diff options
Diffstat (limited to 'transaction.go')
| -rw-r--r-- | transaction.go | 115 |
1 files changed, 32 insertions, 83 deletions
diff --git a/transaction.go b/transaction.go index 8371624..07665ee 100644 --- a/transaction.go +++ b/transaction.go @@ -1,7 +1,6 @@ package bolt import ( - "strings" "unsafe" ) @@ -20,11 +19,12 @@ const ( type txnid uint64 type Transaction struct { - id int - db *DB - meta *meta - sys Bucket - buckets map[string]*Bucket + id int + db *DB + meta *meta + sys Bucket + buckets map[string]*Bucket + pages map[pgid]*page } // init initializes the transaction and associates it with a database. @@ -32,6 +32,7 @@ func (t *Transaction) init(db *DB, meta *meta) { t.db = db t.meta = meta t.buckets = make(map[string]*Bucket) + t.pages = nil t.sys.transaction = t t.sys.bucket = &t.meta.sys } @@ -47,27 +48,21 @@ func (t *Transaction) DB() *DB { // Bucket retrieves a bucket by name. func (t *Transaction) Bucket(name string) (*Bucket, error) { - return t.bucket(name) -} - -func (t *Transaction) bucket(name string) (*Bucket, error) { - // Return bucket if it's already been looked up. + // Return cached reference if it's already been looked up. if b := t.buckets[name]; b != nil { return b, nil } // Retrieve bucket data from the system bucket. - data, err := c.get(&t.sys, []byte(name)) - if err != nil { - return nil, err - } else if data == nil { - return nil, &Error{"bucket not found", nil} + value := t.get(&t.sys, []byte(name)) + if value == nil { + return nil } // Create a bucket that overlays the data. b := &Bucket{ - bucket: (*bucket)(unsafe.Pointer(&data[0])), - name: name, + bucket: (*bucket)(unsafe.Pointer(&data[0])), + name: name, transaction: t, } t.buckets[name] = b @@ -76,85 +71,39 @@ func (t *Transaction) bucket(name string) (*Bucket, error) { } // Cursor creates a cursor associated with a given bucket. -func (t *Transaction) Cursor(b *Bucket) (*Cursor, error) { - if b == nil { - return nil, &Error{"bucket required", nil} - } else - - // Create a new cursor and associate it with the transaction and bucket. - c := &Cursor{ - transaction: t, - bucket: b, - } - - // Set the first page if available. - if b.root != p_invalid { - p := t.db.page(t.db.data, int(b.root)) - c.top = 0 - c.pages = append(c.pages, p) +func (t *Transaction) Cursor(name string) (*Cursor, error) { + b, err := t.Bucket(name) + if err != nil { + return nil, err } - - return nil, nil + return b.Cursor() } -// Get retrieves the value for a key in a given bucket. +// Get retrieves the value for a key in a named bucket. func (t *Transaction) Get(name string, key []byte) ([]byte, error) { - c, err := t.Cursor(name) + b, err := t.Bucket(name) if err != nil { return nil, err } - return c.Get(key) -} - -func (t *Transaction) page(id int) (*page, error) { - return t.db.page(id) + return b.Get(key) } // Stat returns information about a bucket's internal structure. -func (t *Transaction) Stat(name string) *stat { +func (t *Transaction) Stat(name string) *Stat { // TODO return nil } -// // -// // -// // -// // -// // -// ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ CONVERTED ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ // -// // -// // -// // -// // -// // - -// Return the data associated with a given node. -// @param[in] txn The transaction for this operation. -// @param[in] leaf The node being read. -// @param[out] data Updated to point to the node's data. -// @return 0 on success, non-zero on failure. -func (t *Transaction) readNode(leaf *node, data []byte) error { - /* - MDB_page *omp; // overflow page - pgno_t pgno; - int rc; - - if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) { - data->mv_size = NODEDSZ(leaf); - data->mv_data = NODEDATA(leaf); - return MDB_SUCCESS; +// page returns a reference to the page with a given id. +// If page has been written to then a temporary bufferred page is returned. +func (t *Transaction) page(id pgid) *page { + // Check the dirty pages first. + if t.pages != nil { + if p, ok := t.pages[id]; ok { + return p } + } - // Read overflow data. - data->mv_size = NODEDSZ(leaf); - memcpy(&pgno, NODEDATA(leaf), sizeof(pgno)); - if ((rc = mdb_page_get(txn, pgno, &omp, NULL)) != 0) { - DPRINTF(("read overflow page %"Z"u failed", pgno)); - return rc; - } - data->mv_data = METADATA(omp); - - return MDB_SUCCESS; - */ - return nil + // Otherwise return directly from the mmap. + return t.db.page(id) } |