database/sqlite
1
0
Fork 0
mirror of https://github.com/sqlite/sqlite.git synced 2025-07-29 08:01:23 +03:00
Code Activity

Add the "--lost-and-found" option to the ".recover" command. For setting the name of the orphaned rows table.

Browse Source 
FossilOrigin-Name: 67bb88e24c74d02ae0c4ac6ff2f873f6b0035ccefe5cccfc71c5686cbc76b4c3
This commit is contained in:
dan
2019-04-27 18:47:03 +00:00
parent f57bea31ba
commit 42ebb01e9f
5 changed files with 234 additions and 101 deletions
Download Patch File Download Diff File Expand all files Collapse all files

131
ext/misc/dbdata.c
View File

@ -10,10 +10,14 @@
**
******************************************************************************
**
** This file contains an implementation of the eponymous "sqlite_dbdata"
** virtual table. sqlite_dbdata is used to extract data directly from a
** database b-tree page and its associated overflow pages, bypassing the b-tree
** layer. The table schema is equivalent to:
** This file contains an implementation of two eponymous virtual tables,
** "sqlite_dbdata" and "sqlite_dbptr". Both modules require that the
** "sqlite_dbpage" eponymous virtual table be available.
**
** SQLITE_DBDATA:
** sqlite_dbdata is used to extract data directly from a database b-tree
** page and its associated overflow pages, bypassing the b-tree layer.
** The table schema is equivalent to:
**
** CREATE TABLE sqlite_dbdata(
** pgno INTEGER,
@ -23,23 +27,25 @@
** schema TEXT HIDDEN
** );
**
** IMPORTANT: THE VIRTUAL TABLE SCHEMA ABOVE IS SUBJECT TO CHANGE. IN THE
** FUTURE NEW NON-HIDDEN COLUMNS MAY BE ADDED BETWEEN "value" AND "schema".
** IMPORTANT: THE VIRTUAL TABLE SCHEMA ABOVE IS SUBJECT TO CHANGE. IN THE
** FUTURE NEW NON-HIDDEN COLUMNS MAY BE ADDED BETWEEN "value" AND
** "schema".
**
** Each page of the database is inspected. If it cannot be interpreted as a
** b-tree page, or if it is a b-tree page containing 0 entries, the
** sqlite_dbdata table contains no rows for that page. Otherwise, the table
** contains one row for each field in the record associated with each
** cell on the page. For intkey b-trees, the key value is stored in field -1.
** Each page of the database is inspected. If it cannot be interpreted as
** a b-tree page, or if it is a b-tree page containing 0 entries, the
** sqlite_dbdata table contains no rows for that page. Otherwise, the
** table contains one row for each field in the record associated with
** each cell on the page. For intkey b-trees, the key value is stored in
** field -1.
**
** For example, for the database:
** For example, for the database:
**
** CREATE TABLE t1(a, b); -- root page is page 2
** INSERT INTO t1(rowid, a, b) VALUES(5, 'v', 'five');
** INSERT INTO t1(rowid, a, b) VALUES(10, 'x', 'ten');
**
** the sqlite_dbdata table contains, as well as from entries related to
** page 1, content equivalent to:
** the sqlite_dbdata table contains, as well as from entries related to
** page 1, content equivalent to:
**
** INSERT INTO sqlite_dbdata(pgno, cell, field, value) VALUES
** (2, 0, -1, 5 ),
@ -49,19 +55,21 @@
** (2, 1, 0, 'x' ),
** (2, 1, 1, 'ten' );
**
** If database corruption is encountered, this module does not report an
** error. Instead, it attempts to extract as much data as possible and
** ignores the corruption.
**
** This module requires that the "sqlite_dbpage" eponymous virtual table be
** available.
** If database corruption is encountered, this module does not report an
** error. Instead, it attempts to extract as much data as possible and
** ignores the corruption.
**
** SQLITE_DBPTR:
** The sqlite_dbptr table has the following schema:
**
** CREATE TABLE sqlite_dbptr(
** pgno INTEGER,
** child INTEGER,
** schema TEXT HIDDEN
** );
**
** It contains one entry for each b-tree pointer between a parent and
** child page in the database.
*/
#if !defined(SQLITEINT_H)
#include "sqlite3ext.h"
@ -77,8 +85,7 @@ SQLITE_EXTENSION_INIT1
typedef struct DbdataTable DbdataTable;
typedef struct DbdataCursor DbdataCursor;
/* A cursor for the sqlite_dbdata table */
/* Cursor object */
struct DbdataCursor {
sqlite3_vtab_cursor base; /* Base class. Must be first */
sqlite3_stmt *pStmt; /* For fetching database pages */
@ -103,7 +110,7 @@ struct DbdataCursor {
sqlite3_int64 iIntkey; /* Integer key value */
};
/* The sqlite_dbdata table */
/* Table object */
struct DbdataTable {
sqlite3_vtab base; /* Base class. Must be first */
sqlite3 *db; /* The database connection */
@ -111,16 +118,12 @@ struct DbdataTable {
int bPtr; /* True for sqlite3_dbptr table */
};
/* Column and schema definitions for sqlite_dbdata */
#define DBDATA_COLUMN_PGNO 0
#define DBDATA_COLUMN_CELL 1
#define DBDATA_COLUMN_FIELD 2
#define DBDATA_COLUMN_VALUE 3
#define DBDATA_COLUMN_SCHEMA 4
#define DBPTR_COLUMN_PGNO 0
#define DBPTR_COLUMN_CHILD 1
#define DBPTR_COLUMN_SCHEMA 2
#define DBDATA_SCHEMA \
"CREATE TABLE x(" \
" pgno INTEGER," \
@ -130,6 +133,10 @@ struct DbdataTable {
" schema TEXT HIDDEN" \
")"
/* Column and schema definitions for sqlite_dbptr */
#define DBPTR_COLUMN_PGNO 0
#define DBPTR_COLUMN_CHILD 1
#define DBPTR_COLUMN_SCHEMA 2
#define DBPTR_SCHEMA \
"CREATE TABLE x(" \
" pgno INTEGER," \
@ -138,7 +145,8 @@ struct DbdataTable {
")"
/*
** Connect to the sqlite_dbdata virtual table.
** Connect to an sqlite_dbdata (pAux==0) or sqlite_dbptr (pAux!=0) virtual
** table.
*/
static int dbdataConnect(
sqlite3 *db,
@ -166,7 +174,7 @@ static int dbdataConnect(
}
/*
** Disconnect from or destroy a dbdata virtual table.
** Disconnect from or destroy a sqlite_dbdata or sqlite_dbptr virtual table.
*/
static int dbdataDisconnect(sqlite3_vtab *pVtab){
DbdataTable *pTab = (DbdataTable*)pVtab;
@ -178,7 +186,6 @@ static int dbdataDisconnect(sqlite3_vtab *pVtab){
}
/*
**
** This function interprets two types of constraints:
**
** schema=?
@ -239,7 +246,7 @@ static int dbdataBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdx){
}
/*
** Open a new dbdata cursor.
** Open a new sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
DbdataCursor *pCsr;
@ -256,6 +263,10 @@ static int dbdataOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
return SQLITE_OK;
}
/*
** Restore a cursor object to the state it was in when first allocated
** by dbdataOpen().
*/
static void dbdataResetCursor(DbdataCursor *pCsr){
DbdataTable *pTab = (DbdataTable*)(pCsr->base.pVtab);
if( pTab->pStmt==0 ){
@ -271,7 +282,7 @@ static void dbdataResetCursor(DbdataCursor *pCsr){
}
/*
** Close a dbdata cursor.
** Close an sqlite_dbdata or sqlite_dbptr cursor.
*/
static int dbdataClose(sqlite3_vtab_cursor *pCursor){
DbdataCursor *pCsr = (DbdataCursor*)pCursor;
@ -280,8 +291,9 @@ static int dbdataClose(sqlite3_vtab_cursor *pCursor){
return SQLITE_OK;
}
/* Decode big-endian integers */
/*
** Utility methods to decode 16 and 32-bit big-endian unsigned integers.
*/
static unsigned int get_uint16(unsigned char *a){
return (a[0]<<8)|a[1];
}
@ -289,11 +301,21 @@ static unsigned int get_uint32(unsigned char *a){
return (a[0]<<24)|(a[1]<<16)|(a[2]<<8)|a[3];
}
/*
** Load page pgno from the database via the sqlite_dbpage virtual table.
** If successful, set (*ppPage) to point to a buffer containing the page
** data, (*pnPage) to the size of that buffer in bytes and return
** SQLITE_OK. In this case it is the responsibility of the caller to
** eventually free the buffer using sqlite3_free().
**
** Or, if an error occurs, set both (*ppPage) and (*pnPage) to 0 and
** return an SQLite error code.
*/
static int dbdataLoadPage(
DbdataCursor *pCsr,
u32 pgno,
u8 **ppPage,
int *pnPage
DbdataCursor *pCsr, /* Cursor object */
u32 pgno, /* Page number of page to load */
u8 **ppPage, /* OUT: pointer to page buffer */
int *pnPage /* OUT: Size of (*ppPage) in bytes */
){
int rc2;
int rc = SQLITE_OK;
@ -338,6 +360,10 @@ static int dbdataGetVarint(const u8 *z, sqlite3_int64 *pVal){
return 9;
}
/*
** Return the number of bytes of space used by an SQLite value of type
** eType.
*/
static int dbdataValueBytes(int eType){
switch( eType ){
case 0: case 8: case 9:
@ -361,6 +387,10 @@ static int dbdataValueBytes(int eType){
}
}
/*
** Load a value of type eType from buffer pData and use it to set the
** result of context object pCtx.
*/
static void dbdataValue(sqlite3_context *pCtx, int eType, u8 *pData){
switch( eType ){
case 0:
@ -411,7 +441,7 @@ static void dbdataValue(sqlite3_context *pCtx, int eType, u8 *pData){
/*
** Move a dbdata cursor to the next entry in the file.
** Move an sqlite_dbdata or sqlite_dbptr cursor to the next entry.
*/
static int dbdataNext(sqlite3_vtab_cursor *pCursor){
DbdataCursor *pCsr = (DbdataCursor*)pCursor;
@ -575,14 +605,20 @@ static int dbdataNext(sqlite3_vtab_cursor *pCursor){
return SQLITE_OK;
}
/* We have reached EOF if previous sqlite3_step() returned
** anything other than SQLITE_ROW;
/*
** Return true if the cursor is at EOF.
*/
static int dbdataEof(sqlite3_vtab_cursor *pCursor){
DbdataCursor *pCsr = (DbdataCursor*)pCursor;
return pCsr->aPage==0;
}
/*
** Determine the size in pages of database zSchema (where zSchema is
** "main", "temp" or the name of an attached database) and set
** pCsr->szDb accordingly. If successful, return SQLITE_OK. Otherwise,
** an SQLite error code.
*/
static int dbdataDbsize(DbdataCursor *pCsr, const char *zSchema){
DbdataTable *pTab = (DbdataTable*)pCsr->base.pVtab;
char *zSql = 0;
@ -601,7 +637,8 @@ static int dbdataDbsize(DbdataCursor *pCsr, const char *zSchema){
return rc;
}
/* Position a cursor back to the beginning.
/*
** xFilter method for sqlite_dbdata and sqlite_dbptr.
*/
static int dbdataFilter(
sqlite3_vtab_cursor *pCursor,
@ -648,7 +685,9 @@ static int dbdataFilter(
return rc;
}
/* Return a column for the sqlite_dbdata table */
/*
** Return a column for the sqlite_dbdata or sqlite_dbptr table.
*/
static int dbdataColumn(
sqlite3_vtab_cursor *pCursor,
sqlite3_context *ctx,
@ -699,7 +738,9 @@ static int dbdataColumn(
return SQLITE_OK;
}
/* Return the ROWID for the sqlite_dbdata table */
/*
** Return the rowid for an sqlite_dbdata or sqlite_dptr table.
*/
static int dbdataRowid(sqlite3_vtab_cursor *pCursor, sqlite_int64 *pRowid){
DbdataCursor *pCsr = (DbdataCursor*)pCursor;
*pRowid = pCsr->iRowid;