Create An Iterator To Traverse A Changeset
Session Module C Interface#
Create An Iterator To Traverse A Changeset#
int sqlite3changeset_start(\ sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */\ int nChangeset, /* Size of changeset blob in bytes */\ void *pChangeset /* Pointer to blob containing changeset */\ );\ int sqlite3changeset_start_v2(\ sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */\ int nChangeset, /* Size of changeset blob in bytes */\ void *pChangeset, /* Pointer to blob containing changeset */\ int flags /* SESSION_CHANGESETSTART_* flags */\ );\
Create an iterator used to iterate through the contents of a changeset. If successful, *pp is set to point to the iterator handle and SQLITE_OK is returned. Otherwise, if an error occurs, *pp is set to zero and an SQLite error code is returned.
The following functions can be used to advance and query a changeset iterator created by this function:
It is the responsibility of the caller to eventually destroy the iterator by passing it to sqlite3changeset_finalize(). The buffer containing the changeset (pChangeset) must remain valid until after the iterator is destroyed.
Assuming the changeset blob was created by one of the sqlite3session_changeset(), sqlite3changeset_concat() or sqlite3changeset_invert() functions, all changes within the changeset that apply to a single table are grouped together. This means that when an application iterates through a changeset using an iterator created by this function, all changes that relate to a single table are visited consecutively. There is no chance that the iterator will visit a change the applies to table X, then one for table Y, and then later on visit another change for table X.
The behavior of sqlite3changeset_start_v2() and its streaming equivalent may be modified by passing a combination of supported flags as the 4th parameter.
Note that the sqlite3changeset_start_v2() API is still experimental and therefore subject to change.