/*
* __curmetadata_search_near --
* WT_CURSOR->search_near method for the metadata cursor type.
*/
static int
__curmetadata_search_near(WT_CURSOR *cursor, int *exact)
{
WT_CURSOR *file_cursor;
WT_CURSOR_METADATA *mdc;
WT_DECL_RET;
WT_SESSION_IMPL *session;
mdc = (WT_CURSOR_METADATA *)cursor;
file_cursor = mdc->file_cursor;
CURSOR_API_CALL(cursor, session,
search_near, ((WT_CURSOR_BTREE *)file_cursor)->btree);
WT_MD_CURSOR_NEEDKEY(cursor);
if (WT_KEY_IS_METADATA(&cursor->key)) {
WT_ERR(__curmetadata_metadata_search(session, cursor));
*exact = 1;
} else {
WT_WITH_TXN_ISOLATION(session, WT_ISO_READ_UNCOMMITTED,
ret = file_cursor->search_near(file_cursor, exact));
WT_ERR(ret);
WT_ERR(__curmetadata_setkv(mdc, file_cursor));
}
err: if (ret != 0) {
F_CLR(mdc, WT_MDC_POSITIONED | WT_MDC_ONMETADATA);
F_CLR(cursor, WT_CURSTD_KEY_EXT | WT_CURSTD_VALUE_EXT);
}
API_END_RET(session, ret);
}
/*
* __curmetadata_prev --
* WT_CURSOR->prev method for the metadata cursor type.
*/
static int
__curmetadata_prev(WT_CURSOR *cursor)
{
WT_CURSOR *file_cursor;
WT_CURSOR_METADATA *mdc;
WT_DECL_RET;
WT_SESSION_IMPL *session;
mdc = (WT_CURSOR_METADATA *)cursor;
file_cursor = mdc->file_cursor;
CURSOR_API_CALL(cursor, session,
prev, ((WT_CURSOR_BTREE *)file_cursor)->btree);
if (F_ISSET(mdc, WT_MDC_ONMETADATA)) {
ret = WT_NOTFOUND;
goto err;
}
WT_WITH_TXN_ISOLATION(session, WT_ISO_READ_UNCOMMITTED,
ret = file_cursor->prev(file_cursor));
if (ret == 0)
WT_ERR(__curmetadata_setkv(mdc, file_cursor));
else if (ret == WT_NOTFOUND)
WT_ERR(__curmetadata_metadata_search(session, cursor));
err: if (ret != 0) {
F_CLR(mdc, WT_MDC_POSITIONED | WT_MDC_ONMETADATA);
F_CLR(cursor, WT_CURSTD_KEY_EXT | WT_CURSTD_VALUE_EXT);
}
API_END_RET(session, ret);
}
/*
* __curmetadata_next --
* WT_CURSOR->next method for the metadata cursor type.
*/
static int
__curmetadata_next(WT_CURSOR *cursor)
{
WT_CURSOR *file_cursor;
WT_CURSOR_METADATA *mdc;
WT_DECL_RET;
WT_SESSION_IMPL *session;
mdc = (WT_CURSOR_METADATA *)cursor;
file_cursor = mdc->file_cursor;
CURSOR_API_CALL(cursor, session,
next, ((WT_CURSOR_BTREE *)file_cursor)->btree);
if (!F_ISSET(mdc, WT_MDC_POSITIONED))
WT_ERR(__curmetadata_metadata_search(session, cursor));
else {
/*
* When applications open metadata cursors, they expect to see
* all schema-level operations reflected in the results. Query
* at read-uncommitted to avoid confusion caused by the current
* transaction state.
*/
WT_WITH_TXN_ISOLATION(session, WT_ISO_READ_UNCOMMITTED,
ret = file_cursor->next(mdc->file_cursor));
WT_ERR(ret);
WT_ERR(__curmetadata_setkv(mdc, file_cursor));
}
err: if (ret != 0) {
F_CLR(mdc, WT_MDC_POSITIONED | WT_MDC_ONMETADATA);
F_CLR(cursor, WT_CURSTD_KEY_EXT | WT_CURSTD_VALUE_EXT);
}
API_END_RET(session, ret);
}
/*
* __wt_schema_open_index --
* Open one or more indices for a table.
*/
int
__wt_schema_open_index(WT_SESSION_IMPL *session,
WT_TABLE *table, const char *idxname, size_t len, WT_INDEX **indexp)
{
WT_DECL_RET;
WT_WITH_TXN_ISOLATION(session, WT_ISO_READ_UNCOMMITTED,
ret = __schema_open_index(session, table, idxname, len, indexp));
return (ret);
}
/*
* __wt_schema_open_table --
* Open a named table.
*/
int
__wt_schema_open_table(WT_SESSION_IMPL *session,
const char *name, size_t namelen, bool ok_incomplete, WT_TABLE **tablep)
{
WT_DECL_RET;
WT_WITH_TXN_ISOLATION(session, WT_ISO_READ_UNCOMMITTED,
ret = __schema_open_table(
session, name, namelen, ok_incomplete, tablep));
return (ret);
}
/*
* __wt_metadata_search --
* Return a copied row from the metadata.
* The caller is responsible for freeing the allocated memory.
*/
int
__wt_metadata_search(WT_SESSION_IMPL *session, const char *key, char **valuep)
{
WT_CURSOR *cursor;
WT_DECL_RET;
const char *value;
*valuep = NULL;
__wt_verbose(session, WT_VERB_METADATA,
"Search: key: %s, tracking: %s, %s" "turtle",
key, WT_META_TRACKING(session) ? "true" : "false",
__metadata_turtle(key) ? "" : "not ");
if (__metadata_turtle(key)) {
/*
* The returned value should only be set if ret is non-zero, but
* Coverity is convinced otherwise. The code path is used enough
* that Coverity complains a lot, add an error check to get some
* peace and quiet.
*/
if ((ret = __wt_turtle_read(session, key, valuep)) != 0)
__wt_free(session, *valuep);
return (ret);
}
/*
* All metadata reads are at read-uncommitted isolation. That's
* because once a schema-level operation completes, subsequent
* operations must see the current version of checkpoint metadata, or
* they may try to read blocks that may have been freed from a file.
* Metadata updates use non-transactional techniques (such as the
* schema and metadata locks) to protect access to in-flight updates.
*/
WT_RET(__wt_metadata_cursor(session, &cursor));
cursor->set_key(cursor, key);
WT_WITH_TXN_ISOLATION(session, WT_ISO_READ_UNCOMMITTED,
ret = cursor->search(cursor));
WT_ERR(ret);
WT_ERR(cursor->get_value(cursor, &value));
WT_ERR(__wt_strdup(session, value, valuep));
err: WT_TRET(__wt_metadata_cursor_release(session, &cursor));
if (ret != 0)
__wt_free(session, *valuep);
return (ret);
}
/*
* __wt_metadata_search --
* Return a copied row from the metadata.
* The caller is responsible for freeing the allocated memory.
*/
int
__wt_metadata_search(WT_SESSION_IMPL *session, const char *key, char **valuep)
{
WT_CURSOR *cursor;
WT_DECL_RET;
const char *value;
*valuep = NULL;
WT_RET(__wt_verbose(session, WT_VERB_METADATA,
"Search: key: %s, tracking: %s, %s" "turtle",
key, WT_META_TRACKING(session) ? "true" : "false",
__metadata_turtle(key) ? "" : "not "));
if (__metadata_turtle(key))
return (__wt_turtle_read(session, key, valuep));
/*
* All metadata reads are at read-uncommitted isolation. That's
* because once a schema-level operation completes, subsequent
* operations must see the current version of checkpoint metadata, or
* they may try to read blocks that may have been freed from a file.
* Metadata updates use non-transactional techniques (such as the
* schema and metadata locks) to protect access to in-flight updates.
*/
WT_RET(__wt_metadata_cursor(session, &cursor));
cursor->set_key(cursor, key);
WT_WITH_TXN_ISOLATION(session, WT_ISO_READ_UNCOMMITTED,
ret = cursor->search(cursor));
WT_ERR(ret);
WT_ERR(cursor->get_value(cursor, &value));
WT_ERR(__wt_strdup(session, value, valuep));
err: WT_TRET(__wt_metadata_cursor_release(session, &cursor));
return (ret);
}
