| Index: third_party/sqlite/src/src/recover.c
|
| diff --git a/third_party/sqlite/src/src/recover.c b/third_party/sqlite/src/src/recover.c
|
| deleted file mode 100644
|
| index 5ff6f78c90065131eaa6135c15687d14877ea9d8..0000000000000000000000000000000000000000
|
| --- a/third_party/sqlite/src/src/recover.c
|
| +++ /dev/null
|
| @@ -1,2281 +0,0 @@
|
| -/*
|
| -** 2012 Jan 11
|
| -**
|
| -** The author disclaims copyright to this source code. In place of
|
| -** a legal notice, here is a blessing:
|
| -**
|
| -** May you do good and not evil.
|
| -** May you find forgiveness for yourself and forgive others.
|
| -** May you share freely, never taking more than you give.
|
| -*/
|
| -/* TODO(shess): THIS MODULE IS STILL EXPERIMENTAL. DO NOT USE IT. */
|
| -/* Implements a virtual table "recover" which can be used to recover
|
| - * data from a corrupt table. The table is walked manually, with
|
| - * corrupt items skipped. Additionally, any errors while reading will
|
| - * be skipped.
|
| - *
|
| - * Given a table with this definition:
|
| - *
|
| - * CREATE TABLE Stuff (
|
| - * name TEXT PRIMARY KEY,
|
| - * value TEXT NOT NULL
|
| - * );
|
| - *
|
| - * to recover the data from teh table, you could do something like:
|
| - *
|
| - * -- Attach another database, the original is not trustworthy.
|
| - * ATTACH DATABASE '/tmp/db.db' AS rdb;
|
| - * -- Create a new version of the table.
|
| - * CREATE TABLE rdb.Stuff (
|
| - * name TEXT PRIMARY KEY,
|
| - * value TEXT NOT NULL
|
| - * );
|
| - * -- This will read the original table's data.
|
| - * CREATE VIRTUAL TABLE temp.recover_Stuff using recover(
|
| - * main.Stuff,
|
| - * name TEXT STRICT NOT NULL, -- only real TEXT data allowed
|
| - * value TEXT STRICT NOT NULL
|
| - * );
|
| - * -- Corruption means the UNIQUE constraint may no longer hold for
|
| - * -- Stuff, so either OR REPLACE or OR IGNORE must be used.
|
| - * INSERT OR REPLACE INTO rdb.Stuff (rowid, name, value )
|
| - * SELECT rowid, name, value FROM temp.recover_Stuff;
|
| - * DROP TABLE temp.recover_Stuff;
|
| - * DETACH DATABASE rdb;
|
| - * -- Move db.db to replace original db in filesystem.
|
| - *
|
| - *
|
| - * Usage
|
| - *
|
| - * Given the goal of dealing with corruption, it would not be safe to
|
| - * create a recovery table in the database being recovered. So
|
| - * recovery tables must be created in the temp database. They are not
|
| - * appropriate to persist, in any case. [As a bonus, sqlite_master
|
| - * tables can be recovered. Perhaps more cute than useful, though.]
|
| - *
|
| - * The parameters are a specifier for the table to read, and a column
|
| - * definition for each bit of data stored in that table. The named
|
| - * table must be convertable to a root page number by reading the
|
| - * sqlite_master table. Bare table names are assumed to be in
|
| - * database 0 ("main"), other databases can be specified in db.table
|
| - * fashion.
|
| - *
|
| - * Column definitions are similar to BUT NOT THE SAME AS those
|
| - * provided to CREATE statements:
|
| - * column-def: column-name [type-name [STRICT] [NOT NULL]]
|
| - * type-name: (ANY|ROWID|INTEGER|FLOAT|NUMERIC|TEXT|BLOB)
|
| - *
|
| - * Only those exact type names are accepted, there is no type
|
| - * intuition. The only constraints accepted are STRICT (see below)
|
| - * and NOT NULL. Anything unexpected will cause the create to fail.
|
| - *
|
| - * ANY is a convenience to indicate that manifest typing is desired.
|
| - * It is equivalent to not specifying a type at all. The results for
|
| - * such columns will have the type of the data's storage. The exposed
|
| - * schema will contain no type for that column.
|
| - *
|
| - * ROWID is used for columns representing aliases to the rowid
|
| - * (INTEGER PRIMARY KEY, with or without AUTOINCREMENT), to make the
|
| - * concept explicit. Such columns are actually stored as NULL, so
|
| - * they cannot be simply ignored. The exposed schema will be INTEGER
|
| - * for that column.
|
| - *
|
| - * NOT NULL causes rows with a NULL in that column to be skipped. It
|
| - * also adds NOT NULL to the column in the exposed schema. If the
|
| - * table has ever had columns added using ALTER TABLE, then those
|
| - * columns implicitly contain NULL for rows which have not been
|
| - * updated. [Workaround using COALESCE() in your SELECT statement.]
|
| - *
|
| - * The created table is read-only, with no indices. Any SELECT will
|
| - * be a full-table scan, returning each valid row read from the
|
| - * storage of the backing table. The rowid will be the rowid of the
|
| - * row from the backing table. "Valid" means:
|
| - * - The cell metadata for the row is well-formed. Mainly this means that
|
| - * the cell header info describes a payload of the size indicated by
|
| - * the cell's payload size.
|
| - * - The cell does not run off the page.
|
| - * - The cell does not overlap any other cell on the page.
|
| - * - The cell contains doesn't contain too many columns.
|
| - * - The types of the serialized data match the indicated types (see below).
|
| - *
|
| - *
|
| - * Type affinity versus type storage.
|
| - *
|
| - * http://www.sqlite.org/datatype3.html describes SQLite's type
|
| - * affinity system. The system provides for automated coercion of
|
| - * types in certain cases, transparently enough that many developers
|
| - * do not realize that it is happening. Importantly, it implies that
|
| - * the raw data stored in the database may not have the obvious type.
|
| - *
|
| - * Differences between the stored data types and the expected data
|
| - * types may be a signal of corruption. This module makes some
|
| - * allowances for automatic coercion. It is important to be concious
|
| - * of the difference between the schema exposed by the module, and the
|
| - * data types read from storage. The following table describes how
|
| - * the module interprets things:
|
| - *
|
| - * type schema data STRICT
|
| - * ---- ------ ---- ------
|
| - * ANY <none> any any
|
| - * ROWID INTEGER n/a n/a
|
| - * INTEGER INTEGER integer integer
|
| - * FLOAT FLOAT integer or float float
|
| - * NUMERIC NUMERIC integer, float, or text integer or float
|
| - * TEXT TEXT text or blob text
|
| - * BLOB BLOB blob blob
|
| - *
|
| - * type is the type provided to the recover module, schema is the
|
| - * schema exposed by the module, data is the acceptable types of data
|
| - * decoded from storage, and STRICT is a modification of that.
|
| - *
|
| - * A very loose recovery system might use ANY for all columns, then
|
| - * use the appropriate sqlite3_column_*() calls to coerce to expected
|
| - * types. This doesn't provide much protection if a page from a
|
| - * different table with the same column count is linked into an
|
| - * inappropriate btree.
|
| - *
|
| - * A very tight recovery system might use STRICT to enforce typing on
|
| - * all columns, preferring to skip rows which are valid at the storage
|
| - * level but don't contain the right types. Note that FLOAT STRICT is
|
| - * almost certainly not appropriate, since integral values are
|
| - * transparently stored as integers, when that is more efficient.
|
| - *
|
| - * Another option is to use ANY for all columns and inspect each
|
| - * result manually (using sqlite3_column_*). This should only be
|
| - * necessary in cases where developers have used manifest typing (test
|
| - * to make sure before you decide that you aren't using manifest
|
| - * typing!).
|
| - *
|
| - *
|
| - * Caveats
|
| - *
|
| - * Leaf pages not referenced by interior nodes will not be found.
|
| - *
|
| - * Leaf pages referenced from interior nodes of other tables will not
|
| - * be resolved.
|
| - *
|
| - * Rows referencing invalid overflow pages will be skipped.
|
| - *
|
| - * SQlite rows have a header which describes how to interpret the rest
|
| - * of the payload. The header can be valid in cases where the rest of
|
| - * the record is actually corrupt (in the sense that the data is not
|
| - * the intended data). This can especially happen WRT overflow pages,
|
| - * as lack of atomic updates between pages is the primary form of
|
| - * corruption I have seen in the wild.
|
| - */
|
| -/* The implementation is via a series of cursors. The cursor
|
| - * implementations follow the pattern:
|
| - *
|
| - * // Creates the cursor using various initialization info.
|
| - * int cursorCreate(...);
|
| - *
|
| - * // Returns 1 if there is no more data, 0 otherwise.
|
| - * int cursorEOF(Cursor *pCursor);
|
| - *
|
| - * // Various accessors can be used if not at EOF.
|
| - *
|
| - * // Move to the next item.
|
| - * int cursorNext(Cursor *pCursor);
|
| - *
|
| - * // Destroy the memory associated with the cursor.
|
| - * void cursorDestroy(Cursor *pCursor);
|
| - *
|
| - * References in the following are to sections at
|
| - * http://www.sqlite.org/fileformat2.html .
|
| - *
|
| - * RecoverLeafCursor iterates the records in a leaf table node
|
| - * described in section 1.5 "B-tree Pages". When the node is
|
| - * exhausted, an interior cursor is used to get the next leaf node,
|
| - * and iteration continues there.
|
| - *
|
| - * RecoverInteriorCursor iterates the child pages in an interior table
|
| - * node described in section 1.5 "B-tree Pages". When the node is
|
| - * exhausted, a parent interior cursor is used to get the next
|
| - * interior node at the same level, and iteration continues there.
|
| - *
|
| - * Together these record the path from the leaf level to the root of
|
| - * the tree. Iteration happens from the leaves rather than the root
|
| - * both for efficiency and putting the special case at the front of
|
| - * the list is easier to implement.
|
| - *
|
| - * RecoverCursor uses a RecoverLeafCursor to iterate the rows of a
|
| - * table, returning results via the SQLite virtual table interface.
|
| - */
|
| -/* TODO(shess): It might be useful to allow DEFAULT in types to
|
| - * specify what to do for NULL when an ALTER TABLE case comes up.
|
| - * Unfortunately, simply adding it to the exposed schema and using
|
| - * sqlite3_result_null() does not cause the default to be generate.
|
| - * Handling it ourselves seems hard, unfortunately.
|
| - */
|
| -
|
| -#include <assert.h>
|
| -#include <ctype.h>
|
| -#include <stdio.h>
|
| -#include <string.h>
|
| -
|
| -/* Internal SQLite things that are used:
|
| - * u32, u64, i64 types.
|
| - * Btree, Pager, and DbPage structs.
|
| - * DbPage.pData, .pPager, and .pgno
|
| - * sqlite3 struct.
|
| - * sqlite3BtreePager() and sqlite3BtreeGetPageSize()
|
| - * sqlite3BtreeGetOptimalReserve()
|
| - * sqlite3PagerGet() and sqlite3PagerUnref()
|
| - * getVarint().
|
| - */
|
| -#include "sqliteInt.h"
|
| -
|
| -/* For debugging. */
|
| -#if 0
|
| -#define FNENTRY() fprintf(stderr, "In %s\n", __FUNCTION__)
|
| -#else
|
| -#define FNENTRY()
|
| -#endif
|
| -
|
| -/* Generic constants and helper functions. */
|
| -
|
| -static const unsigned char kTableLeafPage = 0x0D;
|
| -static const unsigned char kTableInteriorPage = 0x05;
|
| -
|
| -/* From section 1.2. */
|
| -static const unsigned kiHeaderPageSizeOffset = 16;
|
| -static const unsigned kiHeaderReservedSizeOffset = 20;
|
| -static const unsigned kiHeaderEncodingOffset = 56;
|
| -/* TODO(shess) |static const unsigned| fails creating the header in GetPager()
|
| -** because |knHeaderSize| isn't |constexpr|. But this isn't C++, either.
|
| -*/
|
| -enum { knHeaderSize = 100};
|
| -
|
| -/* From section 1.5. */
|
| -static const unsigned kiPageTypeOffset = 0;
|
| -static const unsigned kiPageFreeBlockOffset = 1;
|
| -static const unsigned kiPageCellCountOffset = 3;
|
| -static const unsigned kiPageCellContentOffset = 5;
|
| -static const unsigned kiPageFragmentedBytesOffset = 7;
|
| -static const unsigned knPageLeafHeaderBytes = 8;
|
| -/* Interior pages contain an additional field. */
|
| -static const unsigned kiPageRightChildOffset = 8;
|
| -static const unsigned kiPageInteriorHeaderBytes = 12;
|
| -
|
| -/* Accepted types are specified by a mask. */
|
| -#define MASK_ROWID (1<<0)
|
| -#define MASK_INTEGER (1<<1)
|
| -#define MASK_FLOAT (1<<2)
|
| -#define MASK_TEXT (1<<3)
|
| -#define MASK_BLOB (1<<4)
|
| -#define MASK_NULL (1<<5)
|
| -
|
| -/* Helpers to decode fixed-size fields. */
|
| -static u32 decodeUnsigned16(const unsigned char *pData){
|
| - return (pData[0]<<8) + pData[1];
|
| -}
|
| -static u32 decodeUnsigned32(const unsigned char *pData){
|
| - return (decodeUnsigned16(pData)<<16) + decodeUnsigned16(pData+2);
|
| -}
|
| -static i64 decodeSigned(const unsigned char *pData, unsigned nBytes){
|
| - i64 r = (char)(*pData);
|
| - while( --nBytes ){
|
| - r <<= 8;
|
| - r += *(++pData);
|
| - }
|
| - return r;
|
| -}
|
| -/* Derived from vdbeaux.c, sqlite3VdbeSerialGet(), case 7. */
|
| -/* TODO(shess): Determine if swapMixedEndianFloat() applies. */
|
| -static double decodeFloat64(const unsigned char *pData){
|
| -#if !defined(NDEBUG)
|
| - static const u64 t1 = ((u64)0x3ff00000)<<32;
|
| - static const double r1 = 1.0;
|
| - u64 t2 = t1;
|
| - assert( sizeof(r1)==sizeof(t2) && memcmp(&r1, &t2, sizeof(r1))==0 );
|
| -#endif
|
| - i64 x = decodeSigned(pData, 8);
|
| - double d;
|
| - memcpy(&d, &x, sizeof(x));
|
| - return d;
|
| -}
|
| -
|
| -/* Return true if a varint can safely be read from pData/nData. */
|
| -/* TODO(shess): DbPage points into the middle of a buffer which
|
| - * contains the page data before DbPage. So code should always be
|
| - * able to read a small number of varints safely. Consider whether to
|
| - * trust that or not.
|
| - */
|
| -static int checkVarint(const unsigned char *pData, unsigned nData){
|
| - unsigned i;
|
| -
|
| - /* In the worst case the decoder takes all 8 bits of the 9th byte. */
|
| - if( nData>=9 ){
|
| - return 1;
|
| - }
|
| -
|
| - /* Look for a high-bit-clear byte in what's left. */
|
| - for( i=0; i<nData; ++i ){
|
| - if( !(pData[i]&0x80) ){
|
| - return 1;
|
| - }
|
| - }
|
| -
|
| - /* Cannot decode in the space given. */
|
| - return 0;
|
| -}
|
| -
|
| -/* Return 1 if n varints can be read from pData/nData. */
|
| -static int checkVarints(const unsigned char *pData, unsigned nData,
|
| - unsigned n){
|
| - unsigned nCur = 0; /* Byte offset within current varint. */
|
| - unsigned nFound = 0; /* Number of varints found. */
|
| - unsigned i;
|
| -
|
| - /* In the worst case the decoder takes all 8 bits of the 9th byte. */
|
| - if( nData>=9*n ){
|
| - return 1;
|
| - }
|
| -
|
| - for( i=0; nFound<n && i<nData; ++i ){
|
| - nCur++;
|
| - if( nCur==9 || !(pData[i]&0x80) ){
|
| - nFound++;
|
| - nCur = 0;
|
| - }
|
| - }
|
| -
|
| - return nFound==n;
|
| -}
|
| -
|
| -/* ctype and str[n]casecmp() can be affected by locale (eg, tr_TR).
|
| - * These versions consider only the ASCII space.
|
| - */
|
| -/* TODO(shess): It may be reasonable to just remove the need for these
|
| - * entirely. The module could require "TEXT STRICT NOT NULL", not
|
| - * "Text Strict Not Null" or whatever the developer felt like typing
|
| - * that day. Handling corrupt data is a PERFECT place to be pedantic.
|
| - */
|
| -static int ascii_isspace(char c){
|
| - /* From fts3_expr.c */
|
| - return c==' ' || c=='\t' || c=='\n' || c=='\r' || c=='\v' || c=='\f';
|
| -}
|
| -static int ascii_isalnum(int x){
|
| - /* From fts3_tokenizer1.c */
|
| - return (x>='0' && x<='9') || (x>='A' && x<='Z') || (x>='a' && x<='z');
|
| -}
|
| -static int ascii_tolower(int x){
|
| - /* From fts3_tokenizer1.c */
|
| - return (x>='A' && x<='Z') ? x-'A'+'a' : x;
|
| -}
|
| -/* TODO(shess): Consider sqlite3_strnicmp() */
|
| -static int ascii_strncasecmp(const char *s1, const char *s2, size_t n){
|
| - const unsigned char *us1 = (const unsigned char *)s1;
|
| - const unsigned char *us2 = (const unsigned char *)s2;
|
| - while( *us1 && *us2 && n && ascii_tolower(*us1)==ascii_tolower(*us2) ){
|
| - us1++, us2++, n--;
|
| - }
|
| - return n ? ascii_tolower(*us1)-ascii_tolower(*us2) : 0;
|
| -}
|
| -static int ascii_strcasecmp(const char *s1, const char *s2){
|
| - /* If s2 is equal through strlen(s1), will exit while() due to s1's
|
| - * trailing NUL, and return NUL-s2[strlen(s1)].
|
| - */
|
| - return ascii_strncasecmp(s1, s2, strlen(s1)+1);
|
| -}
|
| -
|
| -/* Provide access to the pages of a SQLite database in a way similar to SQLite's
|
| -** Pager.
|
| -*/
|
| -typedef struct RecoverPager RecoverPager;
|
| -struct RecoverPager {
|
| - sqlite3_file *pSqliteFile; /* Reference to database's file handle */
|
| - u32 nPageSize; /* Size of pages in pSqliteFile */
|
| -};
|
| -
|
| -static void pagerDestroy(RecoverPager *pPager){
|
| - pPager->pSqliteFile->pMethods->xUnlock(pPager->pSqliteFile, SQLITE_LOCK_NONE);
|
| - memset(pPager, 0xA5, sizeof(*pPager));
|
| - sqlite3_free(pPager);
|
| -}
|
| -
|
| -/* pSqliteFile should already have a SHARED lock. */
|
| -static int pagerCreate(sqlite3_file *pSqliteFile, u32 nPageSize,
|
| - RecoverPager **ppPager){
|
| - RecoverPager *pPager = sqlite3_malloc(sizeof(RecoverPager));
|
| - if( !pPager ){
|
| - return SQLITE_NOMEM;
|
| - }
|
| -
|
| - memset(pPager, 0, sizeof(*pPager));
|
| - pPager->pSqliteFile = pSqliteFile;
|
| - pPager->nPageSize = nPageSize;
|
| - *ppPager = pPager;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* Matches DbPage (aka PgHdr) from SQLite internals. */
|
| -/* TODO(shess): SQLite by default allocates page metadata in a single allocation
|
| -** such that the page's data and metadata are contiguous, see pcache1AllocPage
|
| -** in pcache1.c. I believe this was intended to reduce malloc churn. It means
|
| -** that Chromium's automated tooling would be unlikely to see page-buffer
|
| -** overruns. I believe that this code is safe, but for now replicate SQLite's
|
| -** approach with kExcessSpace.
|
| -*/
|
| -const int kExcessSpace = 128;
|
| -typedef struct RecoverPage RecoverPage;
|
| -struct RecoverPage {
|
| - Pgno pgno; /* Page number for this page */
|
| - void *pData; /* Page data for pgno */
|
| - RecoverPager *pPager; /* The pager this page is part of */
|
| -};
|
| -
|
| -static void pageDestroy(RecoverPage *pPage){
|
| - sqlite3_free(pPage->pData);
|
| - memset(pPage, 0xA5, sizeof(*pPage));
|
| - sqlite3_free(pPage);
|
| -}
|
| -
|
| -static int pageCreate(RecoverPager *pPager, u32 pgno, RecoverPage **ppPage){
|
| - RecoverPage *pPage = sqlite3_malloc(sizeof(RecoverPage));
|
| - if( !pPage ){
|
| - return SQLITE_NOMEM;
|
| - }
|
| -
|
| - memset(pPage, 0, sizeof(*pPage));
|
| - pPage->pPager = pPager;
|
| - pPage->pgno = pgno;
|
| - pPage->pData = sqlite3_malloc(pPager->nPageSize + kExcessSpace);
|
| - if( pPage->pData==NULL ){
|
| - pageDestroy(pPage);
|
| - return SQLITE_NOMEM;
|
| - }
|
| - memset((u8 *)pPage->pData + pPager->nPageSize, 0, kExcessSpace);
|
| -
|
| - *ppPage = pPage;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static int pagerGetPage(RecoverPager *pPager, u32 iPage, RecoverPage **ppPage) {
|
| - sqlite3_int64 iOfst;
|
| - sqlite3_file *pFile = pPager->pSqliteFile;
|
| - RecoverPage *pPage;
|
| - int rc = pageCreate(pPager, iPage, &pPage);
|
| - if( rc!=SQLITE_OK ){
|
| - return rc;
|
| - }
|
| -
|
| - /* xRead() can return SQLITE_IOERR_SHORT_READ, which should be treated as
|
| - ** SQLITE_OK plus an EOF indicator. The excess space is zero-filled.
|
| - */
|
| - iOfst = ((sqlite3_int64)iPage - 1) * pPager->nPageSize;
|
| - rc = pFile->pMethods->xRead(pFile, pPage->pData, pPager->nPageSize, iOfst);
|
| - if( rc!=SQLITE_OK && rc!=SQLITE_IOERR_SHORT_READ ){
|
| - pageDestroy(pPage);
|
| - return rc;
|
| - }
|
| -
|
| - *ppPage = pPage;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* For some reason I kept making mistakes with offset calculations. */
|
| -static const unsigned char *PageData(RecoverPage *pPage, unsigned iOffset){
|
| - assert( iOffset<=pPage->pPager->nPageSize );
|
| - return (unsigned char *)pPage->pData + iOffset;
|
| -}
|
| -
|
| -/* The first page in the file contains a file header in the first 100
|
| - * bytes. The page's header information comes after that. Note that
|
| - * the offsets in the page's header information are relative to the
|
| - * beginning of the page, NOT the end of the page header.
|
| - */
|
| -static const unsigned char *PageHeader(RecoverPage *pPage){
|
| - if( pPage->pgno==1 ){
|
| - return PageData(pPage, knHeaderSize);
|
| - }else{
|
| - return PageData(pPage, 0);
|
| - }
|
| -}
|
| -
|
| -/* Helper to fetch the pager and page size for the named database. */
|
| -static int GetPager(sqlite3 *db, const char *zName,
|
| - RecoverPager **ppPager, unsigned *pnPageSize,
|
| - int *piEncoding){
|
| - int rc, iEncoding;
|
| - unsigned nPageSize, nReservedSize;
|
| - unsigned char header[knHeaderSize];
|
| - sqlite3_file *pFile = NULL;
|
| - RecoverPager *pPager;
|
| -
|
| - rc = sqlite3_file_control(db, zName, SQLITE_FCNTL_FILE_POINTER, &pFile);
|
| - if( rc!=SQLITE_OK ) {
|
| - return rc;
|
| - } else if( pFile==NULL ){
|
| - /* The documentation for sqlite3PagerFile() indicates it can return NULL if
|
| - ** the file has not yet been opened. That should not be possible here...
|
| - */
|
| - return SQLITE_MISUSE;
|
| - }
|
| -
|
| - /* Get a shared lock to make sure the on-disk version of the file is truth. */
|
| - rc = pFile->pMethods->xLock(pFile, SQLITE_LOCK_SHARED);
|
| - if( rc != SQLITE_OK ){
|
| - return rc;
|
| - }
|
| -
|
| - /* Read the Initial header information. In case of SQLITE_IOERR_SHORT_READ,
|
| - ** the header is incomplete, which means no data could be recovered anyhow.
|
| - */
|
| - rc = pFile->pMethods->xRead(pFile, header, sizeof(header), 0);
|
| - if( rc != SQLITE_OK ){
|
| - pFile->pMethods->xUnlock(pFile, SQLITE_LOCK_NONE);
|
| - if( rc==SQLITE_IOERR_SHORT_READ ){
|
| - return SQLITE_CORRUPT;
|
| - }
|
| - return rc;
|
| - }
|
| -
|
| - /* Page size must be a power of two between 512 and 32768 inclusive. */
|
| - nPageSize = decodeUnsigned16(header + kiHeaderPageSizeOffset);
|
| - if( (nPageSize&(nPageSize-1)) || nPageSize>32768 || nPageSize<512 ){
|
| - pFile->pMethods->xUnlock(pFile, SQLITE_LOCK_NONE);
|
| - return rc;
|
| - }
|
| -
|
| - /* Space reserved a the end of the page for extensions. Usually 0. */
|
| - nReservedSize = header[kiHeaderReservedSizeOffset];
|
| -
|
| - /* 1 for UTF-8, 2 for UTF-16le, 3 for UTF-16be. */
|
| - iEncoding = decodeUnsigned32(header + kiHeaderEncodingOffset);
|
| - if( iEncoding==3 ){
|
| - *piEncoding = SQLITE_UTF16BE;
|
| - } else if( iEncoding==2 ){
|
| - *piEncoding = SQLITE_UTF16LE;
|
| - } else if( iEncoding==1 ){
|
| - *piEncoding = SQLITE_UTF8;
|
| - } else {
|
| - /* This case should not be possible. */
|
| - *piEncoding = SQLITE_UTF8;
|
| - }
|
| -
|
| - rc = pagerCreate(pFile, nPageSize, &pPager);
|
| - if( rc!=SQLITE_OK ){
|
| - pFile->pMethods->xUnlock(pFile, SQLITE_LOCK_NONE);
|
| - return rc;
|
| - }
|
| -
|
| - *ppPager = pPager;
|
| - *pnPageSize = nPageSize - nReservedSize;
|
| - *piEncoding = iEncoding;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* iSerialType is a type read from a record header. See "2.1 Record Format".
|
| - */
|
| -
|
| -/* Storage size of iSerialType in bytes. My interpretation of SQLite
|
| - * documentation is that text and blob fields can have 32-bit length.
|
| - * Values past 2^31-12 will need more than 32 bits to encode, which is
|
| - * why iSerialType is u64.
|
| - */
|
| -static u32 SerialTypeLength(u64 iSerialType){
|
| - switch( iSerialType ){
|
| - case 0 : return 0; /* NULL */
|
| - case 1 : return 1; /* Various integers. */
|
| - case 2 : return 2;
|
| - case 3 : return 3;
|
| - case 4 : return 4;
|
| - case 5 : return 6;
|
| - case 6 : return 8;
|
| - case 7 : return 8; /* 64-bit float. */
|
| - case 8 : return 0; /* Constant 0. */
|
| - case 9 : return 0; /* Constant 1. */
|
| - case 10 : case 11 : assert( "RESERVED TYPE"==NULL ); return 0;
|
| - }
|
| - return (u32)((iSerialType>>1) - 6);
|
| -}
|
| -
|
| -/* True if iSerialType refers to a blob. */
|
| -static int SerialTypeIsBlob(u64 iSerialType){
|
| - assert( iSerialType>=12 );
|
| - return (iSerialType%2)==0;
|
| -}
|
| -
|
| -/* Returns true if the serialized type represented by iSerialType is
|
| - * compatible with the given type mask.
|
| - */
|
| -static int SerialTypeIsCompatible(u64 iSerialType, unsigned char mask){
|
| - switch( iSerialType ){
|
| - case 0 : return (mask&MASK_NULL)!=0;
|
| - case 1 : return (mask&MASK_INTEGER)!=0;
|
| - case 2 : return (mask&MASK_INTEGER)!=0;
|
| - case 3 : return (mask&MASK_INTEGER)!=0;
|
| - case 4 : return (mask&MASK_INTEGER)!=0;
|
| - case 5 : return (mask&MASK_INTEGER)!=0;
|
| - case 6 : return (mask&MASK_INTEGER)!=0;
|
| - case 7 : return (mask&MASK_FLOAT)!=0;
|
| - case 8 : return (mask&MASK_INTEGER)!=0;
|
| - case 9 : return (mask&MASK_INTEGER)!=0;
|
| - case 10 : assert( "RESERVED TYPE"==NULL ); return 0;
|
| - case 11 : assert( "RESERVED TYPE"==NULL ); return 0;
|
| - }
|
| - return (mask&(SerialTypeIsBlob(iSerialType) ? MASK_BLOB : MASK_TEXT));
|
| -}
|
| -
|
| -/* Versions of strdup() with return values appropriate for
|
| - * sqlite3_free(). malloc.c has sqlite3DbStrDup()/NDup(), but those
|
| - * need sqlite3DbFree(), which seems intrusive.
|
| - */
|
| -static char *sqlite3_strndup(const char *z, unsigned n){
|
| - char *zNew;
|
| -
|
| - if( z==NULL ){
|
| - return NULL;
|
| - }
|
| -
|
| - zNew = sqlite3_malloc(n+1);
|
| - if( zNew!=NULL ){
|
| - memcpy(zNew, z, n);
|
| - zNew[n] = '\0';
|
| - }
|
| - return zNew;
|
| -}
|
| -static char *sqlite3_strdup(const char *z){
|
| - if( z==NULL ){
|
| - return NULL;
|
| - }
|
| - return sqlite3_strndup(z, strlen(z));
|
| -}
|
| -
|
| -/* Fetch the page number of zTable in zDb from sqlite_master in zDb,
|
| - * and put it in *piRootPage.
|
| - */
|
| -static int getRootPage(sqlite3 *db, const char *zDb, const char *zTable,
|
| - u32 *piRootPage){
|
| - char *zSql; /* SQL selecting root page of named element. */
|
| - sqlite3_stmt *pStmt;
|
| - int rc;
|
| -
|
| - if( strcmp(zTable, "sqlite_master")==0 ){
|
| - *piRootPage = 1;
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - zSql = sqlite3_mprintf("SELECT rootpage FROM %s.sqlite_master "
|
| - "WHERE type = 'table' AND tbl_name = %Q",
|
| - zDb, zTable);
|
| - if( !zSql ){
|
| - return SQLITE_NOMEM;
|
| - }
|
| -
|
| - rc = sqlite3_prepare_v2(db, zSql, -1, &pStmt, 0);
|
| - sqlite3_free(zSql);
|
| - if( rc!=SQLITE_OK ){
|
| - return rc;
|
| - }
|
| -
|
| - /* Require a result. */
|
| - rc = sqlite3_step(pStmt);
|
| - if( rc==SQLITE_DONE ){
|
| - rc = SQLITE_CORRUPT;
|
| - }else if( rc==SQLITE_ROW ){
|
| - *piRootPage = sqlite3_column_int(pStmt, 0);
|
| -
|
| - /* Require only one result. */
|
| - rc = sqlite3_step(pStmt);
|
| - if( rc==SQLITE_DONE ){
|
| - rc = SQLITE_OK;
|
| - }else if( rc==SQLITE_ROW ){
|
| - rc = SQLITE_CORRUPT;
|
| - }
|
| - }
|
| - sqlite3_finalize(pStmt);
|
| - return rc;
|
| -}
|
| -
|
| -/* Cursor for iterating interior nodes. Interior page cells contain a
|
| - * child page number and a rowid. The child page contains items left
|
| - * of the rowid (less than). The rightmost page of the subtree is
|
| - * stored in the page header.
|
| - *
|
| - * interiorCursorDestroy - release all resources associated with the
|
| - * cursor and any parent cursors.
|
| - * interiorCursorCreate - create a cursor with the given parent and page.
|
| - * interiorCursorEOF - returns true if neither the cursor nor the
|
| - * parent cursors can return any more data.
|
| - * interiorCursorNextPage - fetch the next child page from the cursor.
|
| - *
|
| - * Logically, interiorCursorNextPage() returns the next child page
|
| - * number from the page the cursor is currently reading, calling the
|
| - * parent cursor as necessary to get new pages to read, until done.
|
| - * SQLITE_ROW if a page is returned, SQLITE_DONE if out of pages,
|
| - * error otherwise. Unfortunately, if the table is corrupted
|
| - * unexpected pages can be returned. If any unexpected page is found,
|
| - * leaf or otherwise, it is returned to the caller for processing,
|
| - * with the interior cursor left empty. The next call to
|
| - * interiorCursorNextPage() will recurse to the parent cursor until an
|
| - * interior page to iterate is returned.
|
| - *
|
| - * Note that while interiorCursorNextPage() will refuse to follow
|
| - * loops, it does not keep track of pages returned for purposes of
|
| - * preventing duplication.
|
| - *
|
| - * Note that interiorCursorEOF() could return false (not at EOF), and
|
| - * interiorCursorNextPage() could still return SQLITE_DONE. This
|
| - * could happen if there are more cells to iterate in an interior
|
| - * page, but those cells refer to invalid pages.
|
| - */
|
| -typedef struct RecoverInteriorCursor RecoverInteriorCursor;
|
| -struct RecoverInteriorCursor {
|
| - RecoverInteriorCursor *pParent; /* Parent node to this node. */
|
| - RecoverPage *pPage; /* Reference to leaf page. */
|
| - unsigned nPageSize; /* Size of page. */
|
| - unsigned nChildren; /* Number of children on the page. */
|
| - unsigned iChild; /* Index of next child to return. */
|
| -};
|
| -
|
| -static void interiorCursorDestroy(RecoverInteriorCursor *pCursor){
|
| - /* Destroy all the cursors to the root. */
|
| - while( pCursor ){
|
| - RecoverInteriorCursor *p = pCursor;
|
| - pCursor = pCursor->pParent;
|
| -
|
| - if( p->pPage ){
|
| - pageDestroy(p->pPage);
|
| - p->pPage = NULL;
|
| - }
|
| -
|
| - memset(p, 0xA5, sizeof(*p));
|
| - sqlite3_free(p);
|
| - }
|
| -}
|
| -
|
| -/* Internal helper. Reset storage in preparation for iterating pPage. */
|
| -static void interiorCursorSetPage(RecoverInteriorCursor *pCursor,
|
| - RecoverPage *pPage){
|
| - const unsigned knMinCellLength = 2 + 4 + 1;
|
| - unsigned nMaxChildren;
|
| - assert( PageHeader(pPage)[kiPageTypeOffset]==kTableInteriorPage );
|
| -
|
| - if( pCursor->pPage ){
|
| - pageDestroy(pCursor->pPage);
|
| - pCursor->pPage = NULL;
|
| - }
|
| - pCursor->pPage = pPage;
|
| - pCursor->iChild = 0;
|
| -
|
| - /* A child for each cell, plus one in the header. */
|
| - pCursor->nChildren = decodeUnsigned16(PageHeader(pPage) +
|
| - kiPageCellCountOffset) + 1;
|
| -
|
| - /* Each child requires a 16-bit offset from an array after the header,
|
| - * and each child contains a 32-bit page number and at least a varint
|
| - * (min size of one byte). The final child page is in the header. So
|
| - * the maximum value for nChildren is:
|
| - * (nPageSize - kiPageInteriorHeaderBytes) /
|
| - * (sizeof(uint16) + sizeof(uint32) + 1) + 1
|
| - */
|
| - /* TODO(shess): This count is very unlikely to be corrupted in
|
| - * isolation, so seeing this could signal to skip the page. OTOH, I
|
| - * can't offhand think of how to get here unless this or the page-type
|
| - * byte is corrupted. Could be an overflow page, but it would require
|
| - * a very large database.
|
| - */
|
| - nMaxChildren =
|
| - (pCursor->nPageSize - kiPageInteriorHeaderBytes) / knMinCellLength + 1;
|
| - if (pCursor->nChildren > nMaxChildren) {
|
| - pCursor->nChildren = nMaxChildren;
|
| - }
|
| -}
|
| -
|
| -static int interiorCursorCreate(RecoverInteriorCursor *pParent,
|
| - RecoverPage *pPage, int nPageSize,
|
| - RecoverInteriorCursor **ppCursor){
|
| - RecoverInteriorCursor *pCursor =
|
| - sqlite3_malloc(sizeof(RecoverInteriorCursor));
|
| - if( !pCursor ){
|
| - return SQLITE_NOMEM;
|
| - }
|
| -
|
| - memset(pCursor, 0, sizeof(*pCursor));
|
| - pCursor->pParent = pParent;
|
| - pCursor->nPageSize = nPageSize;
|
| - interiorCursorSetPage(pCursor, pPage);
|
| - *ppCursor = pCursor;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* Internal helper. Return the child page number at iChild. */
|
| -static unsigned interiorCursorChildPage(RecoverInteriorCursor *pCursor){
|
| - const unsigned char *pPageHeader; /* Header of the current page. */
|
| - const unsigned char *pCellOffsets; /* Offset to page's cell offsets. */
|
| - unsigned iCellOffset; /* Offset of target cell. */
|
| -
|
| - assert( pCursor->iChild<pCursor->nChildren );
|
| -
|
| - /* Rightmost child is in the header. */
|
| - pPageHeader = PageHeader(pCursor->pPage);
|
| - if( pCursor->iChild==pCursor->nChildren-1 ){
|
| - return decodeUnsigned32(pPageHeader + kiPageRightChildOffset);
|
| - }
|
| -
|
| - /* Each cell is a 4-byte integer page number and a varint rowid
|
| - * which is greater than the rowid of items in that sub-tree (this
|
| - * module ignores ordering). The offset is from the beginning of the
|
| - * page, not from the page header.
|
| - */
|
| - pCellOffsets = pPageHeader + kiPageInteriorHeaderBytes;
|
| - iCellOffset = decodeUnsigned16(pCellOffsets + pCursor->iChild*2);
|
| - if( iCellOffset<=pCursor->nPageSize-4 ){
|
| - return decodeUnsigned32(PageData(pCursor->pPage, iCellOffset));
|
| - }
|
| -
|
| - /* TODO(shess): Check for cell overlaps? Cells require 4 bytes plus
|
| - * a varint. Check could be identical to leaf check (or even a
|
| - * shared helper testing for "Cells starting in this range"?).
|
| - */
|
| -
|
| - /* If the offset is broken, return an invalid page number. */
|
| - return 0;
|
| -}
|
| -
|
| -static int interiorCursorEOF(RecoverInteriorCursor *pCursor){
|
| - /* Find a parent with remaining children. EOF if none found. */
|
| - while( pCursor && pCursor->iChild>=pCursor->nChildren ){
|
| - pCursor = pCursor->pParent;
|
| - }
|
| - return pCursor==NULL;
|
| -}
|
| -
|
| -/* Internal helper. Used to detect if iPage would cause a loop. */
|
| -static int interiorCursorPageInUse(RecoverInteriorCursor *pCursor,
|
| - unsigned iPage){
|
| - /* Find any parent using the indicated page. */
|
| - while( pCursor && pCursor->pPage->pgno!=iPage ){
|
| - pCursor = pCursor->pParent;
|
| - }
|
| - return pCursor!=NULL;
|
| -}
|
| -
|
| -/* Get the next page from the interior cursor at *ppCursor. Returns
|
| - * SQLITE_ROW with the page in *ppPage, or SQLITE_DONE if out of
|
| - * pages, or the error SQLite returned.
|
| - *
|
| - * If the tree is uneven, then when the cursor attempts to get a new
|
| - * interior page from the parent cursor, it may get a non-interior
|
| - * page. In that case, the new page is returned, and *ppCursor is
|
| - * updated to point to the parent cursor (this cursor is freed).
|
| - */
|
| -/* TODO(shess): I've tried to avoid recursion in most of this code,
|
| - * but this case is more challenging because the recursive call is in
|
| - * the middle of operation. One option for converting it without
|
| - * adding memory management would be to retain the head pointer and
|
| - * use a helper to "back up" as needed. Another option would be to
|
| - * reverse the list during traversal.
|
| - */
|
| -static int interiorCursorNextPage(RecoverInteriorCursor **ppCursor,
|
| - RecoverPage **ppPage){
|
| - RecoverInteriorCursor *pCursor = *ppCursor;
|
| - while( 1 ){
|
| - int rc;
|
| - const unsigned char *pPageHeader; /* Header of found page. */
|
| -
|
| - /* Find a valid child page which isn't on the stack. */
|
| - while( pCursor->iChild<pCursor->nChildren ){
|
| - const unsigned iPage = interiorCursorChildPage(pCursor);
|
| - pCursor->iChild++;
|
| - if( interiorCursorPageInUse(pCursor, iPage) ){
|
| - fprintf(stderr, "Loop detected at %d\n", iPage);
|
| - }else{
|
| - int rc = pagerGetPage(pCursor->pPage->pPager, iPage, ppPage);
|
| - if( rc==SQLITE_OK ){
|
| - return SQLITE_ROW;
|
| - }
|
| - }
|
| - }
|
| -
|
| - /* This page has no more children. Get next page from parent. */
|
| - if( !pCursor->pParent ){
|
| - return SQLITE_DONE;
|
| - }
|
| - rc = interiorCursorNextPage(&pCursor->pParent, ppPage);
|
| - if( rc!=SQLITE_ROW ){
|
| - return rc;
|
| - }
|
| -
|
| - /* If a non-interior page is received, that either means that the
|
| - * tree is uneven, or that a child was re-used (say as an overflow
|
| - * page). Remove this cursor and let the caller handle the page.
|
| - */
|
| - pPageHeader = PageHeader(*ppPage);
|
| - if( pPageHeader[kiPageTypeOffset]!=kTableInteriorPage ){
|
| - *ppCursor = pCursor->pParent;
|
| - pCursor->pParent = NULL;
|
| - interiorCursorDestroy(pCursor);
|
| - return SQLITE_ROW;
|
| - }
|
| -
|
| - /* Iterate the new page. */
|
| - interiorCursorSetPage(pCursor, *ppPage);
|
| - *ppPage = NULL;
|
| - }
|
| -
|
| - assert(NULL); /* NOTREACHED() */
|
| - return SQLITE_CORRUPT;
|
| -}
|
| -
|
| -/* Large rows are spilled to overflow pages. The row's main page
|
| - * stores the overflow page number after the local payload, with a
|
| - * linked list forward from there as necessary. overflowMaybeCreate()
|
| - * and overflowGetSegment() provide an abstraction for accessing such
|
| - * data while centralizing the code.
|
| - *
|
| - * overflowDestroy - releases all resources associated with the structure.
|
| - * overflowMaybeCreate - create the overflow structure if it is needed
|
| - * to represent the given record. See function comment.
|
| - * overflowGetSegment - fetch a segment from the record, accounting
|
| - * for overflow pages. Segments which are not
|
| - * entirely contained with a page are constructed
|
| - * into a buffer which is returned. See function comment.
|
| - */
|
| -typedef struct RecoverOverflow RecoverOverflow;
|
| -struct RecoverOverflow {
|
| - RecoverOverflow *pNextOverflow;
|
| - RecoverPage *pPage;
|
| - unsigned nPageSize;
|
| -};
|
| -
|
| -static void overflowDestroy(RecoverOverflow *pOverflow){
|
| - while( pOverflow ){
|
| - RecoverOverflow *p = pOverflow;
|
| - pOverflow = p->pNextOverflow;
|
| -
|
| - if( p->pPage ){
|
| - pageDestroy(p->pPage);
|
| - p->pPage = NULL;
|
| - }
|
| -
|
| - memset(p, 0xA5, sizeof(*p));
|
| - sqlite3_free(p);
|
| - }
|
| -}
|
| -
|
| -/* Internal helper. Used to detect if iPage would cause a loop. */
|
| -static int overflowPageInUse(RecoverOverflow *pOverflow, unsigned iPage){
|
| - while( pOverflow && pOverflow->pPage->pgno!=iPage ){
|
| - pOverflow = pOverflow->pNextOverflow;
|
| - }
|
| - return pOverflow!=NULL;
|
| -}
|
| -
|
| -/* Setup to access an nRecordBytes record beginning at iRecordOffset
|
| - * in pPage. If nRecordBytes can be satisfied entirely from pPage,
|
| - * then no overflow pages are needed an *pnLocalRecordBytes is set to
|
| - * nRecordBytes. Otherwise, *ppOverflow is set to the head of a list
|
| - * of overflow pages, and *pnLocalRecordBytes is set to the number of
|
| - * bytes local to pPage.
|
| - *
|
| - * overflowGetSegment() will do the right thing regardless of whether
|
| - * those values are set to be in-page or not.
|
| - */
|
| -static int overflowMaybeCreate(RecoverPage *pPage, unsigned nPageSize,
|
| - unsigned iRecordOffset, unsigned nRecordBytes,
|
| - unsigned *pnLocalRecordBytes,
|
| - RecoverOverflow **ppOverflow){
|
| - unsigned nLocalRecordBytes; /* Record bytes in the leaf page. */
|
| - unsigned iNextPage; /* Next page number for record data. */
|
| - unsigned nBytes; /* Maximum record bytes as of current page. */
|
| - int rc;
|
| - RecoverOverflow *pFirstOverflow; /* First in linked list of pages. */
|
| - RecoverOverflow *pLastOverflow; /* End of linked list. */
|
| -
|
| - /* Calculations from the "Table B-Tree Leaf Cell" part of section
|
| - * 1.5 of http://www.sqlite.org/fileformat2.html . maxLocal and
|
| - * minLocal to match naming in btree.c.
|
| - */
|
| - const unsigned maxLocal = nPageSize - 35;
|
| - const unsigned minLocal = ((nPageSize-12)*32/255)-23; /* m */
|
| -
|
| - /* Always fit anything smaller than maxLocal. */
|
| - if( nRecordBytes<=maxLocal ){
|
| - *pnLocalRecordBytes = nRecordBytes;
|
| - *ppOverflow = NULL;
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - /* Calculate the remainder after accounting for minLocal on the leaf
|
| - * page and what packs evenly into overflow pages. If the remainder
|
| - * does not fit into maxLocal, then a partially-full overflow page
|
| - * will be required in any case, so store as little as possible locally.
|
| - */
|
| - nLocalRecordBytes = minLocal+((nRecordBytes-minLocal)%(nPageSize-4));
|
| - if( maxLocal<nLocalRecordBytes ){
|
| - nLocalRecordBytes = minLocal;
|
| - }
|
| -
|
| - /* Don't read off the end of the page. */
|
| - if( iRecordOffset+nLocalRecordBytes+4>nPageSize ){
|
| - return SQLITE_CORRUPT;
|
| - }
|
| -
|
| - /* First overflow page number is after the local bytes. */
|
| - iNextPage =
|
| - decodeUnsigned32(PageData(pPage, iRecordOffset + nLocalRecordBytes));
|
| - nBytes = nLocalRecordBytes;
|
| -
|
| - /* While there are more pages to read, and more bytes are needed,
|
| - * get another page.
|
| - */
|
| - pFirstOverflow = pLastOverflow = NULL;
|
| - rc = SQLITE_OK;
|
| - while( iNextPage && nBytes<nRecordBytes ){
|
| - RecoverOverflow *pOverflow; /* New overflow page for the list. */
|
| -
|
| - rc = pagerGetPage(pPage->pPager, iNextPage, &pPage);
|
| - if( rc!=SQLITE_OK ){
|
| - break;
|
| - }
|
| -
|
| - pOverflow = sqlite3_malloc(sizeof(RecoverOverflow));
|
| - if( !pOverflow ){
|
| - pageDestroy(pPage);
|
| - rc = SQLITE_NOMEM;
|
| - break;
|
| - }
|
| - memset(pOverflow, 0, sizeof(*pOverflow));
|
| - pOverflow->pPage = pPage;
|
| - pOverflow->nPageSize = nPageSize;
|
| -
|
| - if( !pFirstOverflow ){
|
| - pFirstOverflow = pOverflow;
|
| - }else{
|
| - pLastOverflow->pNextOverflow = pOverflow;
|
| - }
|
| - pLastOverflow = pOverflow;
|
| -
|
| - iNextPage = decodeUnsigned32(pPage->pData);
|
| - nBytes += nPageSize-4;
|
| -
|
| - /* Avoid loops. */
|
| - if( overflowPageInUse(pFirstOverflow, iNextPage) ){
|
| - fprintf(stderr, "Overflow loop detected at %d\n", iNextPage);
|
| - rc = SQLITE_CORRUPT;
|
| - break;
|
| - }
|
| - }
|
| -
|
| - /* If there were not enough pages, or too many, things are corrupt.
|
| - * Not having enough pages is an obvious problem, all the data
|
| - * cannot be read. Too many pages means that the contents of the
|
| - * row between the main page and the overflow page(s) is
|
| - * inconsistent (most likely one or more of the overflow pages does
|
| - * not really belong to this row).
|
| - */
|
| - if( rc==SQLITE_OK && (nBytes<nRecordBytes || iNextPage) ){
|
| - rc = SQLITE_CORRUPT;
|
| - }
|
| -
|
| - if( rc==SQLITE_OK ){
|
| - *ppOverflow = pFirstOverflow;
|
| - *pnLocalRecordBytes = nLocalRecordBytes;
|
| - }else if( pFirstOverflow ){
|
| - overflowDestroy(pFirstOverflow);
|
| - }
|
| - return rc;
|
| -}
|
| -
|
| -/* Use in concert with overflowMaybeCreate() to efficiently read parts
|
| - * of a potentially-overflowing record. pPage and iRecordOffset are
|
| - * the values passed into overflowMaybeCreate(), nLocalRecordBytes and
|
| - * pOverflow are the values returned by that call.
|
| - *
|
| - * On SQLITE_OK, *ppBase points to nRequestBytes of data at
|
| - * iRequestOffset within the record. If the data exists contiguously
|
| - * in a page, a direct pointer is returned, otherwise a buffer from
|
| - * sqlite3_malloc() is returned with the data. *pbFree is set true if
|
| - * sqlite3_free() should be called on *ppBase.
|
| - */
|
| -/* Operation of this function is subtle. At any time, pPage is the
|
| - * current page, with iRecordOffset and nLocalRecordBytes being record
|
| - * data within pPage, and pOverflow being the overflow page after
|
| - * pPage. This allows the code to handle both the initial leaf page
|
| - * and overflow pages consistently by adjusting the values
|
| - * appropriately.
|
| - */
|
| -static int overflowGetSegment(RecoverPage *pPage, unsigned iRecordOffset,
|
| - unsigned nLocalRecordBytes,
|
| - RecoverOverflow *pOverflow,
|
| - unsigned iRequestOffset, unsigned nRequestBytes,
|
| - unsigned char **ppBase, int *pbFree){
|
| - unsigned nBase; /* Amount of data currently collected. */
|
| - unsigned char *pBase; /* Buffer to collect record data into. */
|
| -
|
| - /* Skip to the page containing the start of the data. */
|
| - while( iRequestOffset>=nLocalRecordBytes && pOverflow ){
|
| - /* Factor out current page's contribution. */
|
| - iRequestOffset -= nLocalRecordBytes;
|
| -
|
| - /* Move forward to the next page in the list. */
|
| - pPage = pOverflow->pPage;
|
| - iRecordOffset = 4;
|
| - nLocalRecordBytes = pOverflow->nPageSize - iRecordOffset;
|
| - pOverflow = pOverflow->pNextOverflow;
|
| - }
|
| -
|
| - /* If the requested data is entirely within this page, return a
|
| - * pointer into the page.
|
| - */
|
| - if( iRequestOffset+nRequestBytes<=nLocalRecordBytes ){
|
| - /* TODO(shess): "assignment discards qualifiers from pointer target type"
|
| - * Having ppBase be const makes sense, but sqlite3_free() takes non-const.
|
| - */
|
| - *ppBase = (unsigned char *)PageData(pPage, iRecordOffset + iRequestOffset);
|
| - *pbFree = 0;
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - /* The data range would require additional pages. */
|
| - if( !pOverflow ){
|
| - /* Should never happen, the range is outside the nRecordBytes
|
| - * passed to overflowMaybeCreate().
|
| - */
|
| - assert(NULL); /* NOTREACHED */
|
| - return SQLITE_ERROR;
|
| - }
|
| -
|
| - /* Get a buffer to construct into. */
|
| - nBase = 0;
|
| - pBase = sqlite3_malloc(nRequestBytes);
|
| - if( !pBase ){
|
| - return SQLITE_NOMEM;
|
| - }
|
| - while( nBase<nRequestBytes ){
|
| - /* Copy over data present on this page. */
|
| - unsigned nCopyBytes = nRequestBytes - nBase;
|
| - if( nLocalRecordBytes-iRequestOffset<nCopyBytes ){
|
| - nCopyBytes = nLocalRecordBytes - iRequestOffset;
|
| - }
|
| - memcpy(pBase + nBase, PageData(pPage, iRecordOffset + iRequestOffset),
|
| - nCopyBytes);
|
| - nBase += nCopyBytes;
|
| -
|
| - if( pOverflow ){
|
| - /* Copy from start of record data in future pages. */
|
| - iRequestOffset = 0;
|
| -
|
| - /* Move forward to the next page in the list. Should match
|
| - * first while() loop.
|
| - */
|
| - pPage = pOverflow->pPage;
|
| - iRecordOffset = 4;
|
| - nLocalRecordBytes = pOverflow->nPageSize - iRecordOffset;
|
| - pOverflow = pOverflow->pNextOverflow;
|
| - }else if( nBase<nRequestBytes ){
|
| - /* Ran out of overflow pages with data left to deliver. Not
|
| - * possible if the requested range fits within nRecordBytes
|
| - * passed to overflowMaybeCreate() when creating pOverflow.
|
| - */
|
| - assert(NULL); /* NOTREACHED */
|
| - sqlite3_free(pBase);
|
| - return SQLITE_ERROR;
|
| - }
|
| - }
|
| - assert( nBase==nRequestBytes );
|
| - *ppBase = pBase;
|
| - *pbFree = 1;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* Primary structure for iterating the contents of a table.
|
| - *
|
| - * leafCursorDestroy - release all resources associated with the cursor.
|
| - * leafCursorCreate - create a cursor to iterate items from tree at
|
| - * the provided root page.
|
| - * leafCursorNextValidCell - get the cursor ready to access data from
|
| - * the next valid cell in the table.
|
| - * leafCursorCellRowid - get the current cell's rowid.
|
| - * leafCursorCellColumns - get current cell's column count.
|
| - * leafCursorCellColInfo - get type and data for a column in current cell.
|
| - *
|
| - * leafCursorNextValidCell skips cells which fail simple integrity
|
| - * checks, such as overlapping other cells, or being located at
|
| - * impossible offsets, or where header data doesn't correctly describe
|
| - * payload data. Returns SQLITE_ROW if a valid cell is found,
|
| - * SQLITE_DONE if all pages in the tree were exhausted.
|
| - *
|
| - * leafCursorCellColInfo() accounts for overflow pages in the style of
|
| - * overflowGetSegment().
|
| - */
|
| -typedef struct RecoverLeafCursor RecoverLeafCursor;
|
| -struct RecoverLeafCursor {
|
| - RecoverInteriorCursor *pParent; /* Parent node to this node. */
|
| - RecoverPager *pPager; /* Page provider. */
|
| - RecoverPage *pPage; /* Current leaf page. */
|
| - unsigned nPageSize; /* Size of pPage. */
|
| - unsigned nCells; /* Number of cells in pPage. */
|
| - unsigned iCell; /* Current cell. */
|
| -
|
| - /* Info parsed from data in iCell. */
|
| - i64 iRowid; /* rowid parsed. */
|
| - unsigned nRecordCols; /* how many items in the record. */
|
| - u64 iRecordOffset; /* offset to record data. */
|
| - /* TODO(shess): nRecordBytes and nRecordHeaderBytes are used in
|
| - * leafCursorCellColInfo() to prevent buffer overruns.
|
| - * leafCursorCellDecode() already verified that the cell is valid, so
|
| - * those checks should be redundant.
|
| - */
|
| - u64 nRecordBytes; /* Size of record data. */
|
| - unsigned nLocalRecordBytes; /* Amount of record data in-page. */
|
| - unsigned nRecordHeaderBytes; /* Size of record header data. */
|
| - unsigned char *pRecordHeader; /* Pointer to record header data. */
|
| - int bFreeRecordHeader; /* True if record header requires free. */
|
| - RecoverOverflow *pOverflow; /* Cell overflow info, if needed. */
|
| -};
|
| -
|
| -/* Internal helper shared between next-page and create-cursor. If
|
| - * pPage is a leaf page, it will be stored in the cursor and state
|
| - * initialized for reading cells.
|
| - *
|
| - * If pPage is an interior page, a new parent cursor is created and
|
| - * injected on the stack. This is necessary to handle trees with
|
| - * uneven depth, but also is used during initial setup.
|
| - *
|
| - * If pPage is not a table page at all, it is discarded.
|
| - *
|
| - * If SQLITE_OK is returned, the caller no longer owns pPage,
|
| - * otherwise the caller is responsible for discarding it.
|
| - */
|
| -static int leafCursorLoadPage(RecoverLeafCursor *pCursor, RecoverPage *pPage){
|
| - const unsigned char *pPageHeader; /* Header of *pPage */
|
| - unsigned nCells; /* Number of cells in the page */
|
| -
|
| - /* Release the current page. */
|
| - if( pCursor->pPage ){
|
| - pageDestroy(pCursor->pPage);
|
| - pCursor->pPage = NULL;
|
| - pCursor->iCell = pCursor->nCells = 0;
|
| - }
|
| -
|
| - /* If the page is an unexpected interior node, inject a new stack
|
| - * layer and try again from there.
|
| - */
|
| - pPageHeader = PageHeader(pPage);
|
| - if( pPageHeader[kiPageTypeOffset]==kTableInteriorPage ){
|
| - RecoverInteriorCursor *pParent;
|
| - int rc = interiorCursorCreate(pCursor->pParent, pPage, pCursor->nPageSize,
|
| - &pParent);
|
| - if( rc!=SQLITE_OK ){
|
| - return rc;
|
| - }
|
| - pCursor->pParent = pParent;
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - /* Not a leaf page, skip it. */
|
| - if( pPageHeader[kiPageTypeOffset]!=kTableLeafPage ){
|
| - pageDestroy(pPage);
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - /* Leaf contains no data, skip it. Empty tables, for instance. */
|
| - nCells = decodeUnsigned16(pPageHeader + kiPageCellCountOffset);;
|
| - if( nCells<1 ){
|
| - pageDestroy(pPage);
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - /* Take ownership of the page and start decoding. */
|
| - pCursor->pPage = pPage;
|
| - pCursor->iCell = 0;
|
| - pCursor->nCells = nCells;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* Get the next leaf-level page in the tree. Returns SQLITE_ROW when
|
| - * a leaf page is found, SQLITE_DONE when no more leaves exist, or any
|
| - * error which occurred.
|
| - */
|
| -static int leafCursorNextPage(RecoverLeafCursor *pCursor){
|
| - if( !pCursor->pParent ){
|
| - return SQLITE_DONE;
|
| - }
|
| -
|
| - /* Repeatedly load the parent's next child page until a leaf is found. */
|
| - do {
|
| - RecoverPage *pNextPage;
|
| - int rc = interiorCursorNextPage(&pCursor->pParent, &pNextPage);
|
| - if( rc!=SQLITE_ROW ){
|
| - assert( rc==SQLITE_DONE );
|
| - return rc;
|
| - }
|
| -
|
| - rc = leafCursorLoadPage(pCursor, pNextPage);
|
| - if( rc!=SQLITE_OK ){
|
| - pageDestroy(pNextPage);
|
| - return rc;
|
| - }
|
| - } while( !pCursor->pPage );
|
| -
|
| - return SQLITE_ROW;
|
| -}
|
| -
|
| -static void leafCursorDestroyCellData(RecoverLeafCursor *pCursor){
|
| - if( pCursor->bFreeRecordHeader ){
|
| - sqlite3_free(pCursor->pRecordHeader);
|
| - }
|
| - pCursor->bFreeRecordHeader = 0;
|
| - pCursor->pRecordHeader = NULL;
|
| -
|
| - if( pCursor->pOverflow ){
|
| - overflowDestroy(pCursor->pOverflow);
|
| - pCursor->pOverflow = NULL;
|
| - }
|
| -}
|
| -
|
| -static void leafCursorDestroy(RecoverLeafCursor *pCursor){
|
| - leafCursorDestroyCellData(pCursor);
|
| -
|
| - if( pCursor->pParent ){
|
| - interiorCursorDestroy(pCursor->pParent);
|
| - pCursor->pParent = NULL;
|
| - }
|
| -
|
| - if( pCursor->pPage ){
|
| - pageDestroy(pCursor->pPage);
|
| - pCursor->pPage = NULL;
|
| - }
|
| -
|
| - if( pCursor->pPager ){
|
| - pagerDestroy(pCursor->pPager);
|
| - pCursor->pPager = NULL;
|
| - }
|
| -
|
| - memset(pCursor, 0xA5, sizeof(*pCursor));
|
| - sqlite3_free(pCursor);
|
| -}
|
| -
|
| -/* Create a cursor to iterate the rows from the leaf pages of a table
|
| - * rooted at iRootPage.
|
| - */
|
| -/* TODO(shess): recoverOpen() calls this to setup the cursor, and I
|
| - * think that recoverFilter() may make a hard assumption that the
|
| - * cursor returned will turn up at least one valid cell.
|
| - *
|
| - * The cases I can think of which break this assumption are:
|
| - * - pPage is a valid leaf page with no valid cells.
|
| - * - pPage is a valid interior page with no valid leaves.
|
| - * - pPage is a valid interior page who's leaves contain no valid cells.
|
| - * - pPage is not a valid leaf or interior page.
|
| - */
|
| -static int leafCursorCreate(RecoverPager *pPager, unsigned nPageSize,
|
| - u32 iRootPage, RecoverLeafCursor **ppCursor){
|
| - RecoverPage *pPage; /* Reference to page at iRootPage. */
|
| - RecoverLeafCursor *pCursor; /* Leaf cursor being constructed. */
|
| - int rc;
|
| -
|
| - /* Start out with the root page. */
|
| - rc = pagerGetPage(pPager, iRootPage, &pPage);
|
| - if( rc!=SQLITE_OK ){
|
| - return rc;
|
| - }
|
| -
|
| - pCursor = sqlite3_malloc(sizeof(RecoverLeafCursor));
|
| - if( !pCursor ){
|
| - pageDestroy(pPage);
|
| - return SQLITE_NOMEM;
|
| - }
|
| - memset(pCursor, 0, sizeof(*pCursor));
|
| -
|
| - pCursor->nPageSize = nPageSize;
|
| - pCursor->pPager = pPager;
|
| -
|
| - rc = leafCursorLoadPage(pCursor, pPage);
|
| - if( rc!=SQLITE_OK ){
|
| - pageDestroy(pPage);
|
| - leafCursorDestroy(pCursor);
|
| - return rc;
|
| - }
|
| -
|
| - /* pPage wasn't a leaf page, find the next leaf page. */
|
| - if( !pCursor->pPage ){
|
| - rc = leafCursorNextPage(pCursor);
|
| - if( rc!=SQLITE_DONE && rc!=SQLITE_ROW ){
|
| - leafCursorDestroy(pCursor);
|
| - return rc;
|
| - }
|
| - }
|
| -
|
| - *ppCursor = pCursor;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* Useful for setting breakpoints. */
|
| -static int ValidateError(){
|
| - return SQLITE_ERROR;
|
| -}
|
| -
|
| -/* Setup the cursor for reading the information from cell iCell. */
|
| -static int leafCursorCellDecode(RecoverLeafCursor *pCursor){
|
| - const unsigned char *pPageHeader; /* Header of current page. */
|
| - const unsigned char *pPageEnd; /* Byte after end of current page. */
|
| - const unsigned char *pCellOffsets; /* Pointer to page's cell offsets. */
|
| - unsigned iCellOffset; /* Offset of current cell (iCell). */
|
| - const unsigned char *pCell; /* Pointer to data at iCellOffset. */
|
| - unsigned nCellMaxBytes; /* Maximum local size of iCell. */
|
| - unsigned iEndOffset; /* End of iCell's in-page data. */
|
| - u64 nRecordBytes; /* Expected size of cell, w/overflow. */
|
| - u64 iRowid; /* iCell's rowid (in table). */
|
| - unsigned nRead; /* Amount of cell read. */
|
| - unsigned nRecordHeaderRead; /* Header data read. */
|
| - u64 nRecordHeaderBytes; /* Header size expected. */
|
| - unsigned nRecordCols; /* Columns read from header. */
|
| - u64 nRecordColBytes; /* Bytes in payload for those columns. */
|
| - unsigned i;
|
| - int rc;
|
| -
|
| - assert( pCursor->iCell<pCursor->nCells );
|
| -
|
| - leafCursorDestroyCellData(pCursor);
|
| -
|
| - /* Find the offset to the row. */
|
| - pPageHeader = PageHeader(pCursor->pPage);
|
| - pCellOffsets = pPageHeader + knPageLeafHeaderBytes;
|
| - pPageEnd = PageData(pCursor->pPage, pCursor->nPageSize);
|
| - if( pCellOffsets + pCursor->iCell*2 + 2 > pPageEnd ){
|
| - return ValidateError();
|
| - }
|
| - iCellOffset = decodeUnsigned16(pCellOffsets + pCursor->iCell*2);
|
| - if( iCellOffset>=pCursor->nPageSize ){
|
| - return ValidateError();
|
| - }
|
| -
|
| - pCell = PageData(pCursor->pPage, iCellOffset);
|
| - nCellMaxBytes = pCursor->nPageSize - iCellOffset;
|
| -
|
| - /* B-tree leaf cells lead with varint record size, varint rowid and
|
| - * varint header size.
|
| - */
|
| - /* TODO(shess): The smallest page size is 512 bytes, which has an m
|
| - * of 39. Three varints need at most 27 bytes to encode. I think.
|
| - */
|
| - if( !checkVarints(pCell, nCellMaxBytes, 3) ){
|
| - return ValidateError();
|
| - }
|
| -
|
| - nRead = getVarint(pCell, &nRecordBytes);
|
| - assert( iCellOffset+nRead<=pCursor->nPageSize );
|
| - pCursor->nRecordBytes = nRecordBytes;
|
| -
|
| - nRead += getVarint(pCell + nRead, &iRowid);
|
| - assert( iCellOffset+nRead<=pCursor->nPageSize );
|
| - pCursor->iRowid = (i64)iRowid;
|
| -
|
| - pCursor->iRecordOffset = iCellOffset + nRead;
|
| -
|
| - /* Start overflow setup here because nLocalRecordBytes is needed to
|
| - * check cell overlap.
|
| - */
|
| - rc = overflowMaybeCreate(pCursor->pPage, pCursor->nPageSize,
|
| - pCursor->iRecordOffset, pCursor->nRecordBytes,
|
| - &pCursor->nLocalRecordBytes,
|
| - &pCursor->pOverflow);
|
| - if( rc!=SQLITE_OK ){
|
| - return ValidateError();
|
| - }
|
| -
|
| - /* Check that no other cell starts within this cell. */
|
| - iEndOffset = pCursor->iRecordOffset + pCursor->nLocalRecordBytes;
|
| - for( i=0; i<pCursor->nCells && pCellOffsets + i*2 + 2 <= pPageEnd; ++i ){
|
| - const unsigned iOtherOffset = decodeUnsigned16(pCellOffsets + i*2);
|
| - if( iOtherOffset>iCellOffset && iOtherOffset<iEndOffset ){
|
| - return ValidateError();
|
| - }
|
| - }
|
| -
|
| - nRecordHeaderRead = getVarint(pCell + nRead, &nRecordHeaderBytes);
|
| - assert( nRecordHeaderBytes<=nRecordBytes );
|
| - pCursor->nRecordHeaderBytes = nRecordHeaderBytes;
|
| -
|
| - /* Large headers could overflow if pages are small. */
|
| - rc = overflowGetSegment(pCursor->pPage,
|
| - pCursor->iRecordOffset, pCursor->nLocalRecordBytes,
|
| - pCursor->pOverflow, 0, nRecordHeaderBytes,
|
| - &pCursor->pRecordHeader, &pCursor->bFreeRecordHeader);
|
| - if( rc!=SQLITE_OK ){
|
| - return ValidateError();
|
| - }
|
| -
|
| - /* Tally up the column count and size of data. */
|
| - nRecordCols = 0;
|
| - nRecordColBytes = 0;
|
| - while( nRecordHeaderRead<nRecordHeaderBytes ){
|
| - u64 iSerialType; /* Type descriptor for current column. */
|
| - if( !checkVarint(pCursor->pRecordHeader + nRecordHeaderRead,
|
| - nRecordHeaderBytes - nRecordHeaderRead) ){
|
| - return ValidateError();
|
| - }
|
| - nRecordHeaderRead += getVarint(pCursor->pRecordHeader + nRecordHeaderRead,
|
| - &iSerialType);
|
| - if( iSerialType==10 || iSerialType==11 ){
|
| - return ValidateError();
|
| - }
|
| - nRecordColBytes += SerialTypeLength(iSerialType);
|
| - nRecordCols++;
|
| - }
|
| - pCursor->nRecordCols = nRecordCols;
|
| -
|
| - /* Parsing the header used as many bytes as expected. */
|
| - if( nRecordHeaderRead!=nRecordHeaderBytes ){
|
| - return ValidateError();
|
| - }
|
| -
|
| - /* Calculated record is size of expected record. */
|
| - if( nRecordHeaderBytes+nRecordColBytes!=nRecordBytes ){
|
| - return ValidateError();
|
| - }
|
| -
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static i64 leafCursorCellRowid(RecoverLeafCursor *pCursor){
|
| - return pCursor->iRowid;
|
| -}
|
| -
|
| -static unsigned leafCursorCellColumns(RecoverLeafCursor *pCursor){
|
| - return pCursor->nRecordCols;
|
| -}
|
| -
|
| -/* Get the column info for the cell. Pass NULL for ppBase to prevent
|
| - * retrieving the data segment. If *pbFree is true, *ppBase must be
|
| - * freed by the caller using sqlite3_free().
|
| - */
|
| -static int leafCursorCellColInfo(RecoverLeafCursor *pCursor,
|
| - unsigned iCol, u64 *piColType,
|
| - unsigned char **ppBase, int *pbFree){
|
| - const unsigned char *pRecordHeader; /* Current cell's header. */
|
| - u64 nRecordHeaderBytes; /* Bytes in pRecordHeader. */
|
| - unsigned nRead; /* Bytes read from header. */
|
| - u64 iColEndOffset; /* Offset to end of column in cell. */
|
| - unsigned nColsSkipped; /* Count columns as procesed. */
|
| - u64 iSerialType; /* Type descriptor for current column. */
|
| -
|
| - /* Implicit NULL for columns past the end. This case happens when
|
| - * rows have not been updated since an ALTER TABLE added columns.
|
| - * It is more convenient to address here than in callers.
|
| - */
|
| - if( iCol>=pCursor->nRecordCols ){
|
| - *piColType = 0;
|
| - if( ppBase ){
|
| - *ppBase = 0;
|
| - *pbFree = 0;
|
| - }
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - /* Must be able to decode header size. */
|
| - pRecordHeader = pCursor->pRecordHeader;
|
| - if( !checkVarint(pRecordHeader, pCursor->nRecordHeaderBytes) ){
|
| - return SQLITE_CORRUPT;
|
| - }
|
| -
|
| - /* Rather than caching the header size and how many bytes it took,
|
| - * decode it every time.
|
| - */
|
| - nRead = getVarint(pRecordHeader, &nRecordHeaderBytes);
|
| - assert( nRecordHeaderBytes==pCursor->nRecordHeaderBytes );
|
| -
|
| - /* Scan forward to the indicated column. Scans to _after_ column
|
| - * for later range checking.
|
| - */
|
| - /* TODO(shess): This could get expensive for very wide tables. An
|
| - * array of iSerialType could be built in leafCursorCellDecode(), but
|
| - * the number of columns is dynamic per row, so it would add memory
|
| - * management complexity. Enough info to efficiently forward
|
| - * iterate could be kept, if all clients forward iterate
|
| - * (recoverColumn() may not).
|
| - */
|
| - iColEndOffset = 0;
|
| - nColsSkipped = 0;
|
| - while( nColsSkipped<=iCol && nRead<nRecordHeaderBytes ){
|
| - if( !checkVarint(pRecordHeader + nRead, nRecordHeaderBytes - nRead) ){
|
| - return SQLITE_CORRUPT;
|
| - }
|
| - nRead += getVarint(pRecordHeader + nRead, &iSerialType);
|
| - iColEndOffset += SerialTypeLength(iSerialType);
|
| - nColsSkipped++;
|
| - }
|
| -
|
| - /* Column's data extends past record's end. */
|
| - if( nRecordHeaderBytes+iColEndOffset>pCursor->nRecordBytes ){
|
| - return SQLITE_CORRUPT;
|
| - }
|
| -
|
| - *piColType = iSerialType;
|
| - if( ppBase ){
|
| - const u32 nColBytes = SerialTypeLength(iSerialType);
|
| -
|
| - /* Offset from start of record to beginning of column. */
|
| - const unsigned iColOffset = nRecordHeaderBytes+iColEndOffset-nColBytes;
|
| -
|
| - return overflowGetSegment(pCursor->pPage, pCursor->iRecordOffset,
|
| - pCursor->nLocalRecordBytes, pCursor->pOverflow,
|
| - iColOffset, nColBytes, ppBase, pbFree);
|
| - }
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static int leafCursorNextValidCell(RecoverLeafCursor *pCursor){
|
| - while( 1 ){
|
| - int rc;
|
| -
|
| - /* Move to the next cell. */
|
| - pCursor->iCell++;
|
| -
|
| - /* No more cells, get the next leaf. */
|
| - if( pCursor->iCell>=pCursor->nCells ){
|
| - rc = leafCursorNextPage(pCursor);
|
| - if( rc!=SQLITE_ROW ){
|
| - return rc;
|
| - }
|
| - assert( pCursor->iCell==0 );
|
| - }
|
| -
|
| - /* If the cell is valid, indicate that a row is available. */
|
| - rc = leafCursorCellDecode(pCursor);
|
| - if( rc==SQLITE_OK ){
|
| - return SQLITE_ROW;
|
| - }
|
| -
|
| - /* Iterate until done or a valid row is found. */
|
| - /* TODO(shess): Remove debugging output. */
|
| - fprintf(stderr, "Skipping invalid cell\n");
|
| - }
|
| - return SQLITE_ERROR;
|
| -}
|
| -
|
| -typedef struct Recover Recover;
|
| -struct Recover {
|
| - sqlite3_vtab base;
|
| - sqlite3 *db; /* Host database connection */
|
| - char *zDb; /* Database containing target table */
|
| - char *zTable; /* Target table */
|
| - unsigned nCols; /* Number of columns in target table */
|
| - unsigned char *pTypes; /* Types of columns in target table */
|
| -};
|
| -
|
| -/* Internal helper for deleting the module. */
|
| -static void recoverRelease(Recover *pRecover){
|
| - sqlite3_free(pRecover->zDb);
|
| - sqlite3_free(pRecover->zTable);
|
| - sqlite3_free(pRecover->pTypes);
|
| - memset(pRecover, 0xA5, sizeof(*pRecover));
|
| - sqlite3_free(pRecover);
|
| -}
|
| -
|
| -/* Helper function for initializing the module. Forward-declared so
|
| - * recoverCreate() and recoverConnect() can see it.
|
| - */
|
| -static int recoverInit(
|
| - sqlite3 *, void *, int, const char *const*, sqlite3_vtab **, char **
|
| -);
|
| -
|
| -static int recoverCreate(
|
| - sqlite3 *db,
|
| - void *pAux,
|
| - int argc, const char *const*argv,
|
| - sqlite3_vtab **ppVtab,
|
| - char **pzErr
|
| -){
|
| - FNENTRY();
|
| - return recoverInit(db, pAux, argc, argv, ppVtab, pzErr);
|
| -}
|
| -
|
| -/* This should never be called. */
|
| -static int recoverConnect(
|
| - sqlite3 *db,
|
| - void *pAux,
|
| - int argc, const char *const*argv,
|
| - sqlite3_vtab **ppVtab,
|
| - char **pzErr
|
| -){
|
| - FNENTRY();
|
| - return recoverInit(db, pAux, argc, argv, ppVtab, pzErr);
|
| -}
|
| -
|
| -/* No indices supported. */
|
| -static int recoverBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
|
| - FNENTRY();
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* Logically, this should never be called. */
|
| -static int recoverDisconnect(sqlite3_vtab *pVtab){
|
| - FNENTRY();
|
| - recoverRelease((Recover*)pVtab);
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static int recoverDestroy(sqlite3_vtab *pVtab){
|
| - FNENTRY();
|
| - recoverRelease((Recover*)pVtab);
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -typedef struct RecoverCursor RecoverCursor;
|
| -struct RecoverCursor {
|
| - sqlite3_vtab_cursor base;
|
| - RecoverLeafCursor *pLeafCursor;
|
| - int iEncoding;
|
| - int bEOF;
|
| -};
|
| -
|
| -static int recoverOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
|
| - Recover *pRecover = (Recover*)pVTab;
|
| - u32 iRootPage; /* Root page of the backing table. */
|
| - int iEncoding; /* UTF encoding for backing database. */
|
| - unsigned nPageSize; /* Size of pages in backing database. */
|
| - RecoverPager *pPager; /* Backing database pager. */
|
| - RecoverLeafCursor *pLeafCursor; /* Cursor to read table's leaf pages. */
|
| - RecoverCursor *pCursor; /* Cursor to read rows from leaves. */
|
| - int rc;
|
| -
|
| - FNENTRY();
|
| -
|
| - iRootPage = 0;
|
| - rc = getRootPage(pRecover->db, pRecover->zDb, pRecover->zTable,
|
| - &iRootPage);
|
| - if( rc!=SQLITE_OK ){
|
| - return rc;
|
| - }
|
| -
|
| - rc = GetPager(pRecover->db, pRecover->zDb, &pPager, &nPageSize, &iEncoding);
|
| - if( rc!=SQLITE_OK ){
|
| - return rc;
|
| - }
|
| -
|
| - rc = leafCursorCreate(pPager, nPageSize, iRootPage, &pLeafCursor);
|
| - if( rc!=SQLITE_OK ){
|
| - pagerDestroy(pPager);
|
| - return rc;
|
| - }
|
| -
|
| - pCursor = sqlite3_malloc(sizeof(RecoverCursor));
|
| - if( !pCursor ){
|
| - leafCursorDestroy(pLeafCursor);
|
| - return SQLITE_NOMEM;
|
| - }
|
| - memset(pCursor, 0, sizeof(*pCursor));
|
| - pCursor->base.pVtab = pVTab;
|
| - pCursor->pLeafCursor = pLeafCursor;
|
| - pCursor->iEncoding = iEncoding;
|
| -
|
| - /* If no leaf pages were found, empty result set. */
|
| - /* TODO(shess): leafCursorNextValidCell() would return SQLITE_ROW or
|
| - * SQLITE_DONE to indicate whether there is further data to consider.
|
| - */
|
| - pCursor->bEOF = (pLeafCursor->pPage==NULL);
|
| -
|
| - *ppCursor = (sqlite3_vtab_cursor*)pCursor;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static int recoverClose(sqlite3_vtab_cursor *cur){
|
| - RecoverCursor *pCursor = (RecoverCursor*)cur;
|
| - FNENTRY();
|
| - if( pCursor->pLeafCursor ){
|
| - leafCursorDestroy(pCursor->pLeafCursor);
|
| - pCursor->pLeafCursor = NULL;
|
| - }
|
| - memset(pCursor, 0xA5, sizeof(*pCursor));
|
| - sqlite3_free(cur);
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* Helpful place to set a breakpoint. */
|
| -static int RecoverInvalidCell(){
|
| - return SQLITE_ERROR;
|
| -}
|
| -
|
| -/* Returns SQLITE_OK if the cell has an appropriate number of columns
|
| - * with the appropriate types of data.
|
| - */
|
| -static int recoverValidateLeafCell(Recover *pRecover, RecoverCursor *pCursor){
|
| - unsigned i;
|
| -
|
| - /* If the row's storage has too many columns, skip it. */
|
| - if( leafCursorCellColumns(pCursor->pLeafCursor)>pRecover->nCols ){
|
| - return RecoverInvalidCell();
|
| - }
|
| -
|
| - /* Skip rows with unexpected types. */
|
| - for( i=0; i<pRecover->nCols; ++i ){
|
| - u64 iType; /* Storage type of column i. */
|
| - int rc;
|
| -
|
| - /* ROWID alias. */
|
| - if( (pRecover->pTypes[i]&MASK_ROWID) ){
|
| - continue;
|
| - }
|
| -
|
| - rc = leafCursorCellColInfo(pCursor->pLeafCursor, i, &iType, NULL, NULL);
|
| - assert( rc==SQLITE_OK );
|
| - if( rc!=SQLITE_OK || !SerialTypeIsCompatible(iType, pRecover->pTypes[i]) ){
|
| - return RecoverInvalidCell();
|
| - }
|
| - }
|
| -
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static int recoverNext(sqlite3_vtab_cursor *pVtabCursor){
|
| - RecoverCursor *pCursor = (RecoverCursor*)pVtabCursor;
|
| - Recover *pRecover = (Recover*)pCursor->base.pVtab;
|
| - int rc;
|
| -
|
| - FNENTRY();
|
| -
|
| - /* Scan forward to the next cell with valid storage, then check that
|
| - * the stored data matches the schema.
|
| - */
|
| - while( (rc = leafCursorNextValidCell(pCursor->pLeafCursor))==SQLITE_ROW ){
|
| - if( recoverValidateLeafCell(pRecover, pCursor)==SQLITE_OK ){
|
| - return SQLITE_OK;
|
| - }
|
| - }
|
| -
|
| - if( rc==SQLITE_DONE ){
|
| - pCursor->bEOF = 1;
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - assert( rc!=SQLITE_OK );
|
| - return rc;
|
| -}
|
| -
|
| -static int recoverFilter(
|
| - sqlite3_vtab_cursor *pVtabCursor,
|
| - int idxNum, const char *idxStr,
|
| - int argc, sqlite3_value **argv
|
| -){
|
| - RecoverCursor *pCursor = (RecoverCursor*)pVtabCursor;
|
| - Recover *pRecover = (Recover*)pCursor->base.pVtab;
|
| - int rc;
|
| -
|
| - FNENTRY();
|
| -
|
| - /* There were no valid leaf pages in the table. */
|
| - if( pCursor->bEOF ){
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - /* Load the first cell, and iterate forward if it's not valid. If no cells at
|
| - * all are valid, recoverNext() sets bEOF and returns appropriately.
|
| - */
|
| - rc = leafCursorCellDecode(pCursor->pLeafCursor);
|
| - if( rc!=SQLITE_OK || recoverValidateLeafCell(pRecover, pCursor)!=SQLITE_OK ){
|
| - return recoverNext(pVtabCursor);
|
| - }
|
| -
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static int recoverEof(sqlite3_vtab_cursor *pVtabCursor){
|
| - RecoverCursor *pCursor = (RecoverCursor*)pVtabCursor;
|
| - FNENTRY();
|
| - return pCursor->bEOF;
|
| -}
|
| -
|
| -static int recoverColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
|
| - RecoverCursor *pCursor = (RecoverCursor*)cur;
|
| - Recover *pRecover = (Recover*)pCursor->base.pVtab;
|
| - u64 iColType; /* Storage type of column i. */
|
| - unsigned char *pColData; /* Column i's data. */
|
| - int shouldFree; /* Non-zero if pColData should be freed. */
|
| - int rc;
|
| -
|
| - FNENTRY();
|
| -
|
| - if( (unsigned)i>=pRecover->nCols ){
|
| - return SQLITE_ERROR;
|
| - }
|
| -
|
| - /* ROWID alias. */
|
| - if( (pRecover->pTypes[i]&MASK_ROWID) ){
|
| - sqlite3_result_int64(ctx, leafCursorCellRowid(pCursor->pLeafCursor));
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - pColData = NULL;
|
| - shouldFree = 0;
|
| - rc = leafCursorCellColInfo(pCursor->pLeafCursor, i, &iColType,
|
| - &pColData, &shouldFree);
|
| - if( rc!=SQLITE_OK ){
|
| - return rc;
|
| - }
|
| - /* recoverValidateLeafCell() should guarantee that this will never
|
| - * occur.
|
| - */
|
| - if( !SerialTypeIsCompatible(iColType, pRecover->pTypes[i]) ){
|
| - if( shouldFree ){
|
| - sqlite3_free(pColData);
|
| - }
|
| - return SQLITE_ERROR;
|
| - }
|
| -
|
| - switch( iColType ){
|
| - case 0 : sqlite3_result_null(ctx); break;
|
| - case 1 : sqlite3_result_int64(ctx, decodeSigned(pColData, 1)); break;
|
| - case 2 : sqlite3_result_int64(ctx, decodeSigned(pColData, 2)); break;
|
| - case 3 : sqlite3_result_int64(ctx, decodeSigned(pColData, 3)); break;
|
| - case 4 : sqlite3_result_int64(ctx, decodeSigned(pColData, 4)); break;
|
| - case 5 : sqlite3_result_int64(ctx, decodeSigned(pColData, 6)); break;
|
| - case 6 : sqlite3_result_int64(ctx, decodeSigned(pColData, 8)); break;
|
| - case 7 : sqlite3_result_double(ctx, decodeFloat64(pColData)); break;
|
| - case 8 : sqlite3_result_int(ctx, 0); break;
|
| - case 9 : sqlite3_result_int(ctx, 1); break;
|
| - case 10 : assert( iColType!=10 ); break;
|
| - case 11 : assert( iColType!=11 ); break;
|
| -
|
| - default : {
|
| - u32 l = SerialTypeLength(iColType);
|
| -
|
| - /* If pColData was already allocated, arrange to pass ownership. */
|
| - sqlite3_destructor_type pFn = SQLITE_TRANSIENT;
|
| - if( shouldFree ){
|
| - pFn = sqlite3_free;
|
| - shouldFree = 0;
|
| - }
|
| -
|
| - if( SerialTypeIsBlob(iColType) ){
|
| - sqlite3_result_blob(ctx, pColData, l, pFn);
|
| - }else{
|
| - if( pCursor->iEncoding==SQLITE_UTF16LE ){
|
| - sqlite3_result_text16le(ctx, (const void*)pColData, l, pFn);
|
| - }else if( pCursor->iEncoding==SQLITE_UTF16BE ){
|
| - sqlite3_result_text16be(ctx, (const void*)pColData, l, pFn);
|
| - }else{
|
| - sqlite3_result_text(ctx, (const char*)pColData, l, pFn);
|
| - }
|
| - }
|
| - } break;
|
| - }
|
| - if( shouldFree ){
|
| - sqlite3_free(pColData);
|
| - }
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static int recoverRowid(sqlite3_vtab_cursor *pVtabCursor, sqlite_int64 *pRowid){
|
| - RecoverCursor *pCursor = (RecoverCursor*)pVtabCursor;
|
| - FNENTRY();
|
| - *pRowid = leafCursorCellRowid(pCursor->pLeafCursor);
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -static sqlite3_module recoverModule = {
|
| - 0, /* iVersion */
|
| - recoverCreate, /* xCreate - create a table */
|
| - recoverConnect, /* xConnect - connect to an existing table */
|
| - recoverBestIndex, /* xBestIndex - Determine search strategy */
|
| - recoverDisconnect, /* xDisconnect - Disconnect from a table */
|
| - recoverDestroy, /* xDestroy - Drop a table */
|
| - recoverOpen, /* xOpen - open a cursor */
|
| - recoverClose, /* xClose - close a cursor */
|
| - recoverFilter, /* xFilter - configure scan constraints */
|
| - recoverNext, /* xNext - advance a cursor */
|
| - recoverEof, /* xEof */
|
| - recoverColumn, /* xColumn - read data */
|
| - recoverRowid, /* xRowid - read data */
|
| - 0, /* xUpdate - write data */
|
| - 0, /* xBegin - begin transaction */
|
| - 0, /* xSync - sync transaction */
|
| - 0, /* xCommit - commit transaction */
|
| - 0, /* xRollback - rollback transaction */
|
| - 0, /* xFindFunction - function overloading */
|
| - 0, /* xRename - rename the table */
|
| -};
|
| -
|
| -CHROMIUM_SQLITE_API
|
| -int recoverVtableInit(sqlite3 *db){
|
| - return sqlite3_create_module_v2(db, "recover", &recoverModule, NULL, 0);
|
| -}
|
| -
|
| -/* This section of code is for parsing the create input and
|
| - * initializing the module.
|
| - */
|
| -
|
| -/* Find the next word in zText and place the endpoints in pzWord*.
|
| - * Returns true if the word is non-empty. "Word" is defined as
|
| - * ASCII alphanumeric plus '_' at this time.
|
| - */
|
| -static int findWord(const char *zText,
|
| - const char **pzWordStart, const char **pzWordEnd){
|
| - int r;
|
| - while( ascii_isspace(*zText) ){
|
| - zText++;
|
| - }
|
| - *pzWordStart = zText;
|
| - while( ascii_isalnum(*zText) || *zText=='_' ){
|
| - zText++;
|
| - }
|
| - r = zText>*pzWordStart; /* In case pzWordStart==pzWordEnd */
|
| - *pzWordEnd = zText;
|
| - return r;
|
| -}
|
| -
|
| -/* Return true if the next word in zText is zWord, also setting
|
| - * *pzContinue to the character after the word.
|
| - */
|
| -static int expectWord(const char *zText, const char *zWord,
|
| - const char **pzContinue){
|
| - const char *zWordStart, *zWordEnd;
|
| - if( findWord(zText, &zWordStart, &zWordEnd) &&
|
| - ascii_strncasecmp(zWord, zWordStart, zWordEnd - zWordStart)==0 ){
|
| - *pzContinue = zWordEnd;
|
| - return 1;
|
| - }
|
| - return 0;
|
| -}
|
| -
|
| -/* Parse the name and type information out of parameter. In case of
|
| - * success, *pzNameStart/End contain the name of the column,
|
| - * *pzTypeStart/End contain the top-level type, and *pTypeMask has the
|
| - * type mask to use for the column.
|
| - */
|
| -static int findNameAndType(const char *parameter,
|
| - const char **pzNameStart, const char **pzNameEnd,
|
| - const char **pzTypeStart, const char **pzTypeEnd,
|
| - unsigned char *pTypeMask){
|
| - unsigned nNameLen; /* Length of found name. */
|
| - const char *zEnd; /* Current end of parsed column information. */
|
| - int bNotNull; /* Non-zero if NULL is not allowed for name. */
|
| - int bStrict; /* Non-zero if column requires exact type match. */
|
| - const char *zDummy; /* Dummy parameter, result unused. */
|
| - unsigned i;
|
| -
|
| - /* strictMask is used for STRICT, strictMask|otherMask if STRICT is
|
| - * not supplied. zReplace provides an alternate type to expose to
|
| - * the caller.
|
| - */
|
| - static struct {
|
| - const char *zName;
|
| - unsigned char strictMask;
|
| - unsigned char otherMask;
|
| - const char *zReplace;
|
| - } kTypeInfo[] = {
|
| - { "ANY",
|
| - MASK_INTEGER | MASK_FLOAT | MASK_BLOB | MASK_TEXT | MASK_NULL,
|
| - 0, "",
|
| - },
|
| - { "ROWID", MASK_INTEGER | MASK_ROWID, 0, "INTEGER", },
|
| - { "INTEGER", MASK_INTEGER | MASK_NULL, 0, NULL, },
|
| - { "FLOAT", MASK_FLOAT | MASK_NULL, MASK_INTEGER, NULL, },
|
| - { "NUMERIC", MASK_INTEGER | MASK_FLOAT | MASK_NULL, MASK_TEXT, NULL, },
|
| - { "TEXT", MASK_TEXT | MASK_NULL, MASK_BLOB, NULL, },
|
| - { "BLOB", MASK_BLOB | MASK_NULL, 0, NULL, },
|
| - };
|
| -
|
| - if( !findWord(parameter, pzNameStart, pzNameEnd) ){
|
| - return SQLITE_MISUSE;
|
| - }
|
| -
|
| - /* Manifest typing, accept any storage type. */
|
| - if( !findWord(*pzNameEnd, pzTypeStart, pzTypeEnd) ){
|
| - *pzTypeEnd = *pzTypeStart = "";
|
| - *pTypeMask = MASK_INTEGER | MASK_FLOAT | MASK_BLOB | MASK_TEXT | MASK_NULL;
|
| - return SQLITE_OK;
|
| - }
|
| -
|
| - nNameLen = *pzTypeEnd - *pzTypeStart;
|
| - for( i=0; i<ArraySize(kTypeInfo); ++i ){
|
| - if( ascii_strncasecmp(kTypeInfo[i].zName, *pzTypeStart, nNameLen)==0 ){
|
| - break;
|
| - }
|
| - }
|
| - if( i==ArraySize(kTypeInfo) ){
|
| - return SQLITE_MISUSE;
|
| - }
|
| -
|
| - zEnd = *pzTypeEnd;
|
| - bStrict = 0;
|
| - if( expectWord(zEnd, "STRICT", &zEnd) ){
|
| - /* TODO(shess): Ick. But I don't want another single-purpose
|
| - * flag, either.
|
| - */
|
| - if( kTypeInfo[i].zReplace && !kTypeInfo[i].zReplace[0] ){
|
| - return SQLITE_MISUSE;
|
| - }
|
| - bStrict = 1;
|
| - }
|
| -
|
| - bNotNull = 0;
|
| - if( expectWord(zEnd, "NOT", &zEnd) ){
|
| - if( expectWord(zEnd, "NULL", &zEnd) ){
|
| - bNotNull = 1;
|
| - }else{
|
| - /* Anything other than NULL after NOT is an error. */
|
| - return SQLITE_MISUSE;
|
| - }
|
| - }
|
| -
|
| - /* Anything else is an error. */
|
| - if( findWord(zEnd, &zDummy, &zDummy) ){
|
| - return SQLITE_MISUSE;
|
| - }
|
| -
|
| - *pTypeMask = kTypeInfo[i].strictMask;
|
| - if( !bStrict ){
|
| - *pTypeMask |= kTypeInfo[i].otherMask;
|
| - }
|
| - if( bNotNull ){
|
| - *pTypeMask &= ~MASK_NULL;
|
| - }
|
| - if( kTypeInfo[i].zReplace ){
|
| - *pzTypeStart = kTypeInfo[i].zReplace;
|
| - *pzTypeEnd = *pzTypeStart + strlen(*pzTypeStart);
|
| - }
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* Parse the arguments, placing type masks in *pTypes and the exposed
|
| - * schema in *pzCreateSql (for sqlite3_declare_vtab).
|
| - */
|
| -static int ParseColumnsAndGenerateCreate(unsigned nCols,
|
| - const char *const *pCols,
|
| - char **pzCreateSql,
|
| - unsigned char *pTypes,
|
| - char **pzErr){
|
| - unsigned i;
|
| - char *zCreateSql = sqlite3_mprintf("CREATE TABLE x(");
|
| - if( !zCreateSql ){
|
| - return SQLITE_NOMEM;
|
| - }
|
| -
|
| - for( i=0; i<nCols; i++ ){
|
| - const char *zSep = (i < nCols - 1 ? ", " : ")");
|
| - const char *zNotNull = "";
|
| - const char *zNameStart, *zNameEnd;
|
| - const char *zTypeStart, *zTypeEnd;
|
| - int rc = findNameAndType(pCols[i],
|
| - &zNameStart, &zNameEnd,
|
| - &zTypeStart, &zTypeEnd,
|
| - &pTypes[i]);
|
| - if( rc!=SQLITE_OK ){
|
| - *pzErr = sqlite3_mprintf("unable to parse column %d", i);
|
| - sqlite3_free(zCreateSql);
|
| - return rc;
|
| - }
|
| -
|
| - if( !(pTypes[i]&MASK_NULL) ){
|
| - zNotNull = " NOT NULL";
|
| - }
|
| -
|
| - /* Add name and type to the create statement. */
|
| - zCreateSql = sqlite3_mprintf("%z%.*s %.*s%s%s",
|
| - zCreateSql,
|
| - zNameEnd - zNameStart, zNameStart,
|
| - zTypeEnd - zTypeStart, zTypeStart,
|
| - zNotNull, zSep);
|
| - if( !zCreateSql ){
|
| - return SQLITE_NOMEM;
|
| - }
|
| - }
|
| -
|
| - *pzCreateSql = zCreateSql;
|
| - return SQLITE_OK;
|
| -}
|
| -
|
| -/* Helper function for initializing the module. */
|
| -/* argv[0] module name
|
| - * argv[1] db name for virtual table
|
| - * argv[2] virtual table name
|
| - * argv[3] backing table name
|
| - * argv[4] columns
|
| - */
|
| -/* TODO(shess): Since connect isn't supported, could inline into
|
| - * recoverCreate().
|
| - */
|
| -/* TODO(shess): Explore cases where it would make sense to set *pzErr. */
|
| -static int recoverInit(
|
| - sqlite3 *db, /* Database connection */
|
| - void *pAux, /* unused */
|
| - int argc, const char *const*argv, /* Parameters to CREATE TABLE statement */
|
| - sqlite3_vtab **ppVtab, /* OUT: New virtual table */
|
| - char **pzErr /* OUT: Error message, if any */
|
| -){
|
| - const int kTypeCol = 4; /* First argument with column type info. */
|
| - Recover *pRecover; /* Virtual table structure being created. */
|
| - char *zDot; /* Any dot found in "db.table" backing. */
|
| - u32 iRootPage; /* Root page of backing table. */
|
| - char *zCreateSql; /* Schema of created virtual table. */
|
| - int rc;
|
| -
|
| - /* Require to be in the temp database. */
|
| - if( ascii_strcasecmp(argv[1], "temp")!=0 ){
|
| - *pzErr = sqlite3_mprintf("recover table must be in temp database");
|
| - return SQLITE_MISUSE;
|
| - }
|
| -
|
| - /* Need the backing table and at least one column. */
|
| - if( argc<=kTypeCol ){
|
| - *pzErr = sqlite3_mprintf("no columns specified");
|
| - return SQLITE_MISUSE;
|
| - }
|
| -
|
| - pRecover = sqlite3_malloc(sizeof(Recover));
|
| - if( !pRecover ){
|
| - return SQLITE_NOMEM;
|
| - }
|
| - memset(pRecover, 0, sizeof(*pRecover));
|
| - pRecover->base.pModule = &recoverModule;
|
| - pRecover->db = db;
|
| -
|
| - /* Parse out db.table, assuming main if no dot. */
|
| - zDot = strchr(argv[3], '.');
|
| - if( !zDot ){
|
| - pRecover->zDb = sqlite3_strdup(db->aDb[0].zName);
|
| - pRecover->zTable = sqlite3_strdup(argv[3]);
|
| - }else if( zDot>argv[3] && zDot[1]!='\0' ){
|
| - pRecover->zDb = sqlite3_strndup(argv[3], zDot - argv[3]);
|
| - pRecover->zTable = sqlite3_strdup(zDot + 1);
|
| - }else{
|
| - /* ".table" or "db." not allowed. */
|
| - *pzErr = sqlite3_mprintf("ill-formed table specifier");
|
| - recoverRelease(pRecover);
|
| - return SQLITE_ERROR;
|
| - }
|
| -
|
| - pRecover->nCols = argc - kTypeCol;
|
| - pRecover->pTypes = sqlite3_malloc(pRecover->nCols);
|
| - if( !pRecover->zDb || !pRecover->zTable || !pRecover->pTypes ){
|
| - recoverRelease(pRecover);
|
| - return SQLITE_NOMEM;
|
| - }
|
| -
|
| - /* Require the backing table to exist. */
|
| - /* TODO(shess): Be more pedantic about the form of the descriptor
|
| - * string. This already fails for poorly-formed strings, simply
|
| - * because there won't be a root page, but it would make more sense
|
| - * to be explicit.
|
| - */
|
| - rc = getRootPage(pRecover->db, pRecover->zDb, pRecover->zTable, &iRootPage);
|
| - if( rc!=SQLITE_OK ){
|
| - *pzErr = sqlite3_mprintf("unable to find backing table");
|
| - recoverRelease(pRecover);
|
| - return rc;
|
| - }
|
| -
|
| - /* Parse the column definitions. */
|
| - rc = ParseColumnsAndGenerateCreate(pRecover->nCols, argv + kTypeCol,
|
| - &zCreateSql, pRecover->pTypes, pzErr);
|
| - if( rc!=SQLITE_OK ){
|
| - recoverRelease(pRecover);
|
| - return rc;
|
| - }
|
| -
|
| - rc = sqlite3_declare_vtab(db, zCreateSql);
|
| - sqlite3_free(zCreateSql);
|
| - if( rc!=SQLITE_OK ){
|
| - recoverRelease(pRecover);
|
| - return rc;
|
| - }
|
| -
|
| - *ppVtab = (sqlite3_vtab *)pRecover;
|
| - return SQLITE_OK;
|
| -}
|
|
|
Chromium Code Reviews
Issue 1700483002:
[sqlite] iOS running recover virtual table. (Closed)
Base URL: https://chromium.googlesource.com/chromium/src.git@zzsql_recover_handle_review2