Begin adding BTree code (CVS 213)

FossilOrigin-Name: bdb1c425f577d455155982ee2cd8cb686bcaf0da

manifest

@@ -1,5 +1,5 @@
-C Version\s1.0.31\s(CVS\s472)
+C Begin\sadding\sBTree\scode\s(CVS\s213)
-D 2001-04-15T02:30:00
+D 2001-04-17T20:09:11
 F COPYRIGHT 74a8a6531a42e124df07ab5599aad63870fa0bd4
 F Makefile.in ac01d6145714b0d1c9e99382caf03cf30d6f4c8d
 F README 51f6a4e7408b34afa5bc1c0485f61b6a4efb6958
@@ -9,6 +9,8 @@ F configure.in 6940e3f88bf3d28a10c73b06ab99fd3a7e039a61
 F doc/lemon.html e233a3e97a779c7a87e1bc4528c664a58e49dd47
 F doc/report1.txt 734cbae63b1310cc643fe5e9e3da1ab55a79b99e
 F src/TODO 38a68a489e56e9fd4a96263e0ff9404a47368ad4
+F src/btree.c 670b20349bd1d1448cc90f7b9487c2bf7a5c039c
+F src/btree.h f21c240d0c95f93e2a128106d04a6c448ed0eb94
 F src/build.c 4f6a2d551c56342cd4a0420654835be3ad179651
 F src/dbbe.c ec82c602c598748204a61a35ab0c31e34ca58223
 F src/dbbe.h 7235b15c6c5d8be0c4da469cef9620cee70b1cc8
@@ -59,7 +61,7 @@ F test/insert2.test 732405e30331635af8d159fccabe835eea5cd0c6
 F test/lock.test bca7d53de73138b1f670a2fbdb1f481ff7eaa45a
 F test/main.test da635f9e078cd21ddf074e727381a715064489ff
 F test/malloc.test 3daa97f6a9577d8f4c6e468b274333af19ce5861
-F test/pager.test 4c27be3e0da89caa36fa3c2b84468785f330acca
+F test/pager.test 3416a155c2dc3b1b3c07d4bb0192cbb15b76a90c
 F test/printf.test 4c71871e1a75a2dacb673945fc13ddb30168798f
 F test/rowid.test 128453599def7435e988216f7fe89c7450b8a9a3
 F test/select1.test 223507655cdb4f9901d83fa7f5c5328e022c211f
@@ -101,7 +103,7 @@ F www/opcode.tcl cb3a1abf8b7b9be9f3a228d097d6bf8b742c2b6f
 F www/sqlite.tcl cb0d23d8f061a80543928755ec7775da6e4f362f
 F www/tclsqlite.tcl 06f81c401f79a04f2c5ebfb97e7c176225c0aef2
 F www/vdbe.tcl 0c8aaa529dd216ccbf7daaabd80985e413d5f9ad
-P 1f07abe46e2de8c5d9659bd5a78efe4ce23144ae
+P a7bfcbb4131ab17a58d5e843c418b2e1a3ab2abc
-R 6b66dff388a84887995d516ce20e212a
+R a9d053b754fd8fb60eea783a8c6d6da7
 U drh
-Z 1ee28b0946e3569d6ec390d67bea5d2f
+Z b0f122553586c19814acf39c12755271

manifest.uuid

@@ -1 +1 @@
-a7bfcbb4131ab17a58d5e843c418b2e1a3ab2abc
+bdb1c425f577d455155982ee2cd8cb686bcaf0da

src/btree.c

@@ -0,0 +1,266 @@
+/*
+** Copyright (c) 2001 D. Richard Hipp
+**
+** This program is free software; you can redistribute it and/or
+** modify it under the terms of the GNU General Public
+** License as published by the Free Software Foundation; either
+** version 2 of the License, or (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+** General Public License for more details.
+** 
+** You should have received a copy of the GNU General Public
+** License along with this library; if not, write to the
+** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+** Boston, MA  02111-1307, USA.
+**
+** Author contact information:
+**   drh@hwaci.com
+**   http://www.hwaci.com/drh/
+**
+*************************************************************************
+** $Id: btree.c,v 1.1 2001/04/17 20:09:11 drh Exp $
+*/
+#include "sqliteInt.h"
+#include "pager.h"
+#include "btree.h"
+#include <assert.h>
+
+typedef unsigned int u32;
+
+/*
+** Everything we need to know about an open database
+*/
+struct Btree {
+  Pager *pPager;        /* The page cache */
+  BtCursor *pCursor;    /* All open cursors */
+  u32 *page1;           /* First page of the database */
+  int inTrans;          /* True if a transaction is current */
+};
+typedef Btree Bt;
+
+/*
+** The maximum depth of a cursor
+*/
+#define MX_LEVEL 20
+
+/*
+** Within a cursor, each level off the search tree is an instance of
+** this structure.
+*/
+typedef struct BtIdxpt BtIdxpt;
+struct BtIdxpt {
+  Pgno pgno;        /* The page number */
+  u32 *aPage;       /* The page data */
+  int idx;          /* Index into pPage[] */
+};
+
+/*
+** Everything we need to know about a cursor
+*/
+struct BtCursor {
+  Btree *pBt;                   /* The whole database */
+  BtCursor *pPrev, *pNext;      /* Linked list of all cursors */
+  int valid;                    /* True if the cursor points to something */
+  int nLevel;                   /* Number of levels of indexing used */
+  BtIdxpt aLevel[MX_LEVEL];     /* The index levels */
+};
+
+/*
+** The first page contains the following additional information:
+**
+**      MAGIC-1
+**      MAGIC-2
+**      First free block
+*/
+#define EXTRA_PAGE_1_CELLS  3
+#define MAGIC_1  0x7264dc61
+#define MAGIC_2  0x54e55d9e
+
+/*
+** Open a new database
+*/
+int sqliteBtreeOpen(const char *zFilename, int mode, Btree **ppBtree){
+  Btree *pBt;
+
+  pBt = sqliteMalloc( sizeof(*pBt) );
+  if( pBt==0 ){
+    **ppBtree = 0;
+    return SQLITE_NOMEM;
+  }
+  rc = sqlitepager_open(&pBt->pPager, zFilename, 100);
+  if( rc!=SQLITE_OK ){
+    if( pBt->pPager ) sqlitepager_close(pBt->pPager);
+    sqliteFree(pBt);
+    *ppBtree = 0;
+    return rc;
+  }
+  pBt->pCursor = 0;
+  pBt->page1 = 0;
+  *ppBtree = pBt;
+  return SQLITE_OK;
+}
+
+/*
+** Close an open database and invalidate all cursors.
+*/
+int sqliteBtreeClose(Btree *pBt){
+  while( pBt->pCursor ){
+    sqliteBtreeCloseCursor(pBt->pCursor);
+  }
+  sqlitepager_close(pBt->pPager);
+  sqliteFree(pBt);
+  return SQLITE_OK;
+}
+
+/*
+** Start a new transaction
+*/
+int sqliteBtreeBeginTrans(Btree *pBt){
+  int rc;
+  if( pBt->inTrans ) return SQLITE_ERROR;
+  if( pBt->page1==0 ){
+    rc = sqlitepager_get(pBt->pPager, 1, &pBt->page1);
+    if( rc!=SQLITE_OK ) return rc;
+  }
+  rc = sqlitepager_write(pBt->page1);
+  if( rc==SQLITE_OK ){
+    pBt->inTrans = 1;
+  }
+  return rc;
+}
+
+/*
+** Get a reference to page1 of the database file.  This will
+** also acquire a readlock on that file.
+*/
+static int lockBtree(Btree *pBt){
+  int rc;
+  if( pBt->page1 ) return SQLITE_OK;
+  rc = sqlitepager_get(pBt->pPager, 1, &pBt->page1);
+  if( rc!=SQLITE_OK ) return rc;
+  /* Sanity checking on the database file format */
+  return rc;
+}
+
+/*
+** Remove the last reference to the database file.  This will
+** remove the read lock.
+*/
+static void unlockBtree(Btree *pBt){
+  if( pBt->pCursor==0 && pBt->page1!=0 ){
+    sqlitepager_unref(pBt->page1);
+    pBt->page1 = 0;
+    pBt->inTrans = 0;
+  }
+}
+
+/*
+** Commit the transaction currently in progress.  All cursors
+** must be closed before this routine is called.
+*/
+int sqliteBtreeCommit(Btree *pBt){
+  int rc;
+  assert( pBt->pCursor==0 );
+  rc = sqlitepager_commit(pBt->pPager);
+  unlockBtree(pBt);
+  return rc;
+}
+
+/*
+** Rollback the transaction in progress.  All cursors must be
+** closed before this routine is called.
+*/
+int sqliteBtreeRollback(Btree *pBt){
+  int rc;
+  assert( pBt->pCursor==0 );
+  rc = sqlitepager_rollback(pBt->pPager);
+  unlockBtree(pBt);
+  return rc;
+}
+
+/*
+** Create a new cursor.  The act of acquiring a cursor
+** gets a read lock on the database file.
+*/
+int sqliteBtreeCursor(Btree *pBt, BtCursor **ppCur){
+  int rc;
+  BtCursor *pCur;
+  if( pBt->page1==0 ){
+    rc = lockBtree(pBt);
+    if( rc!=SQLITE_OK ){
+      *ppCur = 0;
+      return rc;
+    }
+  }
+  pCur = sqliteMalloc( sizeof(*pCur) );
+  if( pCur==0 ){
+    *ppCur = 0;
+    unlockBtree(pBt);
+    return SQLITE_NOMEM;
+  }
+  pCur->pPrev = 0;
+  pCur->pNext = pBt->pCursor;
+  if( pCur->pNext ){
+    pCur->pNext->pPrev = pCur;
+  }
+  pBt->pCursor = pCur;
+  pCur->pBt = pBt;
+  pCur->nLevel = 1;
+  pCur->aLevel[0].pgno = 1;
+  pCur->aLevel[0].aPage = pBt->page1;
+  pCur->aLevel[0].idx = 0;
+}
+
+/*
+** Close a cursor. 
+*/
+int sqliteBtreeCloseCursor(BtCursor *pCur){
+  Btree *pBt = pCur->pBt;
+  int i;
+  if( pCur->pPrev ){
+    pCur->pPrev->pNext = pCur->pNext;
+  }else{
+    pBt->pCursor = pCur->pNext;
+  }
+  if( pCur->pNext ){
+    pCur->pNext->pPrev = pCur->pPrev;
+  }
+  for(i=pCur->nLevel-1; i>0; i--){
+    sqlitepager_unref(pCur->aLevel[i].aPage);
+  }
+  if( pBt->pCursor==0 && pBt->inTrans==0 ){
+    unlockBtree(pBt);
+  }
+  sqliteFree(pCur);
+}
+
+int sqliteBtreeKeySize(BtCursor *pCur){
+  int nEntry;
+  u32 *aPage;
+  BtIdxpt *pIdx;
+  int offset;
+  if( !pCur->valid ) return 0;
+  pIdx = &pCur->aLevel[pCur->nLevel-1];
+  aPage = pIdx->aPage;
+  offset = (pIdx->pgno==1)*EXTRA_PAGE_1_CELLS;
+  nEntry = aPage[offset];
+  if( pIdx->idx<nEntry ){
+    
+}
+int sqliteBtreeKey(BtCursor*, int offset, int amt, char *zBuf);
+int sqliteBtreeDataSize(BtCursor*);
+int sqliteBtreeData(BtCursor*, int offset, int amt, char *zBuf);
+
+
+/* Move the cursor so that it points to an entry near pKey.
+** Return 0 if the cursor is left pointing exactly at pKey.
+** Return -1 if the cursor points to the largest entry less than pKey.
+** Return 1 if the cursor points to the smallest entry greater than pKey.
+*/
+int sqliteBtreeMoveto(BtCursor*, void *pKey, int nKey);
+int sqliteBtreeDelete(BtCursor*);
+int sqliteBtreeInsert(BtCursor*, void *pKey, int nKey, void *pData, int nData);
+int sqliteBtreeNext(BtCursor*);

src/btree.h

@@ -0,0 +1,56 @@
+/*
+** Copyright (c) 2001 D. Richard Hipp
+**
+** This program is free software; you can redistribute it and/or
+** modify it under the terms of the GNU General Public
+** License as published by the Free Software Foundation; either
+** version 2 of the License, or (at your option) any later version.
+**
+** This program is distributed in the hope that it will be useful,
+** but WITHOUT ANY WARRANTY; without even the implied warranty of
+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+** General Public License for more details.
+** 
+** You should have received a copy of the GNU General Public
+** License along with this library; if not, write to the
+** Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+** Boston, MA  02111-1307, USA.
+**
+** Author contact information:
+**   drh@hwaci.com
+**   http://www.hwaci.com/drh/
+**
+*************************************************************************
+** This header file defines the interface that the sqlite B-Tree file
+** subsystem.
+**
+** @(#) $Id: btree.h,v 1.1 2001/04/17 20:09:11 drh Exp $
+*/
+
+typedef struct Btree Btree;
+typedef struct BtCursor BtCursor;
+
+int sqliteBtreeOpen(const char *zFilename, int mode, Btree **ppBtree);
+int sqliteBtreeClose(Btree*);
+
+int sqliteBtreeBeginTrans(Btree*);
+int sqliteBtreeCommit(Btree*);
+int sqliteBtreeRollback(Btree*);
+
+
+int sqliteBtreeCursor(Btree*, BtCursor **ppCur);
+
+/* Move the cursor so that it points to an entry near pKey.
+** Return 0 if the cursor is left pointing exactly at pKey.
+** Return -1 if the cursor points to the largest entry less than pKey.
+** Return 1 if the cursor points to the smallest entry greater than pKey.
+*/
+int sqliteBtreeMoveto(BtCursor*, void *pKey, int nKey);
+int sqliteBtreeDelete(BtCursor*);
+int sqliteBtreeInsert(BtCursor*, void *pKey, int nKey, void *pData, int nData);
+int sqliteBtreeNext(BtCursor*);
+int sqliteBtreeKeySize(BtCursor*);
+int sqliteBtreeKey(BtCursor*, int offset, int amt, char *zBuf);
+int sqliteBtreeDataSize(BtCursor*);
+int sqliteBtreeData(BtCursor*, int offset, int amt, char *zBuf);
+int sqliteBtreeCloseCursor(BtCursor*);

test/pager.test

@@ -23,7 +23,7 @@
 # This file implements regression tests for SQLite library.  The
 # focus of this script is page cache subsystem.
 #
-# $Id: pager.test,v 1.2 2001/04/15 02:27:25 drh Exp $
+# $Id: pager.test,v 1.3 2001/04/17 20:09:11 drh Exp $
 
 
 set testdir [file dirname $argv0]
@@ -171,7 +171,7 @@ do_test pager-2.99 {
 
 do_test pager-3.1 {
   set v [catch {
-    set ::p1 [pager_open ptf1.db 5]
+    set ::p1 [pager_open ptf1.db 15]
   } msg]
   if {$v} {lappend v $msg}
   set v
@@ -205,6 +205,29 @@ for {set i 2} {$i<=20} {incr i} {
     set v
   }] "Page-$i"
 }
+for {set i 1} {$i<=20} {incr i} {
+  regsub -all CNT {
+    set ::g1 [page_get $::p1 CNT]
+    set ::g2 [page_get $::p1 CNT]
+    set ::vx [page_read $::g2]
+    expr {$::g1==$::g2}
+  } $i body;
+  do_test pager-3.7.$i.1 $body {1}
+  regsub -all CNT {
+    page_unref $::g2
+    set vy [page_read $::g1]
+    expr {$vy==$::vx}
+  } $i body;
+  do_test pager-3.7.$i.2 $body {1}
+  regsub -all CNT {
+    page_unref $::g1
+    set gx [page_get $::p1 CNT]
+    set vy [page_read $gx]
+    page_unref $gx
+    expr {$vy==$::vx}
+  } $i body;
+  do_test pager-3.7.$i.3 $body {1}
+}
 do_test pager-3.99 {
   pager_close $::p1
 } {}