Update readme and add patch file to repository for bug 331158.

db/sqlite3/README.MOZILLA

@@ -30,3 +30,8 @@ change, they need to be changed in sqlite3file.h as well.
 
 -- Vlad Vukicevic <vladimir@pobox.com> 02/2006
 
+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

db/sqlite3/preload-cache.patch

@@ -0,0 +1,307 @@
+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