diff options
Diffstat (limited to 'cursor.go')
| -rw-r--r-- | cursor.go | 221 |
1 files changed, 101 insertions, 120 deletions
@@ -2,15 +2,18 @@ package bolt // TODO: #define CURSOR_STACK 32 -// TODO: #define C_INITIALIZED 0x01 /**< cursor has been initialized and is valid */ -// TODO: #define C_EOF 0x02 /**< No more data */ -// TODO: #define C_SUB 0x04 /**< Cursor is a sub-cursor */ -// TODO: #define C_DEL 0x08 /**< last op was a cursor_del */ -// TODO: #define C_SPLITTING 0x20 /**< Cursor is in page_split */ -// TODO: #define C_UNTRACK 0x40 /**< Un-track cursor when closing */ +const ( + c_initialized = 0x01 /**< cursor has been initialized and is valid */ + c_eof = 0x02 /**< No more data */ + c_sub = 0x04 /**< Cursor is a sub-cursor */ + c_del = 0x08 /**< last op was a cursor_del */ + c_splitting = 0x20 /**< Cursor is in page_split */ + c_untrack = 0x40 /**< Un-track cursor when closing */ +) // TODO: #define MDB_NOSPILL 0x8000 /** Do not spill pages to disk if txn is getting full, may fail instead */ +/* type Cursor interface { First() error FirstDup() error @@ -28,37 +31,75 @@ type Cursor interface { Set() ([]byte, []byte, error) SetRange() ([]byte, []byte, error) } +*/ -type cursor struct { +type Cursor struct { flags int - _next *cursor - backup *cursor - xcursor *xcursor - transaction *transaction + next *Cursor + backup *Cursor + subcursor *Cursor + transaction *Transaction bucketId int - bucket *Bucket - // bucketx *bucketx - bucketFlag int - snum int - top int - page []*page - ki []int /**< stack of page indices */ + bucket *txnbucket + subbucket *Bucket + // subbucketx *bucketx + subbucketFlag int + snum int + top int + page []*page + ki []int /**< stack of page indices */ } -type xcursor struct { - cursor cursor - bucket *Bucket - // bucketx *bucketx - bucketFlag int +// Initialize a cursor for a given transaction and database. +func (c *Cursor) init(t *Transaction, b *txnbucket, sub *Cursor) { + c.next = nil + c.backup = nil + c.transaction = t + c.bucket = b + c.snum = 0 + c.top = 0 + // TODO: mc->mc_pg[0] = 0; + c.flags = 0 + + if (b.flags & MDB_DUPSORT) != 0 { + sub.subcursor = nil + sub.transaction = t + sub.bucket = b + sub.snum = 0 + sub.top = 0 + sub.flags = c_sub + // TODO: mx->mx_dbx.md_name.mv_size = 0; + // TODO: mx->mx_dbx.md_name.mv_data = NULL; + c.subcursor = sub + } else { + c.subcursor = nil + } + + // Find the root page if the bucket is stale. + if (c.bucket.flags & txnb_stale) != 0 { + c.findPage(nil, ps_rootonly) + } } +// // +// // +// // +// // +// // +// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ CONVERTED ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ // +// // +// // +// // +// // +// // + // Set or clear P_KEEP in dirty, non-overflow, non-sub pages watched by txn. // @param[in] mc A cursor handle for the current operation. // @param[in] pflags Flags of the pages to update: // P_DIRTY to set P_KEEP, P_DIRTY|P_KEEP to clear it. // @param[in] all No shortcuts. Needed except after a full #mdb_page_flush(). // @return 0 on success, non-zero on failure. -func (c *cursor) xkeep(pflags int, all int) error { +func (c *Cursor) xkeep(pflags int, all int) error { /* enum { Mask = P_SUBP|P_DIRTY|P_KEEP }; MDB_txn *txn = mc->mc_txn; @@ -149,7 +190,7 @@ func (c *cursor) xkeep(pflags int, all int) error { // @param[in] key For a put operation, the key being stored. // @param[in] data For a put operation, the data being stored. // @return 0 on success, non-zero on failure. -func (c *cursor) spill(key []byte, data []byte) error { +func (c *Cursor) spill(key []byte, data []byte) error { /* MDB_txn *txn = m0->mc_txn; MDB_page *dp; @@ -424,7 +465,7 @@ func (p *page) copyTo(dst *page, size int) { // Touch a page: make it dirty and re-insert into tree with updated pgno. // @param[in] mc cursor pointing to the page to be touched // @return 0 on success, non-zero on failure. -func (c *cursor) page_touch() int { +func (c *Cursor) page_touch() int { /* MDB_page *mp = mc->mc_pg[mc->mc_top], *np; MDB_txn *txn = mc->mc_txn; @@ -532,7 +573,7 @@ func (c *cursor) page_touch() int { // in *exactp (1 or 0). // Updates the cursor index with the index of the found entry. // If no entry larger or equal to the key is found, returns NULL. -func (c *cursor) search(key []byte) (*node, bool) { +func (c *Cursor) search(key []byte) (*node, bool) { /* unsigned int i = 0, nkeys; int low, high; @@ -623,7 +664,7 @@ func (c *cursor) search(key []byte) (*node, bool) { return nil, false } -func (c *cursor) pop() { +func (c *Cursor) pop() { /* if (mc->mc_snum) { #if MDB_DEBUG @@ -640,7 +681,7 @@ func (c *cursor) pop() { } /** Push a page onto the top of the cursor's stack. */ -func (c *cursor) push(p *page) error { +func (c *Cursor) push(p *page) error { /* DPRINTF(("pushing page %"Z"u on db %d cursor %p", mp->mp_pgno, DDBI(mc), (void *) mc)); @@ -661,7 +702,7 @@ func (c *cursor) push(p *page) error { // Finish #mdb_page_search() / #mdb_page_search_lowest(). // The cursor is at the root page, set up the rest of it. -func (c *cursor) searchRoot(key []byte, flags int) error { +func (c *Cursor) searchRoot(key []byte, flags int) error { /* MDB_page *mp = mc->mc_pg[mc->mc_top]; int rc; @@ -733,7 +774,7 @@ func (c *cursor) searchRoot(key []byte, flags int) error { // before calling mdb_page_search_root(), because the callers // are all in situations where the current page is known to // be underfilled. -func (c *cursor) searchLowest() error { +func (c *Cursor) searchLowest() error { /* MDB_page *mp = mc->mc_pg[mc->mc_top]; MDB_node *node = NODEPTR(mp, 0); @@ -760,7 +801,7 @@ func (c *cursor) searchLowest() error { // This is used by #mdb_cursor_first() and #mdb_cursor_last(). // If MDB_PS_ROOTONLY set, just fetch root node, no further lookups. // @return 0 on success, non-zero on failure. -func (c *cursor) findPage(key []byte, flags int) error { +func (c *Cursor) findPage(key []byte, flags int) error { /* int rc; pgno_t root; @@ -831,7 +872,7 @@ func (c *cursor) findPage(key []byte, flags int) error { return nil } -func (c *cursor) freeOverflowPage(p *page) error { +func (c *Cursor) freeOverflowPage(p *page) error { /* MDB_txn *txn = mc->mc_txn; pgno_t pg = mp->mp_pgno; @@ -913,7 +954,7 @@ func (c *cursor) freeOverflowPage(p *page) error { // @param[in] move_right Non-zero if the right sibling is requested, // otherwise the left sibling. // @return 0 on success, non-zero on failure. -func (c *cursor) sibling(moveRight bool) error { +func (c *Cursor) sibling(moveRight bool) error { /* int rc; MDB_node *indx; @@ -964,7 +1005,7 @@ func (c *cursor) sibling(moveRight bool) error { } // Move the cursor to the next data item. -func (c *cursor) next(key []byte, data []byte, op int) error { +func (c *Cursor) Next(key []byte, data []byte, op int) error { /* MDB_page *mp; MDB_node *leaf; @@ -1046,7 +1087,7 @@ func (c *cursor) next(key []byte, data []byte, op int) error { } // Move the cursor to the previous data item. -func (c *cursor) prev(key []byte, data []byte, op int) error { +func (c *Cursor) prev(key []byte, data []byte, op int) error { /* MDB_page *mp; MDB_node *leaf; @@ -1124,7 +1165,7 @@ func (c *cursor) prev(key []byte, data []byte, op int) error { // Set the cursor on a specific data item. // (bool return is whether it is exact). -func (c *cursor) set(key []byte, data []byte, op int) (error, bool) { +func (c *Cursor) set(key []byte, data []byte, op int) (error, bool) { /* int rc; MDB_page *mp; @@ -1310,7 +1351,7 @@ func (c *cursor) set(key []byte, data []byte, op int) (error, bool) { } // Move the cursor to the first item in the database. -func (c *cursor) first(key []byte, data []byte) error { +func (c *Cursor) first(key []byte, data []byte) error { /* int rc; MDB_node *leaf; @@ -1355,7 +1396,7 @@ func (c *cursor) first(key []byte, data []byte) error { } // Move the cursor to the last item in the database. -func (c *cursor) last() ([]byte, []byte) { +func (c *Cursor) last() ([]byte, []byte) { /* int rc; MDB_node *leaf; @@ -1401,7 +1442,7 @@ func (c *cursor) last() ([]byte, []byte) { return nil, nil } -func (c *cursor) Get(key []byte, data []byte, op int) ([]byte, []byte, error) { +func (c *Cursor) Get(key []byte, data []byte, op int) ([]byte, []byte, error) { /* int rc; int exact = 0; @@ -1569,7 +1610,7 @@ func (c *cursor) Get(key []byte, data []byte, op int) ([]byte, []byte, error) { // Touch all the pages in the cursor stack. Set mc_top. // Makes sure all the pages are writable, before attempting a write operation. // @param[in] mc The cursor to operate on. -func (c *cursor) touch() error { +func (c *Cursor) touch() error { /* int rc = MDB_SUCCESS; @@ -2072,7 +2113,7 @@ func (c *cursor) touch() error { return nil } -func (c *cursor) Del(flags int) error { +func (c *Cursor) Del(flags int) error { /* MDB_node *leaf; MDB_page *mp; @@ -2152,7 +2193,7 @@ func (c *cursor) Del(flags int) error { // unless allocating overflow pages for a large record. // @param[out] mp Address of a page, or NULL on failure. // @return 0 on success, non-zero on failure. -func (c *cursor) newPage(flags int, num int) ([]*page, error) { +func (c *Cursor) newPage(flags int, num int) ([]*page, error) { /* MDB_page *np; int rc; @@ -2194,7 +2235,7 @@ func (c *cursor) newPage(flags int, num int) ([]*page, error) { // should never happen since all callers already calculate the // page's free space before calling this function. // </ul> -func (c *cursor) addNode(index int, key []byte, data []byte, pgno int, flags int) error { +func (c *Cursor) addNode(index int, key []byte, data []byte, pgno int, flags int) error { /* unsigned int i; size_t node_size = NODESIZE; @@ -2323,7 +2364,7 @@ func (c *cursor) addNode(index int, key []byte, data []byte, pgno int, flags int // @param[in] indx The index of the node to delete. // @param[in] ksize The size of a node. Only used if the page is // part of a #MDB_DUPFIXED database. -func (c *cursor) deleteNode(ksize int) { +func (c *Cursor) deleteNode(ksize int) { /* MDB_page *mp = mc->mc_pg[mc->mc_top]; indx_t indx = mc->mc_ki[mc->mc_top]; @@ -2375,41 +2416,12 @@ func (c *cursor) deleteNode(ksize int) { */ } -// Initial setup of a sorted-dups cursor. -// Sorted duplicates are implemented as a sub-database for the given key. -// The duplicate data items are actually keys of the sub-database. -// Operations on the duplicate data items are performed using a sub-cursor -// initialized when the sub-database is first accessed. This function does -// the preliminary setup of the sub-cursor, filling in the fields that -// depend only on the parent DB. -// @param[in] mc The main cursor whose sorted-dups cursor is to be initialized. -func (c *cursor) xcursor_init0() { - /* - MDB_xcursor *mx = mc->mc_xcursor; - - mx->mx_cursor.mc_xcursor = NULL; - mx->mx_cursor.mc_txn = mc->mc_txn; - mx->mx_cursor.mc_db = &mx->mx_db; - mx->mx_cursor.mc_dbx = &mx->mx_dbx; - mx->mx_cursor.mc_dbi = mc->mc_dbi; - mx->mx_cursor.mc_dbflag = &mx->mx_dbflag; - mx->mx_cursor.mc_snum = 0; - mx->mx_cursor.mc_top = 0; - mx->mx_cursor.mc_flags = C_SUB; - mx->mx_dbx.md_name.mv_size = 0; - mx->mx_dbx.md_name.mv_data = NULL; - mx->mx_dbx.md_cmp = mc->mc_dbx->md_dcmp; - mx->mx_dbx.md_dcmp = NULL; - mx->mx_dbx.md_rel = mc->mc_dbx->md_rel; - */ -} - // Final setup of a sorted-dups cursor. // Sets up the fields that depend on the data from the main cursor. // @param[in] mc The main cursor whose sorted-dups cursor is to be initialized. // @param[in] node The data containing the #MDB_db record for the // sorted-dup database. -func (c *cursor) xcursor_init1(n *node) { +func (c *Cursor) xcursor_init1(n *node) { /* MDB_xcursor *mx = mc->mc_xcursor; @@ -2455,35 +2467,8 @@ func (c *cursor) xcursor_init1(n *node) { */ } -// Initialize a cursor for a given transaction and database. -func (c *cursor) init(t *transaction, bucket *Bucket, mx *xcursor) { - /* - mc->mc_next = NULL; - mc->mc_backup = NULL; - mc->mc_dbi = dbi; - mc->mc_txn = txn; - mc->mc_db = &txn->mt_dbs[dbi]; - mc->mc_dbx = &txn->mt_dbxs[dbi]; - mc->mc_dbflag = &txn->mt_dbflags[dbi]; - mc->mc_snum = 0; - mc->mc_top = 0; - mc->mc_pg[0] = 0; - mc->mc_flags = 0; - if (txn->mt_dbs[dbi].md_flags & MDB_DUPSORT) { - mdb_tassert(txn, mx != NULL); - mc->mc_xcursor = mx; - mdb_xcursor_init0(mc); - } else { - mc->mc_xcursor = NULL; - } - if (*mc->mc_dbflag & DB_STALE) { - mdb_page_search(mc, NULL, MDB_PS_ROOTONLY); - } - */ -} - // Return the count of duplicate data items for the current key. -func (c *cursor) count() (int, error) { +func (c *Cursor) count() (int, error) { /* MDB_node *leaf; @@ -2507,7 +2492,7 @@ func (c *cursor) count() (int, error) { return 0, nil } -func (c *cursor) Close() { +func (c *Cursor) Close() { /* if (mc && !mc->mc_backup) { // remove from txn, if tracked @@ -2522,23 +2507,19 @@ func (c *cursor) Close() { */ } -func (c *cursor) Transaction() Transaction { - /* - if (!mc) return NULL; - return mc->mc_txn; - */ - return nil +func (c *Cursor) Transaction() *Transaction { + return c.transaction } -func (c *cursor) Bucket() *Bucket { - return c.bucket +func (c *Cursor) Bucket() *Bucket { + return c.bucket.bucket } // Replace the key for a branch node with a new key. // @param[in] mc Cursor pointing to the node to operate on. // @param[in] key The new key to use. // @return 0 on success, non-zero on failure. -func (c *cursor) updateKey(key []byte) error { +func (c *Cursor) updateKey(key []byte) error { /* MDB_page *mp; MDB_node *node; @@ -2609,7 +2590,7 @@ func (c *cursor) updateKey(key []byte) error { } // Move a node from csrc to cdst. -func (c *cursor) moveNodeTo(dst *cursor) error { +func (c *Cursor) moveNodeTo(dst *Cursor) error { /* MDB_node *srcnode; MDB_val key, data; @@ -2786,7 +2767,7 @@ func (c *cursor) moveNodeTo(dst *cursor) error { // the \b csrc page will be freed. // @param[in] csrc Cursor pointing to the source page. // @param[in] cdst Cursor pointing to the destination page. -func (c *cursor) mergePage(dst *cursor) error { +func (c *Cursor) mergePage(dst *Cursor) error { /* int rc; indx_t i, j; @@ -2901,7 +2882,7 @@ func (c *cursor) mergePage(dst *cursor) error { // Copy the contents of a cursor. // @param[in] csrc The cursor to copy from. // @param[out] cdst The cursor to copy to. -func (c *cursor) copyTo(dst *cursor) { +func (c *Cursor) copyTo(dst *Cursor) { /* unsigned int i; @@ -2924,7 +2905,7 @@ func (c *cursor) copyTo(dst *cursor) { // @param[in] mc Cursor pointing to the page where rebalancing // should begin. // @return 0 on success, non-zero on failure. -func (c *cursor) rebalance() error { +func (c *Cursor) rebalance() error { /* MDB_node *node; int rc; @@ -3079,7 +3060,7 @@ func (c *cursor) rebalance() error { } // Complete a delete operation started by #mdb_cursor_del(). -func (c *cursor) del0(leaf *node) error { +func (c *Cursor) del0(leaf *node) error { /* int rc; MDB_page *mp; @@ -3149,7 +3130,7 @@ func (c *cursor) del0(leaf *node) error { // @param[in] newpgno The page number, if the new node is a branch node. // @param[in] nflags The #NODE_ADD_FLAGS for the new node. // @return 0 on success, non-zero on failure. -func (c *cursor) splitPage(newKey []byte, newData []byte, newpgno int, nflags int) error { +func (c *Cursor) splitPage(newKey []byte, newData []byte, newpgno int, nflags int) error { /* unsigned int flags; int rc = MDB_SUCCESS, new_root = 0, did_split = 0; @@ -3533,7 +3514,7 @@ func (c *cursor) splitPage(newKey []byte, newData []byte, newpgno int, nflags in // @param[in] mc Cursor on the DB to free. // @param[in] subs non-Zero to check for sub-DBs in this DB. // @return 0 on success, non-zero on failure. -func (c *cursor) drop0(subs int) error { +func (c *Cursor) drop0(subs int) error { /* int rc; |