash = pPager->aHash[h];
-     pPager->aHash[h] = pPg;
-     if( pPg->pNextHash ){
-@@ -3773,16 +3794,80 @@ int sqlite3pager_movepage(Pager *pPager,
-     DATA_TO_PGHDR(pNeedSync)->dirty = 1;
-     sqlite3pager_unref(pNeedSync);
-   }
- 
-   return SQLITE_OK;
- }
- #endif
- 
-+
-+/**
-+ * Addition for Mozilla: This will attempt to populate the database cache with
-+ * the first N bytes of the file, where N is the total size of the cache.
-+ * Because we can load this as one chunk from the disk, this is much faster
-+ * than loading a subset of the pages one at a time in random order.
-+ *
-+ * The pager must be initialized before this function is called. This means a
-+ * statement must be open that has initialized the pager and is keeping the
-+ * cache in memory.
-+ */
-+int sqlite3pager_loadall(Pager* pPager)
-+{
-+  int i;
-+  int rc;
-+  int loadSize;
-+  int loadPages;
-+  unsigned char* fileData;
-+
-+  if (pPager->dbSize < 0 || pPager->pageSize < 0) {
-+    /* pager not initialized, this means a statement is not open */
-+    return SQLITE_MISUSE;
-+  }
-+
-+  /* compute sizes */
-+  if (pPager->mxPage < pPager->dbSize)
-+    loadPages = pPager->mxPage;
-+  else
-+    loadPages = pPager->dbSize;
-+  loadSize = loadPages * pPager->pageSize;
-+
-+  rc = sqlite3OsSeek(pPager->fd, 0);
-+  if (rc != SQLITE_OK)
-+    return rc;
-+
-+  /* load the file as one chunk */
-+  fileData = sqliteMallocRaw(loadSize);
-+  if (! fileData)
-+    return SQLITE_NOMEM;
-+  rc = sqlite3OsRead(pPager->fd, fileData, loadSize);
-+  if (rc != SQLITE_OK) {
-+    sqliteFree(fileData);
-+    return rc;
-+  }
-+
-+  /* Copy the data to each page. Note that the page numbers we pass to _get
-+   * are one-based, 0 is a marker for no page. We also need to check that we
-+   * haven't loaded more pages than the cache can hold total. There may have
-+   * already been a few pages loaded before, so we may fill the cache before
-+   * loading all of the pages we want to.
-+   */
-+  for (i = 1; i <= loadPages && pPager->nPage < pPager->mxPage; i ++) {
-+    void *pPage;
-+    rc = sqlite3pager_get2(pPager, 1, &pPage,
-+                           &fileData[(i-1)*(i64)pPager->pageSize]);
-+    if (rc != SQLITE_OK)
-+      break;
-+    sqlite3pager_unref(pPage);
-+  }
-+  sqliteFree(fileData);
-+  return SQLITE_OK;
-+}
-+
-+
- #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
- /*
- ** Return the current state of the file lock for the given pager.
- ** The return value is one of NO_LOCK, SHARED_LOCK, RESERVED_LOCK,
- ** PENDING_LOCK, or EXCLUSIVE_LOCK.
- */
- int sqlite3pager_lockstate(Pager *pPager){
-   return sqlite3OsLockState(pPager->fd);
-Index: pager.h
-===================================================================
-RCS file: /cvsroot/mozilla/db/sqlite3/src/pager.h,v
-retrieving revision 1.2.8.3
-diff -u -u -8 -p -r1.2.8.3 pager.h
---- pager.h	22 Feb 2006 20:56:28 -0000	1.2.8.3
-+++ pager.h	11 Apr 2006 17:28:51 -0000
-@@ -104,16 +104,17 @@ const char *sqlite3pager_filename(Pager*
- const char *sqlite3pager_dirname(Pager*);
- const char *sqlite3pager_journalname(Pager*);
- int sqlite3pager_nosync(Pager*);
- int sqlite3pager_rename(Pager*, const char *zNewName);
- void sqlite3pager_set_codec(Pager*,void(*)(void*,void*,Pgno,int),void*);
- int sqlite3pager_movepage(Pager*,void*,Pgno);
- int sqlite3pager_reset(Pager*);
- int sqlite3pager_release_memory(int);
-+int sqlite3pager_loadall(Pager*);
- 
- #if defined(SQLITE_DEBUG) || defined(SQLITE_TEST)
- int sqlite3pager_lockstate(Pager*);
- #endif
- 
- #ifdef SQLITE_TEST
- void sqlite3pager_refdump(Pager*);
- int pager3_refinfo_enable;
-Index: sqlite3.h
-===================================================================
-RCS file: /cvsroot/mozilla/db/sqlite3/src/sqlite3.h,v
-retrieving revision 1.2.2.4
-diff -u -u -8 -p -r1.2.2.4 sqlite3.h
---- sqlite3.h	22 Feb 2006 20:56:28 -0000	1.2.2.4
-+++ sqlite3.h	11 Apr 2006 17:28:51 -0000
-@@ -1482,12 +1482,25 @@ int sqlite3_table_column_metadata(
- */
- int sqlite3_bind_parameter_indexes(
-     sqlite3_stmt *pStmt,
-     const char *zName,
-     int **pIndexes
- );
- void sqlite3_free_parameter_indexes(int *pIndexes);
- 
-+/*
-+** Preload the databases into the pager cache, up to the maximum size of the
-+** pager cache.
-+**
-+** For a database to be loaded successfully, the pager must be active. That is,
-+** there must be an open statement on that database. See sqlite3pager_loadall
-+**
-+** There might be many databases attached to the given connection. We iterate
-+** them all and try to load them. If none are loadable successfully, we return
-+** an error. Otherwise, we return OK.
-+*/
-+int sqlite3Preload(sqlite3* db);
-+
- #ifdef __cplusplus
- }  /* End of the 'extern "C"' block */
- #endif
- #endif

mozilla/storage/public/mozIStorageConnection.idl

@@ -54,7 +54,7 @@ interface nsIFile;
  * creating prepared statements, executing SQL, and examining database
  * errors.
  */
-[scriptable, uuid(e42f0655-cdc3-47c6-824a-cdb88c731cb9)]
+[scriptable, uuid(ffddc17b-cec3-492c-b13e-d5393c4b1595)]
 interface mozIStorageConnection : nsISupports {
   /*
    * Initialization and status
@@ -275,20 +275,4 @@ interface mozIStorageConnection : nsISupports {
    */
   nsIFile backupDB(in AString aFileName,
                    [optional] in nsIFile aParentDirectory);
-
-  /**
-   * This is used to preload the database cache. It loads pages from the
-   * start of the database file until the memory cache (specified by
-   * "PRAGMA cache_size=") is full or the entire file is read.
-   *
-   * The cache MUST be active on the database for this to work. This means
-   * that you must have a transaction open on the connection, or have a
-   * transaction open on another connection that shares the same pager cache.
-   * This cached data will go away when the transaction is closed.
-   *
-   * This preload operation can dramatically speed up read operations because
-   * the data is loaded as one large block. Normally, pages are read in on
-   * demand, which can cause many disk seeks.
-   */
-  void preload();
 };

mozilla/storage/src/mozStorageConnection.cpp

@@ -870,20 +870,6 @@ mozStorageConnection::BackupDB(const nsAString &aFileName,
     return mDatabaseFile->CopyTo(parentDir, fileName);
 }
 
-/**
- * Mozilla-specific sqlite function to preload the DB into the cache. See the
- * IDL and sqlite3.h
- */
-nsresult
-mozStorageConnection::Preload()
-{
-/*
-  int srv = sqlite3Preload(mDBConn);
-  return ConvertResultCode(srv);
-*/
-    return NS_OK; // XXX restore after sqlite upgrade
-}
-
 /**
  ** Other bits
  **/

mozilla/toolkit/components/places/src/nsNavHistory.cpp

@@ -749,15 +749,6 @@ nsNavHistory::InitDB(PRBool *aDoImport)
 
   // --- PUT SCHEMA-MODIFYING THINGS (like create table) ABOVE THIS LINE ---
 
-  // This causes the database data to be preloaded up to the maximum cache size
-  // set above. This dramatically speeds up some later operations. Failures
-  // here are not fatal since we can run fine without this.
-  if (cachePages > 0) {
-    rv = mDBConn->Preload();
-    if (NS_FAILED(rv))
-      NS_WARNING("Preload of database failed");
-  }
-
   // DO NOT PUT ANY SCHEMA-MODIFYING THINGS HERE
 
   rv = InitStatements();

mozilla/toolkit/components/satchel/src/nsStorageFormHistory.cpp

@@ -544,10 +544,6 @@ nsFormHistory::StartCache()
   rv = mDummyConnection->ExecuteSimpleSQL(cacheSizePragma);
   NS_ENSURE_SUCCESS(rv, rv);
 
-  // preload the cache
-  rv = mDummyConnection->Preload();
-  NS_ENSURE_SUCCESS(rv, rv);
-
   return NS_OK;
 }