From e99a24eb44bc1da2fc6773a9c8dcf8862746f028 Mon Sep 17 00:00:00 2001 From: Ben Johnson Date: Wed, 7 May 2014 11:23:30 -0600 Subject: [PATCH] Improve bucket code documentation. --- bucket.go | 25 ++++++++++++++----------- 1 file changed, 14 insertions(+), 11 deletions(-) diff --git a/bucket.go b/bucket.go index 4ad62fe..b8dbf25 100644 --- a/bucket.go +++ b/bucket.go @@ -57,17 +57,20 @@ const bucketHeaderSize = int(unsafe.Sizeof(bucket{})) // Bucket represents a collection of key/value pairs inside the database. type Bucket struct { *bucket - tx *Tx - buckets map[string]*Bucket - page *page - rootNode *node - nodes map[pgid]*node + tx *Tx // the associated transaction + buckets map[string]*Bucket // subbucket cache + page *page // inline page reference + rootNode *node // materialized node for the root page. + nodes map[pgid]*node // node cache } // bucket represents the on-file representation of a bucket. +// This is stored as the "value" of a bucket key. If the bucket is small enough, +// then its root page can be stored inline in the "value", after the bucket +// header. In the case of inline buckets, the "root" will be 0. type bucket struct { - root pgid - sequence uint64 + root pgid // page id of the bucket's root-level page + sequence uint64 // monotonically incrementing, used by NextSequence() } // newBucket returns a new bucket associated with a transaction. @@ -171,10 +174,10 @@ func (b *Bucket) CreateBucket(key []byte) (*Bucket, error) { key = cloneBytes(key) c.node().put(key, key, value, 0, bucketLeafFlag) - // De-inline the parent bucket, if necessary. - if b.root == 0 { - b.page = nil - } + // Since subbuckets are not allowed on inline buckets, we need to + // dereference the inline page, if it exists. This will cause the bucket + // to be treated as a regular, non-inline bucket for the rest of the tx. + b.page = nil return b.Bucket(key), nil }