diff options
Diffstat (limited to 'cursor.go')
| -rw-r--r-- | cursor.go | 54 |
1 files changed, 35 insertions, 19 deletions
@@ -34,6 +34,13 @@ func (c *Cursor) First() (key []byte, value []byte) { p, n := c.bucket.pageNode(c.bucket.root) c.stack = append(c.stack, elemRef{page: p, node: n, index: 0}) c.first() + + // If we land on an empty page then move to the next value. + // https://github.com/boltdb/bolt/issues/450 + if c.stack[len(c.stack)-1].count() == 0 { + c.next() + } + k, v, flags := c.keyValue() if (flags & uint32(bucketLeafFlag)) != 0 { return k, nil @@ -209,28 +216,37 @@ func (c *Cursor) last() { // next moves to the next leaf element and returns the key and value. // If the cursor is at the last leaf element then it stays there and returns nil. func (c *Cursor) next() (key []byte, value []byte, flags uint32) { - // Attempt to move over one element until we're successful. - // Move up the stack as we hit the end of each page in our stack. - var i int - for i = len(c.stack) - 1; i >= 0; i-- { - elem := &c.stack[i] - if elem.index < elem.count()-1 { - elem.index++ - break + for { + // Attempt to move over one element until we're successful. + // Move up the stack as we hit the end of each page in our stack. + var i int + for i = len(c.stack) - 1; i >= 0; i-- { + elem := &c.stack[i] + if elem.index < elem.count()-1 { + elem.index++ + break + } } - } - // If we've hit the root page then stop and return. This will leave the - // cursor on the last element of the last page. - if i == -1 { - return nil, nil, 0 - } + // If we've hit the root page then stop and return. This will leave the + // cursor on the last element of the last page. + if i == -1 { + return nil, nil, 0 + } - // Otherwise start from where we left off in the stack and find the - // first element of the first leaf page. - c.stack = c.stack[:i+1] - c.first() - return c.keyValue() + // Otherwise start from where we left off in the stack and find the + // first element of the first leaf page. + c.stack = c.stack[:i+1] + c.first() + + // If this is an empty page then restart and move back up the stack. + // https://github.com/boltdb/bolt/issues/450 + if c.stack[len(c.stack)-1].count() == 0 { + continue + } + + return c.keyValue() + } } // search recursively performs a binary search against a given page/node until it finds a given key. |