62 lines
1.1 KiB
Go
62 lines
1.1 KiB
Go
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package trie
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// Stage implements Copy-on-Write staging area on top of a MerkleTrie.
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type Stage struct {
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*MerkleTrie
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}
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// NewStage returns a Stage initialized with a specified MerkleTrie.
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func NewStage(t *MerkleTrie) *Stage {
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s := &Stage{
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MerkleTrie: New(),
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}
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s.mu = t.mu
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s.root = newNode(nil)
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*s.root = *t.root
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return s
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}
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// Update updates the internal MerkleTrie in a Copy-on-Write manner.
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func (s *Stage) Update(key Key, val Value) error {
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s.mu.Lock()
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defer s.mu.Unlock()
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n := s.root
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for _, k := range key {
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org := n.links[k]
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n.links[k] = newNode(nil)
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if org != nil {
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*n.links[k] = *org
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}
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n.hash = nil
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n = n.links[k]
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}
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if n.value != val {
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n.value = val
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n.hash = nil
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}
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return nil
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}
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// Commit ...
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func (s *Stage) Commit(head *Commit, meta CommitMeta) (*Commit, error) {
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c := NewCommit(head, meta, s.MerkleTrie)
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s.MerkleTrie = New()
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s.mu = c.MerkleTrie.mu
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s.root = newNode(nil)
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*s.root = *c.MerkleTrie.root
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return c, nil
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}
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// CommitVisit ...
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type CommitVisit func(c *Commit)
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// Log ...
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func Log(commit *Commit, visit CommitVisit) {
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for commit != nil {
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visit(commit)
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commit = commit.Prev
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}
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}
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