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Diffstat (limited to 'ext/intck/sqlite3intck.h')
-rw-r--r-- | ext/intck/sqlite3intck.h | 171 |
1 files changed, 171 insertions, 0 deletions
diff --git a/ext/intck/sqlite3intck.h b/ext/intck/sqlite3intck.h new file mode 100644 index 0000000..e08a86f --- /dev/null +++ b/ext/intck/sqlite3intck.h @@ -0,0 +1,171 @@ +/* +** 2024-02-08 +** +** 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. +** +************************************************************************* +*/ + +/* +** Incremental Integrity-Check Extension +** ------------------------------------- +** +** This module contains code to check whether or not an SQLite database +** is well-formed or corrupt. This is the same task as performed by SQLite's +** built-in "PRAGMA integrity_check" command. This module differs from +** "PRAGMA integrity_check" in that: +** +** + It is less thorough - this module does not detect certain types +** of corruption that are detected by the PRAGMA command. However, +** it does detect all kinds of corruption that are likely to cause +** errors in SQLite applications. +** +** + It is slower. Sometimes up to three times slower. +** +** + It allows integrity-check operations to be split into multiple +** transactions, so that the database does not need to be read-locked +** for the duration of the integrity-check. +** +** One way to use the API to run integrity-check on the "main" database +** of handle db is: +** +** int rc = SQLITE_OK; +** sqlite3_intck *p = 0; +** +** sqlite3_intck_open(db, "main", &p); +** while( SQLITE_OK==sqlite3_intck_step(p) ){ +** const char *zMsg = sqlite3_intck_message(p); +** if( zMsg ) printf("corruption: %s\n", zMsg); +** } +** rc = sqlite3_intck_error(p, &zErr); +** if( rc!=SQLITE_OK ){ +** printf("error occured (rc=%d), (errmsg=%s)\n", rc, zErr); +** } +** sqlite3_intck_close(p); +** +** Usually, the sqlite3_intck object opens a read transaction within the +** first call to sqlite3_intck_step() and holds it open until the +** integrity-check is complete. However, if sqlite3_intck_unlock() is +** called, the read transaction is ended and a new read transaction opened +** by the subsequent call to sqlite3_intck_step(). +*/ + +#ifndef _SQLITE_INTCK_H +#define _SQLITE_INTCK_H + +#include "sqlite3.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* +** An ongoing incremental integrity-check operation is represented by an +** opaque pointer of the following type. +*/ +typedef struct sqlite3_intck sqlite3_intck; + +/* +** Open a new incremental integrity-check object. If successful, populate +** output variable (*ppOut) with the new object handle and return SQLITE_OK. +** Or, if an error occurs, set (*ppOut) to NULL and return an SQLite error +** code (e.g. SQLITE_NOMEM). +** +** The integrity-check will be conducted on database zDb (which must be "main", +** "temp", or the name of an attached database) of database handle db. Once +** this function has been called successfully, the caller should not use +** database handle db until the integrity-check object has been destroyed +** using sqlite3_intck_close(). +*/ +int sqlite3_intck_open( + sqlite3 *db, /* Database handle */ + const char *zDb, /* Database name ("main", "temp" etc.) */ + sqlite3_intck **ppOut /* OUT: New sqlite3_intck handle */ +); + +/* +** Close and release all resources associated with a handle opened by an +** earlier call to sqlite3_intck_open(). The results of using an +** integrity-check handle after it has been passed to this function are +** undefined. +*/ +void sqlite3_intck_close(sqlite3_intck *pCk); + +/* +** Do the next step of the integrity-check operation specified by the handle +** passed as the only argument. This function returns SQLITE_DONE if the +** integrity-check operation is finished, or an SQLite error code if +** an error occurs, or SQLITE_OK if no error occurs but the integrity-check +** is not finished. It is not considered an error if database corruption +** is encountered. +** +** Following a successful call to sqlite3_intck_step() (one that returns +** SQLITE_OK), sqlite3_intck_message() returns a non-NULL value if +** corruption was detected in the db. +** +** If an error occurs and a value other than SQLITE_OK or SQLITE_DONE is +** returned, then the integrity-check handle is placed in an error state. +** In this state all subsequent calls to sqlite3_intck_step() or +** sqlite3_intck_unlock() will immediately return the same error. The +** sqlite3_intck_error() method may be used to obtain an English language +** error message in this case. +*/ +int sqlite3_intck_step(sqlite3_intck *pCk); + +/* +** If the previous call to sqlite3_intck_step() encountered corruption +** within the database, then this function returns a pointer to a buffer +** containing a nul-terminated string describing the corruption in +** English. If the previous call to sqlite3_intck_step() did not encounter +** corruption, or if there was no previous call, this function returns +** NULL. +*/ +const char *sqlite3_intck_message(sqlite3_intck *pCk); + +/* +** Close any read-transaction opened by an earlier call to +** sqlite3_intck_step(). Any subsequent call to sqlite3_intck_step() will +** open a new transaction. Return SQLITE_OK if successful, or an SQLite error +** code otherwise. +** +** If an error occurs, then the integrity-check handle is placed in an error +** state. In this state all subsequent calls to sqlite3_intck_step() or +** sqlite3_intck_unlock() will immediately return the same error. The +** sqlite3_intck_error() method may be used to obtain an English language +** error message in this case. +*/ +int sqlite3_intck_unlock(sqlite3_intck *pCk); + +/* +** If an error has occurred in an earlier call to sqlite3_intck_step() +** or sqlite3_intck_unlock(), then this method returns the associated +** SQLite error code. Additionally, if pzErr is not NULL, then (*pzErr) +** may be set to point to a nul-terminated string containing an English +** language error message. Or, if no error message is available, to +** NULL. +** +** If no error has occurred within sqlite3_intck_step() or +** sqlite_intck_unlock() calls on the handle passed as the first argument, +** then SQLITE_OK is returned and (*pzErr) set to NULL. +*/ +int sqlite3_intck_error(sqlite3_intck *pCk, const char **pzErr); + +/* +** This API is used for testing only. It returns the full-text of an SQL +** statement used to test object zObj, which may be a table or index. +** The returned buffer is valid until the next call to either this function +** or sqlite3_intck_close() on the same sqlite3_intck handle. +*/ +const char *sqlite3_intck_test_sql(sqlite3_intck *pCk, const char *zObj); + + +#ifdef __cplusplus +} /* end of the 'extern "C"' block */ +#endif + +#endif /* ifndef _SQLITE_INTCK_H */ |